title: Bedside assessment of quadriceps muscle by ultrasound after admission for acute exacerbations of chronic respiratory disease.
abstract: BACKGROUND
  Hospitalization represents a major event for the patient with chronic respiratory disease. There is a high risk of readmission, which over the longer term may be related more closely to the underlying condition of the patient, such as skeletal muscle dysfunction.
  
  
  OBJECTIVE
  We assessed the risk of hospital readmission at 1 year, including measures of lower limb muscle as part of a larger clinical trial.
  
  
  METHODS
  Patients hospitalized with an exacerbation of chronic respiratory disease underwent measures of muscle function including quadriceps ultrasound. Independent factors influencing time to hospital readmission or death were identified. Patients were classified into four quartiles based on quadriceps size and compared.
  
  
  RESULTS
  One hundred and ninety-one patients (mean age, 71.6 [SD, 9.1] yr) were recruited. One hundred and thirty (68%) were either readmitted or died. Factors associated with readmission or death were age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01-1.08; P = 0.015), Medical Research Council (MRC) dyspnea grade (OR, 4.57; 95% CI, 2.62-7.95; P < 0.001), home oxygen use (OR, 12.4; 95% CI, 4.53-33.77; P < 0.001), quadriceps (rectus femoris) cross-sectional area (Qcsa) (OR, 0.34; 95% CI, 0.17-0.65; P = 0.001), and hospitalization in the previous year (OR, 4.82; 95% CI, 2.42-9.58; P < 0.001). In the multivariate analyses, home oxygen use (OR, 4.80; 95% CI, 1.68-13.69; P = 0.003), MRC dyspnea grade (OR, 2.57; 95% CI, 1.44-4.59; P = 0.001), Qcsa (OR, 0.46; 95% CI, 0.22-0.95; P = 0.035), and previous hospitalization (OR, 3.04; 95% CI, 1.47-6.29; P = 0.003) were independently associated with readmission or death. Patients with the smallest muscle spent more days in hospital than those with largest muscle (28.1 [SD, 33.9] vs. 12.2 [SD, 23.5] d; P = 0.007).
  
  
  CONCLUSIONS
  Smaller quadriceps muscle size, as measured by ultrasound in the acute care setting, is an independent risk factor for unscheduled readmission or death, which may have value both in clinical practice and for risk stratification.
authors.affiliation: 1 Centre for Exercise and Rehabilitation Science, Institute of Lung Health, Leicester Respiratory Biomedical Research Unit, Department of Respiratory Medicine, Glenfield Hospital, Leicester, United Kingdom.|2 Department of Infection, Inflammation and Immunity, University of Leicester, Leicester, United Kingdom; and.
authors.forename: Neil J
authors.identifier: http://orcid.org/0000-0003-0453-7529
authors.initials: NJ
authors.lastname: Greening
authors.affiliation: 1 Centre for Exercise and Rehabilitation Science, Institute of Lung Health, Leicester Respiratory Biomedical Research Unit, Department of Respiratory Medicine, Glenfield Hospital, Leicester, United Kingdom.|2 Department of Infection, Inflammation and Immunity, University of Leicester, Leicester, United Kingdom; and.
authors.forename: Theresa C
authors.initials: TC
authors.lastname: Harvey-Dunstan
authors.affiliation: 1 Centre for Exercise and Rehabilitation Science, Institute of Lung Health, Leicester Respiratory Biomedical Research Unit, Department of Respiratory Medicine, Glenfield Hospital, Leicester, United Kingdom.
authors.forename: Emma J
authors.initials: EJ
authors.lastname: Chaplin
authors.affiliation: 1 Centre for Exercise and Rehabilitation Science, Institute of Lung Health, Leicester Respiratory Biomedical Research Unit, Department of Respiratory Medicine, Glenfield Hospital, Leicester, United Kingdom.
authors.forename: Emma E
authors.initials: EE
authors.lastname: Vincent
authors.affiliation: 1 Centre for Exercise and Rehabilitation Science, Institute of Lung Health, Leicester Respiratory Biomedical Research Unit, Department of Respiratory Medicine, Glenfield Hospital, Leicester, United Kingdom.
authors.forename: Mike D
authors.initials: MD
authors.lastname: Morgan
authors.affiliation: 1 Centre for Exercise and Rehabilitation Science, Institute of Lung Health, Leicester Respiratory Biomedical Research Unit, Department of Respiratory Medicine, Glenfield Hospital, Leicester, United Kingdom.|2 Department of Infection, Inflammation and Immunity, University of Leicester, Leicester, United Kingdom; and.|3 School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom.
authors.forename: Sally J
authors.initials: SJ
authors.lastname: Singh
authors.affiliation: 1 Centre for Exercise and Rehabilitation Science, Institute of Lung Health, Leicester Respiratory Biomedical Research Unit, Department of Respiratory Medicine, Glenfield Hospital, Leicester, United Kingdom.|3 School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Steiner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D016330:Frail Elderly; D006304:Health Status; D006801:Humans; D007902:Length of Stay; D010359:Patient Readmission / Q000706:statistics & numerical data*; D000067716:Point-of-Care Testing; D011379:Prognosis; D052097:Quadriceps Muscle / Q000000981:diagnostic imaging*; D012307:Risk Factors; D014463:Ultrasonography
keywords: chronic obstructive pulmonary disease; frail elderly; risk factors; skeletal muscle; ultrasonography