Bronchiolitis-associated encephalopathy in critically-ill infants: an underestimated complication?

OBJECTIVE: To investigate the bronchiolitis-associated encephalopathy in critically ill infants. METHODS: The records of infants with severe bronchiolitis admitted to our intensive care unit between 1991 and 2003 were reviewed. Subjects with underlying neurological disorders were excluded. Encephalopathy was defined as occurrence of seizures or at least two nonconvulsive neurologic manifestations. A semistructured telephone interview investigated long-term neurodevelopmental outcome. RESULTS: Twenty-one infants (11 newborns) were enrolled. All patients required oxygen supplementation and 14 required mechanical ventilation. Encephalopathy occurred in 10 infants, six of whom developed seizures. Encephalopathic infants frequently (six of nine) showed transient EEG abnormalities, and occasionally (one of nine) cranial ultrasound abnormalities. A positive respiratory syncytial virus test was found in five of nine encephalopathic infants. One encephalopathic patient died, while 20 infants clinically normalised before discharge and showed a good neurodevelopmental outcome. CONCLUSIONS: Acute encephalopathy was frequently observed in our patients with severe bronchiolitis. Long-term prognosis of encephalopathic infants was good.