Standard dose azithromycin in class 3 obese patients undergoing unscheduled cesarean delivery.

OBJECTIVE: Perioperative antibiotic prophylaxis reduces cesarean wound complications. Some antibiotic doses are increased in obese patients. This study investigates whether integration of standard-dose (500 mg) azithromycin prophylaxis reduced wound complications in patients with class 3 obesity (BMI ≥ 40 kg/m2) undergoing unscheduled cesarean delivery.

STUDY DESIGN: Retrospective cohort study of patients with class 3 obesity undergoing unscheduled cesarean delivery in single hospital system 1/1/2017-1/1/2020. A standard dose (500 mg) of azithromycin was integrated into system order sets in 2018. Medical history and post-operative wound outcomes were compared in pre- and post- integration cohorts. Wound complication was defined as composite of wound seroma, hematoma, superficial or deep infection.

RESULTS: 1,273 patients met inclusion criteria, 303 patients in the pre-order set group, and 970 patients in the post-order set group. Demographics were similar between the pre- and post-integration cohorts, including BMI (median 44.4 kg/m2, p= 0.84) and weight at delivery (mean 121.2 ± 17.8 kg, p=0.57). Patients in the post-integration cohort had lower rates of composite postpartum wound complication (7.9% vs 13.9%, p=0.002), superficial infection or deep infection/abscess (6.7% vs 10.2%, p=0.042), and postpartum readmission or unscheduled visits (18.7% vs 24.4%, p<0.029). Rates of chorioamnionitis and endometritis were similar between the pre- and post-integration groups (8.6% vs 6.9%, p=0.33, and 1.7% vs 1.9%, p=0.81, respectively). Patients in the post-integration cohort had lower risk of post-operative composite wound complication (unadjusted OR 0.54, CI 0.36-0.80, p=0.002) and lower rates of wound infection (unadjusted OR 0.63, 95% CI 0.40-0.99, p=0.044). When comparing patients who received azithromycin at delivery and patients who did not, standard-dose azithromycin reduced risk of post-operative wound complication (unadjusted OR 0.67, 95% CI 0.46-0.99, p=0.043).

CONCLUSION: A standard dose of azithromycin provides adequate perioperative prophylaxis in the most obese patients, decreasing rates of post-cesarean wound complications and unscheduled postpartum outpatient visits.