title: The course of diaphragm atrophy in ventilated patients assessed with ultrasound: a longitudinal cohort study.
abstract: BACKGROUND
  Mechanical ventilation and the effect of respiratory muscle unloading on the diaphragm cause ventilator-induced diaphragmatic dysfunction (VIDD). Atrophy of the diaphragmatic muscle is a major part of VIDD, and has a rapid onset in most animal models. We wanted to assess the clinical evolution and risk factors for VIDD in an adult intensive care unit (ICU) by measuring diaphragm thickness using ultrasound.
  
  
  METHODS
  We performed a single-centre observational cohort study, including 54 mechanically ventilated patients. The right hemidiaphragm was measured daily at the zone of apposition on the midaxillary line.
  
  
  RESULTS
  Mean baseline thickness was 1.9 mm (SD ± 0.4 mm), and mean nadir was 1.3 mm (SD ± 0.4 mm), corresponding with a mean change in thickness of 32 % (95 % CI 27-37 %). Length of mechanical ventilation (MV) was associated with the degree of atrophy, whereas other known risk factors for muscle atrophy in an ICU were not. The largest decrease in thickness occurred during the first 72 hours of MV.
  
  
  CONCLUSIONS
  Diaphragm atrophy occurs quickly in mechanically ventilated patients and can accurately be monitored using ultrasound. Length of MV, as opposed to other variables, is associated with the degree of atrophy.
  
  
  BACKGROUND
  Clinicaltrials.gov NCT02299986 . Registered 10/11/2014.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, Antwerp University Hospital, University of Antwerp, Edegem, Belgium. tom.schepens@uza.be.
authors.forename: Tom
authors.initials: T
authors.lastname: Schepens
authors.affiliation: Department of Critical Care Medicine, Antwerp University Hospital and University of Antwerp, Edegem, Belgium. walter.verbrugghe@uza.be.
authors.forename: Walter
authors.initials: W
authors.lastname: Verbrugghe
authors.affiliation: Department of Critical Care Medicine, Antwerp University Hospital and University of Antwerp, Edegem, Belgium. karolien.dams@uza.be.
authors.forename: Karolien
authors.initials: K
authors.lastname: Dams
authors.affiliation: Department of Radiology, Antwerp University Hospital and University of Antwerp, Edegem, Belgium. bob.corthouts@uza.be.
authors.forename: Bob
authors.initials: B
authors.lastname: Corthouts
authors.affiliation: Department of Radiology, Antwerp University Hospital and University of Antwerp, Edegem, Belgium. paul.parizel@uza.be.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Parizel
authors.affiliation: Department of Critical Care Medicine, Antwerp University Hospital and University of Antwerp, Edegem, Belgium. philippe.jorens@uza.be.
authors.forename: Philippe G
authors.initials: PG
authors.lastname: Jorens
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003964:Diaphragm / Q000002:abnormalities* / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009133:Muscular Atrophy / Q000000981:diagnostic imaging* / Q000209:etiology; D012121:Respiration, Artificial / Q000009:adverse effects*; D014463:Ultrasonography; D055397:Ventilator-Induced Lung Injury / Q000473:pathology*