Antibiotic Duration and Postoperative Infection Rates ...

CLINICAL STUDY

Antibiotic Duration and Postoperative Infection Rates in Mandibular Fractures Yonitte H. Hindawi, MD,* Gretchen M. Oakley, MD,* Christopher R. Kinsella Jr, MD,Þ James J. Cray, PhD,Þ Kathryn Lindsay, MSN,* and Aaron M. Scifres, MDþ Background: Although the use of preoperative antibiotics has been proven effective, the value of postoperative antibiotics in the setting of mandibular fracture remains in question as does the appropriate duration of therapy. Methods: A retrospective study of all patients 18 years and older who presented with mandibular fractures to St Louis University Hospital between December 2001 and July 2006 was conducted. Collected variables included age, injury severity score, fracture type and location, preoperative antibiotic administration, antibiotic type, duration of antibiotic course, and postoperative infection. Infections were statistically compared with each. Results: Of 253 identified patients, 197 qualified for study inclusion. A total of 9 postoperative infections were documented. When comparing individuals with postoperative infection to those without, age was the only significant difference between infected and uninfected groups, with older patients more likely to acquire infection. Injury severity score, fracture type, duration of antibiotic course, and antibiotic type were not significantly different. Conclusions: Our findings suggest that patient factors make a greater contribution to postoperative infection when compared with iatrogenic factors in the treatment of mandibular fractures. We found no evidence to support prolonged postoperative antibiotic therapy. Our findings bring into question the need for postoperative antibiotics for the treatment of mandibular fractures. Key Words: Mandible, fracture, antibiotics (J Craniofac Surg 2011;22: 1375Y1377)

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he National Trauma Data Bank from the American College of Surgeons includes 560,452 injured patients from 2008. Twentyfive percent of these traumas included injuries to the face.1 Second only to the nasal bone, the mandible is the most commonly fractured bone in facial trauma.2,3 Because the treatment of mandibular fractures commonly involves operative management, postoperative infecFrom the *Department of Surgery, Saint Louis University School of Medicine, St Louis, Missouri; and †Division of Plastic Surgery, and ‡Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania. Received October 26, 2010. Accepted for publication November 14, 2010. Address correspondence and reprint requests to Aaron M. Scifres, MD, Mercy Trauma Services, University of Pittsburgh Medical Center, 1400 Locust St, Pittsburgh, PA 15219; E-mail: [email protected] This study was presented at the Western Trauma Conference, Crested Butte, Colorado, February 2009. The authors report no conflicts of interest. Copyright * 2011 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0b013e31821c9498

The Journal of Craniofacial Surgery

tions are a concern. The reported incidence of postoperative infections in maxillary and mandibular surgery ranges from 10% to 15%.4Y7 The use of preoperative antibiotics in the setting of mandibular surgery has been proven effective in decreasing the rates of postoperative infection.4,7Y10 However, there is still controversy over the appropriate duration of postoperative antibiotics. In the absence of better evidence, the increased burden of oral flora and the risk of postoperative infection may compel physicians to lengthen the postoperative antibiotic course in an effort to limit complications. Any benefits of extending antibiotic therapy must be balanced with the benefits of limiting antibiotic therapy.11Y13 Several studies on patients with maxillary and mandibular fracture have questioned the need for administration of any antibiotics postoperatively.5,11,14Y16 Additional studies have investigated a treatment effect between 1 day and 5 days,6,17 between 1 day and 7 days,18 and between 2 days and 14 days19 of postoperative antibiotic therapy, with no significant difference seen in infection rates. The only study to report an increase in infection between 2 treatment groups showed a difference between 1 day and 5 days of postoperative antibiotic therapy.20 Given the results and limited sample sizes of these previous investigations, it remains unclear that limiting the duration of antibiotic therapy in this patient population is beneficial. We hypothesize that prolonged courses of antibiotics after mandibular fracture repair do not reduce surgical site infection rates.

MATERIALS AND METHODS We conducted a retrospective cohort study of all patients 18 years and older who presented with mandibular fractures to St Louis University Hospital between December 2001 and July 2006. Two members of the study team extracted data from patient records and the trauma registry. Collected variables included age, sex, injury severity score (ISS), fracture type and location, length of hospital stay, duration between injury and operation, preoperative antibiotic administration, antibiotic type, duration of antibiotic course by antibiotic type, postoperative infection, and required subsequent operations. Postoperative infection was defined as purulent drainage from an incision or drain, growth of a predominant organism from wound drainage cultures, spontaneous dehiscence or surgical reopening of a wound, or a surgeon diagnosis of infection.6,20 Included patients presented with open and closed mandibular fractures and underwent operative repair during the initial hospitalization. Patients with nonoperative injuries, penetrating trauma, multiple operations unrelated to the mandible, and unrelated surgical site infections were excluded. Infections were compared with each variable with student t-test or Fisher exact test. A Welch correction was performed when population variances were found to be unequal.

RESULTS There were 253 patients with mandibular fractures during the study period. Of these, 32 did not have operative repair during the

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FIGURE 1. Mandible fracture location frequency. initial admission, 3 were transferred to other institutions before operation, 13 had multiple nonmandibular operations, and 6 patients developed unrelated surgical site infections. After exclusions, 199 patients remained. Data were incomplete for 2 patients, resulting in 197 patients for statistical analysis. The patient population had an average age of 32.28 years (range, 15Y83 years), was 22.33% female, and had an average ISS of 9.02 (range, 1Y38). Closed fractures were more common, representing 78.7% (155) of presenting cases. Fracture type on presentation is summarized in Figure 1. The duration of hospital stay and time between injury and operation varied greatly (Table 1). Most patients (93.4%) received preoperative antibiotics within an hour of surgery. More than 23 different oral or parenteral antibiotics were prescribed for this patient population, representing 350 prescriptions (Fig. 2). These prescriptions were given across a range of 1 to 30 days with a mode of 7 days (Fig. 3) and often overlapped with each other for the same patient. In addition, topical and intraoral prescriptions were given concurrently for most patients with 92.4% receiving a 30-day prescription. Because of the variability in prescribed antibiotics, there was insufficient statistical power to assess any relationship among specific antibiotics used, infection, and type of injury. We elected to collapse our data for antibiotic usage into 3 categories. Systemic antibiotics included all antibiotics ingested orally or administered intravenously. When overlap occurred, the longest prescribed antibiotic duration was recorded. Intraoral antibiotics included Peridex (chlorhexidine gluconate 0.12% solution; Zila Inc, Phoenix, AZ). Topical antibiotics similarly included bacitracin and neomycin ointment (Neopsporin: neomycin 3.5 mg/g, bacitracin zinc 400 U/g, polyTABLE 1. Treatment and Postoperative Antibiotic Therapy Characteristics Treatment Characteristics Average length of hospital stay, d Average time between injury and operation, d Preoperative antibiotic administration

5.96 (range, 0Y36) 3.4 (range, 0Y28) 184 patients (93.4%)

Postoperative Antibiotic Therapy Type Systemic (oral or intravenous) Intraoral (eg, Peridex) Topical (eg, bacitracin)

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Patients Average Prescribed Prescribed, % Duration, d 98.47

6.87

89.34 47.21

27.8 29.34


FIGURE 2. Breakdown of all antibiotic prescriptions for study subjects (number of prescriptions per drug). myxin B sulfate 5000 U/g; Johnson & Johnson, New Brunswick, NJ). This categorization allowed for appropriate statistical analysis. A total of 9 postoperative infections were documented (4.5% of patients). Those with postoperative infection were significantly older (mean, 40.400 [SD, 9.709]) than those patients without infection (mean, 31.670 [SD, 12.047]), t = 2.252, P = 0.025. For other demographic data, there were no statistically significant differences between groups based on sex (risk ratio, 2.5548), ISS (t = 0.492, P = 0.629), fracture type (risk ratio, 1.602), or fracture location (W2 = 2.185, P = 0.960). No significant differences existed between infected and noninfected individuals with regard to their length of hospital stay (t = 0.486, P = 0.628), time between injury and operation (t = 0.949, P = 0.367), and administration of preoperative antibiotics (risk ratio, 1.899). Furthermore, there were no significant differences based on the use of systemic (risk ratio, 0.0957), intraoral (risk ratio, 0.4176), or topical (risk ratio, 0.3131) antibiotics. The effect of antibiotic duration on infection rate was not found to be statistically significant for any antibiotic category. The need for additional surgeries did not differ between infected and noninfected groups (W2 = 0.270, P = 1.000). Using antibiotics in combination had no effect on postoperative infections (W2 = 1.828, P = 0.402).

DISCUSSION Antibiotic therapy has been shown to decrease postoperative infection rates in mandibular surgery.4,5,8Y11,14Y16 However, the optimal duration of therapy remains unclear. The indiscriminate administration of antibiotics prophylactically can have detrimental effects for the patient and the community as a whole.11Y13 Modern health care delivery systems must consider the cost of standard practice treatments, and antimicrobial therapy is not different. Those costs must take into account both the direct costs of antimicrobial administration and the indirect costs of the development of bacterial resistance to the antibiotic and subsequent potential for superinfection after elimination of normal bacterial flora, as in Clostridium difficile colitis. Additional concerns include possible life-threatening toxic hypersensitivity or bone marrow depression reactions such as Stevens-Johnson syndrome or aplastic anemia. There has been a rising concern among physicians that the rate of antibiotic resistance is increasing at a faster pace than our ability to counteract it with newly developed antibiotics. Spellberg et al21 reported in 1994 that there was a 56% decline in Food and Drug Administration approval of new antibacterial agents for the preceding 20 years. It is thus apparent that limiting the duration of antibiotic therapy is in the best interest of both the medical community and the patient. Our results show a large variability in current physician practices. While the ordering of preoperative antibiotics occurred in 93.4% of cases, the duration of postoperative antibiotics varied from 1 to 30 days with most physicians ordering courses for 3 (15.6%), * 2011 Mutaz B. Habal, MD




Antibiotic Duration in Mandibular Fractures

the relative homogeneity of urban trauma center patients with young men predominating. In the absence of prospective controlled data, our study adds to the growing body of literature that suggests judicious antimicrobial use is beneficial to a wide range of patient populations. Future studies should prospectively examine if any benefit is conferred onto those patients who receive postoperative antibiotics for mandibular fracture repair compared with those who receive only preoperative antibiotic therapy.

REFERENCES

FIGURE 3. Total length prescribed antibiotic course (days). 7 (52.6%), or 10 (10.4%) days. Several investigators have attempted to determine the division between a necessary and unnecessary duration for postoperative antibiotic treatment. Nelson et al,18 in a study of orthopedic operations, compared 1 day versus 7 days of antibiotic therapy. Abubaker and Rollert6 compared 5 days of postoperative antibiotics to the same duration of placebo, whereas Bentley et al20 looked at a 1-day versus a 5-day regimen. Although there are many cut-off periods that can be selected, our study made no special distinction between different time courses of antibiotics, electing instead to examine the data for significant differences at any time point. Our study suggests that longer duration of antibiotic therapy is not advantageous in the setting of mandibular fracture, regardless of the antibiotic category or nature of the fracture. Considering these findings, the need for any postoperative antibiotics should be brought into question. When comparing those patients who acquired a postoperative infection from those who did not, no factors pertaining to their management within the hospital or operatively were found to be significantly different. The only factor that was significantly different was age, with those acquiring an infection 9 years older on average. This finding suggests that patient factors, and not iatrogenic factors, are largely responsible for patients’ postoperative course. Strengths of this study include a larger patient population in comparison to other studies examining antibiotic prophylaxis.6,20 The next largest study comparing groups about postoperative antibiotics was that of Miles et al.14 Their study examined 181 patients who were randomly placed into 2 groups based on whether they received postoperative antibiotics. In addition, their study was limited to the use of penicillin G as an antibiotic treatment, whereas we included all types of antibiotic therapies, of which the most commonly used was clindamycin (Fig. 2). In addition, the baseline rate of infection in our population is consistent with the published rates.6,17,22 For open and closed mandibular fractures, the literature suggests a baseline rate of infection of 6.9%.22 This compares closely with our observed infection rate of 4.5% compared with the reported 10% to 15% infection rate seen in combined maxillomandibular fractures. Miles et al14 suggests that the baseline rate of open mandibular fractures is 6.25% that is similar to our rate found in combined open and closed fractures.23 Our study is limited by its retrospective design and potential for observer bias. It is also possible that postoperative infection was diagnosed and treated at another institution, but this is unlikely given the propensity of providers to refer complications back to the operating surgeon. Although patients who received shorter or longer courses of antibiotics appeared similar based on available demographic data, it is possible that patients who received longer antibiotic courses had risk factors that were not captured by our analysis. Although this would mask the possibility of benefit from longer courses of antibiotics, we feel the likelihood of this is small given

1. Nathens AB, Fantus RJ. National Trauma Data Bank Annual Report 2008. Chicago: American College of Surgeons, 2008: 3Y5 2. Ogundare BO, Bonnick A, Bayley N. Pattern of mandibular fractures in an urban major trauma center. J Oral Maxillofac Surg 2003;61:713Y718 3. Huag RH, Prather J, Indresano AT. An epidemiological survey of facial fractures and concomitant injuries. J Oral Maxillofac Surg 1990;48:926 4. Peterson LJ. Antimicrobial prophylaxis against wound infections in oral and maxillofacial surgery. J Oral Maxillofac Surg 1990;48:617 5. Peterson LJ, Augusta GA, Booth DF. Efficacy of prophylaxis in intraoral orthognathic surgery. J Oral Surg 1976;34:1088 6. Abubaker AO, Rollert MK. Postoperative antibiotic prophylaxis in mandibular fractures: a preliminary randomized, double-blind, and placebo-controlled clinical study. J Oral Maxillofac Surg 2001;59: 1415Y1419 7. Zijderveld SA, van den Bergh JP, Schulten EA, et al. Preoperative antibiotic prophylaxis in orthognathic surgery: a randomized double-blind, and placebo controlled clinical study. J Oral Maxillofac Surg 1999;57:1403Y1406 8. Berger SA, Nagar H, Weitzman S. Prophylactic antibiotics in surgical procedures. Surg Gynecol Obstet 1978;146:469 9. Guglielmo BJ, Hohn DC, Koo PJ, et al. Antibiotic prophylaxis in surgical procedures: a critical analysis of the literature. Arch Surg 1983;118:943 10. Kaiser AB. Antimicrobial prophylaxis in surgery. N Engl J Med 1986;315:1129 11. Wittman DH. Let us shorten antibiotic prophylaxis and therapy in surgery. Am J Surg 1996;172:27S 12. Gustilo RB, Merkow RL, Templeman D. Current concepts review: the management of open fractures. J Bone Joint Surg Am 1990;72:299Y303 13. Zallen RD, Black SL. Antibiotic therapy in oral and maxillofacial surgery. J Oral Surg 1976;34:349Y351 14. Miles B, Potter J, Ellis E. The efficacy of postoperative antibiotic regimens in the open treatment of mandibular fractures: a prospective randomized trial. J Oral Maxillofac Surg 2006;64:576Y582 15. Stone H, Haney BB, Kolb LD, et al. Prophylactic and preventive antibiotic therapy: timing, duration, and economics. Ann Surg 1979;189:691Y698 16. Yrastorza JA. Indications for antibiotics in orthognathic surgery. J Oral Surg 1976;34:514 17. Dellinger EP, Caplan ES, Weaver LD, et al. Duration of preventive antibiotic administration for open extremity fractures. Arch Surg 1988;123:333Y338 18. Nelson CL, Green TG, Porter RA, et al. One day versus seven days of preventive antibiotic therapy in orthopedic surgery. Clin Orthop Relat Res 1983;176:258Y263 19. Chow LK, Singh B, Chiu WK, et al. Prevalence of postoperative complications after orthognathic surgery: a 15-year review. J Oral Maxillofac Surg 2007;65:984Y992 20. Bentley KC, Head TW, Aiello GA. Antibiotic prophylaxis in orthognathic surgery: a 1-day versus 5-day regimen. J Oral Maxillofac Surg 1999;57:226Y230 21. Spellberg B, Powers JH, Brass EP, et al. Trends in antimicrobial drug development: implications for the future. Clin Infect Dis 2004;38:1279Y1286 22. Chu L, Gussack GS, Muller T. A treatment protocol for mandible fractures. J Trauma 1994;36:48Y52 23. James RB, Fredrickson C, Kent JN. Prospective study of mandibular fractures. J Oral Surg 1981;39:275Y281

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