Hyperkalemia and Dialysis in the Deployed Setting.

Acute kidney injury is a recognized complication of combat trauma. The complications associated with acute kidney injury, such as life-threatening hyperkalemia, are usually delayed in onset. In the recent conflicts, rapid evacuation of U.S. and coalition personnel generally resulted in these complications occurring at higher echelons of care where renal replacement therapies were available. In the future however, deployed providers may not have this luxury and should be prepared to temporize patients while they await transport. In this clinical practice guideline, recommendations are made for the management of patients with, or at risk for, acute kidney injury and hyperkalemia in the austere, deployed environment.

The potential utility of urinary biomarkers for risk prediction in combat casualties: a prospective observational cohort study.

INTRODUCTION: Traditional risk scoring prediction models for trauma use either anatomically based estimations of injury or presenting vital signs. Markers of organ dysfunction may provide additional prognostic capability to these models. The objective of this study was to evaluate if urinary biomarkers are associated with poor outcomes, including death and the need for renal replacement therapy. METHODS: We conducted a prospective, observational study in United States Military personnel with traumatic injury admitted to the intensive care unit at a combat support hospital in Afghanistan. RESULTS: Eighty nine patients with urine samples drawn at admission to the intensive care unit were studied. Twelve patients subsequently died or needed renal replacement therapy. Median admission levels of urinary cystatin C (CyC), interleukin 18 (IL-18), L-type fatty acid binding protein (LFABP) and neutrophil gelatinase-associated lipocalin (NGAL) were significantly higher in patients that developed the combined outcome of death or need for renal replacement therapy. Median admission levels of kidney injury molecule-1 were not associated with the combined outcome. The area under the receiver operating characteristic curves for the combined outcome were 0.815, 0.682, 0.842 and 0.820 for CyC, IL-18, LFABP and NGAL, respectively. Multivariable regression adjusted for injury severity score, revealed CyC (OR 1.97, 95 % confidence interval 1.26-3.10, p = 0.003), LFABP (OR 1.92, 95 % confidence interval 1.24-2.99, p = 0.004) and NGAL (OR 1.80, 95 % confidence interval 1.21-2.66, p = 0.004) to be significantly associated with the composite outcome. CONCLUSIONS: Urinary biomarker levels at the time of admission are associated with death or need for renal replacement therapy. Larger multicenter studies will be required to determine how urinary biomarkers can best be used in future prediction models.

Early acute kidney injury in military casualties.

BACKGROUND: While acute kidney injury (AKI) has been well studied in a variety of patient settings, there is a paucity of data in patients injured in the course of the recent wars in Iraq and Afghanistan. We sought to establish the rate of early AKI in this population and to define risk factors for its development. METHODS: We combined the results of two studies performed at combat support hospitals in Afghanistan. Only US service members who required care in the intensive care unit were included for analysis. Data on age, race, sex, Injury Severity Score (ISS), first available lactate, and requirement for massive transfusion were collected. Univariate analyses were performed to identify factors associated with the subsequent development of early AKI. Multivariable Cox regression was used to adjust for potential confounders. RESULTS: The two observational cohorts yielded 134 subjects for analysis. The studies had broadly similar populations but differed in terms of age and need for massive transfusion. The rate of early AKI in the combined cohort was 34.3%, with the majority (80.5%) occurring within the first two hospital days. Patients with AKI had higher unadjusted mortality rates than those without AKI (21.7% vs. 2.3%, p < 0.001). After adjustment, ISS (hazard ratio, 1.02; 95% confidence interval, 1.00-1.03; p = 0.046) and initial lactate (hazard ratio, 1.16; 95% confidence interval, 1.03-1.31; p = 0.015) were independently associated with the development of AKI. CONCLUSION: AKI is common in combat casualties enrolled in two prospective intensive care unit studies, occurring in 34.3%, and is associated with crude mortality. ISS and initial lactate are independently associated with the subsequent development of early AKI. LEVEL OF EVIDENCE: Prognostic and epidemiologic study, level III.