title: Differences in clinical outcomes according to weaning classifications in medical intensive care units.
abstract: BACKGROUND
  Although the weaning classification based on the difficulty and duration of the weaning process has been evaluated in the different type of intensive care units (ICUs), little is known about clinical outcomes and validity among the three groups in medical ICU. The objectives of this study were to evaluate the clinical relevance of weaning classification and its association with hospital mortality in a medical ICU with a protocol-based weaning program.
  
  
  METHODS
  All consecutive patients admitted to the medical ICU and requiring mechanical ventilation (MV) for more than 24 hours were prospectively registered and screened for weaning readiness by a standardized weaning program between July 2010 and June 2013. Baseline characteristics and outcomes were compared across weaning classifications.
  
  
  RESULTS
  During the study period, a total of 680 patients were weaned according to the standardized weaning protocol. Of these, 457 (67%) were classified as simple weaning, 136 (20%) as difficult weaning, and 87 (13%) as prolonged weaning. Ventilator-free days within 28 days decreased significantly from simple to difficult to prolonged weaning groups (P < 0.001, test for trends). In addition, reintubation within 48 hours after extubation (P < 0.001) and need for tracheostomy during the weaning process (P < 0.001) increased significantly across weaning groups. Finally, ICU (P < 0.001), post-ICU (P = 0.001), and hospital (P < 0.001) mortalities significantly increased across weaning groups. In a multiple logistic regression model, prolonged weaning but not difficult weaning was still independently associated with ICU (adjusted OR 8.265, 95% CI 3.484-19.605, P < 0.001), and post-ICU (adjusted OR 3.180, 95% CI 1.349-7.497, P = 0.005), and hospital (adjusted OR 5.528, 95% CI 2.801-10.910, P < 0.001) mortalities.
  
  
  CONCLUSIONS
  Weaning classification based on the difficulty and duration of the weaning process may provide prognostic information for mechanically ventilated patients who undergo the weaning process.
authors: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Byeong Ho
authors: BH
authors: Jeong
authors: Intensive Care Unit Nursing Department, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Myeong Gyun
authors: MG
authors: Ko
authors: Intensive Care Unit Nursing Department, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Jimyoung
authors: J
authors: Nam
authors: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Hongseok
authors: H
authors: Yoo
authors: Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Chi Ryang
authors: CR
authors: Chung
authors: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Gee Young
authors: GY
authors: Suh
authors: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Kyeongman
authors: K
authors: Jeon
mesh_terms: D000368:Aged; D005260:Female; D006761:Hospitals; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D009026:Mortality; D010100:Oxygen / Q000008:administration & dosage; D012121:Respiration, Artificial / Q000379:methods*; D012131:Respiratory Insufficiency / Q000401:mortality / Q000628:therapy*; D016896:Treatment Outcome; D015300:Ventilator Weaning / Q000379:methods*
chemical_list: D010100:Oxygen