Sex Differences in Opioid Administration After Cardiac Surgery

Abstract

ObjectivesAre there sex-based differences in the administration of opioid analgesic drugs among inpatients after cardiac surgery? DesignThis is a retrospective cohort study. SettingA tertiary academic referral centre. ParticipantsAdult patients who underwent cardiac surgery from 2014 to 2019. InterventionsNone Measurements and Main ResultsThe primary outcome was the cumulative oral morphine equivalent dose (OMED) for the post-operative admission. Secondary outcomes were the daily difference in OMED and the administration of non-opioid analgesics. We developed multivariable regression models controlling for known confounders, including weight and length of stay.A total of 3,822 patients (1,032 women and 2,790 men) were included. The mean cumulative OMED was 139 mg for women and 180 mg for men, and this difference remained significant after adjustment for confounders (adjusted mean difference [aMD], -33.21 mg; 95% confidence interval [CI], -47.05 to -19.36 mg; p < 0.001). The cumulative OMED was significantly lower in female patients on postoperative days 1 to 5, with the greatest disparity observed on day 5 (aMD, -89.83 mg; 95% CI, -155.9 to -23.80 mg; p = 0.009). By contrast, women were more likely to receive a gabapentinoid (OR, 1.91; 95% CI, 1.42 to 2.58; p < 0.001). We found no association between patient sex and the administration of other non-opioid analgesics or specific types of opioid analgesics. We found no association between patient sex and pain scores recorded within the first 48 hours following extubation, or the amount of opioid administered in close proximity to pain assessments. ConclusionsFemale sex was associated with significantly lower amounts of opioid administered after cardiac surgery.