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Single, double or multiple-injection techniques for axillary brachial plexus block for hand, wrist or forearm surgery in adults

  1. Ki Jinn Chin1,*,
  2. Helen HG Handoll2

Editorial Group: Cochrane Anaesthesia Group

Published Online: 6 JUL 2011

Assessed as up-to-date: 13 MAR 2011

DOI: 10.1002/14651858.CD003842.pub3


How to Cite

Chin KJ, Handoll HHG. Single, double or multiple-injection techniques for axillary brachial plexus block for hand, wrist or forearm surgery in adults. Cochrane Database of Systematic Reviews 2011, Issue 7. Art. No.: CD003842. DOI: 10.1002/14651858.CD003842.pub3.

Author Information

  1. 1

    University of Toronto, Department of Anesthesia, Toronto, Ontario, Canada

  2. 2

    Teesside University, Health and Social Care Institute, Middlesborough, Tees Valley, UK

*Ki Jinn Chin, Department of Anesthesia, University of Toronto, Toronto Western Hospital, 399 Bathurst Street, Toronto, Ontario, M5T 2S8, Canada. gasgenie@yahoo.co.uk.

Publication History

  1. Publication Status: New search for studies and content updated (no change to conclusions)
  2. Published Online: 6 JUL 2011

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This is not the most recent version of the article. View current version (02 SEP 2016)

 
Characteristics of included studies [ordered by study ID]
Baranowski 1990

MethodsMethod of randomization: not stated.
No blinding indicated.
No loss to follow-up.


ParticipantsLondon, UK
Period of study: not stated.
100 people scheduled for outpatient hand surgery. Informed consent.
Male: not stated; mean age: 49 years.
Excluded: no details.


InterventionsMultiple (neurostimulation method) versus multiple (paraesthesia method) versus single injection.

All received local anaesthetic (LA solution): up to 40 ml lignocaine 1.5% with adrenaline 200 µg.

No premedication. No sedation or IV analgesia. All blocks performed or supervised by 1 of the 2 trial authors.

1. Multiple injection using neurostimulator: unsheathed block needle. Attempts made to locate 3 to 4 main branches of brachial plexus; nerve specific muscle twitches. Incremental LA injections.
2. Multiple injection using paraesthesia: 22 gauge regional block needle. Attempts made to locate 3 to 4 main peripheral nerves. Incremental LA injections. Distal pressure applied.
3. Single injection via catheter on its insertion (introduction with 18 gauge needle) in brachial plexus sheath. Fascial 'click' and easy insertion used to identify sheath. Distal pressure applied.


OutcomesLength of follow-up: 30 minutes
Sensory blockade
Motor blockade (no data)
Anaesthesia failure (less than 3 nerves fully blocked, general anaesthesia, failure to penetrate brachial plexus sheath)


NotesRequest for details of methods, types of surgery and results, including adverse effects, sent to Dr Baranowski on 02/12/04.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear risk“One hundred patients ... were randomly allocated”. No details of method.

Allocation concealment (selection bias)Unclear riskNo details of method.

Blinding (performance bias and detection bias)
All outcomes
High riskNo mention of blinding.

Incomplete outcome data (attrition bias)
All outcomes
Low riskNo loss to follow-up seemed likely. 

Selective reporting (reporting bias)Unclear riskPossible but no protocol available.

Balance in baseline characteristics?Unclear riskIncomplete information to judge: no gender or type of surgery. Single injection group was 6 years younger (not statistically significant).

Free from performance bias?Low risk"All of the blocks were performed or supervised by one of the two authors.” There were a register and a consultant. Other treatment (none) seemed comparable.

Coventry 2001

MethodsMethod of randomization: "Technique written on card and placed in envelope. Envelopes sealed, shuffled and numbered 1-60." "Envelope opened immediately pre-op by 'regional anaesthetist'".
Double-blind: anaesthetist carrying out assessments and surgeon were blind to injection technique.
Blinded outcome assessor.
No loss to follow-up.


ParticipantsDundee, UK
Period of study: 1995.
60 people undergoing elective upper limb surgery: Dupuytren's, carpal tunnel, tendon surgery, arthrodesis/arthroplasty, wrist arthroscopy and miscellaneous.
Male: 45%; age range: 20 to 85 years.
Excluded: patients refusing a local anaesthetic technique, dementia; age <17 years; peripheral neuropathy, sensitivity to amide local anaesthetics; ASA physical status > 3 (see notes).


InterventionsMultiple versus double injection (both groups using the neurostimulation method).

All received LA solution: 30 ml lidocaine 15 mg/ml with epinephrine 5 ug/ml. Nerve blockade facilitated using 22G insulated short-bevelled needle and peripheral nerve stimulator. All blocks carried out by one operator.

Initial sedation with midazolam. Skin anaesthetised with 1 to 2 ml plain lidocaine 10 mg/ml. Musculocutaneous nerve was first located and 5 ml LA solution injected.
1. Multiple injection: 15 ml LA to median nerve followed by 10 ml LA to radial nerve.
2. Double injection: single injection of 25 ml LA to median nerve.


OutcomesLength of follow-up: 30 minutes (and duration of surgery)
Sensory blockade
Motor blockade
Analgesic failure (use of supplementary anaesthesia)
Duration of surgery
Tourniquet discomfort
Problems (all nerves located; no problems indicated)


NotesReply to request for details of methods and adverse effects received from Dr Coventry on 13/10/04.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear risk“randomly allocated” “Technique written on card and placed in envelope. Envelopes sealed, shuffled and numbered 1-60.” Unclear how well shuffled.

Allocation concealment (selection bias)Low riskSealed "Envelope opened immediately pre-op by 'regional anaesthetist'".

Blinding (performance bias and detection bias)
All outcomes
Low riskDouble-blind. Blinded investigator anaesthetist then carried out all assessments. This investigator was totally blind as was the surgeon. No assessment was carried out by the regional anaesthetists thus ensuring blinding.

Incomplete outcome data (attrition bias)
All outcomes
Low riskNo loss to follow-up.

Selective reporting (reporting bias)Unclear riskLikely but no protocol available and took 6 years to publish. 

Balance in baseline characteristics?Low riskBaseline characteristics including types of surgery detailed and appeared balanced.

Free from performance bias?Low riskAll blocks carried out by one operator. No cause for concern.

Goldberg 1987

MethodsMethod of randomization: not stated.
Blinded outcome assessor: operating surgeon
No loss to follow-up.


ParticipantsPhiladelphia, USA
Period of study: not stated.
59 people scheduled for upper extremity surgery, wrist or more distal, amenable to brachial plexus block outpatient hand surgery: carpal tunnel repair/median nerve release; Dupuytren's contracture release; arthroplasty of interphalangeal joint; ganglion excision; distal radial and/or ulnar plating; foreign body excision; miscellaneous finger operations. Consenting.
Male: not stated; mean age: 50 years, age 18+ years.
Excluded: no details.


InterventionsDouble versus single (neurostimulation method) versus single (paraesthesia method) injection.

All received local anaesthetic (LA) solution: 40 ml/70 kg mepivacaine 1.5%.

No mention of premedication, sedation or IV analgesia. All blocks performed by first or second year anaesthesiology residents supervised by staff anaesthesiologist (usually first author).

1. Double transarterial injection: 22 gauge short bevel needle inserted transarterial fixation - half of LA volume administered posterior to axillary artery and half anterior to artery.
2. Single injection using nerve stimulator: 23 gauge insulated needle connected to stimulator. Whole volume of LA injected when maximum stimulation no longer produced muscle activity.
3. Single injection using paraesthesia: 22 gauge short bevel needle inserted until hand paraesthesia elicited - whole volume of LA injected.


OutcomesLength of follow-up: hand clinic (timing not specified)
Sensory blockade
Anaesthesia failure (non-blocked nerves)
Adverse effects (none at hand clinic)


NotesRequest for details of methods, types of surgery and results, including adverse effects, sent to Prof Goldberg on 15/12/04.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear risk“Three methods of blockade were randomly selected.” No details of method.

Allocation concealment (selection bias)Unclear riskNo details of method.

Blinding (performance bias and detection bias)
All outcomes
Low riskPain was tested “by a surgeon (with an Allis clamp) unaware of the method utilized.”

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskNo mention of loss to follow-up. 

Selective reporting (reporting bias)Unclear riskPossible but no protocol available.

Balance in baseline characteristics?Unclear riskIncomplete information to judge: no gender or type of surgery. Single injection groups were 6 and 11 years younger than transarterial groups.

Free from performance bias?Unclear riskNo difference in “the level of training of the residents who performed the blocks, which ranged from 1-19 months”. No other problems detected - blinded surgeon.

Hickey 1993

MethodsMethod of randomization: not specified.
No blinding of patient, care-giver or outcome assessor described.
No loss to follow-up.


ParticipantsTexas, USA.
Period of study: not stated.
60 adults scheduled for surgery of the upper extremity (not otherwise specified).
Male: 1.7%; mean age 56 years.
Excluded: ASA physical status> 3 (see notes).


InterventionsDouble versus single posterior versus single anterior injection (transarterial method in all groups).

All received local anaesthetic (LA) solution: 1.5% mepivacaine with 5 mcg/ml epinephrine; total volume 50 ml. Transarterial technique in all cases with a 22G short-bevel block needle. All blocks performed by residents supervised by one staff anaesthesiologist.

Sedative premedication with IV midazolam: up to 3 mg

1. Double injection: injection of half of LA volume (25 ml) anterior to axillary artery, injection of other half (25 ml) posterior to axillary artery.
2. Single posterior injection: injection of all of LA volume (50 ml) posterior to axillary artery.
3. Single anterior injection: injection of all of LA volume (50 ml) anterior to axillary artery.

Subcutaneous injection of 3 ml of LA over the axillary artery to block the intercostobrachial nerve.


OutcomesLength of follow-up: 30 minutes
Sensory blockade
Motor blockade
Analgesic failure (use of supplementary anaesthesia; general anaesthesia)
Onset of analgesia and anaesthesia in individual nerve territories
Complications during block injection and operation


NotesOne double injection patient excluded from the analyses because of an aborted block.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear risk"Randomized study". No further details.

Allocation concealment (selection bias)Unclear riskNo details on allocation concealment.

Blinding (performance bias and detection bias)
All outcomes
High riskNo blinding stated (seems unlikely given the supervisory aspect).

Incomplete outcome data (attrition bias)
All outcomes
Low riskAll participants accounted for.

Selective reporting (reporting bias)Unclear riskNo protocol. Insufficient information to judge this.

Balance in baseline characteristics?Unclear riskInsufficient information to judge this in terms of lack of details on surgical interventions. Double injection group on average 8 years older.

Free from performance bias?Low riskAll blocks performed by residents directly supervised by the same member of staff.

Imbelloni 2005

MethodsMethod of randomization: not stated.
No blinding of patient, care-giver or outcome assessor described.
No loss to follow-up.


ParticipantsSao Jose do Rio Preto, Brazil
Period of study: not stated.
70 adults scheduled for orthopedic surgery of the forearm and hand. Informed consent.
Male: 56%; mean age 38 years.
Exclusions: ASA physical status> 2 (see notes), Age < 20 years or > 60 years.


InterventionsMultiple (neurostimulation method) versus double injection (transarterial method).
All received local anaesthetic (LA) solution: 1.6% lidocaine with 5 mcg/ml epinephrine; total volume 50 ml. The identity and experience level of the operator performing the blocks was not stated.

No premedication given.

1. Multiple injection: neurostimulation-guided, injection of 20 ml to ulnar or distal radial nerve response, 20 ml to median nerve, 10 ml to musculocutaneous nerve.
2. Double injection: transarterial technique, injection of 30 ml posterior to axillary artery, injection of 20 ml anterior to artery.

Incomplete blocks were supplemented but the definition of incomplete blocks and the timing of supplementation were not specified.


OutcomesLength of follow-up: sensory and motor block follow-up duration was not specified. Patients were followed up for 48 hours postoperatively to assess for complications.
Sensory blockade
Analgesic failure (use of supplementary anaesthesia; general anaesthesia, pain at surgical site)
Time to readiness for surgery
Tourniquet discomfort and pain
Complications during block injection and operation, and up to 48 hours after
Block duration
Patient satisfaction


NotesBlock outcomes were vaguely defined, and assessment timing not specified.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear risk“prospective study”;  “who were randomly distributed in two groups (group MNS= 40 patients and group TA = 30 patients) according to the technique.” Unexplained imbalance.

Allocation concealment (selection bias)Unclear riskNo details of method.

Blinding (performance bias and detection bias)
All outcomes
High riskNo mention.

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskLikely that all participants accounted for, but not stated explicitly.

Selective reporting (reporting bias)Unclear riskNo prior protocol and vague in the definition of outcomes.

Balance in baseline characteristics?Unclear riskBalanced for sex, age, weight and height but no information on surgery.

Free from performance bias?Unclear riskInsufficient information to judge this.

Inberg 1999

MethodsMethod of randomization: computer based, organised by the statistical department.
Patient blinded.
Blinded outcome assessor.
No loss to follow-up.


ParticipantsTampere, Finland
Period of study: 1996 to 1997.
50 adults scheduled for upper limb surgery under axillary block anaesthesia. Informed consent.
Male: 74%; mean age: 44.5 years.
Excluded: weight < 50 kg or > 100 kg; surgery proximal from the elbow joint.


InterventionsDouble versus single injection (both groups using neurostimulation method).

All received local anaesthetic (LA) solution: Prilocaine 1% and bupivacaine 0.5% in 1:1 ratio; total volume 0.7 ml/kg body weight. Nerve blockade facilitated using 22G insulated needle and nerve stimulator. All blocks carried out by one operator.

Initial sedation with diazepam. Initial subcutaneous injection of 2 to 3 ml LA.
1. Double injection: injection (half volume) LA to median nerve followed by injection (rest of volume) LA to radial nerve (14 cases) or ulnar (11 cases).
2. Single injection: single injection of LA to median nerve (23 cases); radial nerve (1 case) or ulnar nerve (1 case).

Subcutaneous injection of 5 ml LA to block medial cutaneous nerves of the arm.


OutcomesLength of follow-up: 40 minutes (and duration of surgery).
Sensory blockade
Motor blockade
Analgesic failure (use of supplementary anaesthesia; new plexus block, general anaesthesia; use of opioids for tourniquet pain or pain in operation area)
Duration of surgery
Duration of tourniquet use
Tourniquet discomfort and pain
Problems (during operation)


NotesReply to request for details of methods, type of surgery and details of participants receiving general and another full plexus block received from Dr Annila on 21/12/04. Original patient papers are now missing.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk"computer-based randomization", organised by the statistical department.

Allocation concealment (selection bias)Unclear riskNo information on concealment.

Blinding (performance bias and detection bias)
All outcomes
Low risk“The evaluation of the sensory and motor blocks was blinded, and the patient was unaware of the method used, which makes the study double blind.”

Incomplete outcome data (attrition bias)
All outcomes
Low riskNo loss to follow-up. Information supplied by trial author on the particular circumstances of two patients, who received respectively a new plexus block and general anaesthesia.

Selective reporting (reporting bias)Unclear riskPossible but no protocol available.

Balance in baseline characteristics?Unclear riskNo information on type of surgery or mental status. No statistically significant differences between the two groups in age, gender, weight or height.

Free from performance bias?Low riskSeemingly so: same experienced operator and anaesthetic procedures. "All blocks were performed by the first author, who is experienced in axillary block."

K-Nielsen 1997

MethodsMethod of randomization: computer-generated random allocation assuring an equal number of patients in both groups was obtained beforehand and sealed in numbered envelopes. An envelope containing the random assignment was opened after the patient's arrival at the anaesthesia room.
Blinded outcome assessor.
No loss to follow-up.


ParticipantsCopenhagen, Denmark
Period of study: 1995 to 1996.
80 people undergoing elective hand surgery: arthrodeses, arthroplasties, osteosyntheses (K-wire, Herbert screw etc), nerve sutures, finger amputations, neuroma or ganglion removals, hardware removals, wrist arthroscopies. Informed consent.
Male: 66%; mean age: 46 years, range: 18 to 75 years.
Excluded: ASA physical status > 3 (see notes). Allergy to amide type LA, pregnancy, inability to communicate, neurological disorders affecting peripheral nerves and resulting sensory loss and/or motor weakness (e.g. advanced neuropathies - uraemic or diabetic)


InterventionsMultiple versus single injection (both groups using neurostimulation method).

All received local anaesthetic (LA) solution: 1% mepivacaine with adrenaline 5 µg/ml.

Nerve blockade facilitated using 22G insulated short-bevelled needle and nerve stimulator. All blocks carried out by one operator.

Initial sedation with diazepam. Initial subcutaneous injection of 5 ml LA to anaesthetise medial cutaneous nerves of arm or forearm.
1. Multiple injection: injection of 10 ml LA cephalad to artery, then injection below artery - 20 ml at point of maximum stimulation OR if 2 nerves located: 15 ml close to each nerve. If just one located then final 10 ml into coracobrachial muscle.
2. Single injection: injection of 40 ml LA to one nerve: median nerve (32), ulnar (6), radial (2); then 20 ml to radial nerve.


OutcomesLength of follow-up: surgical follow-up (not stated) for adverse neurological outcomes; onset of sensory block assessed every 10 minutes (and duration of surgery).
Sensory blockade
Motor blockade
Analgesic failure (use of supplementary anaesthesia; general anaesthesia; use of opioids for tourniquet pain in operation area)
Time to be ready for surgery
Duration of tourniquet use
Tourniquet discomfort and pain
Problems (during injection and operation)
Long-term complications (none)


NotesReply to request for details of types of surgery, exclusion criteria and so on received from Dr Koscielniak-Nielsen on 11/11/2004.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk"A computer-generated random allocation assuring an equal number of patients in both groups was obtained beforehand ...."

Allocation concealment (selection bias)Low risk"A computer-generated random allocation assuring an equal number of patients in both groups was obtained beforehand and sealed in numbered envelopes. An envelope containing the random assignment was opened after the patient's arrival at the anaesthesia room."

Blinding (performance bias and detection bias)
All outcomes
Low risk“All the blocks were performed by the first author [who left the room] and assessed by the others. .. The [randomization] envelope was then resealed and attached to the assessment form.”

Incomplete outcome data (attrition bias)
All outcomes
Low riskNo loss to follow-up.

Selective reporting (reporting bias)Low riskNo protocol but same plan for series of trials. Clearly reported primary outcomes. Ethics committee acceptance reported.

Balance in baseline characteristics?Unclear riskYes, aside from the distribution of the various elective hand operations.

Free from performance bias?Low riskAll the blocks were performed by the first author [an experienced anaesthetist]. Other care seemed comparable.

K-Nielsen 1998

MethodsMethod of randomization: computer-generated random allocation assuring an equal number of patients in both groups was obtained beforehand and sealed in numbered envelopes. An envelope containing the random assignment was opened after the patient's arrival at the anaesthesia room.
Blinded outcome assessor.
No loss to follow-up.


ParticipantsCopenhagen, Denmark
Period of study: 1996 to 1997.
100 people undergoing acute (nerve and/or tendon sutures, K-wire or Hoffmann osteosynthesis) or elective hand, wrist or forearm surgery. Informed consent.
Male: 64%; mean age: 47 years, range: 18 to 80 years.
Excluded: ASA physical status > 3 (see notes). Allergy to amide type LA, pregnancy, inability to co-operate, diseases affecting sensory or motor function of the upper extremity.


InterventionsMultiple (neurostimulation method) versus double injection (transarterial method).

All received local anaesthetic (LA) solution: 1% mepivacaine with adrenaline 5 µg/ml.

Nerve blockade facilitated using 22G or 24G insulated short-bevelled needle with nerve stimulator in place. All blocks carried out by one operator.

Initial sedation with diazepam. Initial subcutaneous injection of 5 ml LA to anaesthetise medial cutaneous nerves of arm or forearm.
1. Multiple injection: injection of 10 ml LA to 4 terminal motor nerves (musculocutaneous, median, radial and ulnar). Connected to nerve stimulator, current = 1.5 mA.
2. Double injection "transarterial": injection of 20 ml LA deep to and 20 ml superficial to axillary artery. Connected to nerve stimulator but current = 0 mA.


OutcomesLength of follow-up: surgical follow-up (not stated) for adverse neurological outcomes; onset of sensory block assessed every 10 minutes (and duration of surgery).
Sensory blockade
Motor blockade
Analgesic failure (use of supplementary anaesthesia; use of opioids for tourniquet pain in operation area)
Time to be ready for surgery
Duration of tourniquet use
Tourniquet discomfort and pain
Problems (during injection and operation)
Long-term complications (none)


NotesReply to request for details of types of surgery received from Dr Koscielniak-Nielsen on 15/11/2004.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk"A computer-generated random allocation assuring an equal number of patients in both groups was obtained beforehand ...."

Allocation concealment (selection bias)Low risk"A computer-generated random allocation assuring an equal number of patients in both groups was obtained beforehand and sealed in numbered envelopes. An envelope containing the random assignment was opened after the patient's arrival at the anaesthesia room."

Blinding (performance bias and detection bias)
All outcomes
Low risk“All the blocks were performed by the first author [who left the room] and assessed by the others, who were unaware of the applied nerve block."

Incomplete outcome data (attrition bias)
All outcomes
Low riskNo loss to follow-up.

Selective reporting (reporting bias)Low riskNo protocol but same plan for series of trials. Clearly reported primary outcomes. Ethics committee acceptance reported.

Balance in baseline characteristics?Unclear riskYes, aside from the distribution of the various operations, which were elective or acute hand, wrist or forearm surgery.

Free from performance bias?Low riskAll the blocks were performed by the first author [an experienced anaesthetist]. Other care seemed comparable.

K-Nielsen 1999a

MethodsMethod of randomization: computer-generated random allocation assuring an equal number of patients in both groups was obtained beforehand and sealed in numbered envelopes. An envelope containing the random assignment was opened after the patient's arrival at the anaesthesia room.
Blinded outcome assessor(s).
No loss to follow-up but 1 excluded due to serious adverse effect.


ParticipantsCopenhagen, Denmark
Period of study: 1998.
101 people undergoing acute (nerve and/or tendon sutures, fracture osteosyntheses, amputations, wound revisions etc) or elective (Dupuytrens, arthroplasties, arthrodeses, ligament reconstructions, Hunter I or II, caput ulnae resections, scaphoideum osteosyntheses, neuroma or ganglion removals, carpal tunnel surgery etc) hand, wrist or forearm surgery. Informed consent.
Male: 64%; mean age: 49.5 years, range: 18 to 80 years.
Excluded: ASA physical status > 2 (see notes). Allergy to amide type LA, pregnancy, inability to co-operate, diseases affecting sensory or motor function of the upper extremity.


InterventionsMultiple (neurostimulation method) versus double injection (transarterial method).

All received local anaesthetic (LA) solution: 2% mepivacaine with adrenaline 5 µg/ml.

Nerve blockade facilitated using 22G or 24G insulated short-bevelled needle with nerve stimulator in place. Blocks carried out by one operator or under his supervision.

Initial sedation with diazepam. Initial subcutaneous injection of 5 ml LA (1% mepivacaine) to anaesthetise medial cutaneous nerves of arm or forearm.
1. Multiple injection: injection of 10 ml LA to 4 terminal motor nerves (Musculocutaneous, median, radial and ulnar). Connected to nerve stimulator, current = 1.5 mA.
2. Double injection "transarterial": injection of 20 ml LA deep to and 20 ml superficial to axillary artery. Connected to nerve stimulator but current = 0 mA.


OutcomesLength of follow-up: surgical follow up (5 to 10 days, then 3 to 4 weeks after) for adverse neurological outcomes; onset of sensory block assessed every 10 minutes.
Sensory blockade
Motor blockade
Analgesic failure (use of supplementary anaesthesia; use of opioids for tourniquet pain in operation area)
Time to be ready for surgery
Pain during block
Duration of tourniquet use
Tourniquet discomfort and pain
Problems (during injection and operation)
Long-term complications (none)


NotesExcluded patient was a cardiovascularly medicated participant of the multiple injection group who developed hypertension, atrial fibrillation, became agitated and lost consciousness 12 minutes after block performance. After intravenous administration of labetol, metoprolol and midazolam his condition improved and he woke up 15 minutes later.

Details of types of surgery, study period received from Dr Koscielniak-Nielsen on 02/12/2004.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk"A computer-generated random allocation assuring an equal number of patients in both groups was obtained beforehand ...."

Allocation concealment (selection bias)Low risk"A computer-generated random allocation assuring an equal number of patients in both groups was obtained beforehand and sealed in numbered envelopes. An envelope containing the random assignment was opened after the patient's arrival at the anaesthesia room."

Blinding (performance bias and detection bias)
All outcomes
Low risk“All blocks were assessed by the anaesthetists, who were unaware of the applied nerve block technique."

Incomplete outcome data (attrition bias)
All outcomes
Low riskNo loss to follow-up but 1 excluded due to serious adverse effect.

Selective reporting (reporting bias)Low riskNo protocol but same plan for series of trials. Clearly reported primary outcomes. Ethics committee acceptance reported.

Balance in baseline characteristics?Unclear riskYes, aside from the distribution of the various operations, which were elective or acute hand, wrist or forearm surgery.

Free from performance bias?Unclear riskWhile 38% versus 32% of blocks were done by residents and other staff members (rather than the first author [an experienced anaesthetist], the first author supervised all blocks. Other care seemed comparable.

K-Nielsen 1999b

MethodsMethod of randomization: computer-generated random allocation assuring an equal number of patients in both groups was obtained beforehand and sealed in numbered envelopes. An envelope containing the random assignment was opened after the patient's arrival at the anaesthesia room.
Blinded outcome assessor.
No loss to follow-up.


ParticipantsCopenhagen, Denmark
Period of study: 1998.
106 people undergoing acute (nerve and/or tendon sutures, fracture osteosyntheses, amputations, wound revisions etc) or elective (Dupuytrens, arthroplasties, arthrodeses, ligament reconstructions, Hunter I or II, caput ulnae resections, scaphoideum osteosyntheses, neuroma or ganglion removals, carpal tunnel surgery etc) hand, wrist or forearm surgery. Informed consent.
Male: 57%; mean age: 45.5 years, range: 18 to 80 years.
Excluded: ASA physical status > 2 (see notes). Allergy to amide type local anaesthetic (LA), pregnancy, inability to co-operate, diseases affecting sensory or motor function of the upper extremity.


InterventionsMultiple (neurostimulation method) versus single injection (transarterial/paraesthesia method).

Blocks carried out by first author - consultant anaesthetist - other staff members or supervised residents.

Initial sedation with diazepam to apprehensive patients. Initial subcutaneous injection of 5 ml mepivacaine 1% with adrenaline 5 µg/ml to anaesthetise medial cutaneous nerves of arm or forearm.
1. Multiple injection: injection using 24 gauge, 25 mm long insulated short-bevelled cannula of 5 ml mepivacaine 1% with adrenaline 5 µg/ml to 4 terminal motor nerves (Musculocutaneous, median, radial and ulnar). Connected to nerve stimulator, current = 1.5 mA.
2. Single injection: injection with 25 gauge, 35 mm long hypodermic needle of 80 ml mepivacaine 1% with adrenaline 2.5 µg/ml LA behind transfixed axillary artery (beforehand if hand paraesthesia elicited). Connected to nerve stimulator but current = 0 mA.


OutcomesLength of follow-up: surgical follow up (5 to 10 days, then 3 to 4 weeks after) for adverse neurological outcomes; onset of sensory block assessed every 10 minutes.
Sensory blockade
Motor blockade
Analgesic failure (use of supplementary anaesthesia; use of opioids for tourniquet pain in operation area; use of propofol for restlessness caused by tourniquet)
Time to be ready for surgery
Pain during block
Duration of tourniquet use
Tourniquet discomfort and pain
Problems (during injection and operation)
Long-term complications (none)


NotesOne of the two excluded trial participants was an Inuit who didn't understand trial procedures. The other participant, who already had coronary artery disease, developed chest pain - the surgery was cancelled.
Details of types of surgery, study period and other clarification received from Dr Koscielniak-Nielsen on 14/12/2004.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk"A computer-generated random allocation assuring an equal number of patients in both groups was obtained beforehand ...."

Allocation concealment (selection bias)Low risk"A computer-generated random allocation assuring an equal number of patients in both groups was obtained beforehand and sealed in numbered envelopes. An envelope containing the random assignment was opened after the patient's arrival at the anaesthesia room."

Blinding (performance bias and detection bias)
All outcomes
Low risk“The anesthetist performing the block ... restarted the stopwatch and left the room. The blocks were ...assessed by an anesthesiologist unaware of the applied technique."

Incomplete outcome data (attrition bias)
All outcomes
Low riskNo loss to follow-up although 2 were excluded;  because of language and heart problems respectively.

Selective reporting (reporting bias)Low riskNo protocol but same plan for series of trials. Clearly reported primary outcomes. Ethics committee acceptance reported.

Balance in baseline characteristics?Unclear riskYes, aside from the distribution of the various operations, which were elective or acute hand, wrist or forearm surgery.

Free from performance bias?Low riskBlocks carried out by first author - consultant anaesthetist - other staff members or supervised residents. Other care seemed comparable.

Lavoie 1992

MethodsMethod of randomization: use of random number table. "The 75 patients were blocked in 15 groups of 5 patients each (group 1, group 2 etc allocated in a random way into each one of the 15 groups)."
Double-blind: anaesthetist carrying out assessments and patients were blind to injection technique.
No loss to follow-up.


ParticipantsSherbrooke, Quebec, Canada
Period of study: 1991.
75 people undergoing upper limb surgery including the elbow down to the hand: fractures, soft tissues. Informed consent.
Male: 55%; mean age: 41 years.
Excluded: no details.


InterventionsMultiple versus double versus single (radial nerve) versus single (median nerve) versus single (ulnar nerve) injection.

All received local anaesthetic (LA) solution: 30 ml/square metre body surface (approximately 50 ml/70 kg body weight) lidocaine 1% with adrenaline 5 µg/ml. A tourniquet was used in all cases.

No premedication, sedation or IV analgesia mentioned. Anaesthetist performing the blocks was aware of the surgical site. After locating, by palpation, the axillary nerve in the axilla, 2 ml of 2% lidocaine injected subcutaneously to block medial cutaneous nerves of the arm. A 22-gauge insulated needle connected to peripheral nerve stimulator used to locate the nerves (0.5 mA current).

1. Multiple injection: to musculocutaneous, radial, median and ulnar nerves. LA volume equally divided between the 4 injections.
2. Double injection: to musculocutaneous and one of radial, median or ulnar nerves directly related to surgical site. LA volume equally divided between the 2 injections.
3. Single injection: to radial nerve of full volume of LA.
4. Single injection: to median nerve of full volume of LA.
5. Single injection: to ulnar nerve of full volume of LA.


OutcomesLength of follow-up: 30 minutes.
Sensory blockade
Motor blockade
Anaesthesia failure (incomplete sensory blockade, general anaesthesia: none)
Adverse effects (none recalled by contact trialist)


NotesReply to request for details of methods, types of surgery and results, including adverse effects, received from Dr Martin on 05/01/05.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk"We used a random number table. The 75 patients were blocked in 15 groups of 5 patients each (group 1, group 2 etc allocated in a random way into each one of the 15 groups)."

Allocation concealment (selection bias)Unclear riskNo information, but some predictability may have occurred at the end of each block.

Blinding (performance bias and detection bias)
All outcomes
Low risk“The anaesthetist performing the block was aware of the surgery but another anaesthetist unaware of the patients’ group evaluated the sensory and motor blocks ..” ".. the patient did not know what aspect of his axillary block was studied specifically .."

Incomplete outcome data (attrition bias)
All outcomes
Low riskNo loss to follow-up.

Selective reporting (reporting bias)Unclear risk Possible but no protocol available.

Balance in baseline characteristics?Low riskFine. Although no details of surgery, there was balance in the implicated nerves.

Free from performance bias?Low riskSeems likely and the author suggested that the "technique of randomisation by blocks allows that the learning of the technique is uniform on the 5 groups of patients".

Pere 1993

MethodsMethod of randomization: not stated.
No blinding indicated.
No loss to follow-up (assumed for 3 hours follow-up).


ParticipantsHelsinki, Finland
Period of study: not stated.
50 people undergoing hand, forearm or elbow surgery. Informed consent.
Male: not stated; mean age: 37 years.
Excluded: ASA physical status > 2 (see notes).


InterventionsDouble (transarterial method) versus single injection (neurostimulation method).

All received LA solution: mepivacaine 1% with adrenaline 5 µg/ml.

Premedication with diazepam and oxycodone.
1. Double injection "transarterial": injection using 0.7 x 50 mm needle advanced through the artery. Injection of half of 45 ml LA deep to and half superficial to axillary artery.
2. Single "perivascular" injection: injection using 0.7 x 50 mm needle and facilitated by nerve stimulator of 45 ml LA after location of axillary brachial plexus.

Neurovasular sheath compressed during the injection and for 3 minutes afterwards.


OutcomesLength of follow-up: 3 hours.
Sensory blockade - 8 nerves
Motor blockade
Analgesic failure (use of supplementary blocks; general anaesthesia; use of opioids)
Duration of tourniquet use


NotesSubsidiary radiological study of 16 people also performed. It was not clear if the people were randomized to the same comparison as the clinical trial. Need for supplementary blocks (2/8 versus 2/8) and more than 1 dose of opoid (1 versus 1) was the same in both groups.

Response from Dr Pere, received 10/02/05, indicated, with regret, that there was now no more information available on this trial.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear risk"Patients were allocated randomly to two groups."

Allocation concealment (selection bias)Unclear riskNo details of method.

Blinding (performance bias and detection bias)
All outcomes
High riskNo mention of blinding.

Incomplete outcome data (attrition bias)
All outcomes
Low riskSeemed fine.

Selective reporting (reporting bias)Unclear riskProtocol not available. No mention of complications.

Balance in baseline characteristics?Unclear risk"There were no differences between the groups in patient age, height or weight.." However, no details of type of surgery or gender.

Free from performance bias?Unclear riskNo details of who administered the anaesthesia.

Rodriguez 2005

MethodsMethod of randomization: computer-generated randomization list.
Blinded outcome assessor.
No loss to follow-up. Four incomplete procedures included in intention-to-treat analysis.


ParticipantsSantiago, Spain
Period of study: not stated.
120 people undergoing surgery of the upper limb (not otherwise specified). Informed consent.
Male: 27%; mean age: 51 years.
Excluded: ASA physical status > 3 (see notes).


InterventionsMultiple versus double versus single (median nerve) versus single (radial nerve) injection.

All received local anaesthetic (LA) solution: 1.5% mepivacaine; total volume 40 ml. All blocks were neurostimulation-guided with a 22G insulated block needle. All blocks were performed by one of two senior anaesthesiologists.

Sedative premedication with 1 to 3 mg of IV midazolam according to clinical judgement.

1. Multiple injection: injection of 15 ml to radial nerve, 15 ml to median nerve, 10 ml to musculocutaneous nerve.
2. Double injection: injection of 35 ml on radial nerve, injection of 5 ml on musculocutaneous nerve.
3. Single injection (median): injection of 40 ml on median nerve.
4. Single injection (radial): injection of 40 ml on radial nerve.

Blocks were supplemented preoperatively if the operative nerve distributions did not have complete sensory block before operation; timing of this was not specified.

Intraoperative pain was treated with infiltration of local anaesthetic at the site, or with injection of 50 to 100 mcg of fentanyl. General anaesthesia was used if pain was persistent.


OutcomesLength of follow-up: sensory and motor block assessed at 5 and 20 minutes. No follow-up detailed beyond that.
Sensory blockade
Motor blockade
Analgesic failure (use of supplementary anaesthesia; general anaesthesia; pain in operative field)
Block performance time


NotesRequest for additional information on method of randomization, blinding, and results sent to Dr Rodriguez on 13/07/2010; no reply received.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk“Assignment was performed by means of a computer-generated randomization list.”

Allocation concealment (selection bias)Unclear riskNo information on allocation concealment.

Blinding (performance bias and detection bias)
All outcomes
Low riskParticipants - not blinded. Caregivers - not blinded. Outcome assessors - blinded. No mention of safeguards, but plausible. Blinding is within study limitations and unlikely to influence outcome.

Incomplete outcome data (attrition bias)
All outcomes
High riskIntention-to-treat analysis was done and there were none lost to follow-up. But the length of follow-up was only 20 minutes, yet authors state “we had the clinical impression that many incomplete blocks progressed until 30 minutes.” It is unclear if they supplemented the blocks after 20 minutes, or later, yet this is reported as an outcome.

Selective reporting (reporting bias)Unclear riskProtocol not available. No reporting of complications, which is unusual for this type of study.

Balance in baseline characteristics?Unclear riskNo details of type of surgery performed.

Free from performance bias?Low riskBlocks were administered by one of two senior anaesthesiologists.

Rodriguez 2008

MethodsMethod of randomization: computer-generated randomization list.
Blinded outcome assessor.
Loss for follow-up: one patient in the double group excluded after randomization and block performance as assessment was not possible.


ParticipantsSantiago, Spain
Period of study: not stated.
60 people undergoing surgery of the hand (49), forearm (3), elbow (8). Informed consent.
Male: 48.3%; mean age: 58 years.
Excluded: ASA physical status > 3 (see notes).


InterventionsMultiple versus double injection (both groups using neurostimulation method).

All received local anaesthetic (LA) solution: 2% mepivacaine of volume 30 ml, and 1% mepivacaine of volume 5 ml (to musculocutaneous nerve); total volume 35 ml. All blocks were neurostimulation-guided with a 22G insulated block needle. Identity and experience level of operators performing block were not specified.

Sedative premedication with 1 to 3 mg of IV midazolam.

1. Multiple injection: injection of 15 ml to radial nerve, 15 ml to median nerve, 5 ml to musculocutaneous nerve.
2. Double injection: injection of 30 ml on radial nerve, injection of 5 ml on musculocutaneous nerve.


OutcomesLength of follow-up: sensory and motor block assessed at 10, 20 and 30 minutes.
Sensory blockade
Motor blockade
Analgesic failure (use of supplementary anaesthesia; general anaesthesia; pain in operative field)
Block performance time (reported as median and ranges)
Acute complications during block procedure


NotesRequest for additional information on method of randomization, blinding, and results sent to Dr Rodriguez on 13/07/2010; no reply received.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk“Assignment was performed by computer-generated randomization list.”

Allocation concealment (selection bias)Unclear riskNo information provided.

Blinding (performance bias and detection bias)
All outcomes
Low riskParticipants - not blinded. Caregivers - not blinded. Outcome assessors - blinded. No mention of safeguards, but plausible. Blinding is within study limitations and unlikely to influence outcome.

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskMostly: four incomplete procedures were included -  but there is slight concern over the one excluded patient; the percentages in Table 4 imply patient was included in the analysis.

Selective reporting (reporting bias)Unclear riskNo protocol and side effects not reported

Balance in baseline characteristics?Unclear riskBaseline characteristics balanced but no details of distribution of types of surgery.

Free from performance bias?Unclear riskThe identity and experience of care providers was not stated.

Serradell Catalan 2001

MethodsMethod of randomization: use of a computer-generated table of random numbers to generate a randomization list.
Blinded outcome assessor.
No loss to follow-up.


ParticipantsBarcelona, Spain
Period of study: 1999 to 2000.
100 adults (> 18 years) undergoing upper limb (forearm, wrist or hand) post-traumatic orthopaedic surgery. ASA physical status1-3 (see notes). Informed consent.
Male: 56%; mean age: 55 years.
Excluded: usual contraindications for axillary nerve blockade and regional anaesthesia. Motor or sensory disease of limb involved in surgical procedure. Non-palpable axillary artery pulse.


InterventionsMultiple (musculocutaneous, radial, median and ulnar nerves) versus multiple (triple: musculocutaneous + two of radial/ median/ ulnar nerves) versus double (two of radial/ median/ ulnar nerves) versus
double (musculocutaneous + radial/ median/ ulnar nerve) versus single (radial/ median/ ulnar nerve) injection.

All received local anaesthetic (LA) solution: 40 ml mepivacaine 1%.

Oral premedication with lorazepam 1 mg and sedation with IV midazolam. One anaesthetist performed all the blocks. After locating the axillary artery in the axilla, lidocaine 1% injected subcutaneously over the arterial pulse. A 22 gauge 50 mm long insulated needle connected to nerve stimulator was used to locate the nerves.

1. Multiple injection: to musculocutaneous, radial, median and ulnar nerves.
2. Multiple injection: to musculocutaneous nerve (10 ml LA) and either to the radial and median nerves or the radial and ulnar nerves or the median and ulnar nerves.
3. Double injection: to the radial and median nerves or the radial and ulnar nerves or the median and ulnar nerves.
4. Double injection: to musculocutaneous nerve (10 ml LA) and either to the radial, median or ulnar nerve.
5. Single injection: to the radial or median or ulnar nerve.


OutcomesLength of follow-up: 3 months surgical follow-up (also 24 hours) for adverse neurological outcomes; onset of sensory block assessed every 10 minutes, 40 minutes; also duration of block.
Sensory blockade
Motor blockade
Anaesthesia failure (incomplete sensory blockade, incomplete motor blockade)
Time for block
Duration of sensory blockade
Duration of tourniquet use
Tourniquet discomfort
Problems (during injection)
Long term neurological complication
Participant opinion of technique


NotesPart translation from Spanish provided by co-author (SR).
Response to request for details of methods, trial setting and use of intra-operative opioids and sedatives received from Dr Serradell Catalan on 03/02/05.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk"A computer-generated table of random numbers.”

Allocation concealment (selection bias)High risk"read off the allocation from a list."

Blinding (performance bias and detection bias)
All outcomes
Low risk"Single blind" Blinded doctor for motor and sensory block evaluation.

Incomplete outcome data (attrition bias)
All outcomes
Low riskNo loss to follow-up.

Selective reporting (reporting bias)Unclear riskPossible but no protocol available. There was a sample size calculation.

Balance in baseline characteristics?Unclear riskYes, aside from the distribution of the various operations, which were upper limb (forearm, wrist or hand) post-traumatic orthopaedic surgery.

Free from performance bias?Low riskAll blocks were performed by the same doctor. Other care seemed comparable.

Sia 2001

MethodsMethod of randomization: not stated.
Double-blind.
Blinded outcome assessor.
No loss to follow-up (assumed for 30 days follow-up).


ParticipantsFlorence, Italy
Period of study: 2000?
100 people undergoing elective upper limb surgery in hand, wrist or forearm. Informed consent.
Male: 55%; mean age: 41.5 years.
Excluded: ASA physical status > 2 (see notes).


InterventionsMultiple versus double injection (both groups using neurostimulation method).

All received local anaesthetic (LA) solution: lidocaine 2% and bupivacaine 0.5% in 1:1 ratio. Nerve blockade facilitated using 22G insulated short-bevelled needle and nerve stimulator. All blocks carried out by one operator.

All received IV midazolam (sedation) and fentanyl 5 minutes before block. Initial subcutaneous injection of 4 ml LA to anaesthetise medial cutaneous nerves of arm or forearm.
1. Multiple (triple) injection: injection of 10 ml LA to musculocutaneous nerve; then 10 ml to median nerve and 20 ml to radial nerve.
2. Double injection: injection of 20 ml LA to median nerve; then 20 ml to radial nerve.


OutcomesLength of follow-up: nerve injury at 48 hours, neurological sequelae at 10 and 30 days; 30 minutes or until sensory block (and duration of surgery).
Sensory blockade
Motor blockade
Analgesic failure (use of supplementary anaesthesia; use of opioids for tourniquet pain in operation area)
Duration of anaesthesia
Duration of surgery
Duration of tourniquet use
Tourniquet discomfort and pain
Problems (during injection and operation)
Long-term neurological complication (none)


NotesRequest for details of method of randomization, types of surgery and some of the results sent to Dr Sia on 09/11/04.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear risk"One hundred patients were randomly allocated to 2 groups." No details of method.

Allocation concealment (selection bias)Unclear riskNo information.

Blinding (performance bias and detection bias)
All outcomes
Low risk"double-blind study"; "All blocks .... were assessed by an investigator unaware of group assignment."

Incomplete outcome data (attrition bias)
All outcomes
Low riskNo loss of follow-up apparent for block performance.

Selective reporting (reporting bias)Unclear riskPossible but no protocol available. The selection of primary outcome for sample size calculation of the blocking of the musculocutaneous nerve is unusual.

Balance in baseline characteristics?Unclear riskYes, aside from the distribution of the various operations, which were elective forearm, wrist or hand surgery.

Free from performance bias?Low risk"All blocks were performed or supervised by the first author." Other care seemed comparable.

Sia 2010a

MethodsMethod of randomization: computer-generated randomization list.
Blinded outcome assessor.
No loss to follow-up (14 patients - distributed between the three trials Sia 2010 a,b+c - were excluded after randomization because of inability to locate the desired nerves).


ParticipantsFlorence, Italy
Period of study: 2005 to 2008.
138 people undergoing surgery on the fifth finger (fractures, neoformations, tendon injuries) and on the fifth metacarpal bone. Informed consent.
Male: 56.5%; mean age: 44 years.
Excluded: ASA physical status > 2 (see notes)


InterventionsMultiple (triple) versus single (ulnar) injection (both groups using neurostimulation method).

All received local anaesthetic (LA) solution: lidocaine 2% and bupivacaine 0.5% in 1:1 ratio; total volume 40 ml. Nerve blockade facilitated using 22G insulated short-bevelled needle and nerve stimulator. All blocks carried out by one experienced operator.

All received IV midazolam 20 µg/kg and fentanyl 1 µg/kg 5 minutes before block. Initial subcutaneous injection of 4 ml LA over the axillary artery to anaesthetise medial cutaneous nerves of arm and forearm.
1. Multiple (triple) injection: injection of 10 ml LA to median nerve; 6 ml to musculocutaneous nerve and 20 ml to radial nerve.
2. Single injection: injection of 36 ml LA to ulnar nerve.


OutcomesLength of follow-up: 30 minutes for sensory and motor block; 48 hours for nerve injury; neurological sequelae at 10 and 30 days.
Sensory blockade
Motor blockade
Analgesic failure (use of supplementary anaesthesia; use of opioids for tourniquet pain in operation area)
Block performance time
Block onset time
Time to readiness for surgery
Duration of surgery
Duration of tourniquet use
Tourniquet discomfort and pain
Need for intraoperative sedation
Problems (during injection and operation)
Long-term neurological complication (none)


NotesRequest for clarification on patient enrolment and additional data on complications sent to Dr Salvatore Sia on 14/10/2010; reply received 06/11/2010.

Although the Results section for the 3 trials states that 6 patients were excluded in the triple injections groups (TNS) and 8 patients in single injection groups (SEL), Dr Sia clarified in a personal communication that these were treated as "pre-operative" dropouts and were replaced by other patients.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk"Patients undergoing each type of surgery were randomly assigned by a computer-generated list ..."

Allocation concealment (selection bias)Unclear riskAllocation concealment was not stated. 

Blinding (performance bias and detection bias)
All outcomes
Low riskPatients - not blinded. Caregiver - unblinded. Assessors - blinded. “All the blocks were... assessed by a blinded investigator.” Blinding is within study limitations.

Incomplete outcome data (attrition bias)
All outcomes
Unclear risk“Six patients in group TNS and 8 in group SEL were excluded from the study because all the prearranged nerves were not located by nerve stimulation.” Personal communication from the author indicates that these were post-randomization exclusions.

Selective reporting (reporting bias)Low riskNo protocol but same plan for series of trials. Clearly reported primary outcomes. Ethics committee acceptance reported.

Balance in baseline characteristics?Low riskBalanced.

Free from performance bias?Unclear riskAll the blocks were performed or supervised by the first author, however the number and experienced level of supervised care providers is not stated.

Sia 2010b

MethodsMethod of randomization: computer-generated randomization list.
Blinded outcome assessor.
No loss to follow-up (14 patients - distributed between the three trials Sia 2010 a,b+c were excluded after randomization because of inability to locate the desired nerves).


ParticipantsFlorence, Italy
Period of study: 2005 to 2008.
138 people undergoing superficial surgery (without bone involvement) on the palm (e.g., Dupuytren contracture, tendons or nerve injuries, neoformations) or on the dorsum of the hand (e.g., cysts, neoformations, pathologies of extensor tendons). Informed consent.
Male: 45%; mean age: 49.5 years.
Excluded: ASA physical status > 2 (see notes).


InterventionsMultiple (triple) versus double (median and ulnar) injection.

All received local anaesthetic (LA) solution: lidocaine 2% and bupivacaine 0.5% in 1:1 ratio; total volume 40 ml. Nerve blockade facilitated using 22G insulated short-bevelled needle and nerve stimulator. All blocks carried out by one experienced operator.

All received IV midazolam 20 mcg/kg and fentanyl 1 mcg/kg 5 minutes before block. Initial subcutaneous injection of 4 ml LA over the axillary artery to anaesthetise medial cutaneous nerves of arm and forearm.
1. Multiple (triple) injection: injection of 10 ml LA to median nerve; 6 ml to musculocutaneous nerve and 20 ml to radial nerve.
2. Double injection: injection of 18 ml LA to ulnar nerve, injection of 18 ml LA to median nerve.


OutcomesLength of follow-up: 30 minutes for sensory and motor block; 48 hours for nerve injury; neurological sequelae at 10 and 30 days.
Sensory blockade
Motor blockade
Analgesic failure (use of supplementary anaesthesia; use of opioids for tourniquet pain in operation area)
Block performance time

Block onset time

Time to readiness for surgery
Duration of surgery
Duration of tourniquet use
Tourniquet discomfort and pain

Need for intraoperative sedation
Problems (during injection and operation)
Long-term neurological complication (none)


NotesRequest for clarification on patient enrolment and additional data on complications sent to Dr Salvatore Sia on 14/10/2010; reply received 06/11/2010.

Although the Results section for the 3 trials states that 6 patients were excluded in the triple injections groups (TNS) and 8 patients in single injection groups (SEL), Dr Sia clarified in a personal communication that these were treated as "pre-operative" dropouts and were replaced by other patients.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk"Patients undergoing each type of surgery were randomly assigned by a computer-generated list ..."

Allocation concealment (selection bias)Unclear riskAllocation concealment was not stated. 

Blinding (performance bias and detection bias)
All outcomes
Low riskPatients - not blinded. Caregiver - unblinded. Assessors - blinded. “All the blocks were... assessed by a blinded investigator.” Blinding is within study limitations.

Incomplete outcome data (attrition bias)
All outcomes
Unclear risk“Six patients in group TNS and 8 in group SEL were excluded from the study because all the prearranged nerves were not located by nerve stimulation.” Personal communication from the author indicates that these were post-randomization exclusions.

Selective reporting (reporting bias)Low riskNo protocol but same plan for series of trials. Clearly reported primary outcomes. Ethics committee acceptance reported.

Balance in baseline characteristics?Low riskBalanced.

Free from performance bias?Unclear riskAll the blocks were performed or supervised by the first author, however the number and experienced level of supervised care providers is not stated.

Sia 2010c

MethodsMethod of randomization: computer-generated randomization list.
Blinded outcome assessor.
No loss to follow-up (14 patients - distributed between the three trials Sia 2010 a,b+c - were excluded after randomization because of inability to locate the desired nerves).


ParticipantsFlorence, Italy
Period of study: 2005 to 2008.
138 people undergoing any surgery on the first three fingers in which only 1 or 2 nerves were involved. Informed consent.
Male: 52%; mean age: 45.5 years.
Exclued: ASA physical status > 2 (see notes).


InterventionsMultiple (triple) versus double (median and radial) injection.

All received local anaesthetic (LA) solution: lidocaine 2% and bupivacaine 0.5% in 1:1 ratio; total volume 40 ml. Nerve blockade facilitated using 22G insulated short-bevelled needle and nerve stimulator. All blocks carried out by one experienced operator.

All received IV midazolam 20 µg/kg and fentanyl 1 µg/kg 5 minutes before block. Initial subcutaneous injection of 4 ml LA over the axillary artery to anaesthetise medial cutaneous nerves of arm and forearm.
1. Multiple (triple) injection: injection of 10 ml LA to median nerve; 6 ml to musculocutaneous nerve and 20 ml to radial nerve.
2. Double injection: injection of 18 ml LA to median nerve, and injection of 18 ml LA to radial nerve.


OutcomesLength of follow-up: 30 minutes for sensory and motor block; 48 hours for nerve injury; neurological sequelae at 10 and 30 days.
Sensory blockade
Motor blockade
Analgesic failure (use of supplementary anaesthesia; use of opioids for tourniquet pain in operation area)
Block performance time
Block onset time
Time to readiness for surgery
Duration of surgery
Duration of tourniquet use
Tourniquet discomfort and pain
Need for intraoperative sedation
Problems (during injection and operation)
Long-term neurological complication (none)


NotesRequest for clarification on patient enrolment and additional data on complications sent to Dr Salvatore Sia on 14/10/2010; reply received 06/11/2010.

Although the Results section for the 3 trials states that 6 patients were excluded in the triple injections groups (TNS) and 8 patients in single injection groups (SEL), Dr Sia clarified in a personal communication that these were treated as "pre-operative" dropouts and were replaced by other patients.

The ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low risk"Patients undergoing each type of surgery were randomly assigned by a computer-generated list ..."

Allocation concealment (selection bias)Unclear riskAllocation concealment was not stated. 

Blinding (performance bias and detection bias)
All outcomes
Low riskPatients - not blinded. Caregiver - unblinded. Assessors - blinded. “All the blocks were... assessed by a blinded investigator.” Blinding is within study limitations.

Incomplete outcome data (attrition bias)
All outcomes
Unclear risk“Six patients in group TNS and 8 in group SEL were excluded from the study because all the prearranged nerves were not located by nerve stimulation.” Personal communication from the author indicates that these were post-randomization exclusions.

Selective reporting (reporting bias)Low riskNo protocol but same plan for series of trials. Clearly reported primary outcomes. Ethics committee acceptance reported.

Balance in baseline characteristics?Low riskBalanced.

Free from performance bias?Unclear riskAll the blocks were performed or supervised by the first author, however the number and experienced level of supervised care providers is not stated.

Turkan 2002

MethodsMethod of randomization: not stated.
Blinded outcome assessor.
No loss to follow-up apparent.


ParticipantsAnkara, Turkey
Period of study: not stated.
69 people undergoing orthopedic or trauma surgery of the upper extremity (not otherwise specified). Informed consent.
Male: 75%; mean age: 49 years.
Excluded: ASA physical status > 2 (see notes).


InterventionsDouble versus single (Winnie's technique) versus single (transarterial) injection.

All received local anaesthetic (LA) solution: 2% prilocaine and 0.5% bupivacaine in 1:1 ratio; total volume 40 ml. Identity of operators performing block were not specified; but they were described as experienced.

Sedative premedication with 0.15 mg/kg of IM midazolam.

1. Double injection: injection of 20 ml using Winnie's technique (endpoint of fascial click and paraesthesia in hand or forearm), and injection of 20 ml using transarterial technique posterior to the axillary artery.
2. Single injection: injection of 40 ml using Winnie's technique (endpoint of fascial click and paraesthesia in hand or forearm).
3. Single injection: injection of 40 ml using transarterial technique posterior to the axillary artery.

When patient in extreme anxiety or block was incomplete, propofol (≤ 3 mg/kg) and/or fentanyl (≤ 1µg/kg) was administered intraoperatively.


OutcomesLength of follow-up: sensory and motor block assessed at 10, 20 and 30 minutes.
Sensory blockade
Analgesic failure (use of supplementary anaesthesia)
Tourniquet discomfort and pain


NotesThe ASA (American Society of Anesthesiologists) physical status classification is a system for assessing the fitness of patients before surgery. It has five categories (1-5): 1 = healthy, 2 = mild systemic disease, 3 = severe systemic disease, 4 = severe disease that is a constant threat to life, 5 = moribund.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear risk"The patients were divided randomly into three groups..". No further details given.

Allocation concealment (selection bias)Unclear risk Allocation concealment not stated.

Blinding (performance bias and detection bias)
All outcomes
Unclear riskNot stated for participants, operators. It is mentioned that part of sensory testing was done by a blinded surgeon, but no detail given for other outcomes.

Incomplete outcome data (attrition bias)
All outcomes
Low riskNot evident.

Selective reporting (reporting bias)Unclear riskA bit vague in definition of outcomes and some of the P values seem excessive. 

Balance in baseline characteristics?Unclear riskBalanced for sex, age, weight & height but no information on surgery.

Free from performance bias?Unclear riskInsufficient detail given regarding operator experience. “Experienced hands” implied in Discussion but no information to judge this.

 
Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion

Bloc 2010Not in scope of review: use of ultrasound-guided method.

Bouaziz 1997Not in scope of review: comparison of two approaches: midhumeral versus axillary.

Carre 2000Not in scope of review: children only.

Gianesello 2010Not in scope of review: review of full text revealed that the study compared two different multiple-injection methods.

Imasogie 2010Not in scope of review: use of ultrasound-guided method.

K-Nielsen 2000Not in scope of review: comparison of two approaches: subcoracoid versus axillary.

Kjelstrup 2006Non randomized study.

Liu 2005Not in scope of review: use of ultrasound-guided method

Sia 2001bNot in scope of review: both interventions tested belonged to the multiple-injection group.

Singelyn 1992Not in scope of review: single injection in both groups.

Sites 2006Not in scope of review: use of ultrasound-guided method.

Tuominen 1987Not in scope of review: review of the full text revealed that these were both single-injection techniques.

Vester-Andersen 1984Not in scope of review: single injection into the same site via indwelling catheter.

Vester-Andersen 1986Not in scope of review: single injection into the same site via indwelling catheter.

Youssef 1988Not in scope of review: review of the full text revealed that these were both single-injection techniques.

Yu 2007Not in scope of review: use of ultrasound-guided method.

 
Characteristics of studies awaiting assessment [ordered by study ID]
Ramirez-Gomez 2010

MethodsRandomized controlled trial.

Participants50 adult patients undergoing trauma surgery of the arm.

InterventionsMultiple-injection technique compared with single-injection technique; both guided by neurostimulation.

Outcomes
  1. Surgical anaesthesia
  2. Sensory block
  3. Motor block
  4. Duration of post-operative analgesia

NotesStudy, which is published in Spanish, was identified by an EMBASE search conducted in March 2011.

 
Comparison 1. Double versus single-injection technique

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Primary anaesthesia failure (incomplete sensory block)8497Risk Ratio (M-H, Random, 95% CI)0.51 [0.30, 0.85]

    1.1 Transarterial injection (for double injection)
4237Risk Ratio (M-H, Random, 95% CI)0.72 [0.33, 1.58]

    1.2 Location by neurostimulation (for double injection)
4260Risk Ratio (M-H, Random, 95% CI)0.40 [0.22, 0.73]

 2 Primary anaesthesia failure - subgrouped by outcome definition8Risk Ratio (M-H, Random, 95% CI)Subtotals only

    2.1 Incomplete overall sensory block
4238Risk Ratio (M-H, Random, 95% CI)0.43 [0.24, 0.76]

    2.2 Supplemental blocks for surgical area
5309Risk Ratio (M-H, Random, 95% CI)0.43 [0.17, 1.11]

 3 Complete failure of block: general anaesthesia or new plexus block6338Risk Ratio (M-H, Fixed, 95% CI)1.29 [0.33, 5.01]

 4 Incomplete motor block4229Risk Ratio (M-H, Fixed, 95% CI)0.78 [0.58, 1.03]

 5 Secondary analgesia failure4Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    5.1 Pain in surgical site/operative field
3160Risk Ratio (M-H, Fixed, 95% CI)0.56 [0.25, 1.25]

    5.2 Tourniquet pain
2104Risk Ratio (M-H, Fixed, 95% CI)0.58 [0.22, 1.52]

    5.3 Intra-operative sedatives
2129Risk Ratio (M-H, Fixed, 95% CI)0.64 [0.31, 1.31]

 6 Timing (in minutes)4Mean Difference (IV, Fixed, 95% CI)Subtotals only

    6.1 Time for block
160Mean Difference (IV, Fixed, 95% CI)1.65 [0.72, 2.58]

    6.2 Duration of operation
150Mean Difference (IV, Fixed, 95% CI)9.0 [-8.19, 26.19]

    6.3 Duration of tourniquet
3154Mean Difference (IV, Fixed, 95% CI)2.44 [-5.24, 10.13]

    6.4 Duration of block
2129Mean Difference (IV, Fixed, 95% CI)11.98 [-6.73, 30.68]

 7 Complications during nerve block3Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    7.1 Arterial puncture
2110Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]

    7.2 Venous puncture
2110Risk Ratio (M-H, Fixed, 95% CI)1.5 [0.17, 13.52]

    7.3 Paraesthesia
2110Risk Ratio (M-H, Fixed, 95% CI)2.5 [0.31, 19.99]

    7.4 Tachycardia (intra-vascular injections)
160Risk Ratio (M-H, Fixed, 95% CI)5.86 [0.25, 137.66]

 8 Adverse effects (> 24 hours)2Risk Ratio (M-H, Fixed, 95% CI)Totals not selected

 9 Patient discomfort and dissatisfaction with method1Risk Ratio (M-H, Fixed, 95% CI)Totals not selected

    9.1 Patient uncomfortable
1Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]

    9.2 Patient would not have method again
1Risk Ratio (M-H, Fixed, 95% CI)0.0 [0.0, 0.0]

 
Comparison 2. Multiple versus single-injection technique

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Primary anaesthesia failure (incomplete sensory block)7632Risk Ratio (M-H, Random, 95% CI)0.28 [0.16, 0.48]

    1.1 No use of nerve stimulator (for single injection)
2204Risk Ratio (M-H, Random, 95% CI)0.40 [0.25, 0.65]

    1.2 Location by neurostimulation (for single injection)
5428Risk Ratio (M-H, Random, 95% CI)0.21 [0.09, 0.48]

 2 Primary anaesthesia failure - subgrouped by outcome definition7Risk Ratio (M-H, Random, 95% CI)Subtotals only

    2.1 Incomplete overall sensory block
3264Risk Ratio (M-H, Random, 95% CI)0.28 [0.12, 0.64]

    2.2 Supplemental blocks for surgical area
4368Risk Ratio (M-H, Random, 95% CI)0.26 [0.11, 0.63]

 3 Complete failure of block: general anaesthesia or new plexus block5404Risk Ratio (M-H, Random, 95% CI)0.44 [0.01, 17.76]

 4 Incomplete motor block4304Risk Ratio (M-H, Random, 95% CI)0.61 [0.39, 0.96]

 5 Secondary analgesia failure5Risk Ratio (M-H, Random, 95% CI)Subtotals only

    5.1 Pain in surgical site/operative field
3244Risk Ratio (M-H, Random, 95% CI)0.53 [0.05, 5.37]

    5.2 Tourniquet pain
4379Risk Ratio (M-H, Random, 95% CI)0.97 [0.30, 3.11]

    5.3 Intra-operative sedatives
5482Risk Ratio (M-H, Random, 95% CI)0.70 [0.41, 1.19]

 6 Timing (in minutes)4Mean Difference (IV, Random, 95% CI)Subtotals only

    6.1 Time for block
3278Mean Difference (IV, Random, 95% CI)3.34 [2.66, 4.03]

    6.2 Time for readiness for surgery
2206Mean Difference (IV, Random, 95% CI)-3.33 [-23.23, 16.56]

    6.3 Duration of tourniquet
4379Mean Difference (IV, Random, 95% CI)2.30 [-2.22, 6.82]

    6.4 Duration of block
160Mean Difference (IV, Random, 95% CI)-19.5 [-44.62, 5.62]

    6.5 Length of surgery
1138Mean Difference (IV, Random, 95% CI)2.0 [-3.53, 7.53]

 7 Complications during nerve block4Risk Ratio (M-H, Random, 95% CI)Subtotals only

    7.1 Arterial puncture
3278Risk Ratio (M-H, Random, 95% CI)1.90 [0.64, 5.66]

    7.2 Venous puncture
3278Risk Ratio (M-H, Random, 95% CI)2.58 [0.89, 7.48]

    7.3 Paraesthesia
4382Risk Ratio (M-H, Random, 95% CI)0.75 [0.20, 2.79]

    7.4 Tachycardia (intra-vascular injections)
3322Risk Ratio (M-H, Random, 95% CI)0.87 [0.09, 8.44]

    7.5 Local anaesthesia toxicity (intra-arterial injections)
1104Risk Ratio (M-H, Random, 95% CI)0.20 [0.01, 4.07]

    7.6 Subcutaneous/axillary haematoma
2184Risk Ratio (M-H, Random, 95% CI)0.33 [0.01, 7.95]

 8 Adverse effects > 24 hours3Risk Ratio (M-H, Fixed, 95% CI)Totals not selected

 9 Patient discomfort and dissatisfaction with method2Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    9.1 Patient uncomfortable
160Risk Ratio (M-H, Fixed, 95% CI)2.0 [0.77, 5.20]

    9.2 Patient would not have method again
2192Risk Ratio (M-H, Fixed, 95% CI)1.09 [0.43, 2.77]

 
Comparison 3. Multiple versus double-injection technique

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Primary anaesthesia failure (incomplete sensory block)11936Risk Ratio (M-H, Fixed, 95% CI)0.28 [0.20, 0.40]

    1.1 Transarterial injection (for double injection)
3270Risk Ratio (M-H, Fixed, 95% CI)0.27 [0.15, 0.49]

    1.2 Location by neurostimulation (for double injection)
8666Risk Ratio (M-H, Fixed, 95% CI)0.28 [0.18, 0.44]

 2 Primary anaesthesia failure - subgrouped by outcome definition11Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    2.1 Incomplete overall sensory block
7570Risk Ratio (M-H, Fixed, 95% CI)0.24 [0.15, 0.37]

    2.2 Supplemental blocks for surgical area
7586Risk Ratio (M-H, Fixed, 95% CI)0.40 [0.24, 0.66]

 3 Complete failure of block: general anaesthesia or new plexus block8600Risk Ratio (M-H, Fixed, 95% CI)0.24 [0.04, 1.41]

 4 Incomplete motor block6470Risk Ratio (M-H, Random, 95% CI)0.55 [0.36, 0.85]

 5 Secondary analgesia failure8Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    5.1 Pain in surgical site/operative field
5450Risk Ratio (M-H, Fixed, 95% CI)0.33 [0.04, 3.14]

    5.2 Tourniquet pain
7719Risk Ratio (M-H, Fixed, 95% CI)0.53 [0.33, 0.84]

    5.3 Intra-operative sedatives
7716Risk Ratio (M-H, Fixed, 95% CI)0.75 [0.55, 1.03]

 6 Timing (in minutes)6Mean Difference (IV, Random, 95% CI)Subtotals only

    6.1 Time for block
5556Mean Difference (IV, Random, 95% CI)1.74 [1.04, 2.45]

    6.2 Time for readiness for surgery
5524Mean Difference (IV, Random, 95% CI)-0.08 [-2.92, 2.77]

    6.3 Duration of tourniquet
5549Mean Difference (IV, Random, 95% CI)2.99 [-1.03, 7.01]

    6.4 Duration of surgery
3376Mean Difference (IV, Random, 95% CI)0.63 [-4.97, 6.24]

    6.5 Duration of block
2150Mean Difference (IV, Random, 95% CI)0.89 [-27.95, 29.73]

 7 Complications during nerve block8Risk Ratio (M-H, Random, 95% CI)Subtotals only

    7.1 Arterial puncture
6616Risk Ratio (M-H, Random, 95% CI)1.37 [0.66, 2.84]

    7.2 Venous puncture
6616Risk Ratio (M-H, Random, 95% CI)1.28 [0.75, 2.17]

    7.3 Paraesthesia
7716Risk Ratio (M-H, Random, 95% CI)0.71 [0.31, 1.62]

    7.4 Tachycardia (intra-vascular injections)
4476Risk Ratio (M-H, Random, 95% CI)0.55 [0.23, 1.32]

    7.5 Local anaesthesia toxicity (intra-arterial injections)
2170Risk Ratio (M-H, Random, 95% CI)1.0 [0.15, 6.82]

    7.6 Axillary haematoma/bruises
3260Risk Ratio (M-H, Random, 95% CI)0.30 [0.09, 1.06]

    7.7 Accidental intravascular injection
2200Risk Ratio (M-H, Random, 95% CI)0.81 [0.20, 3.26]

    7.8 Transient bradycardia
1100Risk Ratio (M-H, Random, 95% CI)0.33 [0.01, 7.99]

 8 Adverse effects > 24 hours6Risk Ratio (M-H, Fixed, 95% CI)Totals not selected

 9 Patient discomfort and dissatisfaction with method4Risk Ratio (M-H, Fixed, 95% CI)Subtotals only

    9.1 Patient uncomfortable
180Risk Ratio (M-H, Fixed, 95% CI)1.33 [0.73, 2.45]

    9.2 Patient would not have method again
3356Risk Ratio (M-H, Fixed, 95% CI)1.13 [0.59, 2.13]

    9.3 Patient dissatisfied
170Risk Ratio (M-H, Fixed, 95% CI)0.25 [0.01, 5.98]

 
Summary of findings for the main comparison. Double versus single-injection technique

Double injection versus single-injection technique of axillary brachial plexus block for hand, wrist or forearm surgery in adults

Patient or population: Adult patients undergoing hand, wrist or forearm surgery

Settings: Hospital

Intervention: Double-injection technique of axillary brachial plexus block

Comparison: Single-injection technique of axillary brachial plexus block

OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No of Participants
(studies)
Quality of the evidence
(GRADE)
Comments

Assumed riskCorresponding risk

Single injectionDouble injection

Primary anaesthesia failure38 per 10019 per 100
(11 to 32)
RR 0.51

(0.30 to 0.85)
497
(8 studies)
+++O
moderate

Secondary analgesia failure: Intraoperative sedation required27 per 10017 per 100
(8 to 35)
RR 0.64

(0.31 to 1.31)
129
(2 studies)
++OO
low

Secondary analgesia failure : Tourniquet pain16 per 1009 per 100
(4 to 25)
RR 0.58

(0.22 to 1.52)
104
(2 studies)
++OO
low

Complete failure of block116 per 100021 per 1000
(5 to 80)
RR 1.29

(0.33 to 5.01)
338
(6 studies)
+OOO
very low
There were no events in 4 out of 6 studies.

Time to readiness for surgery2 (minutes)See commentSee commentSee comment+OOO
very low
None of the included studies assessed this outcome.

Intravascular injection55 per 1000322 per 1000
(14 to 7571)
RR 5.86

(0.25 to 137.66)
60
(1 study)
+OOO
very low
Only 1 event occurred in the study.

Adverse effects lasting more than 24 hours313 per 100016 per 1000
(4 to 77)
RR 1.25

(0.27 to 5.89)
119
(2 studies)
+OOO
very low
There were no events in 1 of the 2 studies.

*The assumed risk for the 'control' group is based on the mean value of the results for all single injection groups in the included trials reporting the outcome. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

CI: Confidence interval; RR: Risk Ratio

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

 1. Complete failure of block is defined as the need for general anaesthesia or a new plexus block to provide surgical anaesthesia.
2. Time to readiness for surgery is defined as the time required to perform the block plus the time from completion of the block to development of surgical anaesthesia.
3. Adverse effects lasting more than 24 hours refers mainly to neurological symptoms or deficits in the arm that was blocked.
 
Summary of findings 2. Multiple versus single-injection technique

Multiple injection versus single-injection technique of axillary brachial plexus block for hand, wrist or forearm surgery in adults

Patient or population: Adult patients undergoing hand, wrist or forearm surgery

Settings: Hospital

Intervention: Multiple-injection technique of axillary brachial plexus block

Comparison: Single-injection technique of axillary brachial plexus block

OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No of Participants
(studies)
Quality of the evidence
(GRADE)
Comments

Assumed riskCorresponding risk

Single injectionMultiple injection

Primary anaesthesia failure38 per 10011 per 100
(6 to 18)
RR 0.28

(0.16 to 0.48)
632
(7 studies)
+++O
moderate

Secondary analgesia failure: Intraoperative sedation required27 per 10019 per 100
(11 to 32)
RR 0.70

(0.41 to 1.19)
482
(5 studies)
++OO
low

Secondary analgesia failure : Tourniquet pain16 per 10014 per 100
(4 to 44)
RR 0.97

(0.30 to 3.11)
379
(4 studies)
++OO
low

Complete failure of block116 per 10007 per 1000
(0 to 284)
RR 0.44

(0.01 to 17.76)
404
(5 studies)
+OOO
very low
There were no events in 3 out of 5 studies

Time to readiness for surgery2 (minutes)The mean block performance time ranged across control groups from 14.3 to 38.5 minutesThe mean block performance time ranged across intervention group from 21.1 to 25.0 minutes206
(2 studies)
++OO
low

Intravascular injection55 per 100048 per 1000
(5 to 464)
RR 0.87

(0.09 to 8.44)
322
(3 studies)
+OOO
very low

Adverse effects lasting more than 24 hours313 per 10003 per 1000
(0 to 34)
RR 0.25 (0.02 to 2.59)244
(3 studies)
+OOO
very low
There were no events in 2 of the 3 studies.4

*The assumed risk for the 'control' group is based on the mean value of the results for all single-injection groups in the included trials reporting the outcome. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

CI: Confidence interval; RR: Risk Ratio

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

 1. Complete failure of block is defined as the need for general anaesthesia or a new plexus block to provide surgical anaesthesia.
2. Time to readiness for surgery is defined as the time required to perform the block plus the time from completion of the block to development of surgical anaesthesia.
3. Adverse effects lasting more than 24 hours refers mainly to neurological symptoms or deficits in the arm that was blocked.
4. Fanelli 1999 observed a 1% risk of transient neurological deficit in their study of 1650 patients receiving multiple-injection brachial plexus blocks.
 
Summary of findings 3. Multiple versus double-injection technique

Multiple-injection versus double-injection technique of axillary brachial plexus block for hand, wrist or forearm surgery in adults

Patient or population: Adult patients undergoing hand, wrist or forearm surgery

Settings: Hospital

Intervention: Multiple-injection technique of axillary brachial plexus block

Comparison: Double-injection technique of axillary brachial plexus block

OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No of Participants
(studies)
Quality of the evidence
(GRADE)
Comments

Assumed riskCorresponding risk

Double injectionMultiple injection

Primary anaesthesia failure26 per 1007 per 100
(5 to 10)
RR 0.28

(0.20 to 0.40)
936
(11 studies)
+++O
moderate

Secondary analgesia failure: Intraoperative sedation required19 per 10015 per 100
(11 to 20)
RR 0.75

(0.55 to 1.03)
716
(7 studies)
++OO
low

Secondary analgesia failure : Tourniquet pain13 per 1007 per 100
(4 to 11)
RR 0.53

(0.33 to 0.84)
719
(7 studies)
+++O
moderate

Complete failure of block123 per 10006 per 1000
(1 to 32)
RR 0.24

(0.04 to 1.41)
600
(8 studies)
+OOO
very low
There were no events in 6 out of 8 studies.

Time to readiness for surgery2 (minutes)The mean block performance time ranged across control groups from 8.8 to 38.0 minutesThe mean block performance time ranged across intervention group from 10.2 to 30 minutes524
(5 studies)
++OO
low

Intravascular injection66 per 100036 per 1000
(15 to 87)
RR 0.55

(0.23 to 1.32)
476
(4 studies)
+OOO
very low

Adverse effects lasting more than 24 hours319 per 10004 per 1000
(0 to 31)
RR 0.20 (0.02 to 1.64)510
(6 studies)
+OOO
very low
There were no events in 5 of the 6 studies.4

*The assumed risk for the 'control' group is based on the mean value of the results for all double-injection groups in the included trials reporting the outcome. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

CI: Confidence interval; RR: Risk Ratio

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

 1. Complete failure of block is defined as the need for general anaesthesia or a new plexus block to provide surgical anaesthesia.
2. Time to readiness for surgery is defined as the time required to perform the block plus the time from completion of the block to development of surgical anaesthesia.
3. Adverse effects lasting more than 24 hours refers mainly to neurological symptoms or deficits in the arm that was blocked.
4. Fanelli 1999 observed a 1% risk of transient neurological deficit in their study of 1650 patients receiving multiple-injection brachial plexus blocks.
 
Table 1. Methods of nerve location

Method of nerve locationNumber of injectionsTrials

Transarterial

The axillary artery is palpated and deliberately transfixed with a needle. The needle is then either withdrawn to inject LA anterior (superficial) to the artery, or inserted deeper to inject LA posterior to the artery, or both.
Single - anteriorHickey 1993

Single - posteriorHickey 1993; K-Nielsen 1999b

DoubleGoldberg 1987; Hickey 1993; Imbelloni 2005; K-Nielsen 1998; K-Nielsen 1999a; Pere 1993

Winnie's perivascular technique

A needle is inserted adjacent to the axillary artery until a fascial click is felt, signifying penetration of the neurovascular fascial sheath. A catheter may be also inserted proximally within the sheath. LA is then injected, usually as a single bolus, while applying distal pressure to promote proximal spread of the LA.
SingleBaranowski 1990; Turkan 2002

Paraesthesia

A needle is inserted adjacent to the axillary artery and manipulated to elicit paraesthesia in the distribution of one or more of the four terminal nerves. LA is then injected at these locations.
SingleGoldberg 1987

MultipleBaranowski 1990

Neurostimulation (electrolocation)

A needle is inserted adjacent to the axillary artery and manipulated until it comes into close proximity to one or more of the four terminal nerves. An electric current is passed through the needle and needle-nerve proximity is signalled by an appropriate movement (motor response) of the forearm or hand, usually at currents of ≤ 0.5 mA. LA is injected at these locations.
SingleInberg 1999; K-Nielsen 1997; Pere 1993; Rodriguez 2005; Serradell Catalan 2001; Sia 2010a

DoubleCoventry 2001; Inberg 1999; Lavoie 1992; Rodriguez 2005; Rodriguez 2008; Serradell Catalan 2001; Sia 2001; Sia 2010b; Sia 2010c

MultipleBaranowski 1990; Coventry 2001; Imbelloni 2005; K-Nielsen 1997; K-Nielsen 1998; K-Nielsen 1999a; K-Nielsen 1999b; Lavoie 1992; Rodriguez 2005; Rodriguez 2008; Serradell Catalan 2001; Sia 2001; Sia 2010a; Sia 2010b; Sia 2010c

 LA = local anaesthetic; mA = milliamperes.