Analgesic Outcomes of Tramadol Alone and in Combination with Butorphanol or Flurbiprofen Axetil after Caesarean Section: A Retrospective Study with Propensity Score Matching Analysis

Background: To our knowledge, the Society for Obstetric Anesthesia and Perinatology recommends a multimodal analgesic regimen for caesarean delivery analgesia. Therefore, this study aimed to compare the analgesic effects of tramadol alone and in combination with butorphanol or flurbiprofen axetil after caesarean section.Methods: We retrospectively analysed 2323 women with puerperas who had undergone caesarean section based on the electronic medical records of a teaching hospital in China from January 2018 to January 2020. We collected data on demographic characteristics, perioperative complications, surgical factors, and anaesthesia. We also recorded the postoperative analgesic solution, pain intensity (assessed by the numeric rating scale [NRS]) during the first 48 hours after surgery. Postoperative inadequate analgesia during the postoperative 48 hours was defined as an NRS score ≥4. We also collected data regarding off-bed activity and intestinal function recovery. Analgesic outcomes of three groups were compared using propensity score matching analysis.Results: Compared to the tramadol mixed with butorphanol group (group B), the incidence of inadequate analgesia at rest and while moving was lower in the tramadol combined with flurbiprofen axetil group (group F), and the relative risks (RRs) for women with puerperas suffering from inadequate analgesia at rest and while moving in group F were 0.34 (95% confidence interval [CI]: 0.21–0.54; P<0.001) and 0.24 (95% CI: 0.19–0.31, P<0.001), respectively. The percentage of intestinal function recovery and off-bed activity at 2 days postoperatively was higher in group B than in group F (74.1 versus [vs.] 66.4, P=0.006 and 79.4% vs. 66.4%, P<0.001, respectively). Group F was also associated with a lower incidence of inadequate control of pain at rest and while moving than group T (RR, 0.37 [0.23–0.60], P<0.001, and 0.43 [0.33–0.55], P<0.001, respectively). Group B was associated with a higher incidence of inadequate control of moving pain than group T (RR, 1.78, [1.40–2.26], P<0.001).Conclusions: A combination of tramadol and flurbiprofen axetil could enhance the analgesic effect and be safely used for analgesia after caesarean section, but the combination of tramadol and butorphanol may produce an antagonistic effect.Trial registration: Not applicable.