Battle of Antisepsis Titans in new study: Povidone Iodine vs Chlorhexidine Gluconate in Alcohol to Prevent SSIs

The randomized clinical trial that included 3360 patients revealed that povidone-iodine is noninferior to chlorhexidine gluconate as preoperative skin antisepsis in preventing SSIs after cardiac or abdominal surgery.

"Surgical site infections after abdominal or cardiac surgery were identified in 5.1% of patients in the povidone-iodine group versus 5.5% in the chlorhexidine gluconate group," the researchers reported, "a difference of 0.4% that met the predefined noninferiority margin of an absolute difference of 2.5%."

Surgical procedures carry inherent risks, with SSIs posing a significant threat to patient recovery and healthcare costs. Antisepsis, particularly the skin preparation before incision, plays a pivotal role in reducing these infections. Traditionally, povidone-iodine and chlorhexidine gluconate in alcohol have been mainstays in surgical settings, each with its proponents and perceived advantages. However, the choice of antiseptic agent, chlorhexidine gluconate or povidone-iodine, remains debated.

Against the above background, Andreas F. Widmer, University Hospital Basel and University of Basel, Basel, Switzerland, and colleagues aimed to determine whether povidone iodine in alcohol is noninferior to chlorhexidine gluconate in alcohol for SSIs prevention after cardiac or abdominal surgery.

For this purpose, the researchers conducted a multicenter, cluster-randomized, investigator-masked, crossover, noninferiority trial comprising 4403 patients undergoing abdominal or cardiac surgery in three tertiary care hospitals in Switzerland between 2018 and 2020; 3360 patients were enrolled (cardiac, n = 2187; abdominal, n = 1173).

Over 18 consecutive months, study sites were randomly assigned each month to either chlorhexidine gluconate or povidone-iodine, each formulated in alcohol. Disinfectants and skin application processes were standardized and followed published protocols.

1598 patients (26 cluster periods) were randomly assigned to receive povidone-iodine versus 1762 patients (26 cluster periods) to chlorhexidine gluconate. Patients' mean age was 65.0 years in the povidone-iodine group and 65.0 years in the chlorhexidine gluconate group. Patients were 33.9% and 32.7% female in the chlorhexidine gluconate and povidone-iodine groups, respectively.

The primary outcome was SSI within 30 days following abdominal surgery and 1 year after cardiac surgery. A noninferiority margin of 2.5% was used. Secondary outcomes were SSIs stratified by type of surgery and depth of infection.

The following were the key findings of the study:

• SSIs were identified in 5.1% of patients in the povidone-iodine group vs 5.5% in the chlorhexidine gluconate group, a difference of 0.4% with the lower limit of the CI not exceeding the predefined noninferiority margin of −2.5%; results were similar when corrected for clustering.
• The unadjusted relative risk for povidone iodine vs chlorhexidine gluconate was 0.92.
• Nonsignificant differences were observed following stratification by type of surgical procedure.
• In cardiac surgery, SSIs were present in 4.2% of patients with povidone-iodine versus 3.3% with chlorhexidine gluconate (relative risk, 1.26); in abdominal surgery, SSIs were present in 6.8% with povidone-iodine vs 9.9% with chlorhexidine gluconate (relative risk, 0.69).

"The findings showed that povidone-iodine in alcohol as preoperative skin antisepsis was noninferior to chlorhexidine gluconate in alcohol in preventing SSIs after cardiac or abdominal surgery," the researchers concluded.

Reference:

Widmer AF, Atkinson A, Kuster SP, et al. Povidone Iodine vs Chlorhexidine Gluconate in Alcohol for Preoperative Skin Antisepsis: A Randomized Clinical Trial. JAMA. Published online June 17, 2024. doi:10.1001/jama.2024.8531