RESUMO
OBJECTIVE: Children are presented with an unknown intoxication at emergency department (ED) after carbon monoxide (CO) poisoning. Although CO poisoning is well defined in the adult literature, little information exists regarding CO poisoning in childhood, especially in infants. The only diagnostic test for CO poisoning is elevation of the carboxyhemoglobin level in the blood. CASE: We report the second youngest neonate in literature who was severely poisoned by CO and treated with hyperbaric oxygen at the ED. He present to the ED with fussiness and feeding difficulty. Upon arrival, he was lethargic, hypotonic, and crying weak. He had a high carboxyhemoglobin measurement, and the levels of cardiac markers elevated. He was treated with hyperbaric oxygen and discharged a good clinical condition. CONCLUSIONS: If there is a baby with unexplained neurologic symptoms and signs, CO poisoning should be considered in the differential diagnosis. Early diagnosis and treatment prevent complications and sequelaes.