Neurological Effects of Acute Carbon Monoxide Poisoning in Children

Abstract

Carbon monoxide poisoning (COP) is one of the most common causes of mortality and morbidity due to poisoning in all over the world. Although the incidence of COP has not been known exactly in the childhood, almost one-third of CO exposures occurred in children. The data regarding COP in children are inconclusive. Children may be more vulnerable to CO exposure than adults as a result of their high respiration and metabolic rates, high oxygen metabolism, and immature central nervous system. Recent researches proposed new theories about neurological effects of CO toxicity. The clinical presentations associated acute COP may be various and nonspecific. Unrecognized CO exposure may lead to significant morbidity and mortality. CO exposed children often become symptomatic earlier, and recover more rapidly, than similarly CO exposed adults. Mild clinical signs and symptoms associated with COP are headache, dizziness, weakness, lethargy, and myalgia; however, severe signs and symptoms such as blurred vision, syncope, convulsion, coma, cardiopulmonary arrest and death can also accompany with COP. Neurologic manifestations can include altered mental status at different degrees, neck stiffness, tremor, ataxia, and positive Babinski's sign. Delayed neurologic sequels (DNS) of COP might be seen in children like adults. DNS symptoms and signs in children include memory problems, mental retardation, mutism, fecal and urinary incontinence, motor deficits, facial palsy, psychosis, chronic headache, seizures, and epilepsy. After CO exposure children must be cared to detect and treat DNS. Although hyperbaric oxygen therapy (HBOT) is reported to prevent development of DNS, its indications, application duration and procedures are controversial in both of the children and adults. Although their predictive values are limited, exposing to CO more than eight hours and suffering from CO-induced coma, cardiac arrest, lactic acidosis, high COHb levels, and pathologic findings at neuroimaging are reported to increase the risk factor for developing DNS. Since physiological properties of children are unique, clinical and experimental studies must be done to provide new perspectives in order to prevent or reduce both acute and delayed neurological effects of CO toxicity.