Initial Emergency Department Concentrations of Serum Bicarbonate and Lactate Are Associated With Survival to Hospital Discharge in Children Following Submersion Injuries

OBJECTIVE: There is a lack of objective measures to determine outcome and disposition following pediatric submersion injury. This study described a cohort of pediatric patients who presented to the emergency department (ED) after a submersion injury and the factors associated with survival to hospital discharge. In addition, the study examined the ability of 2 laboratory measures of acidemia, venous lactate and bicarbonate, to predict severity of injury and ED disposition following submersion. METHODS: This cross-sectional cohort study evaluated consecutive pediatric submersion cases from February 2018 to November 2019 seen at Arnold Palmer Hospital for Children's Emergency Department, a tertiary care pediatric level 1 trauma center. Data collected were based on Utstein recommendations for submersion injury and included demographics, event information, vital signs, laboratory data, and hospital disposition. The main outcomes included survival to hospital discharge and hospital admission. RESULTS: There were 208 patients with submersion injuries included in the analysis; 197 survived to hospital discharge, and 11 did not (5%). There were 135 (65%) patients admitted to the hospital, and 52 (25%) admitted to the Intensive Care Unit (ICU). The average age of patients was 47 months, 67% were males, and bystander cardiopulmonary resuscitation (CPR) was performed on 66% of patients. Mean lactate levels were 4.8 mmol/L (95% CI: 4.3 to 5.4) in survivors and 12.9 (95% CI: 10.9 to 14.9) in nonsurvivors (P < 0.001), and mean venous bicarbonate levels were 19 mmol/L (95% CI: 19 to 20) and 11 (95% CI: 9 to 14), respectively (P < 0.001). Lactate levels were significantly and negatively correlated with venous bicarbonate [r = -0.69 (95% CI: -0.78 to -0.58)] and with pH on arterial blood gas [r = -0.81 (95% CI: -0.87 to -0.73)]. The area under the curve for lactate predicting mortality from submersion was 0.97 (95% CI: 0.95 to 1.00) and for predicting admission to the hospital was 0.77 (95% CI: 0.67 to 0.88). The area under the curve for venous bicarbonate predicting mortality was 0.93 (95% CI: 0.87 to 1.00) and for predicting admission 0.69 (95% CI: 0.56 to 0.83). CONCLUSION: Elevations in venous bicarbonate and lactate levels measured in the pediatric ED were significantly associated with severity of submersion injury as measured by survival to hospital discharge and hospital admission. Both correlated with arterial pH levels. Prospective studies should evaluate the utility of using these objective measures to determine hospital disposition in these children.