Dysnatremias and survival in adult burn patients: a retrospective analysis.

BACKGROUND/AIMS: Dysnatremias have been evaluated in many populations and have been found to be significantly associated with mortality. However, this relationship has not been well described in the burn population. METHODS: Admissions to the burn center at our institution from January 2003 to December 2008 were examined. Independent variables included gender, age, percentage total body surface area burned (%TBSA), percentage of third-degree burn, inhalation injury, injury severity score (ISS), Acute Kidney Injury Network (AKIN) stage, hypernatremia, and hyponatremia. They were examined via Cox proportional hazard regression models against death. Moderate to severe hypo- and hypernatremia were defined as serum sodium <130 and >150 mmol/l, respectively. RESULTS: In 1,969 subjects with a mean age of 36.3 ± 16.4 years, a median %TBSA of 9 (interquartile range 4-20) and a median ISS of 5 (interquartile range 1-16) hypernatremia occurred in 9.9% (n = 194), while hyponatremia occurred in 6.8% (n = 134) with mortality rates of 33.5 and 13.8%, respectively. Patients without a dysnatremia had a mortality rate of 4.3%. On Cox proportional hazard regression age, %TBSA, ISS, and AKIN stage were found to be significant predictors of mortality. Hypernatremia (HR 2.00, 95% CI 1.212-3.31; p = 0.0066), but not hyponatremia (HR 1.72, 95% CI 0.89-3.34; p = 0.1068) was associated with mortality. CONCLUSIONS: In the burn population, hypernatremia, but not hyponatremia, is an independent predictor of mortality.

Hypertension after injury among burned combat veterans: A retrospective cohort study.

BACKGROUND: The long-term health effects of burn are poorly understood. We sought to evaluate the relationship between burn and the subsequent development of hypertension. METHODS: Retrospective cohort study of patients admitted to our burn center from 2003 to 2010. Data collected included demographic variables, burn size, injury severity score, presence of inhalation injury, serum creatinine, need for renal replacement therapy, as well as days spent in the hospital, in the intensive care unit and on mechanical ventilation. Data for the subsequent diagnosis of hypertension was obtained from medical records. Cox proportional hazard regression models were performed to determine what factors were associated with hypertension. RESULTS: Of the 711 patients identified, 670 were included for analysis after exclusions. After adjustment, only age (HR 1.06 per one year increase, 95% confidence interval 1.03-1.08; p<0.001), percentage of total body surface area burned (HR 1.11 per 5% increase, 95% confidence interval 1.04-1.19; p=0.002) and acute kidney injury (HR 1.68, 95% confidence interval 1.05-2.69; p=0.03) were associated with hypertension. CONCLUSION: Burn size is independently associated with the subsequent risk of hypertension in combat casualties. Clinical support for primary prevention techniques to reduce the incidence of hypertension specific to burn patients may be warranted.

Hyperkalemia in Combat Casualties: Implications for Delayed Evacuation.

OBJECTIVE: Fixed facilities and rapid global evacuation ensured that delayed complications of trauma, such as hyperkalemia, occurred late in the evacuation chain where renal replacement therapies were available. However, future conflicts or humanitarian disasters may involve prolonged evacuation times. We sought to quantify one potential risk of delayed evacuation by assessing hyperkalemia in combat casualties. METHODS: Retrospective study of military members admitted to intensive care units in Iraq and Afghanistan from February 1, 2002, to February 1, 2011. This study was approved by the U.S. Army Medical Research and Materiel Command Institutional Review Board. Demographics, injury severity score, burn injury, mechanism of injury, vital signs, creatinine, and potassium were collected. Logistic regression models were used to identify incidence and risk factors for hyperkalemia. RESULTS: Of 6,011 patient records, 1,472 had sufficient data to be included for analysis. Hyperkalemia occurred in 5.8% of patients. Those with hyperkalemia had higher injury severity scores, higher shock index, were more likely to have acute kidney injury, and were more likely to die. On multivariate analysis, acute kidney injury and shock index were significantly associated with the development of hyperkalemia. In a subgroup of patients with data on creatine kinase, rhabdomyolysis was associated with hyperkalemia in the univariate model, but was not significant after adjustment. CONCLUSION: Hyperkalemia occurred in 5.8% of patients in our cohort of critically injured combat casualties. The development of hyperkalemia was independently associated with acute kidney injury and shock index. In future conflicts, with prolonged evacuation times, mitigation strategies should be developed to treat hyperkalemia in casualties before arrival at definitive care.

Association of rhabdomyolysis with renal outcomes and mortality in burn patients.

The contribution of rhabdomyolysis to acute kidney injury (AKI) in the context of burn injury is poorly studied. We sought to determine the impact of rhabdomyolysis on AKI (defined by the AKI Network classification), renal replacement therapy (RRT), and death. Patients admitted to the burn unit at our institution were examined. Information on sex, age, presence of inhalation injury, electrical burn, percentage TBSA burned, percentage of full-thickness burns, Injury Severity Score, and peak creatine kinase (CK) were recorded. These variables were examined via multivariate logistic regression analysis against AKI Network stage, RRT, and death. Of 1973 consecutive admissions meeting the inclusion criteria, 525 met our eligibility criteria. Log peak CK was found to be correlated with any stage of AKI (odds ratio [OR], 1.71; 95% confidence interval [CI], 1.36-2.16; P < .0001), moderate to severe AKI (OR, 2.09; 95% CI, 1.40-3.11; P = .0003), need for RRT (OR, 1.67; 95% CI, 1.16-2.40; P = .0057), and mortality (OR, 1.49; 95% CI, 1.01-2.20; P = .0441), after adjustment. Each 10-fold increase in peak CK was associated with a 70% increase in the odds of AKI, more than a 100% increase in the odds of moderate to severe AKI, a nearly 70% increase in the odds of RRT, and an almost 50% increase in the odds of mortality in patients with burn injury.