Method of measuring residual lung volume in infants

摘要

Apparatus for measuring residual lung volume (RV) in infants by washout of nitrogen or other inert gas using a compression jacket for rapid thoracoabdominal compression (RTC). RTC is performed from a raised lung volume (V30) to an airway opening pressure of 30 cm H2O. The jacket pressure (Pj) (range 65-92 cm H2O) which generates the highest forced expiratory volume is used during the RV maneuver. The infant is manually hyperventilated to briefly inhibit the respiratory drive. RTC is initiated during the last passive expiration. By measuring the volume of nitrogen expired after end-forced expiratory switching of the inspired gas from a breathable mixture containing an inert gas to 100 % oxygen while RTC is maintained during the post-expiratory pause, RV is calculated.