title: Decelerating inspiratory flow waveform improves lung mechanics and gas exchange in patients on intermittent positive-pressure ventilation.
abstract: The effects of two inspiratory flow waveforms (WFs), decelerating and constant have been studied in 14 patients undergoing intermittent positive-pressure ventilation (IPPV). With tidal volume (VT), inspiratory time, inspiratory-expiratory (I/E) ratio and frequency being kept constant, the decelerating waveform produced statistically significant reduction of peak pressure, total respiratory resistance, work of inspiration, ratio of dead space to tidal volume (VD/VT) and alveolar-arterial gradient for oxygen (A-a)PO2. There was significant increase in total static and kinetic compliances and PaO2, with no significant changes in PaCO2, in cardiac output (CO) and in other haemodynamic measurements.
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D001784:Blood Gas Analysis; D005260:Female; D006801:Humans; D007320:Inspiratory Capacity / Q000295:instrumentation; D007385:Intermittent Positive-Pressure Ventilation; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010313:Partial Pressure; D011175:Positive-Pressure Respiration; D011659:Pulmonary Gas Exchange; D012131:Respiratory Insufficiency / Q000503:physiopathology / Q000628:therapy; D013147:Spirometry; D013990:Tidal Volume; D012122:Ventilators, Mechanical