Orthognathic Surgery and Postoperative Antibiotic Use

Capital Health Research Ethics Board Orthognathic Surgery and Postoperative Antibiotic Use Protocol

Background, Rationale and Statement of Research Question(s):

Surgical site infection is a potential problem with any surgical procedure. Surgical procedures done through the oral cavity are at a higher risk due to the presence of bacterial pathogens. Orthognathic surgery, involves incising through oral mucosa and creating osteotomies in underlying bony structures. Of the potential complications that can arise from this surgery, post operative infection (POI) is the most common. POI can have a significant impact on surgical outcomes and are associated with an increased cost to the health care system. The literature is quite clear on the benefits of presurgical prophylactic antibiotics in reducing the rate of post operative surgical site infections.1 Currently there is conflicting literature as to the recommended length patients should receive antibiotics during the postoperative course, and the majority of studies have small sample sizes.2,3

Orthognathic surgery is considered a clean-contaminated surgery with a suspected POI rate of 10-15%.2 In 1999 Bentley et. al conducted a randomized control trial comparing 1day vs 5day regimen of antibiotics following orthognathic surgery.4 This trial was stopped due to the drastic difference seen between the two groups, 6.7% in the 5 day course compared with 60% seen in the 1 day group.4 This data varies greatly from the rates of infection that the investigators have seen in their department using a 1 day course of antibiotics. Chow et al. in 2007 did a retrospective chart review of complications seen in orthognathic surgery. They found the rate of infection was significantly decreased by continuing antibiotics in the post operative course when compared to using only one prophylactic dose. They found the infection rates to be 17.3% with a single preoperative IV dose, 5.1% with a pre-operative dose and 2 days post-operative, and 7.7% with a pre-operative dose and 3 days of post-operative antibiotics.5 They also found no significant difference in rates of infection comparing 2 days and up to 14 days.5 A meta-analysis by Danda et al. in 2011 found that a regimen consisting of a single dose of preoperative antibiotics followed with an extended term postoperatively is the most effective in decreasing surgical site infections. They found the incidence decreased by 3.2 times, with the greatest effect noted with administration for 2 days.2 Even in this meta-analysis the average number of patients in each of the 8 studies was 67, with the total number of patients included being 532.2 This shows the need for randomized controlled studies with large sample sizes in order to determine the best antimicrobial regimen for these patients. The majority of studies investigating the rates of infection in orthognathic surgery use penicillin as the antibiotic of choice due to its spectrum of coverage for oral microbes and it is reasonably tolerated by patients.2,4-8 In the investigators department cefazolin is the antibiotic of choice and lower rates of infection have been observed compared to penicillin. The investigators suspect the lower rates of infection with cefazolin is due to the increased gram negative coverage and better resistance to beta lactamases. This has influenced the investigators decision to use first generation cephalosporins instead of penicillin as first line antimicrobials. In patients allergic to penicillin, clindamycin is used. The criteria for diagnosis of infection will follow the CDC guidelines for SSI. The primary outcome is to determine if there is any benefit to extending antimicrobials in the postoperative course following orthognathic surgery. Secondary outcomes include comparing the rates of infection between cefazolin/cephalexin groups and the clindamycin groups, and the rate of infection with different surgical procedures.

Currently at the CDHA the standard perioperative antimicrobial regimen for orthognathic surgery patients is one preoperative prophylactic dose of 2g of IV cefazolin followed by 1g IV every 8 hrs for 3 doses. Patients with an allergy to penicillin receive one preoperative prophylactic dose of IV Clindamycin 600mg, followed by 600mg IV every 8 hrs for 3 doses.