A device for nasally applied bilevel positive airway pressure, BiPAP (Respironics Inc., Murrysville, PA), is currently being evaluated for the treatment of respiratory failure in pediatric and adult patients. This retrospective case review examines our experience with using BiPAP in the treatment of acute ventilatory deterioration in pediatric patients with chronic respiratory insufficiency. All patients who presented to the intensive care unit with chronic respiratory insufficiency and ventilatory failure but without hypoxia were given a trial on BiPAP. Fifteen patients, ages 4-21 years, received such ventilatory support. Four of them had cystic fibrosis (CF) and 11 had neuromuscular disease (2, spinal muscular atrophy; 7, Duchenne muscular dystrophy; 1, spinal cord injury; and 1, myopathy of undetermined origin). Hospital days, respiratory rates, resting heart rates, arterial blood gases, serum bicarbonates, and subjective assessment by parents and or patients of dyspnea, sleep pattern, and activity tolerance were compared prior to and after initiation of BiPAP. Patients were followed from 1 day to 21 months. In 14 of 15 patients placement of an artificial airway could be avoided. Significant decreases in hospital days, respiratory rate, heart rate, serum bicarbonate, and arterial PCO2 were observed after initiation of BiPAP. Decline in dyspnea (87% with severe distress at rest prior vs. 80% comfortable at rest after BiPAP), increased activity tolerance (57% attending school after BiPAP vs. none prior to BiPAP), and improved quality of sleep (93% with comfortable sleep, no daytime somnolence vs. none with comfortable sleep and 36% with daytime somnolence prior to BiPAP).(ABSTRACT TRUNCATED AT 250 WORDS)