Post-cesarean cephalexin, metronidazole reduce SSIs in women with obesity

Women with obesity who received a 48-hour course of cephalexin and metronidazole after undergoing cesarean delivery experienced reduced rates of surgical site infections compared with those who received a placebo, study data showed.

“Routine use of preoperative cephalosporin antibiotics has been shown to decrease the risk of SSI and is considered the standard of care,” Amy M. Valent, DO, of the department of obstetrics and gynecology at Oregon Health and Science University, Portland, and colleagues wrote. “Obesity is an independent risk factor for SSI despite recommended preoperative antibiotic regimens. Various post-partum antibiotic combinations and durations have been studied with conflicting benefit, but no studies have specifically addressed the obese population.”

The researchers performed a randomized, double blind trial of pregnant women with obesity, all of whom had received standard intravenous preoperative cephalosporin prophylaxis. Patients were randomly assigned to receive either a placebo (n = 201) or 500 mg each of cephalexin and metronidazole at 8-hour intervals for 48 hours following cesarean delivery (n = 202). The main outcome was SSI within 30 days.

Three hundred eighty-two patients finished the trial, with an overall SSI rate of 10.9% (95% CI, 7.9%-14%), the researchers reported.

Among women in the cephalexin-metronidazole group, the SSI rate was 6.4% (n = 13), compared with 15.4% (n = 31) in the placebo group (difference, 9%; 95% CI, 2.9%-15%; relative risk, 0.41; 95% CI, 0.22-0.77), Valent and colleagues wrote. No patients experienced any adverse events, including allergic reaction.

“Additional studies are needed to confirm these findings and to determine if there are specific subpopulations within this group to whom the benefit is limited to avoid unnecessary antibiotic exposure and its associated risks among those unlikely to benefit,” David P. Calfee, MS, MS, and Amos Grünebaum, MD, both of Weill Cornell Medicine wrote in an accompanying editorial.

Calfee and Grünebaum noted that although the intervention appeared effective, the women in the study still demonstrated a higher rate of SSIs than women without obesity.

“This finding is important because it highlights that this strategy is not a panacea, that obese women remain at high risk of infectious complications and that additional strategies to mitigate this risk are needed,” Grünebaum and Calfee wrote. – by Andy Polhamus

Disclosures: Grünebaum reports no relevant financial disclosures. Calfee reports grants from Merck, Sharp and Dohme. The authors report no relevant financial disclosures.