Ultrasound-Guided Bilateral Erector Spinae Plane Block vs. Ultrasound-Guided Bilateral Posterior Quadratus Lumborum Block for Postoperative Analgesia after Caesarean Section: An Observational Closed Mixed Cohort Study.

ESP block (ESPB) and posterior Quadratus Lumborum Block (pQLB) have been proposed as opioid-sparing techniques for the management of pain after abdominal surgery. Between December 2021 and October 2022, we conducted a retrospective comparative study at the delivery suite of Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy, to compare the efficacy of ESPB and pQLB in preventing postoperative pain after an elective caesarean section (CS). The primary outcome was total morphine consumption in the first 24 h. Secondary outcomes were time to first opioid request; Numerical Pain Rating Scale (NPRS) at 0, 2, 6, 12 and 24 h; vital signs; adverse events. Fifty-two women were included. The total cumulative dose of morphine was not significantly different between the two groups of patients ( p = 0.897). Time to first dose of morphine, NPRS values and haemodynamic parameters were not statistically different between the two groups. NPRS values significantly increased ( p < 0.001) at the different time intervals considered. The need for rescue doses of morphine was lower in the ESPB group compared to the pQLB group (hazard ratio of 0.51, 95% CI (0.27 to 0.95), p = 0.030). No adverse event was reported. ESPB seems to be as effective as pQLB in providing analgesia after CS.