title: Weaning chronically critically ill adults from mechanical ventilatory support: a descriptive study.
abstract: BACKGROUND
  Ventilator-dependent patients average 11,419 daily in US acute care hospitals.
  
  
  OBJECTIVE
  To describe the process of ventilatory weaning among chronically critically ill adults. METHODS A retrospective survey was used to study ventilator-dependent adults enrolled in a larger randomized study. Patients records were used to obtain duration of mechanical ventilatory support, success of weaning, serum albumin level, left ventricular function, number of drugs used to treat heart failure, and 24-hour fluid balance. Data were collected on admission to the intensive care unit; 24 hours after initiation of mechanical ventilation; and 7 days before, and on the day of, weaning status determination.
  
  
  RESULTS
  Of 174 subjects, 120 were weaned from mechanical ventilation. There were no differences in maximum inspiratory pressure, minute ventilation, or ventilatory capacity between successful and unsuccessful candidates. There were differences in serum albumin level, rapid shallow breathing index, fraction of inspired oxygen, and 24-hour fluid balance. Among subjects who were weaned, the duration of mechanical ventilation was significantly longer in those with left ventricular dysfunction (n = 53; 29.1 +/- 25.2 days) than in those with normal left ventricular function (n = 67; 21.1 +/- 18.1 days). Subjects who were weaned received a greater number of drugs to treat heart failure (1.46 +/- 1.24) than did those who were not (0.77 +/- 1.04). CONCLUSIONS Many weaning parameters do not differentiate patients able to be weaned from those who are unable. The presence of left ventricular dysfunction, number of drugs used to treat heart failure, serum albumin level, and 24-hour fluid balance were associated with weaning success and/or duration of mechanical ventilation in adults requiring prolonged mechanical ventilation.
authors.affiliation: University of Pittsburgh, Pa, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Clochesy
authors.forename: B J
authors.initials: BJ
authors.lastname: Daly
authors.forename: H D
authors.initials: HD
authors.lastname: Montenegro
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002303:Cardiac Output, Low; D016009:Chi-Square Distribution; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D015588:Observer Variation; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D012709:Serum Albumin / Q000378:metabolism; D013997:Time Factors; D016896:Treatment Outcome; D015300:Ventilator Weaning; D016277:Ventricular Function, Left; D014882:Water-Electrolyte Balance
chemical_list: D012709:Serum Albumin