Association of serum lactate with outcome after pediatric out-of-hospital cardiac arrest: a secondary analysis of the Therapeutic Hypothermia After Pediatric Cardiac Arrest (THAPCA) trial.

Abstract

Neuroprognostication after pediatric out-of-hospital cardiac arrest (OHCA) is challenging. Serum lactate has potential as an adjunct biomarker. We examined the association of lactate measurements with 12-month neurobehavioral outcomes and hospital mortality in a secondary analysis of the Therapeutic Hypothermia After Pediatric Cardiac Arrest Out-of-Hospital (THAPCA-OH) trial. Study participants with at least one lactate measurement (mmol/L) within 24-h of return of spontaneous circulation (ROSC) were included. The primary outcome was unfavorable neurobehavioral functioning or death at 12-months. Univariable, multivariable and area under the receiver operator characteristic curve (AUROC) analyses were performed at four timepoints: first lactate within 6 or 12-h, and peak lactate within 12 or 24-h of ROSC. The primary analysis included 213 patients, 82% of which had a primary unfavorable outcome. AUROCs showed strong association of lactate with all outcomes and were similar between timepoints, thus we reported the analyses of first lactate within 6 h of ROSC. Median lactate measurements were higher among those with primary unfavorable versus favorable 12-month outcome (7.8 versus 3.1, difference [95%CI]: 4.8[3.7-5.9]) and those who died in the hospital versus survivors (8.6 versus 3.6, difference [95%CI]: 5.1[4.0-6.1]). For each lactate increase of 1 mmol/L, odds (95%CI) of primary unfavorable outcome at 12-months increased 1.40 (1.17, 1.69). Among subjects enrolled in the THAPCA-OH trial, higher lactates within 6-h of ROSC were associated with unfavorable outcome at one year. Lactate has potential as an adjunct for early neuroprognostication and mortality prediction.