Abstract: We included 12 trials with 798 participants undergoing elective laparoscopic cholecystectomy randomised to different methods of intraperitoneal local anaesthetic instillation. All the trials were at high risk of bias. Most trials included only people with low anaesthetic risk. The comparisons included in the trials that met the eligibility criteria were the following; comparison of one local anaesthetic agent with another local anaesthetic agent (three trials); comparison of timing of delivery (six trials); comparison of different methods of delivery of the anaesthetic agent (two trials); comparison of location of the instillation of the anaesthetic agent (one trial); three trials reported mortality and morbidity. There were no mortalities or serious adverse events in either group in the following comparisons: bupivacaine (0/100 (0%)) versus lignocaine (0/106 (0%)) (one trial; 206 participants); just after creation of pneumoperitoneum (0/55 (0%)) versus end of surgery (0/55 (0%)) (two trials; 110 participants); just after creation of pneumoperitoneum (0/15 (0%)) versus after the end of surgery (0/15 (0%)) (one trial; 30 participants); end of surgery (0/15 (0%)) versus after the end of surgery (0/15 (0%)) (one trial; 30 participants). None of the trials reported quality of life, the time taken to return to normal activity, or the time taken to return to work. The differences in the proportion of people who were discharged as day-surgery and the length of hospital stay were imprecise in all the comparisons included that reported these outcomes (very low quality evidence). There were some differences in the pain scores on the visual analogue scale (1 to 10 cm) but these were neither consistent nor robust to fixed-effect versus random-effects meta-analysis or sensitivity analysis. The currently available evidence is inadequate to determine the effects of one method of local anaesthetic intraperitoneal instillation compared with any other method of local anaesthetic intraperitoneal instillation in low anaesthetic risk individuals undergoing elective laparoscopic cholecystectomy. Further randomised clinical trials of low risk of systematic and random errors are necessary. Such trials should include important clinical outcomes such as quality of life and time to return to work in their assessment.

Plain-language summary: We identified 12 randomised clinical trials involving 798 people undergoing planned laparoscopic cholecystectomy. The trials compared different methods addressing the various controversies mentioned above. The choice of the method of administration of the local anaesthetic was determined by a method similar to the toss of a coin so that the treatments compared were conducted in participants who were as similar as possible. There were no deaths or serious complications in either group in the comparisons that reported these. None of the trials reported quality of life, the time taken to return to normal activity, or the time taken to return to work. The differences in hospital stay between the methods being compared was imprecise in all the comparisons that reported hospital stay. Although there were some differences in the pain scores on the visual analogue scale (a chart that rates the amount of pain on a scale of 1 to 10 cm), these differences were neither consistent nor robust to different methods of statistical analysis. The evidence currently available is inadequate to determine the effects of one method of local anaesthetic intraperitoneal instillation compared with any other method of local anaesthetic intraperitoneal instillation in low anaesthetic risk individuals undergoing elective laparoscopic cholecystectomy. Most of the trials were of high risk of bias, that is, there is possibility of arriving at wrong conclusions overestimating benefits or underestimating harms of one method or the other because of the way that the study was conducted. The overall quality of evidence was very low. Further trials are necessary. Such trials should include outcomes such as quality of life, the time taken to return to normal activity, and the time taken to return to work, which are important for the person undergoing the procedure and the people who provide funds for the treatment.