Prehospital capillary lactate in children differentiates epileptic seizure from febrile seizure, syncope, and psychogenic nonepileptic seizure.

Purpose: The aim of the study was to examine prehospital capillary lactate in children as a diagnostic biomarker to differentiate epileptic seizures from febrile seizures, syncope, and psychogenic nonepileptic seizures (PNES).

Methods: Capillary lactate concentrations taken in a pediatric prehospital setting within 2 h of the paroxysmal event were compared retrospectively between patients with epileptic seizure, febrile seizure, syncope, and PNES, based on the final diagnosis from the hospitalization report.

Results: One hundred and two patients were included, 53 (52%) with epileptic seizures, 41 (40%) with febrile seizures, and 8 (8%) with syncope or PNES. Capillary lactate in patients with a final diagnosis of epileptic seizure was significantly increased in comparison to the concentrations in patients with febrile seizure (p < 0.0007) and in comparison to the concentrations in patients with syncope or PNES (p < 0.0204). The area under the ROC-curve was 0.71 (95% CI 0.61-0.80). For a cutoff concentration of prehospital capillary lactate >3.9 mmol/l (Youden index), the sensitivity was 49% and the specificity 92%.

Conclusion: Prehospital capillary lactate concentrations are a useful tool for differentiating the nature of a paroxysmal event in children.