Mechanical ventilation results in progressive contractile dysfunction in the diaphragm

ASU Author/Contributor (non-ASU co-authors, if there are any, appear on document)
Andrew Shanely Ph.D, Associate Professor (Creator)
Appalachian State University (ASU )
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Abstract: These experiments tested the hypothesis that a relatively short duration of controlled mechanical ventilation (MV) will im-pair diaphragmatic maximal speci?c force generation (specific Po) and that this force de?cit will be exacerbated with increased time on the ventilator. To test this postulate, adult Sprague-Dawley rats were randomly divided into one of six experimental groups: 1) control (n = 12); 2)12hofMV(n = 4); 3)18hofMV(n = 4); 4) 18 h of anesthesia and sponta-neous breathing (n = 4); 5)24hofMV(n = 7); and 6)24hof anesthesia and spontaneous breathing (n = 4). MV animals were anesthetized, tracheostomized, and ventilated with room air. Animals in the control group were acutely anesthe-tized but were not exposed to MV. Animals in two spontane-ous breathing groups were anesthetized and breathed spon-taneously for either 18 or 24 h. No differences (P = 0.05) existed in diaphragmatic speci?c Po between control and the two spontaneous breathing groups. In contrast, compared with control, all durations of MV resulted in a reduction (P = 0.05) in diaphragmatic speci?c tension at stimulation fre-quencies ranging from 15 to 160 Hz. Furthermore, the MV-induced decrease in diaphragmatic speci?c Po was time dependent, with speci?c Po being =18 and =46% lower (P = 0.05) in animals mechanically ventilated for 12 and 24 h, respectively. These data support the hypothesis that relatively short-term MV impairs diaphragmatic contractile function and that the magnitude of MV-induced force de?cit increases with time on the ventilator.

Additional Information

Powers, Scott K., R. Andrew Shanely, Jeff S. Coombes, Thomas J. Koesterer, Michael McKenzie, Darin Van Gammeren, Michael Cicale, and Stephen L. Dodd. (2002) "Mechanical ventilation results in progressive contractile dysfunction in the diaphragm" American Physiological Society Version of Record Available @ (DOI 10.1152/japplphysiol.00881.2001.)
Language: English
Date: 2002
respiratory muscles, muscle atrophy, weaning from mechanical ventilation, muscle injury

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