TY - JOUR
T1 - Positive end-expiratory pressure affects geometry and function of the human diaphragm
AU - Jansen, Diana
AU - Jonkman, Annemijn H.
AU - De Vries, Heder J.
AU - Wennen, Myrte
AU - Elshof, Judith
AU - Hoofs, Maud A.
AU - Van Den Berg, Marloes
AU - De Man, Angélique M.E.
AU - Keijzer, Christiaan
AU - Scheffer, Gert Jan
AU - Van Der Hoeven, Johannes G.
AU - Girbes, Armand
AU - Tuinman, Pieter Roel
AU - Marcus, J. Tim
AU - Ottenheijm, Coen A.C.
AU - Heunks, Leo
N1 - Publisher Copyright:
Copyright © 2021 the American Physiological Society.
PY - 2021/10
Y1 - 2021/10
N2 - Positive end-expiratory pressure (PEEP) is routinely applied in mechanically ventilated patients to improve gas exchange and respiratory mechanics by increasing end-expiratory lung volume (EELV). In a recent experimental study in rats, we demonstrated that prolonged application of PEEP causes diaphragm remodeling, especially longitudinal muscle fiber atrophy. This is of potential clinical importance, as the acute withdrawal of PEEP during ventilator weaning decreases EELV and thereby stretches the adapted, longitudinally atrophied diaphragm fibers to excessive sarcomere lengths, having a detrimental effect on force generation. Whether this series of events occurs in the human diaphragm is unknown. In the current study, we investigated if shortterm application of PEEP affects diaphragm geometry and function, which are prerequisites for the development of longitudinal atrophy with prolonged PEEP application. Nineteen healthy volunteers were noninvasively ventilated with PEEP levels of 2, 5, 10, and 15 cmH2O. Magnetic resonance imaging was performed to investigate PEEP-induced changes in diaphragm geometry. Subjects were instrumented with nasogastric catheters to measure diaphragm neuromechanical efficiency (i.e., diaphragm pressure normalized to its electrical activity) during tidal breathing with different PEEP levels. We found that increasing PEEP from 2 to 15 cmH2O resulted in a caudal diaphragm displacement (19 [14-26] mm, P < 0.001), muscle shortening in the zones of apposition (20.6% anterior and 32.7% posterior, P < 0.001), increase in diaphragm thickness (36.4% [0.9%-44.1%], P < 0.001) and reduction in neuromechanical efficiency (48% [37.6%-56.6%], P < 0.001). These findings demonstrate that conditions required to develop longitudinal atrophy in the human diaphragm are present with the application of PEEP.
AB - Positive end-expiratory pressure (PEEP) is routinely applied in mechanically ventilated patients to improve gas exchange and respiratory mechanics by increasing end-expiratory lung volume (EELV). In a recent experimental study in rats, we demonstrated that prolonged application of PEEP causes diaphragm remodeling, especially longitudinal muscle fiber atrophy. This is of potential clinical importance, as the acute withdrawal of PEEP during ventilator weaning decreases EELV and thereby stretches the adapted, longitudinally atrophied diaphragm fibers to excessive sarcomere lengths, having a detrimental effect on force generation. Whether this series of events occurs in the human diaphragm is unknown. In the current study, we investigated if shortterm application of PEEP affects diaphragm geometry and function, which are prerequisites for the development of longitudinal atrophy with prolonged PEEP application. Nineteen healthy volunteers were noninvasively ventilated with PEEP levels of 2, 5, 10, and 15 cmH2O. Magnetic resonance imaging was performed to investigate PEEP-induced changes in diaphragm geometry. Subjects were instrumented with nasogastric catheters to measure diaphragm neuromechanical efficiency (i.e., diaphragm pressure normalized to its electrical activity) during tidal breathing with different PEEP levels. We found that increasing PEEP from 2 to 15 cmH2O resulted in a caudal diaphragm displacement (19 [14-26] mm, P < 0.001), muscle shortening in the zones of apposition (20.6% anterior and 32.7% posterior, P < 0.001), increase in diaphragm thickness (36.4% [0.9%-44.1%], P < 0.001) and reduction in neuromechanical efficiency (48% [37.6%-56.6%], P < 0.001). These findings demonstrate that conditions required to develop longitudinal atrophy in the human diaphragm are present with the application of PEEP.
KW - Diaphragm contractile function
KW - Diaphragm geometry
KW - Positive end-expiratory pressure
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U2 - 10.1152/japplphysiol.00184.2021
DO - 10.1152/japplphysiol.00184.2021
M3 - Article
C2 - 34473571
AN - SCOPUS:85117163744
SN - 8750-7587
VL - 131
SP - 1328
EP - 1339
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 4
ER -