A heat and humidification system for high frequency jet ventilation.

The clinical application of high frequency jet ventilation (HFJV), especially in pediatrics, has been hindered by the lack of adequate heating and humidification of the delivered gas. A technique of injecting particulate water into the gas from the jet ventilator has been described in the literature. However, it has been used primarily on adults and may cause fluid overload or hypothermia when used on infants. We describe a device for use during HFJV that provides gas (free of particulate water) to the patient at or near body temperature, with a relative humidity of 91%. This system has been used on 34 persons (14 premature infants, 17 small children, and 3 adults) without complications associated with improper conditioning of inspired gas.