Cefazolin and an aminoglycoside compared with cefazolin alone for the antimicrobial prophylaxis of type III open orthopedic fractures

Use of single agent Cefotetan for Gustilo-Anderson type III open fracture prophylaxis

INTRODUCTION

The prophylactic intravenous antibiotic regimen for Gustilo-Anderson Type III open fractures traditionally consists of cefazolin with an aminoglycoside plus penicillin for gross contamination. Cefotetan, a second-generation cephalosporin, offers a wide spectrum of activity against both aerobes and anaerobes as well as against Gram-positive and Gram-negative bacteria. Cefotetan has not been previously established within orthopedic surgery as a prophylactic intravenous agent.

PATIENTS AND METHODS

Cefotetan monotherapeutic prophylaxis versus any other antibiotic regimen (standard/literature-supported and otherwise) was studied for patient encounters between September 2010 and December 2019 within a single Level 1 regional trauma center. Patient comorbidities, preoperative fracture characteristics, and in-hospital/operative metrics (including length of stay [LOS], number of antibiotic doses, and antibiotic costs [US$]) were included for analysis. Postoperative outcomes up to 1 year included rates of surgical site infection (SSI), deep infection necessitating return to the operating room (OR), non-union, prescribed outpatient antibiotics, hospital readmissions, and related returns to the emergency department (ED). Sensitivity analyses were also conducted to include standard/literature-supported antibiotic regimens as a nested random factor within the non-cefotetan cohort.

RESULTS

The nested variable accounting for standard/literature-supported antibiotic regimens had no significant effect in any model for any outcome (for each, P ≥ 0.302). Thus, 1-year data for 138 Type III open fractures were included, accounting for only the binary effect of cefotetan (n = 42) versus non-cefotetan cohorts. The cohorts did not differ significantly at baseline. The cefotetan cohort received fewer in-house dose/day antibiotics (P < 0.001), was less likely to receive outpatient antibiotics in the following year (P = 0.023), had decreased return to the OR (35.7% versus 54.2%, P = 0.045), and demonstrated non-union rates of 16.7% versus 28.1% (P = 0.151). When adjusted for length of stay (LOS), the dose/day total costs for antibiotics were $8.71/day more expensive for the cefotetan cohort (P = 0.002). Type III open fractures incurred overall rates of SSI reaching 16.7% in the cefotetan cohort and 14.7% for non-cefotetan (P = 0.773). Deep infections necessitating return to the OR were 9.5% and 11.6%, respectively (P = 0.719).

CONCLUSION

Cefotetan alone may provide superior antibiotic stewardship with similar infectious sequalae compared to more traditional antibiotic prophylaxis regimens for Gustilo-Anderson Type III open long bone fractures.

LEVEL OF EVIDENCE

Level III Retrospective Cohort Study.

Type III Gustilo-Anderson open fracture does not justify routine prophylactic Gram-negative antibiotic coverage

Postoperative surgical site infection (SSI) is common in open long bone fractures, so early administration of prophylactic antibiotics is critical to prevent SSI. However, the necessity of initial broad-spectrum coverage for Gram-positive and -negative pathogens remains unclear. The purpose of this study was to clarify the effectiveness of prophylactic broad-spectrum antibiotics in a large, national-wide sample. We reviewed an open fracture database of prospectively collected data from 111 institutions managed by our society. A retrospective cohort study was designed to compare the rates of deep SSI between narrow- and broad-spectrum antibiotics, which were initiated within three hours after injury. A total of 1041 type III fractures were evaluated at three months after injury. Overall deep SSI rates did not differ significantly between the narrow-spectrum group (43/538, 8.0%) and broad-spectrum group (49/503, 9.8%) (p = 0.320). During propensity score-matched analysis, 425 pairs were analyzed. After matching, no significant difference in the SSI rate was seen between the narrow- and broad-spectrum groups, with 42 SSIs (9.9%) and 40 SSIs (9.4%), respectively (p = 0.816). The probability of deep SSI was not reduced by broad-spectrum antibiotics compared with narrow-spectrum antibiotics in type III open long bone fractures.

Ampicillin/sulbactam versus cefazolin plus aminoglycosides for antimicrobial prophylaxis in management of Gustilo type IIIA open fractures: A retrospective cohort study

BACKGROUND

The antibiotic regimens for prophylaxis in the management of open fractures remain controversial. Although the use of aminoglycosides is widely accepted for treatment of Gustilo type III open fractures, aminoglycosides are often avoided in patients with risk factors. This study aimed to compare efficacy and safety of two regimens, cephazolin plus aminoglycoside (amikacin or gentamicin) and ampicillin/sulbactam (ABPC/SBT), in patients with Gustilo type IIIA open fractures.

METHODS

A total of 95 Gustilo type IIIA fractures in 90 patients were retrospectively reviewed in this study. The cohort was categorized into two groups that were treated in accordance with the institutional prescribed regimen in different periods: (1) cefazolin plus aminoglycoside (January 1, 2014-September 30, 2017) and (2) ABPC/SBT monotherapy (October 1, 2017-September 30, 2020). Cefazolin was used at 1-2 g every 8 h, aminoglycoside (amikacin or gentamicin) was used daily depending on body weight, and ABPC/SBT was used at 3 g every 8 h The antibiotic administration was continued within 3 days or until successful soft tissue coverage was achieved. The infection rate and the incidence of acute kidney injury (AKI) in both groups were assessed.

RESULTS

ABPC/SBT was used in 34 patients (36 fractures), and 56 patients (59 fractures) received cefazolin plus aminoglycoside for antibiotic prophylaxis. Infection developed in 2 of 36 fractures in ABPC/SBT group and 4 of 59 fractures in the cefazolin plus aminoglycoside group (p > 0.99). The average serum creatinine levels on admission, baseline, and peak during the hospital stay were not significantly different between the two groups. One case of AKI was identified in each group, indicating that incidence rate of AKI was not significantly different between the two groups.

CONCLUSION

We demonstrated the non-inferiority of ABPC/SBT therapy over cefazolin plus aminoglycoside regimen for type IIIA open fractures. The ABPC/SBT regimen may be an alternative option for managing Gustilo type IIIA open fractures. Further prospective studies with larger samples are needed to verify these results.

Evaluation of Piperacillin-Tazobactam for Antibiotic Prophylaxis in Traumatic Grade III Open Fractures

Background: Broad-spectrum antibiotic agents are sometimes utilized for prophylaxis of Gustilo grade III open fractures. However, this practice is not recommended by current guidelines, and it is unknown how patient outcomes are impacted. This study aimed to determine if prophylaxis with piperacillin-tazobactam (PT) results in different rates of infection versus guideline-concordant therapy (GCT). Patients and Methods: This was a single-center, retrospective cohort study of adult trauma patients with Gustilo grade III open long bone fractures admitted between January 2008 and August 2018. The primary outcome of infection (superficial or deep) at six weeks and secondary outcomes of delayed union, nonunion, Clostridioides difficile, and development of resistant organisms were abstracted from medical records. Guideline-concordant therapy was defined as a first-generation cephalosporin with or without an aminoglycoside. Univariable and multivariable analyses controlling for injury severity score (ISS) were performed. Results: One hundred twenty patients were included; 97 (81%) received PT, 23 (19%) received GCT. Common injury mechanisms were motor vehicle/motorcycle accident (57%) and falls (17%), and a majority involved a lower extremity (65%). Baseline characteristics were similar except higher median ISS in PT (14; interquartile range [IQR], 9-22) versus GCT (9; IQR, 9-14). Guideline-concordant therapy was given for a median of four (range, 2-8) days and PT for six (range, 3-11) days (p = 0.078). On univariable analysis, PT patients had more infections at six weeks (23.7% vs. 4.3%; p = 0.042), but multivariable analysis demonstrated no difference (odds ratio [OR], 5.81; 95% confidence interval [CI], 0.73-46.25; p = 0.096). Patients receiving prophylaxis with PT had a longer median length of stay at 16 days (range, 10-22) versus nine days (range, 4-16). No statistically significant differences in delayed union, non-union, Clostridioides difficile, or development of resistant organisms were observed. Conclusions: Broad-spectrum antibiotic prophylaxis with PT did not improve infection rates compared to GCT, suggesting it may not be warranted.