Which skin antiseptic is preferred for preoperative prep, and what precautions are taken for mucous membranes and allergies?

• A. Soap and water is preferred; avoid mucous membranes and document allergies.
• B. Alcohol is preferred; mucous membranes may be contacted.
• C. Benzalkonium chloride is preferred; document allergies.
• D. Chlorhexidine-alcohol is preferred; avoid contact with mucous membranes and document allergies; use povidone-iodine if indicated.

Answer: (D)

Chlorhexidine-alcohol is preferred for preoperative skin antisepsis because it combines rapid killing with broad-spectrum activity and a lasting residual effect on the skin, which helps reduce surgical-site infections more effectively than other common prep agents. Because mucous membranes are sensitive and chlorhexidine can irritate them, avoid letting the prep contact mucous membranes and nearby areas; if exposure to mucous membranes is possible or if the surgical field is close to them, take precautions and consider alternatives as indicated. Document any allergies to antiseptics so alternatives can be planned; if indicated by allergy or other factors, povidone-iodine may be used instead. Other options like soap and water or alcohol alone do not provide the same level of antisepsis, and benzalkonium chloride has less evidence of effectiveness for surgical prep, which is why the chlorhexidine-alcohol regimen with the noted precautions is favored.