Opioid use after cesarean: a cohort study comparing combined versus separate oxycodone and acetaminophen regimens

Abstract

Objective To determine whether an inpatient post-cesarean analgesic regimen which separated oxycodone and acetaminophen resulted in less inpatient opioid use, when compared to a regimen using combination medications containing both acetaminophen and oxycodone in a cohort including patients of all gestational ages, acuity levels, and modes of operative anesthesia. Methods This is a retrospective cohort study which was conducted at a single tertiary care center Labor and Delivery unit. Data were collected via retrospective chart review, and a total of 170 records were examined with a final N = 150. Inclusion criteria were all patients over the age of 18, and >23.0 weeks gestational age, who had a singleton or twin cesarean delivery regardless of their mode of operative anesthesia and whether or not they received intrathecal opioid at time of delivery. Exclusion criteria were pregnancies of higher-level multiples (triplets or greater), prolonged intensive care unit (ICU) stay, and patients who received both combination oxycodone-acetaminophen and separately administered oxycodone. For analysis patients were classified into two groups: the “Combined Medication” group representing patients who received combination oxycodone-acetaminophen medication only (n = 83) and the “Separate Medication” group representing patients who received oxycodone and acetaminophen separately (n = 67). Differences between the groups with respect to opioid use and acetaminophen use were assessed. Results The primary outcome was inpatient opioid medication use per 12-h period in intravenous morphine mg equivalents (MME). Patients received an average of 4.6 ± 3.5 MME IV morphine per 12 h in the Separate Medication group and 5.7 ± 3.7 MME IV morphine per 12 h in the Combined Medication group. When controlled for several covariates, the Separate Medication group took significantly fewer MME per 12-h period (mean difference = −1.2, 95% CI: (−2.3, −0.1), p = .04). There was no appreciable difference in acetaminophen utilization between groups. Conclusions An analgesic regimen where oxycodone is ordered separately from acetaminophen is associated with reduced inpatient opioid medication use in patients of all gestational ages, acuity levels, and modes of operative anesthesia.