What is the evidence for use of antibiotic prophylaxis in clean‐contaminated head and neck surgery? (2011)

Antibiotic prophylaxis is commonly used in head and neck surgery. Prophylactic use of antibiotics in clean surgical cases is not clearly indicated, but evidence exists for use in cases of clean-contaminated surgery, such as major head and neck oncologic procedures. Despite evidence specifically outlining the indications for antibiotic prophylaxis, there continues to be widespread variability in the use (and overuse) of prophylactic antibiotics in head and neck oncologic surgery. In an era of increasing resistance to antimicrobial therapy, it is worthwhile to revisit the evidence for the use of antibiotic prophylaxis in head and neck surgery. A literature review was conducted using the search terms “antibiotics,” “prophylaxis,” “clean-contaminated,” and “head and neck surgery.” Studies with the highest level of evidence presenting novel information were included in this review (Table I). A series of five randomized controlled trials established clear guidelines for the prophylactic use of antibiotics in clean-contaminated head and neck surgery. The results and implications of these trials are succinctly related by Johnson and Yu1 and are herein described. In all of these studies, patients underwent clean-contaminated oncologic surgery with closure of skin. All prophylactic antibiotics were administered 1 hour prior to the start of surgery. In the first study, 107 patients were randomized to receive cefazolin (500 mg intravenously [IV] every 8 hours [q8h]) or clindamycin (300 mg IV q8h) plus gentamicin (1.7 mg/kg IV q8h) for either 1 or 5 days. Thirty-three percent and 20% of patients receiving cefazolin for 1 and 5 days, respectively, developed wound infections, versus 7% and 4% of patients receiving clindamycin plus gentamicin for 1 and 5 days, respectively. These results demonstrated a statistically significant advantage for the combination of clindamycin plus gentamicin over cefazolin alone when used at a low dose. Additionally, no advantage was seen for prolonged prophylaxis (5 days versus 1 day). The second study was designed to evaluate the efficacy of third-generation cephalosporins. Patients were randomized to receive either cefoperazone or cefotaxime at a high dose (2 g IV q8h) for 24 hours. Four of 39 (10%) patients receiving cefoperazone developed wound infection, compared with 3/32 (9.4%) of patients receiving cefotaxime, demonstrating the efficacy of high-dose third-generation cephalosporins. In the third study, a high-dose first-generation cephalosporin (cefazolin 2 g) was compared with a high-dose third-generation cephalosporin (moxalactam) in 118 patients. This was done to test the hypothesis that the poor efficacy of cefazolin seen in the first study was due to administration at a low dose. Wound infection rates were similar for both groups (8.5% for cefazolin, 3.4% for moxalactam, not statistically significant), demonstrating similar efficacy for high-dose first- and third-generation cephalosporins. The fourth study was designed to test the necessity for coverage of gram-negative aerobic organisms. One hundred four patients were randomized to receive clindamycin versus clindamycin plus gentamicin. Both groups demonstrated a 3.4% rate of infection, suggesting coverage of gram-negative organisms may not be necessary. A subsequent randomized controlled study performed by Weber et al.2 generated conflicting results. Two hundred twelve patients were randomized to clindamycin (600 mg) versus ampicillin-sulbactam (1.5 g) for 8 doses at 6-hour intervals. Infections occurred in 14 patients (13.3%) in the ampicillin-sulbactam group versus 29 patients (27.1%) in the clindamycin group, suggesting an advantage to gram-negative coverage. The fifth study in this series was designed to test the hypothesis that a prolonged course of antibiotics benefits patients undergoing pectoralis major flap reconstruction. In this multicenter study, 109 such patients were randomized to receive 1 or 5 days of cefoperazone (2 g). Ten of 53 (18.9%) patients receiving 1 day of prophylaxis developed wound infection, compared with 14/56 (25%) receiving 5 days. These findings suggest there is no advantage to administering antibiotic prophylaxis beyond 24 hours postoperatively, even in the setting of regional flap reconstruction. More recently, a prospective randomized trial was performed to assess the need for prolonged antibiotic prophylaxis in patients undergoing immediate free-flap reconstruction.3 Seventy-four patients were randomized to receive either a short or long course of clindamycin (900 mg IV q8h for 3 or 15 doses, respectively). Wound infection rates were 4/35 (11%) in the short-course group and 4/39 (10%) in the long-course group. These findings corroborate previous data suggesting prolonged antibiotic prophylaxis is unnecessary, even in the setting of free-flap reconstruction. Recently, a retrospective review of 407 patients undergoing clean-contaminated surgery demonstrated an increased rate of wound infection in malnourished versus well-nourished patients (18% vs. 3%, respectively, P < .0001). The presence of diabetes was not associated with increased risk of wound infection. Prolonged antibiotics did not alter the rate of wound infection in malnourished or diabetic patients.4 Antibiotic prophylaxis is effective when used in clean-contaminated oncologic surgery and administered prior to the start of surgery. Importantly, there is no evidence to support the use of antibiotic prophylaxis beyond 24 hours postoperatively. Multiple drug regimens are effective, including first-generation cephalosporins, when used in a high dose of 2 g q8h for 24 hours. Coverage of gram-negative organisms remains a controversial issue. The body of literature pertaining to clean-contaminated surgery is level 1b1-3 and 4,4 according to the Oxford classification of levels of evidence.