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Interactive effects of corticosteroid and mechanical ventilation on diaphragm muscle function
Author(s) -
Sassoon Catherine S.H.,
Zhu Ercheng,
Fang Liwei,
Ramar Kannan,
Jiao GuangYu,
Caiozzo Vincent J.
Publication year - 2011
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.21821
Subject(s) - diaphragm (acoustics) , mechanical ventilation , methylprednisolone , ventilation (architecture) , myofibril , muscle atrophy , medicine , endocrinology , chemistry , atrophy , loudspeaker , mechanical engineering , physics , acoustics , engineering
Information on the interactive effects of methylprednisolone, controlled mechanical ventilation (CMV), and assisted mechanical ventilation (AMV) on diaphragm function is sparse. Sedated rabbits received 2 days of CMV, AMV, and spontaneous breathing (SB), with either methylprednisolone (MP; 60 mg/kg/day intravenously) or saline. There was also a control group. In vitro diaphragm force, myofibril ultrastructure, αII‐spectrin proteins, insulin‐like growth factor‐1 (IGF‐1), and muscle atrophy F‐box (MAF‐box) mRNA were measured. Maximal tetanic tension (P o ) decreased significantly with CMV. Combined MP plus CMV did not decrease P o further. With AMV, P o was similar to SB and controls. Combined MP plus AMV or MP plus SB decreased P o substantially. Combined MP plus CMV, MP plus AMV, or MP plus SB induced myofibrillar disruption that correlated with the reduced P o . αII‐spectrin increased, IGF‐1 decreased, and MAF‐box mRNA increased in both the CMV group and MP plus CMV group. Short‐term, high‐dose MP had no additive effects on CMV‐induced diaphragm dysfunction. Combined MP plus AMV impaired diaphragm function, but AMV alone did not. We found that acute, high‐dose MP produces diaphragm dysfunction depending on the mode of mechanical ventilation. Muscle Nerve, 2011