title: Risk factors in critical illness myopathy during the early course of critical illness: a prospective observational study.
abstract: BACKGROUND
  Non-excitable muscle membrane indicates critical illness myopathy (CIM) during early critical illness. We investigated predisposing risk factors for non-excitable muscle membrane at onset of critical illness.
  
  
  METHODS
  We performed sequential measurements of muscle membrane excitability after direct muscle stimulation (dmCMAP) in 40 intensive care unit (ICU) patients selected upon a simplified acute physiology (SAPS-II) score >OR= 20 on 3 successive days within 1 week after ICU admission. We then investigated predisposing risk factors, including the insulin-like growth factor (IGF)-system, inflammatory, metabolic and hemodynamic parameters, as well as suspected medical treatment prior to first occurrence of abnormal dmCMAP. Nonparametric analysis of two-factorial longitudinal data and multivariate analysis were used for statistical analysis.
  
  
  RESULTS
  22 patients showed abnormal muscle membrane excitability during direct muscle stimulation within 7 (5 to 9.25) days after ICU admission. Significant risk factors for the development of impaired muscle membrane excitability in univariate analysis included inflammation, disease severity, catecholamine and sedation requirements, as well as IGF binding protein-1 (IGFBP-I), but did not include either adjunctive hydrocortisone treatment in septic shock, nor administration of neuromuscular blocking agents or aminoglycosides. In multivariate Cox regression analysis, interleukin-6 remained the significant risk factor for the development of impaired muscle membrane excitability (HR 1.006, 95%-CI (1.002 to 1.011), P = 0.002).
  
  
  CONCLUSIONS
  Systemic inflammation during early critical illness was found to be the main risk factor for development of CIM during early critical illness. Inflammation-induced impairment of growth-factor mediated insulin sensitivity may be involved in the development of CIM.
authors.affiliation: Clinic of Anesthesiology and Intensive Care Medicine, Charité University Medicine, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany. steffen.weber-carstens@charite.de
authors.forename: Steffen
authors.initials: S
authors.lastname: Weber-Carstens
authors.forename: Maria
authors.initials: M
authors.lastname: Deja
authors.forename: Susanne
authors.initials: S
authors.lastname: Koch
authors.forename: Joachim
authors.initials: J
authors.lastname: Spranger
authors.forename: Florian
authors.initials: F
authors.lastname: Bubser
authors.forename: Klaus D
authors.initials: KD
authors.lastname: Wernecke
authors.forename: Claudia D
authors.initials: CD
authors.lastname: Spies
authors.forename: Simone
authors.initials: S
authors.lastname: Spuler
authors.forename: Didier
authors.initials: D
authors.lastname: Keh
mesh_terms: D000328:Adult; D000368:Aged; D016638:Critical Illness; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D009135:Muscular Diseases / Q000453:epidemiology / Q000209:etiology*; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D018746:Systemic Inflammatory Response Syndrome / Q000150:complications; D055815:Young Adult