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Preoperative bathing or showering with skin antiseptics to prevent surgical site infection

  1. Joan Webster1,2,3,*,
  2. Sonya Osborne4

Editorial Group: Cochrane Wounds Group

Published Online: 12 SEP 2012

Assessed as up-to-date: 29 JUN 2012

DOI: 10.1002/14651858.CD004985.pub4


How to Cite

Webster J, Osborne S. Preoperative bathing or showering with skin antiseptics to prevent surgical site infection. Cochrane Database of Systematic Reviews 2012, Issue 9. Art. No.: CD004985. DOI: 10.1002/14651858.CD004985.pub4.

Author Information

  1. 1

    Royal Brisbane and Women's Hospital, Centre for Clinical Nursing, Brisbane, QLD, Australia

  2. 2

    Griffith University, NHMRC Centre of Research Excellence in Nursing, Brisbane, Queensland, Australia

  3. 3

    University of Queensland, School of Nursing & Midwifery, Brisbane, Queensland, Australia

  4. 4

    Queensland University of Technology, School of Nursing, Kelvin Grove (Brisbane), Queensland, Australia

*Joan Webster, joan_webster@health.qld.gov.au.

Publication History

  1. Publication Status: New search for studies and content updated (no change to conclusions)
  2. Published Online: 12 SEP 2012

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This is not the most recent version of the article. View current version (20 FEB 2015)

 
Characteristics of included studies [ordered by study ID]
Byrne 1992

MethodsRCT.
Power calculation: yes.
Follow-up period: 6 weeks after discharge.


Participants3733 patients undergoing elective or potentially contaminated surgery.
Exclusion criteria: patients undergoing day surgery, emergency surgery, re-operation or contaminated surgery and those unable to comply with the washing procedure, or with a known allergy to chlorhexidine or having more than the standard prophylactic antibiotic regimen.
Baseline comparability: age, sex, type of surgery, ASEPSIS score.


InterventionsAll patients showered 3 times (on admission, the night before surgery and the morning of surgery) using 50 ml of either:
Group 1: 4% chlorhexidine, or
Group 2: a placebo.
Written instructions were provided to all participants.


OutcomesPrimary outcome:
Wound infection was defined as discharge of pus from a wound for inpatients or outpatients, or an ASEPSIS score greater than 10.
Group 1: 256/1754 (14.6%);
Group 2: 272/1735 (15.7%).
Secondary outcomes:
Death, allergic reactions, cost.


NotesData were extracted from 3 papers reporting results from 1 study (see Lynch 1992 & Byrne 1994). There were minor discrepancies in numbers reported between the 3 studies. The version reported is the definitive study (personal correspondence with author). The abstract stated there were 1753 patients in the placebo group but this should have been 1735


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskRandomisation was performed in blocks of 6. Randomisation in each group of 6 was by computer-generated random numbers.

Allocation concealment (selection bias)Low riskPersonal communication with author. Allocation in sealed envelopes.

Blinding (performance bias and detection bias)
Investigator and participant
Low risk2 bottles of either 4% chlorhexidine detergent solution or a physically-identical placebo detergent were given to the patient. Neither the investigators nor the patient were aware of the allocation.
Outcome blinding was not specifically mentioned, however, it seems likely that those assessing infection status would have been unaware of the allocation.

Blinding (performance bias and detection bias)
Outcome assessor
Low riskOutcome assessment blinded

Incomplete outcome data (attrition bias)
All outcomes
Low riskOf 3733 patients randomised, 244 (6.5%) were excluded from the outcome analysis. The majority of these, 219 (5.9%) were because the operation was cancelled after randomisation. 4 patients in the chlorhexidine group and 9 patients in the control group were excluded for protocol violations. However, as these numbers are extremely small (0.4% of those randomised), it is unlikely that results were compromised.

Selective reporting (reporting bias)Low riskThe study reported on all of the stated outcomes.

Other biasLow riskThe trial was supported by ICI Pharmaceuticals. However, as results did not support the use of chlorhexidine, it is unlikely that results were compromised.

Earnshaw 1989

MethodsRCT.
Power calculation: no.
Follow-up period: until hospital discharge.


Participants66 patients undergoing vascular reconstruction surgery.
Exclusion: none reported.
Baseline comparability: stated that groups were similar, no data.


InterventionsAll patients had 2 baths.
Group 1: painted entire body with undiluted 4% chlorhexidine followed by rinsing in the bath. Precise instructions given;
Group 2: non-medicated soap used. No specific instructions provided.


OutcomesPrimary outcome:
Wound infection was defined as discharge of pus from a wound; 1 patient with severe cellulitis was also included.
Group 1: 8/31 (26%);
Group 2: 4/35, (11.4%).
Secondary outcome:
Death.


NotesDifferent washing information provided to participants in each group.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot described. Investigator contacted - no further information available.

Allocation concealment (selection bias)Unclear riskNot described. Investigator contacted - no further information available.

Blinding (performance bias and detection bias)
Investigator and participant
High riskBoth the investigator and the participant were aware of the allocation.
Postoperatively wounds were reviewed blind until patients left hospital.

Blinding (performance bias and detection bias)
Outcome assessor
Low riskOutcome assessment blinded.

Incomplete outcome data (attrition bias)
All outcomes
Low riskResults were available for all those enrolled. No drop outs or exclusions were described.

Selective reporting (reporting bias)Low riskThe study reported on wound infection. A number of post hoc analyses were also conducted.

Other biasHigh riskBaseline data tables were not provided but the author stated that "clinical details of the two groups were similar".
Different washing information provided to participants in each group.
Hibiscrub (chlorhexidine) was provided by ICI. However, as results favoured the use of soap, it is unlikely that the involvement of the pharmaceutical company influenced results.

Hayek 1987

MethodsCluster RCT.
Power calculation: no.
Follow-up period: until hospital discharge.


Participants2015 patients undergoing routine surgery.
Exclusion: those receiving antibiotics or with an existing infection.
Baseline comparability: age, sex, preoperative skin preparation, wound classification, proportion who washed their hair.


InterventionsAll patients had either a shower or bath on the day before and morning of their operation.
Group 1: chlorhexidine 4%. Instruction card for washing provided.
Group 2: placebo. Instruction card for washing provided (5 months into the study, the placebo was found to have antimicrobial properties and was changed).
Group 3: bar soap. No washing instructions provided.


OutcomesPrimary outcome:
Wound infection was defined as either discharge of pus from a wound, or erythema, or swelling considered to be greater than expected.
Group 1: 62/689 (9.0%);
Group 2: 83/700 (11.7%);
Group 3: 80/626 (12.8%).


NotesData were extracted from 2 papers reporting results from 1 study (Hayek 1988).


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskNot described.

Allocation concealment (selection bias)Unclear riskNot described.

Blinding (performance bias and detection bias)
Investigator and participant
High risk3 arms to the study. "None of the ward staff or those assessing the wounds were aware of whether placebo or active compound was being used as these were issued in identical coded sachets, though no form of double blind was possible for the bar soap group".

Blinding (performance bias and detection bias)
Outcome assessor
Low riskOutcome assessment blinded.

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskIt appears from the text that results were available from all patients who entered the study. However, as patients were followed up for 6 weeks postoperatively; it seems unusual that none were lost to follow-up.

Selective reporting (reporting bias)Low riskAll data reported.

Other biasHigh riskNo baseline data presented. The authors state that "The three groups are comparable except for one interesting facet; only 14% washed their hair with bar soap against 28% with either of the liquids.
Specific washing instructions were provided to the chlorhexidine and placebo groups but not to the bar soap group.
5 months into the study, the placebo was found to have antimicrobial properties and was changed.
It is unclear how this large study was funded. No competing interests were declared.

Randall 1983

MethodsRCT.
Power calculation: no.
Follow-up period: 1 week after discharge.


Participants94 patients undergoing vasectomy.
Exclusion: none stated.
Baseline comparability: none stated.


InterventionsGroup 1: 1 preoperative shower with chlorhexidine 4%,
Group 2: 1 shower with normal soap.
Group 3: no shower.


OutcomesPrimary outcome:
Wound infection was defined as discharging either purulent or serous fluid.
Group 1: 12/32 (37.5%);
Group 2: 10/30 (33.3%);
Group 3: 9/32 (28.1%).


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskPersonal correspondence with study authors confirmed that trialists used computer-generated random numbers.

Allocation concealment (selection bias)Unclear riskMethod not described.

Blinding (performance bias and detection bias)
Investigator and participant
High riskBlinding of the intervention was not possible.

Blinding (performance bias and detection bias)
Outcome assessor
Unclear riskIt is unclear if outcome assessment was blinded.

Incomplete outcome data (attrition bias)
All outcomes
Low riskAll but 1 enrolled patient were assessed 7 days postoperatively; 83 returned to the ward, 10 were contacted at home and 1 was lost to follow-up (it is unclear which group this patient was in); results were presented for the total number enrolled.

Selective reporting (reporting bias)Low riskAll data reported.

Other biasLow riskNo baseline data presented.
No competing interests declared.

Rotter 1988

MethodsCluster RCT.
Power calculation: no.
Follow-up period: 3 weeks after discharge.


Participants2953 patients undergoing elective clean surgery.
Exclusion: patients with a temperature of 37.5oC on the day of or day before surgery, infection remote from operation site, antibiotics given within 7 days prior to surgery for infection, incarcerated inguinal hernia, radical mastectomy.
Baseline comparability: age, sex, type of surgery, antibiotic prophylaxis, hair washed, hair removal method, wound drainage.


InterventionsAll patients had 2 showers;1 the day before surgery and 1 on the day of surgery.
Group 1: used 50 ml of chlorhexidine 4% for each shower;
Group 2: placebo.
Special application instructions were provided to all participants.


OutcomesPrimary outcome:
Wound infection was defined in the report as "inflammation of the surgical wound with discharge of pus, spontaneous and/or after surgical intervention that occurs during hospitalisation or during routine follow-up"
Group 1: 37/1413 (2.6%);
Group 2: 33/1400 (2.4%).


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskRandomisation was carried out for each surgical unit by means of computer-generated patient trial numbers.

Allocation concealment (selection bias)Low riskBottles of solution were contained in boxes of 10, each holding 5 chlorhexidine and 5 placebo in random sequence. Unless the code was broken, it was impossible to know which preparation the patient had used.

Blinding (performance bias and detection bias)
Investigator and participant
Low riskNeither patients nor investigators were aware of group allocation.

Blinding (performance bias and detection bias)
Outcome assessor
Low riskOutcome assessment was by routine surveillance methods employed by individual hospitals (infection control nurse or surgeon). They were unaware of group allocation.

Incomplete outcome data (attrition bias)
All outcomes
Low risk140 (4.7%) patients were withdrawn after randomisation either because the patient was not operated on (62 patients), had had 1 bath only (26), operation not stated 'clean' (14) or had a current infection (38). The withdrawals were evenly distributed between the chlorhexidine and placebo groups.

Selective reporting (reporting bias)Low riskAll data reported.

Other biasLow riskICI supplied the bathing materials. However, as results favoured the placebo group, this is unlikely to have affected results.

Veiga 2009

MethodsRCT.
Power calculation: no.
Follow-up period: 30 days.


ParticipantsAdult patients, scheduled for plastic surgery at a University-affiliated hospital in Brazil.

Exclusions: hypersensitivity to chlorhexidine, presence of skin lesions, antibiotic use at time of surgery, diabetes, heavy smoking, immunosuppression.


InterventionsGroup 1: shower with liquid-based detergent containing 4% chlorhexidine;
Group 2: shower with the same liquid-based detergent, without chlorhexidine;
Group 3: no preoperative showering instructions were given.
Patients in Groups 1 and 2 were asked to rinse thoroughly, lather with the antiseptic, rinse, lather and rinse again.


OutcomesPrimary outcome:
Surgical site infection (defined using Centers for Disease Control criteria for wound infection and wound classification)
Group 1: 1/50 (2%);
Group 2: 1/50 (2%);
Group 3: 0/50 (0%).

Secondary outcome:
Adverse reactions: no adverse reactions were reported.


Notes


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskComputer-generated.

Allocation concealment (selection bias)Unclear riskNot described.

Blinding (performance bias and detection bias)
Investigator and participant
Low riskSurgeons and patients were all blinded to the allocation group.

Blinding (performance bias and detection bias)
Outcome assessor
Low riskOutcome assessors and microbiologists were all blinded to the allocation group.

Incomplete outcome data (attrition bias)
All outcomes
Low riskAll patients were followed for the nominated 30 days.

Selective reporting (reporting bias)Low riskExpected outcomes were reported.

Other biasLow riskThe placebo solution was provided by Rioquimica Industria Farmaceutica, the manufacturer of the intervention product. However, as results in different groups were similar, this is unlikely to have affected results.

Wihlborg 1987

MethodsRCT.
Power calculation: no.
Follow-up period: until hospital discharge.


Participants1530 patients undergoing elective surgery of the biliary tract, inguinal hernia and breast cancer.
Exclusion: none stated.
Baseline comparability: age, duration of surgery > 2 hours, steroids, diabetes, malignancy (other than breast cancer), type of surgery.


InterventionsGroup 1: patients washed their entire body with chlorhexidine on the day before surgery using 2 consecutive applications followed by rinsing under the shower;
Group 2: washed only that part of the body to be submitted to surgery with chlorhexidine soap;
Group 3: No chlorhexidine wash.


OutcomesPrimary outcome:
Wound infection was defined as a definite collection of pus emptying itself spontaneously or after incision:
Group 1: 9/541 (1.7%);
Group 2: 23/552 (4.2%);
Group 3: 20/437 (4.6).


NotesThis study was conducted over a 7 year period from 1978 to 1984.
It was unclear from the text whether patients allocated to the 'no chlorhexidine wash' group had any preoperative shower. 3 patients died and were not included in the analysis.
Strength of wash solution was not stated.


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskPersonal correspondence with study authors confirmed that they used a randomisation list.

Allocation concealment (selection bias)Low riskPatients were randomly allocated to 1 of 3 wards in which different preoperative preparation schedules were used. The author states that "The randomisation was done by the Chief surgeon in such a way that he did not know the identity of the patients allocated to each ward."

Blinding (performance bias and detection bias)
Investigator and participant
High riskBlinding would have been impossible because of the allocation method.

Blinding (performance bias and detection bias)
Outcome assessor
High riskOutcome assessment was not blinded (personal correspondence with study authors).

Incomplete outcome data (attrition bias)
All outcomes
Low risk3 patients died in the few days following surgery, these were not identified by group.

Selective reporting (reporting bias)Low riskAll data reported.

Other biasUnclear riskBaseline risk factors were similar across groups.
No competing interests declared.

 
Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion

Ayliffe 1983Not a randomised controlled trial.

Bergman 1979No data on wound infection. Not a randomised controlled trial.

Bode 2010Co-intervention (mupirocin and chlorhexidine soap). Also included patients who did not undergo surgery.

Brandberg 1980Not a randomised controlled trial. Local wash versus full body wash with chlorhexidine.

Edminson 2010Not a clinical trial.

Edmiston 2008Healthy volunteers used to compare skin concentration levels of chlorhexidine gluconate (CHG) following washing with various CHG products.

Eiselt 2009Not a randomised controlled trial. Used a pre and post intervention design.

Enjabert 1984Not a randomised controlled trial.

Garabaldi 1988No no-antiseptic group. Did not report infection rates by group.

Jakobsson 2010Systematic review.

Kaiser 1988Did not report infection rates by group.

Kalanter-Hormozi 2005Patients in both groups showered with water. The trial compared methods of skin preparation prior to surgery.

Leigh 1983Not a randomised controlled trial.

Murray 20112% chlorhexidine gluconate cloths were used to wipe over the entire body one hour after showering.

Newsom 1988Not a randomised controlled trial. Patients were allocated by month.

Paulson 1993Assessed reduction in microbial loads in healthy volunteers.

Tanner 2011Trial of healthy volunteers

Veiga 2008Assessed the influence of povidone-iodine preoperative showers on skin colonization. Rates of wound infection not reported.

Wells 1983Not a randomised controlled trial. Did not report infection rates by group.

 
Comparison 1. Chlorhexidine 4% versus placebo

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

 1 Surgical site infection47791Risk Ratio (M-H, Fixed, 95% CI)0.91 [0.80, 1.04]

 2 Surgical site infection (high quality studies)26302Risk Ratio (M-H, Fixed, 95% CI)0.95 [0.82, 1.10]

 3 Allergic reaction23589Risk Ratio (M-H, Fixed, 95% CI)0.89 [0.36, 2.19]

 
Comparison 2. Chlorhexidine 4% versus bar soap

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

 1 Surgical site infection31443Risk Ratio (M-H, Random, 95% CI)1.02 [0.57, 1.84]

 
Comparison 3. Chlorhexadine 4% versus no wash

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

 1 Surgical site infection31142Risk Ratio (M-H, Random, 95% CI)0.82 [0.26, 2.62]

 
Comparison 4. Chlorhexidine full wash versus partial wash

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

 1 Surgical site infection11093Risk Ratio (M-H, Fixed, 95% CI)0.40 [0.19, 0.85]

 
Summary of findings for the main comparison. Preoperative showering with chlorhexidine 4% compared to placebo

pre-operative showering with Chlorhexidine 4% compared to placebo for surgical patients

Patient or population: surgical patients

Settings: Hospitals

Intervention: pre-operative showering with Chlorhexidine 4%

Comparison: placebo

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

Assumed riskCorresponding risk

placebopre-operative showering with Chlorhexidine 4%

Surgical site infection
Follow-up: 1 - 6 weeks1
Low risk populationRR 0.91
(0.8 to 1.04)
7791
(4 studies)
⊕⊕⊕⊕
high2

30 per 100027 per 1000
(24 to 31)

High risk population

100 per 100091 per 1000
(80 to 104)

Allergic reaction
Follow-up: 1 - 6 weeks1
Study populationRR 0.89
(0.36 to 2.19)
3589
(2 studies)
⊕⊕⊕⊝
moderate3

6 per 10005 per 1000
(2 to 13)

Medium risk population

3 per 10003 per 1000
(1 to 7)

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. 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 Some studies followed patients only until hospital discharge; however, as these studies are over 20 years old, we have assumed 7 days.
2 In one trial, five months into the study, the placebo solution was found to contain a microbiological agent. The solution was changed for the remaining 17 months of the trial. There was a total of over 7,000 participants included in this outcome, so we do not believe that the overall effect estimate would have been substantially altered.
3 Only 19 events were reported. All of these were from one trial.
 
Summary of findings 2. Chlorhexidine 4% compared with bar soap

Chlorhexidine 4% compared to bar soap for Surgical patients

Patient or population: Surgical patients

Settings:

Intervention: Chlorhexidine 4%

Comparison: bar soap

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

Assumed riskCorresponding risk

bar soapChlorhexidine 4%

Surgical site infectionStudy populationRR 1.02
(0.57 to 1.84)
1443
(3 studies)
⊕⊝⊝⊝
very low1,2,3

136 per 1000139 per 1000
(78 to 250)

Medium risk population

128 per 1000131 per 1000
(73 to 236)

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. 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 The method of allocation was unclear in some studies and outcome assessment was not blinded.
2 Heterogeneity between trials was evident; this was most probably due to the different types of surgeries and different definitions used for infection.
3 95% confidence interval around the pooled estimate of effect includes both 1) no effect and 2) appreciable benefit or appreciable harm.
 
Summary of findings 3. Chlorhexadine 4% compared with no wash

Chlorhexadine 4% compared to no wash for surgical patients

Patient or population: surgical patients

Settings: Hospital

Intervention: Chlorhexadine 4%

Comparison: no wash

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

Assumed riskCorresponding risk

no washChlorhexadine 4%

Surgical site infection
Follow-up: 1 - 3 weeks1
Study populationRR 0.82
(0.26 to 2.62)
1142
(3 studies)
⊕⊝⊝⊝
very low2,3,4

56 per 100046 per 1000
(15 to 147)

Medium risk population

46 per 100038 per 1000
(12 to 121)

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. 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 Some studies followed patients only until hospital discharge; as the studies were over 20 years old, we have assumed this to be one week.
2 A number of potential biases existed including inadequate allocation concealment and blinding.
3 Hetrogeneity between studies was evident; this was most likely due to different types of surgeries, differences in length of follow-up, varying sample sizes and ways of defining infection.
4 Wide confidence intervals, low event rate.