TY - JOUR
T1 - Adaptations in the diaphragm's in vivo force-length relationship in patients on continuous ambulatory peritoneal dialysis
AU - Prezant, D. J.
AU - Aldrich, T. K.
AU - Karpel, J. P.
AU - Lynn, R. I.
PY - 1990
Y1 - 1990
N2 - In patients on continuous ambulatory peritoneal dialysis (CAPD) for more than 6 wk, we measured functional residual capacity (FRC), maximum inspiratory and transdiaphragmatic pressure, diaphragm length, and radius of curvature (roentgenographic methods) as functions of the volume of peritoneal dialysate (PD) instilled within the abdominal cavity. This allowed in vivo characterization of the human diaphragm's force-length relationship. As PD volume increased from zero to 3 L, FRC decreased from 2.41 ± 0.29 L to 1.93 ± 0.072 L; mean total diaphragm length index (TDLI) increased efrom 0.22 ± 0.01 to 0.28 ± 0.01, and diaphragm radius of curvature remained unchanged. Respiratory muscle strength increased as a function of dialysate volume, reaching its maximum after the infusion of 3 L PD. In contrast, normal subjects achieved maximal inspiratory muscle force at their normal FRC, with a mean TDLI of 0.26 ± 0.01 and showed no further increase as the diaphragm lengthened. We conclude that the human diaphragm may be capable of an adaptive rightward shift in its force-length relationship when it is chronically lengthened by CAPD.
AB - In patients on continuous ambulatory peritoneal dialysis (CAPD) for more than 6 wk, we measured functional residual capacity (FRC), maximum inspiratory and transdiaphragmatic pressure, diaphragm length, and radius of curvature (roentgenographic methods) as functions of the volume of peritoneal dialysate (PD) instilled within the abdominal cavity. This allowed in vivo characterization of the human diaphragm's force-length relationship. As PD volume increased from zero to 3 L, FRC decreased from 2.41 ± 0.29 L to 1.93 ± 0.072 L; mean total diaphragm length index (TDLI) increased efrom 0.22 ± 0.01 to 0.28 ± 0.01, and diaphragm radius of curvature remained unchanged. Respiratory muscle strength increased as a function of dialysate volume, reaching its maximum after the infusion of 3 L PD. In contrast, normal subjects achieved maximal inspiratory muscle force at their normal FRC, with a mean TDLI of 0.26 ± 0.01 and showed no further increase as the diaphragm lengthened. We conclude that the human diaphragm may be capable of an adaptive rightward shift in its force-length relationship when it is chronically lengthened by CAPD.
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U2 - 10.1164/ajrccm/141.5_pt_1.1342
DO - 10.1164/ajrccm/141.5_pt_1.1342
M3 - Article
C2 - 2339851
AN - SCOPUS:0025311837
SN - 0003-0805
VL - 141
SP - 1342
EP - 1349
JO - American Review of Respiratory Disease
JF - American Review of Respiratory Disease
IS - 5 I
ER -