Hyperchloremia on Admission to Pediatric Intensive Care in Mechanically Ventilated Children is Associated with Impaired Renal Function.

Objective  There is recent interest in the association between hyperchloremic metabolic acidosis and adverse outcomes. In vitro, hyperchloremia causes renal vasoconstriction and fall in glomerular filtration rate (GFR). The objective of this retrospective, observational study is to examine associations between chloride level at admission to pediatric intensive care (PICU) and worst GFR and requirement for renal replacement therapy. Materials and Methods  All admissions to PICU between 2009 and 2019 who received invasive mechanical ventilation and had blood gas analysis performed were included. Data analyzed included patient characteristics (age, gender, diagnosis, pediatric index of mortality [PIM]-2 score); results of initial blood gas; and maximum serum creatinine (then used to calculate minimum GFR). Primary outcome measure was worst GFR during PICU stay. Secondary outcome measures were requirement for renal replacement therapy and PICU mortality. Multivariable regression analysis was used to assess if admission chloride level was independently predictive of minimum GFR during PICU stay and to examine associations between hyperchloremia (>110 mEq/L) at admission and requirement for renal replacement therapy after adjustment for confounders. Results  Data were available for 2,217 patients. Median age was 16.4 months and 39% of patients were hyperchloremic at admission to PICU. Admission chloride level was independently predictive of worst GFR during PICU stay after adjustment for known confounders. Patients with hyperchloremia were not more likely to require renal replacement therapy or die than patients with normochloremia. Conclusion  Prospective studies are necessary to determine if high chloride, specifically chloride containing resuscitation fluids, have a causal relationship with poor outcomes.