Early type II fiber atrophy in intensive care unit patients with nonexcitable muscle membrane

Item Type:	Article
Title:	Early type II fiber atrophy in intensive care unit patients with nonexcitable muscle membrane
Creators Name:	Bierbrauer, J. and Koch, S. and Olbricht, C. and Hamati, J. and Lodka, D. and Schneider, J. and Luther-Schroeder, A. and Kleber, C. and Faust, K. and Wiesener, S. and Spies, C.D. and Spranger, J. and Spuler, S. and Fielitz, J. and Weber-Carstens, S.
Abstract:	OBJECTIVE: Intensive care unit-acquired weakness indicates increased morbidity and mortality. Nonexcitable muscle membrane after direct muscle stimulation develops early and predicts intensive care unit-acquired weakness in sedated, mechanically ventilated patients. A comparison of muscle histology at an early stage in intensive care unit-acquired weakness has not been done. We investigated whether nonexcitable muscle membrane indicates fast-twitch myofiber atrophy during the early course of critical illness. DESIGN, SETTING, AND PATIENTS: We studied patients at increased risk for development of intensive care unit-acquired weakness with Sepsis-related Organ Failure Assessment scores ≥8 on 3 of 5 consecutive days within the first week in the intensive care unit. Electrophysiological compound muscle action potentials after direct muscle stimulation and muscle biopsies were obtained at median days 7 and 5, respectively. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients with nonexcitable muscle membranes (n = 15) showed smaller median type II cross-sectional areas (p < .05), whereas type I muscle fibers did not compared with patients with preserved muscle membrane excitability (compound muscle action potentials after direct muscle stimulation ≥3.0 mV; n = 9). We also observed decreased mRNA transcription levels of myosin heavy chain isoform IIa and a lower densitometric ratio of fast-to-slow myosin heavy chain protein content. CONCLUSION:: We suggest that electrophysiological nonexcitable muscle membrane predicts preferential type II fiber atrophy in intensive care unit patients during early critical illness.
Keywords:	ICU-Acquired Weakness, ICUAW, Acute Critical Illness, Critical Illness Myopathy, Sepsis, Neuromuscular Dysfunction, Muscle Biopsy, Direct Muscle Stimulation
Source:	Critical Care Medicine
ISSN:	0090-3493
Publisher:	Lippincott Williams & Wilkins
Volume:	40
Number:	2
Page Range:	647-650
Date:	February 2012
Official Publication:	https://doi.org/10.1097/CCM.0b013e31823295e6
PubMed:	View item in PubMed

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