Postoperative analgesic consumption for primary versus first repeat Cesarean delivery: a historical cohort study

It is unclear if postoperative pain experience and opioid consumption differ in patients undergoing primary vs repeat Cesarean delivery (CD) as prior studies have yielded conflicting results and none used the same patients as their own controls. We sought to compare opioid consumption and pain scores in patients undergoing both a primary and a first repeat CD, using the same patients as their own controls.

We conducted a single-centre historical cohort study of patients who underwent both a primary and a first repeat CD under neuraxial anesthesia between 1 January 2016 and 30 November 2022. The same standardized multimodal analgesic regimen was used for all patients. The primary outcome was opioid consumption in oral morphine equivalents (OME) at 48 hr after surgery. Secondary outcomes included area under the curve for pain scores at 24 and 48 hr, and opioid consumption at 24 hr.

We included 409 patients. In unadjusted analysis, there were no significant differences between primary and repeat CD in median [interquartile range] opioid consumption at 48 hr (45 [15-89] mg vs 45 [15-83] mg OME) or in any of the secondary outcomes. In the multivariable model adjusting for age, body mass index, anxiety, depression, priority, surgery duration, gestational age, receipt of postoperative ketorolac, and neuraxial type, repeat CD was still not associated with increased opioid consumption compared with primary CD (adjusted rate ratio, 1.20; 95% confidence interval, 0.95 to 1.51).

In this retrospective study, we found no differences in postoperative opioid consumption or reported pain scores in patients who underwent both a primary and a first repeat CD.