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Keywords:

  • Anaesthesia; day case;
  • Analgesia; postoperative;
  • Analgesics; ketorolac, tramadol;
  • Surgery; laparoscopic sterilisation

Abstract

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. References

We conducted a prospective, randomised, double-blind study to compare the analgesic efficacy of intravenous tramadol 1.5 mg.kg−1 and ketorolac 10 mg in 60 ASA grade 1 and 2 patients scheduled to undergo day-case laparoscopic sterilisation by application of Filshie clips. Patients who received tramadol had significantly less postoperative pain in the recovery room (p = 0.007) and at discharge from the day-surgery unit (p = 0.03), and they required rescue analgesia with morphine less often (p = 0.02) than patients who received ketorolac. No difference in either the incidence or severity of nausea and vomiting was observed between the two groups. Both analgesic drugs were well tolerated at the doses given in the study, although dry mouth was significantly more common after the administration of tramadol (p = 0.009). Three patients in the tramadol group and five in the ketorolac group required overnight admission due to pain or nausea and vomiting.

Satisfactory analgesia is difficult to achieve after day-case laparoscopic sterilisation. Postoperative opioids are often required [1[2][3]–4] which may cause drowsiness and nausea, resulting in delayed discharge from the day-surgery unit. Overnight hospital admission for pain relief is also necessary in a significant number of patients [5[6]–7]. Tramadol is a synthetic 4-phenylpiperidine analogue of codeine introduced into the UK in 1994. Although it is a relatively weak opioid agonist, tramadol also antagonises the neuronal uptake of noradrenaline and serotonin and displaces serotonin stores within the spinal cord, facilitating descending inhibitory pain pathways [8[9]–10]. The side-effect profile of tramadol may therefore be more acceptable to day-case patients compared with other opioids. The aim of the present study was to compare the analgesic effect of intravenous tramadol for day-case laparoscopic sterilisation with our normal practice of giving ketorolac, a parenteral nonsteroidal anti-inflammatory analgesic.

Methods

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. References

Following approval by the local ethics committee and written informed consent, 60 ASA grade 1 and 2 patients scheduled to undergo day-case laparoscopic sterilisation were recruited into this prospective, randomised, double-blind study. Patients with a history of epilepsy, asthma, peptic ulceration or hypersensitivity to nonsteroidal anti-inflammatory drugs were not studied. None of the patients had taken any analgesic drugs in the preceding 24 h.

The patients did not receive any premedication. They were randomly allocated by sealed envelope to receive either intravenous ketorolac 10 mg 30 min before the anticipated start of surgery or intravenous tramadol 1.5 mg.kg−1 at induction of anaesthesia. Patients, nursing staff and the investigator supervising completion of the study questionnaire (AJP) were blinded to the choice of analgesic.

An intravenous cannula was inserted into a suitable vein 30 min before the anticipated start of surgery and either ketorolac 10 mg or an equal volume of saline was administered. Anaesthesia was induced in all patients with fentanyl 2 μg.kg−1 and propofol 2–3 mg.kg−1, followed by mivacurium 0.15 mg.kg−1 to facilitate tracheal intubation and controlled ventilation. Patients in the tramadol group also received intravenous tramadol 1.5 mg.kg−1. Anaesthesia was maintained with 66% nitrous oxide in oxygen and isoflurane, adjusted to an end-tidal concentration of 1%. The electrocardiogram, noninvasive arterial blood pressure, oxygen saturation, respiratory gases and neuromuscular transmission were monitored throughout anaesthesia. Laparoscopic sterilisation was performed by application of Filshie clips to the Fallopian tubes. Reversal of residual neuromuscular block was not necessary in any patient.

The duration of anaesthesia, defined as the time from induction to the cessation of administration of anaesthetic agents, was recorded by the anaesthetist. The time to early recovery, defined as the time taken until able to state name and date of birth correctly, and the time to hospital discharge were recorded by the nursing staff. Patients were asked to indicate the severity of their pain and nausea using 100-mm visual analogue scales (VAS). They had been educated in the use of these scales before surgery. Severe nausea was defined as a VAS > 50 mm. Patients were assessed in the recovery room (before administration of further analgesia if this was required) and also at 1 h, 2 h and discharge from the day-surgery unit. Patients were also questioned as to the presence of dizziness, sweating, headache, dry mouth, shivering and any other side-effects. Rescue analgesia was given at the discretion of the nursing staff who were blinded to the treatment groups. This consisted of either two tablets of cocodamol 30/500 (each containing codeine 30 mg and paracetamol 500 mg) or intramuscular morphine 10 mg and cyclizine 50 mg, according to the degree of discomfort.

Patient age and weight, the duration of anaesthesia and times to early recovery and hospital discharge were analysed by Student's unpaired t-test. VAS scores for pain and nausea were analysed using the Mann–Whitney U-test. The Chi-squared test was used for categorical data. A value of p < 0.05 was considered significant.

Results

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. References

The demographic characteristics of the patients and postoperative data are shown in Table 1. Both study groups were comparable with respect to age, weight, duration of anaesthesia and times to early recovery and hospital discharge. Patients who received tramadol had less pain in the recovery room (p = 0.007) and at discharge from the day-surgery unit (p = 0.03) (Table 2) and required rescue analgesia with morphine less often (p = 0.02) than patients who received ketorolac. VAS nausea scores were similar after administration of either tramadol or ketorolac. Severe nausea (VAS > 50 mm) or vomiting occurred in five (17%) patients who received tramadol compared with six (20%) patients who received ketorolac and was a factor necessitating overnight admission in two patients from the tramadol group and one from the ketorolac group. There was no significant difference in the hospital admission rates of the two study groups. Both analgesic drugs were well tolerated at the doses given in the study although dry mouth was significantly more common after administration of tramadol, being reported in 18 (60%) patients vs. eight (27%) in the ketorolac group (p = 0.009).

Table 1.  Demographic and postoperative data. Values are expressed as mean (SD) or numbers [percentage]. Patients who required overnight hospital admission were excluded from the analysis of discharge times. *Significant difference between groups (p = 0.02).Thumbnail image of
Table 2.  VAS scores for postoperative pain and nausea. Values are expressed as median (interquartile range). Thumbnail image of

Discussion

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. References

Pain after laparoscopic sterilisation is often severe in the immediate postoperative period. Although nonsteroidal anti-inflammatory drugs are used extensively for laparoscopic sterilisation [11], studies have often failed to demonstrate a significant reduction in either postoperative pain or the need for additional opioids [1, 3, 5, 12[13][14]–15]. A variety of local anaesthetic techniques, including dripping local anaesthetic solution onto the Fallopian tubes [16, 17], transcervical injection of local anaesthetic [18], mesosalpingeal [19, 20] and rectus sheath [21] blockade, and application of lignocaine gel to Filshie clips [22[23]–24] have also been assessed. Although the use of local anaesthesia appears to be of some benefit in reducing postoperative pain after laparoscopic sterilisation in most of these studies, such techniques are often not employed, perhaps due to a perception that they are time-consuming and difficult to perform.

In the present study, the administration of tramadol 1.5 mg.kg−1 at induction of anaesthesia significantly reduced pain following laparoscopic sterilisation compared with patients who received ketorolac. Although the trend towards lower pain scores after 1 h and 2 h did not reach statistical significance, it is likely that differences in the severity of pain reported by patients at these times were masked by the effects of morphine which was required by only 33% patients in the tramadol group vs. 63% patients in the ketorolac group.

Tramadol is a novel opioid drug. Previous studies have demonstrated a potency similar to that of pethidine [25, 26] and both intravenous and extradural tramadol have been shown to be effective for the treatment of moderate to severe postoperative pain following a variety of surgical procedures [25[26][27][28][29]–30]. The side-effect profile of tramadol may be more favourable than that of equipotent doses of other opioids, particularly in the context of day surgery and tramadol has been shown to be associated with decreased sedation [26, 31], a lack of clinically significant respiratory depression [26, 28, 30, 31] and minimal effect on gastrointestinal function [32, 33].

Although tramadol was introduced into the U.K. in 1994, there has been very little published work of its use in day surgery patients. Only one other study (published in abstract form) has examined the efficacy of intravenous tramadol after day-case laparoscopic sterilisation [34]. Although pain scores in the recovery room were similar after administration of either intravenous tramadol 1 mg.kg−1 or ketorolac 10 mg, additional analgesia was needed in only 4/21 patients in the tramadol group compared with 11/21 patients in the ketorolac group (p = 0.02). The lower dose of tramadol given in this study may account for the similarity in pain scores between the two groups. However, it is also possible that further analgesia given to patients may have obscured any difference as its timing relative to assessment of pain scores was not stated.

The results of the present study suggest that tramadol is well tolerated at the dose given. Both the incidence and severity of nausea and vomiting were similar between the two treatment groups. VAS scores for nausea were also similar in a subgroup analysis of patients who did not receive morphine, with severe nausea or vomiting occurring in only 1/20 patients given tramadol compared with 2/11 given ketorolac. Although other side-effects have been reported with tramadol, dry mouth was the only symptom reported more frequently than in patients given ketorolac.

The interval between the admission of patients scheduled for laparoscopic sterilisation onto our day-surgery unit and the start of surgery is only about 1 h. We therefore use intravenous ketorolac routinely as this may be insufficient time for reliable absorption after oral or rectal administration of a nonsteroidal anti-inflammatory drug [35]. Ketorolac 10 mg is the maximum permitted on the product licence following concerns over its safety at higher doses. However, we gave it 30 min prior to the anticipated start of surgery as recommended on the data sheet to ensure that the maximum analgesic effect was achieved in the immediate postoperative period.

In conclusion, the results of the present study suggest that tramadol is an effective and well-tolerated analgesic for day-case laparoscopic sterilisation. Further work is required to determine the optimal dose of tramadol and its efficacy when used in combination with nonsteroidal anti-inflammatory drugs and local anaesthetic techniques.

References

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. References