AT THE PREGNANCY MEETING
ATLANTA (FRONTLINE MEDICAL NEWS) – A chlorhexidine/alcohol skin antiseptic cut cesarean section surgical site infections by half, compared with a solution of iodine and alcohol.
The chlorhexidine solution significantly reduced the risk of both superficial and deep incisional infections, Dr. Methodius G. Tuuli reported at the annual Pregnancy Meeting sponsored by the Society for Maternal-Fetal Medicine. The study was simultaneously published in the New England Journal of Medicine ( 2016 Feb 4. doi: 10.1056/NEJMoa1511048 ).
The randomized trial is the first to examine the two antiseptics in obstetric surgery, noted Dr. Tuuli of Washington University, St. Louis. The results echo those repeatedly found in the general surgical literature, and, he said, clearly show that chlorhexidine-based skin prep is more effective than the more often–employed iodine-based prep.
“We become comfortable doing the things we have always done, because that’s the way we were taught, and we see no reason to change,” he said in an interview. “I think now is the time to make a change for our patients.”
Dr. Tuuli’s study comprised 1,147 patients who delivered via cesarean section from 2011-2015. They were randomized to either a chlorhexidine/alcohol antiseptic (2% chlorhexidine gluconate with 70% isopropyl alcohol) or the iodine/alcohol combination (8.3% povidone-iodine with 72.5% isopropyl alcohol). Both groups received standard-of-care systemic antibiotic prophylaxis.
They were followed daily until discharge from the hospital, and then with a telephone call 30 days after delivery to assess whether a surgical site infection had occurred, as well as any visits to a physician’s office or emergency department that were related to a wound complication.
The co-primary endpoints were superficial and deep incisional infections. Secondary endpoints included length of hospital stay; physician office visits; hospital readmissions for infection-related complications; endometritis; positive wound culture; skin irritation; and allergic reaction.
Surgical site infections occurred in 23 patients in the chlorhexidine group and 42 in the iodine group (4.0% vs. 7.3%) – a significant 45% risk reduction (relative risk, 0.55). Superficial infections were significantly less common in the chlorhexidine group (3.0% vs. 4.9%), as were deep infections (1.0% vs. 2.4%).
A subgroup analysis examined unscheduled vs. scheduled cesarean; obese vs. nonobese patients; suture vs. staple closure; diabetes vs. no diabetes; and chronic comorbidities vs. none. Chlorhexidine was significantly more effective than iodine in each of these groups.
Antiseptic type did not affect rates of skin separation, seroma, hematoma, or cellulitis. Nor did it affect the rates of endometritis, hospitalization for infectious complications, or length of hospital stay. However, those in the chlorhexidine group were significantly less likely to visit a physician for wound care (7.9% vs. 12.5%)
Cultures were obtained on 32 patients with a confirmed infection; 27 of these specimens were positive. About half of the positive cultures were polymicrobial. The most common isolate was Staphylococcus aureus (37%). Methicillin-resistant S. aureus (MRSA) was present in 12% of cultures in the chlorhexidine group and 17% in the iodine group.
In an interview, Dr. Tuuli said that chlorhexidine has several properties that make it more effective than iodine. It is effective against both gram-negative and gram-positive organisms, including MRSA, and is not inactivated by organic matter. Although chlorhexidine is more likely than iodine to provoke an allergic reaction, none were observed in this study.
The study was supported by a grant from the National Institutes of Health. Dr. Tuuli reported having no financial disclosures; the antiseptics were procured and paid for by the medical center.
Watch Dr. Tuuli discuss the study results here .