Interventions for intra-operative pain relief during postpartum mini-laparotomy tubal ligation

Postpartum mini-laparotomy tubal ligation (PPTL) is a contraceptive method that works by interrupting the patency of the fallopian tubes. Several methods are used for intraoperative pain relief, such as systemic administration of opioids or intraperitoneal instillation of lidocaine.

To evaluate the effectiveness of and adverse effects associated with interventions for pain relief in women undergoing PPTL.

We searched for eligible studies published on or before 31 July 2017 in the CENTRAL Register of Studies Online, MEDLINE, Embase, PsycINFO, and CINAHL. We examined review articles and searched registers of ongoing clinical trials, citation lists of included studies, key textbooks, grey literature, and previous systematic reviews for potentially relevant studies.

We included randomised controlled trials (RCT) that compared perioperative pain relief measures during PPTL.

Two review authors independently assessed the titles, abstracts, and full-text articles of potentially relevant studies for inclusion. We extracted the data from the included studies, assessed risk of bias, and calculated and compared results. Discrepancies were resolved by discussion, or by consulting a third review author. We computed the inverse variance risk ratio (RR) with 95% confidence interval (CI) for binary outcomes, and the mean difference (MD) with 95% CI for continuous variables.

We found only three RCTs, in which a total of 230 postpartum women participated. Most of our analyses were based on relatively small numbers of patients and studies. Overall, the certainty of evidence regarding the effectiveness of interventions was low, due to risk of bias and imprecision. We found very low-certainty evidence regarding the safety of interventions because of risk of bias and imprecision. Two studies had unclear risk of selection bias. One study had unclear risk of reporting bias and a high risk of other bias associated with the study protocol.Women who received an intraperitoneal instillation of lidocaine experienced lower intensity intraperitoneal pain than those given a placebo (pooled MD -3.34, 95% CI -4.19 to -2.49, three studies, 190 participants, low-certainty evidence), or an intramuscular injection of morphine (MD -4.8, 95% CI -6.43 to -3.17, one study, 40 participants, low-certainty evidence). We found no clear difference in intraperitoneal pain between women who had an intramuscular injection of morphine added to an intraperitoneal instillation of lidocaine and those who had an intraperitoneal instillation of lidocaine alone (MD -0.40, 95% CI -1.52 to 0.72, one study, 40 participants, low-certainty evidence). An intramuscular injection of morphine alone was not effective for intraperitoneal pain relief compared to placebo (MD 0.50, 95% CI -1.33 to 2.33, one study, 40 women, low-certainty evidence). None of the studies reported any serious adverse events but the evidence was very low-certainty. Intraperitoneal instillation of lidocaine may reduce the number of women requiring additional pain control when compared to placebo (RR 0.27, 95% CI 0.17 to 0.44, three studies, 190 women, low-certainty evidence).

An intraperitoneal instillation of lidocaine during postpartum mini-laparotomy tubal ligation before fallopian tubes were tied may offer better intraperitoneal pain control, although the evidence regarding adverse effects is uncertain. We found no clear difference in intraperitoneal pain between women who received a combination of an injection of morphine, and intraperitoneal instillation of lidocaine and those who received an intraperitoneal instillation of lidocaine alone. These results must be interpreted with caution, since the evidence overall was low to very low-certainty.