Cardiorespiratory effects of changing inspiratory to expiratory ratio during high-frequency oscillation in an animal model of respiratory failure.
To examine the effects of varying inspiratory/expiratory ratio (I/E) on cardiorespiratory function during high-frequency oscillation (HFO), 11 saline-lavaged rabbits were ventilated at I/E = 1:2, 1:1.5, 1.5:1, and 2:1 in a paired comparison to a baseline of I/E = 1:1. HFO was delivered by a SensorMedics model 3100 oscillator at a frequency of 10 Hz. Pressure amplitude and proximal mean airway pressure (PPaw) were held constant as I/E was varied from baseline to the experimental I/E. During each paired observation, PaO2, PaCO2, cardiac output, blood pressure, and distal mean airway pressure (DPaw) were measured. We found that as I/E was increased or decreased from 1:1, no significant changes in PaO2, PaCO2, blood pressure, or cardiac output occurred. We conclude that in this model, varying I/E has no significant effect on oxygenation, ventilation, or cardiovascular function.
Courtney
S E
SE
Division of Newborn Medicine, Wright State University, Dayton, Ohio.
Weber
K R
KR
Spohn
W A
WA
Bender
C V
CV
Malin
S W
SW
Gotshall
R W
RW
D000704:Analysis of Variance; D000818:Animals; D001794:Blood Pressure; D002302:Cardiac Output; D006321:Heart / Q000503:physiopathology*; D006612:High-Frequency Ventilation; D008168:Lung / Q000503:physiopathology*; D008170:Lung Compliance; D011817:Rabbits; D012119:Respiration; D012131:Respiratory Insufficiency / Q000503:physiopathology / Q000628:therapy*