We evaluated the efficacy of the Respironics bi-level positive airway pressure (BiPAP) device, a continuous positive airway pressure (CPAP) blower that cyclically superimposes a pressure boost (PB) upon the baseline CPAP, in functioning as a ventilatory assist device. METHODS: We tested the device with an artificial lung model with normal lung compliance and airway resistance, ventilatory rates of 12-20/min, and PB levels up to 15 cm H2O 1.5 kPa. We also tested it on four patients who had been receiving home nocturnal nasal positive-pressure ventilatory assistance via either standard portable ventilators or nasal CPAP alone. RESULTS: When used with the artificial lung model at the above-described settings, the BiPAP device functioned as a time-cycled, pressure-limited ventilator. Further increases in PB, lung compliance, or airway resistance-or reductions in inspiratory time-resulted in flow-limitation as well. Patients found the BiPAP device as comfortable as their previous devices, or more so. After long-term nocturnal use of the BiPAP device, patients' PaCO2 was either stabilized or improved. CONCLUSIONS: We conclude that the Respironics BiPAP device offers an effective, simple, lightweight, and less expensive alternative to standard portable ventilators for patients with chronic respiratory failure who receive intermittent ventilatory support via the nasal route .
Strumpf et al. (Tue,) studied this question.