(748) Hypertonic Saline, Hyperchloremia, and the Development of Acute Kidney Injury in PICU Patients

Introduction: Hypertonic saline is frequently used to decrease cerebral edema and treat intracranial hypertension in the Pediatric Intensive Care Unit (PICU). Hyperchloremia has been associated with acute kidney injury (AKI) and mortality in adult ICU patients. We aimed to study the relationship between hypertonic saline, hyperchloremia, and acute kidney injury in the PICU.

Methods: This is a single center, observational, retrospective cohort study of patients who received hypertonic saline in a tertiary care PICU over a 5-year period. Hypertonic saline was defined as intravenous fluids with NaCl concentration > 154 mEq/L. We excluded patients with AKI on admission, a history of chronic kidney disease, and patients without a measured chloride level within 3 days. The exposure was the peak chloride level over the first 3 days of admission and the presence of hyperchloremia, defined as >= 110mmol/L. The clinical outcome was the presence of AKI, as defined by the KDIGO Criteria (serum creatinine increase by >= 0.3mg/dL, >1.5x baseline, or urine output < 0.5 mL/kg/hr for >=12 hours). Our primary outcome was the association of hyperchloremia and AKI.

Results: A total of 119 patients were included. Median age was 8.8 (IQR 3.6 – 14.0); 58% of patients were males. A diagnosis of traumatic brain injury (TBI) comprised 33% of patients; 67% were non-TBI. All patients received hypertonic saline as either 3% saline boluses (97%) and/or a 3% saline infusion (34%). Patients received a mean 27.9mEq/kg of chloride (SD 38). Mean peak chloride level was 118.15 (SD 8.0); 82 (69%) patients developed hyperchloremia. In total, 40 (34%) patients developed AKI. In a multivariate logistic regression adjusted for age and gender, higher peak chloride was significantly associated with development of AKI (OR 1.06, 95% CI 1.01- 1.12, p = .02). Mortality rate was 8%; the association between hyperchloremia and mortality was not statistically significant (X2 (1) = .006, p=1.00, Fisher’s Exact Test).

Conclusions: Higher peak chloride was associated with AKI in patients who received hypertonic saline. Identifying which patients would benefit from hypertonic saline may be advantageous given the potential deleterious effects of hyperchloremia.