Lithium toxicity in a neonate owing to false elevation of blood lithium levels caused by contamination in a lithium heparin container: case report and review of the literature

Abstract

Lithium toxicity in a neonate can occur owing to antenatal exposure as a result of maternal treatment for psychiatric illnesses. False elevation of lithium levels has been reported in the paediatric population when the sample was mistakenly collected in a lithium heparin container. A term, male infant was born to a mother who was on lithium treatment for a psychiatric illness. On day 1, the infant was jittery, had a poor suck with difficulties in establishing feeds. Blood taken from the infant approximately 8 hours after birth demonstrated a lithium level of 4.9 mmol/L (adult toxic level w1.5 mmol/L). However, the sample for lithium levels was sent in a lithium heparin container and the probability of false elevation was considered. He was closely monitored in the neonatal intensive care unit and his hydration was optimised with intravenous fluids. Clinically, he remained well and commenced feeding, and his jitteriness had decreased the following day. A repeat blood lithium level, collected in a gel container, was only 0.4 mmol/L. The initially raised lithium level was owing to contamination from the lithium heparin container.