Australia: Current guidelines suggest that during surgical procedures, alcohol-based chlorhexidine solutions should be used for surgical skin preparation. In disagreement with this, a new study found that povidone-iodine with alcohol (PI-Alc) is non-inferior to chlorhexidine with alcohol (C-Alc) and not superior to PI-Aq in preventing surgical site infections. The study article was published in the Annals of Surgery.

Globally, SSI rates are approximately from 2.5% to 41.9%. A surgical site infection (SSI) is an infection that occurs after surgery in the part of the body where the surgery took place caused by germs, mainly the bacteria Staphylococcus, Streptococcus, and Pseudomonas. Surgical site skin preparation is the preoperative treatment (cleaning and disinfection) of the patient's intact skin done before surgery. The most common skin preparation agents used include products containing iodophors or chlorhexidine gluconate. Agents are further classified by whether they are aqueous-based or alcohol-based solutions Chlorhexidine belongs to a group of medicines called antiseptic antibacterial agents, It works by killing or preventing the growth of bacteria on the skin.
Guidelines suggest that alcohol-based antiseptic solutions containing chlorhexidine gluconate (CHG) should be used for surgical site skin preparation in patients undergoing surgical procedures It remains difficult to determine whether it is the chlorhexidine component or the addition of alcohol that confers the most benefit. Povidone iodine is an effective antiseptic that does not hinder wound healing. Povidone iodine is bactericidal against Gram-positive and -negative organisms. No acquired bacterial resistance or cross-resistance has been reported for iodine. It is commonly used as surgical scrub preparations.
Smith SR, John Hunter Hospital and the University of Newcastle, Australia, and his research conducted a clinical trial to compare Surgical site infection rates between the skin preparation agents: povidone-iodine aqueous solution( PI-Aq), povidone-iodine with alcohol (PI-Alc), and chlorhexidine with alcohol (C-Alc).
Researchers conducted a multicenter, prospective, combined non-inferiority (PI-Alc vs C-Alc) and superiority (PI-Alc vs PI-Aq) randomized clinical trial that included 3213 patients. Participants were randomized 1:1:1 to receive either C-Alc(n-: 1076), PI-Alc(n-1075), or PI-Aq(n-1062). The primary outcome was the SSI rate as defined by the Centers for Disease Control. Secondary outcomes were complication rates, length of hospital stay, readmissions, and skin reactions.
Key observations made during the trial,
• SSI rates were: C-Alc 11.09%, PI-Alc 10.88%, and PI-Aq 12.56%.
• PI-Alc was found to be non-inferior to C-Alc (mean difference, −0.21%), whereas PI-Alc was not superior to PI-Aq (mean difference, −1.68).
• There were no differences seen in secondary outcomes between groups and no treatment-related adverse events or deaths occurred.
The authors conclude that povidone-iodine with alcohol shows results non-inferior to chlorhexidine with alcohol, but its effect is not superior to povidone-iodine aqueous solution as skin preparation agents for surgical procedures.
Reference:
Smith SR, Gani J, Carroll R, Lott N, Hampton J, Oldmeadow C, Clapham M, Attia J. Antiseptic Skin Agents to Prevent Surgical Site Infection After Incisional Surgery: A Randomized, Three-armed Combined Non-inferiority and Superiority Clinical Trial (NEWSkin Prep Study). Ann Surg. 2022 May 1;275(5):842-848. doi: 10.1097/SLA.0000000000005244.