title: Peripheral muscle strength and correlates of muscle weakness in patients receiving mechanical ventilation.
abstract: BACKGROUND
  Intensive care unit-acquired weakness is a frequent complication of critical illness because of patients' immobility and prolonged use of mechanical ventilation.
  
  
  OBJECTIVE
  To describe daily measurements of peripheral muscle strength in patients receiving mechanical ventilation and explore relationships among factors that influence intensive care unit-acquired weakness.
  
  
  METHODS
  Peripheral muscle strength of 120 critically ill patients receiving mechanical ventilation was measured daily by using a standardized handgrip dynamometry protocol. Three grip measurements for each hand were recorded in pounds-force; the mean of these 3 assessments was used in the analysis. Correlates of intensive care unit-acquired weakness (age, sex, illness severity, duration of mechanical ventilation, medications) were analyzed by using mixed models to explore the relationship to grip strength.
  
  
  RESULTS
  Median baseline grip strength was variable yet diminished (7.7 pounds-force), with either a pattern of diminishing grip strength or maintenance of the baseline low grip strength over time. With controls for days of measurement, female sex (β = -10.4; P < .001), age (β = -0.24; P = .004), and days receiving mechanical ventilation (β = -0.34; P = .005) explained a significant amount of variance in grip strength over time.
  
  
  CONCLUSIONS
  Patients receiving prolonged mechanical ventilation had marked decrements in grip strength, measured by hand dynamometry, a marker for peripheral muscle strength. Hand dynamometry is a reliable method for measuring muscle strength in cooperative critically ill patients and can be used to develop interventions to prevent intensive care unit-acquired weakness.
authors.affiliation: Linda L. Chlan was the Dean's Distinguished Professor of Symptom Management Research, College of Nursing, Ohio State University, Columbus, Ohio at the time of this research. Mary Fran Tracy is a critical care clinical nurse specialist, University of Minnesota Medical Center, Fairview, Minneapolis, Minnesota. Jill Guttormson is an assistant professor, College of Nursing, Marquette University, Milwaukee, Wisconsin. Kay Savik is a senior statistician, School of Nursing, University of Minnesota, Minneapolis, Minnesota. chlan.linda@mayo.edu.
authors.forename: Linda L
authors.initials: LL
authors.lastname: Chlan
authors.affiliation: Linda L. Chlan was the Dean's Distinguished Professor of Symptom Management Research, College of Nursing, Ohio State University, Columbus, Ohio at the time of this research. Mary Fran Tracy is a critical care clinical nurse specialist, University of Minnesota Medical Center, Fairview, Minneapolis, Minnesota. Jill Guttormson is an assistant professor, College of Nursing, Marquette University, Milwaukee, Wisconsin. Kay Savik is a senior statistician, School of Nursing, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Mary Fran
authors.initials: MF
authors.lastname: Tracy
authors.affiliation: Linda L. Chlan was the Dean's Distinguished Professor of Symptom Management Research, College of Nursing, Ohio State University, Columbus, Ohio at the time of this research. Mary Fran Tracy is a critical care clinical nurse specialist, University of Minnesota Medical Center, Fairview, Minneapolis, Minnesota. Jill Guttormson is an assistant professor, College of Nursing, Marquette University, Milwaukee, Wisconsin. Kay Savik is a senior statistician, School of Nursing, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Jill
authors.initials: J
authors.lastname: Guttormson
authors.affiliation: Linda L. Chlan was the Dean's Distinguished Professor of Symptom Management Research, College of Nursing, Ohio State University, Columbus, Ohio at the time of this research. Mary Fran Tracy is a critical care clinical nurse specialist, University of Minnesota Medical Center, Fairview, Minneapolis, Minnesota. Jill Guttormson is an assistant professor, College of Nursing, Marquette University, Milwaukee, Wisconsin. Kay Savik is a senior statistician, School of Nursing, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Kay
authors.initials: K
authors.lastname: Savik
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016638:Critical Illness; D005260:Female; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D053581:Muscle Strength Dynamometer / Q000706:statistics & numerical data; D018908:Muscle Weakness / Q000175:diagnosis* / Q000503:physiopathology*; D012121:Respiration, Artificial; D012720:Severity of Illness Index; D012737:Sex Factors; D013997:Time Factors; D055815:Young Adult