(1522) Lactate Measurements for Prognostication After Pediatric Out-of-Hospital Cardiac Arrest

Introduction: Prognostication after pediatric out-of-hospital cardiac arrest (OHCA) is challenging given the high morbidity and mortality. Lactate represents the extent of global ischemic injury and has been associated with poor neurologic outcome after OHCA. However, little is known about the prognostic use of lactate based on the timing of its measurement. We sought to determine the association of timing of lactate measurement with in-hospital mortality and neurobehavioral outcome at 12 months after pediatric OHCA.

Methods: We performed a secondary analysis of the Therapeutic Hypothermia After Pediatric Cardiac Arrest: Out-of-Hospital (THAPCA-OH) study. All enrolled patients with at least one lactate measurement within 24 hours of Return of Spontaneous Circulation (ROSC) were included. Our primary outcome was in-hospital mortality and secondary outcome was a dichotomous outcome of a Vineland Adaptive Behavior Scale 2nd Edition (VABS-II) of < 70 at 12-months. We compared the predictability of the following 4 lactate time periods for each outcome using Area Under the Receiver Operating Characteristic Curves (AUC): 1) First lactate within 6 hours of ROSC, 2) First lactate within 12 hours of ROSC, 3) Peak lactate within 12 hours of ROSC, and 4) Peak lactate within 24 hours of ROSC.

Results: 288 subjects were included, with a mean age of 4.6 years. Top diagnoses included Apparent Life-Threatening Event/Sudden Unexpected Infant Death (ALTE/SUID) (n=45), drowning (n=75), and other respiratory events (n=91). Higher lactate values at any time point were associated with in-hospital mortality and poor neurobehavioral outcomes at 12-months. AUCs were similar for all outcomes at each timepoint. Peak lactate within 12 and 24 hours of ROSC had the largest AUCs for predicting in-hospital mortality (AUC, 95% CI: 0.79, 0.73-0.84). Peak lactate within 12 hours of ROSC had the largest AUC for predicting a poor neurobehavioral outcome (AUC, 95% CI: 0.84, 0.78-0.90).

Conclusions: Lactate measurements are strongly associated with in-hospital mortality and 12-month neurobehavioral outcomes after a pediatric OHCA. Peak lactate within 12 hours of ROSC was most predictive, however this was not statistically different from other time intervals. Lactate measurements may be useful information for prognosis discussions with families.