The Effect of Underdosing Prophylactic Antibiotics in the Care of Open Tibial Fractures

SLR - September 2018 - Preston Panicco

Reference: Olinger CR, Carver DC, Nolan VG, Weinlein JC. The Effect of Underdosing Prophylactic Antibiotics in the Care of Open Tibial Fractures. J Orthop Trauma – Volume 32, Number 7, July 2018.

Scientific Literature Review

Reviewed By: Preston Panicco, DPM
Residency Program: St. Vincent Charity Medical Center, Cleveland, OH

Podiatric Relevance: This article is significant because it is important to properly dose prophylactic antibiotics in open tibial fractures. Podiatric surgeons routinely administer two grams of Cefazolin regardless of the severity of an open fracture and irrespective of a patient’s body mass. A more comprehensive understanding of high-grade open fractures may lead to improved patient care and a lower incidence of infections.

Methods: A retrospective study of patients above the age of 18 years old who sustained a high-grade (Gustilo-Anderson IIIA and IIIB) open extraarticular tibial fracture at a regional Level 1 trauma center from January 2011 to January 2016. Inclusion criteria included age, weight, sex, body mass index (BMI), type and dose of initial prophylactic antibiotic(s), time from hospital arrival to initial prophylactic antibiotic(s), OTA/AO classification, injury severity score, method of definitive treatment, length of hospital stay and infectious organisms. The designated primary outcome was deep infection, which was defined as an infection requiring surgical debridement within one year of operative open fracture treatment.

Results:
--Sixty-three patients met the inclusion criteria and received Cefazolin for antibiotic prophylaxis.
--Twenty-one of 61 patients (33 percent) were underdosed with Cefazolin based on weight at the time of initial presentation.
--Patient characteristics demonstrated little to no difference between those who developed an infection and those who did not develop an infection.
--Patients who developed an infection were more likely to have a history of hypertension.
--Twenty-six of 61 patients (41 percent) also received Gentamycin. This was not found to be a predictor of infection.
--The average time from hospital arrival to antibiotic administration was 157 minutes for those who developed an infection versus 62 minutes for those who did not develop an infection.
--Of 20 patients with an infection, only 55 percent received appropriate weight-based dosing of Cefazolin.

Conclusions: Patients with open fractures must receive appropriate antibiotics to maximize the chance of avoiding the development of an infection. Recent literature has recommended Cefazolin to be dosed at one gram for patients weighing <80 kg, two grams for patients weighing >80 kg and three grams for patients weighting >120 kg. Penicillin may be added in highly contaminated wounds for Clostridium coverage. In addition to body mass, consideration of additional antibiotics should be considered given the severity of open fractures and the potential damage to vital soft-tissue structures.