Antimicrobial prophylaxis for contaminated head and neck surgery

Abstract

The use of antibiotic prophylaxis in head and neck surgery is controversial. Most surgeons agree that when surgery requires entry into the aerodigestive tract through the skin the wound is by definition contaminated and antibiotic prophylaxis is indicated as it is in other contaminated wounds. There is no general agreement as to which antibiotic or combination of antibiotics to use or what the schedule of dosage administration should be. In order to obtain a meaningful data to help in decision making, a double blind, randomized study was performed to investigate whether cefazolin alone or a combination of gentamicin and clindamycin was more effective in prophylaxis. All patients entered into the study underwent major oncologic head and neck surgery requiring entry into the upper aerodigestive tract through the skin. Patients were stratified at entry according to the stage of disease, surgical procedure, and the existence of a prior tracheotomy or prior radiation therapy. Subsequently, patients were randomly assigned to 1 of 4 treatment groups. Group I: Cefazolin 1 day, placebo day 2 to 5. Group II: Cefazolin days 1 to 5, Group III: Gentamicin and clindamycin 1 day, placebo days 2 to 5. Group IV: Gentamicin and clindamycin days 1 to 5. Drugs were given intravenously beginning 3 hours preoperatively and continued postoperatively every 8 hours, according to the assigned schedule. All wounds were observed daily following surgery and were graded on a predetermined scale by 3 unbiased observers. Significantly wound infections occurred in 15% of all patients. Group I, 33%; Group II, 20%; Group III, 7%; Group IV, 4%. In Group III and Group IV there was a statistically significant (P less than .05) reduction in the rate of postoperative wound infection. Multifactorial analysis demonstrated that patients whose surgery included repair with a regional pectoral flap had a statistically significant increased chance of developing postoperative wound infection (P less than .05). Patients undergoing laryngectomy, with or without neck dissection, were at less risk of postoperative infection tham patients undergoing oropharyngeal resection (P less than .05). The preoperative existence of tracheotomy or prior radiation therapy had no demonstrable effect on the incidence of wound infection postoperatively in this study.