Comparing the effects of rise time and inspiratory cycling criteria on 6 different mechanical ventilators.
BACKGROUND
Inspiratory rise time and cycling criteria are important settings in pressure support ventilation. The purpose of this study was to investigate the impact of minimum and maximum rise time and inspiratory cycling criteria settings on 6 new generation ventilators. Our hypothesis was there would be a difference in the exhaled tidal volume, inspiratory time, and peak flow among 6 different ventilators, based, on change in rise time and cycling criteria.


METHODS
The research utilized a breathing simulator and 4 different ventilator models. All mechanical ventilators were set to a spontaneous mode of ventilation with settings of pressure support 8 cm H2O and PEEP of 5 cm H2O. A minimum and maximum setting for rise time and cycling criteria were examined. Exhaled tidal volume, inspiratory time, and peak flow measurements were recorded for each simulation.


RESULTS
Significant (P < .001) differences were found when comparing minimum and maximum rise time and minimum and maximum cycling criteria for each ventilator.


CONCLUSIONS
Significant differences in exhaled tidal volume, inspiratory time, and peak flow were observed by adjusting rise time and cycling criteria. This research demonstrates that during pressure support ventilation strategy, adjustments in rise time and/or cycling criteria can produce changes in inspiratory parameters. Obviously, this finding has important implications for practitioners who utilize a similar pressure support strategy when conducting a ventilator wean. Additionally, this study outlines major differences among ventilator manufacturers when considering inspiratory rise time and cycling criteria.
Department of Respiratory Care, Texas State University-San Marcos, 601 University Drive, San Marcos TX 78666, USA. jg61@txstate.edu
Joshua F
JF
Gonzales
Christopher J
CJ
Russian
S
S
Gregg Marshall
Kevin P
KP
Collins
D004867:Equipment Design; D006801:Humans; D012123:Pulmonary Ventilation; D012129:Respiratory Function Tests; D013990:Tidal Volume; D013997:Time Factors; D012122:Ventilators, Mechanical; D014939:Work of Breathing