Continuous negative chest-wall pressure therapy for assisting ventilation in older children with progressive respiratory insufficiency.

Continuous negative chest-wall pressure (CNP) was used to assist ventilation in 14 children, 6 months to 14 years of age, who had progressive respiratory insufficiency caused by diffuse bilateral alveolar disease. Before the start of CNP therapy, each child had a respiratory rate greater than 50/min, arterial oxygen tension (PaO2) less than 70 mmHg (FIO2 greater than or equal to 50%), and arterial carbon dioxide tension (PaCO2) less than 45 mmHg. The mean intrapulmonary right-to-left shunt was 28.7 +/- 3.8%. Within 6 hours after therapy was started, PaO2 increased from 55.4 +/- 15.9 to 81.6 +/-17.7 mmHg (p less than 0.005). This improvement was sustained and within 24 hours permitted a decrease in fractional concentration inspired oxygen (FIO2) from 51.8 +/- 6.2 to 41.0 +/- 8.4% (p less than 0.001) and in respiratory rate from 78.1 +/-23.0 to 56.4 +/- 21.3 (p less than 0.01). There was a concomitant decrease in intrapulmonary right-to-left shunt. Four of the 14 patients developed pneumothorax that was successfully decompressed. Ten patients survived. These observations establish CNP therapy as an effective means of improving arterial oxygenation in spontaneously breathing older children. Of added significance, this mode of therapy eliminates the need for endotracheal intubation and prolonged use of muscle relaxants and sedatives. It also minimizes exposure to high FIO2, thereby minimizing the hazards of pulmonary oxygen toxicity.