A Noninvasive Device for Ventilatory Assistance

Recent studies suggest that therapy with continuous positive airway pressure (CPAP) may be useful in treating patients in or at risk of developing acute respiratory failure and as a technique to facilitate discontinuation of mechanical ventilatory support. This therapy often requires tracheal intubation of the patient and attachment to closed gas delivery circuits with pressurized oxygen reservoirs. Such therapy incurs risk of laryngeal and tracheal injury, infection, diminished cough, inadequate humidification, and sensory isolation due to speech loss. To avoid these problems, we designed a noninvasive ventilatory assistance chamber (NIVAC) for adult CPAP therapy. The NIVAC is a square, hyperbarically pressurized chamber fitted over the patient's head and sealed at the neck. It is intended as a benign intervention for trial on patients in impending respiratory failure before one resorts to intubation and mechanical ventilation. The use of the prototype NIVAC in dogs is reported here.