Prophylactic Gentamicin is Not Associated with Acute Kidney Injury in Patients with Open Fractures
Jeffrey Tessier, JPS Health System, Fort Worth, TX; Billy Moore, JPS Health Network, Fort Worth, TX; Therese Duane, JPS Health Network
Data on antimicrobial prophylaxis for open fractures is limited, with many protocols based on expert opinion from 50 years ago. These protocols include aminoglycosides (AGs), particularly for fractures associated with significant soft tissue injury, and these drugs are associated with an increased risk of acute kidney injury (AKI) in other settings; this risk has not been defined for open fracture prophylaxis.Hypothesis:
The purpose of this trial was to evaluate the risk of AKI with the use of AGs for prophylaxis of open fractures.Methods:
We performed a retrospective study of trauma registry data from May 2012 to October 2014 at our Level 1 trauma center. Patients with open fractures were evaluated for demographics, location/type of fracture, injury severity, and receipt of an AG. Patients with and without AG therapy were compared for rates of AKI, infection, and outcomes. Groups were compared statistically using Student's t-test and logistic regression was used to calculate odds ratios for risk factors associated with AKI.Results:
There were 167 patients with open fractures during the study period (119 males, mean age 42±17), with 80 (48%) receiving an AG (gentamicin) for prophylaxis (AG+ group). AG+ and AG- patients had similar sites of fracture and injury severity scores (ISS, 12.6±9.9 AG+; 15.9±13.2 AG-, P=0.07), but were more likely to have blunt trauma (96% AG+; 77% AG-, P<0.001) or receive iv contrast ≤48hours from admission (75% AG+; 56% AG-, P=0.01). In a multivariate logistic regression model, receipt of gentamicin was not associated with AKI (OR 0.2, 0.02-2.44, P=0.22), while hypotension on admission (OR 10.7, 1.42-80.93, P=0.02) and ISS (OR 1.1, 1.01-1.20, P=0.02) were both associated with AKI during the incident admission. All patients with AKI had received iv contrast ≤48 hours from admission. Only 4 fracture site infections were identified, all in the AG- group. Overall mortality was higher in the AG- group (3.8% AG+, 12.6% AG-, P=0.04).Conclusions:
Gentamicin is not associated with AKI when used for prophylaxis of open fractures. Not surprisingly, hypotension on admission and higher ISS were associated with an increased risk of AKI in patients with open fractures. Only 4 fracture site infections were identified in this study, all in patients that did not receive AGs. Gentamicin was not associated with an increased risk for AKI in this study, but the use of nephrotoxic agents should be limited in open fracture patients presenting with hypotension or high injury severity.