title: Association of myocardial ischemia with failure to wean from mechanical ventilation.
abstract: OBJECTIVE
  To determine if myocardial ischemia, as detected by continuous electrocardiographic monitoring, is correlated with continued ventilator dependence in patients who have had difficulties weaning from mechanical ventilation.
  
  
  METHODS
  A prospective, observational study.
  
  
  METHODS
  A university, tertiary care hospital.
  
  
  METHODS
  Seventeen medical and postsurgical patients (age 70 +/- 9 yrs; range 54 to 84) who had received mechanical ventilation for 5 to 67 days at the time of entry into the study.
  
  
  METHODS
  None.
  
  
  RESULTS
  Patients wore a calibrated, frequency-modulated, two-channel electrocardiographic recorder with two bipolar chest leads attached to exploring electrodes for 24 hrs. We recorded the following data: a) electrocardiographic evidence of myocardial ischemia; b) eventual separation from mechanical ventilation; c) whether the patient survived to be discharged from the hospital; d) duration of tracheal intubation and mechanical ventilation; and e) length of hospital stay. The key outcome variable tested was successful weaning, which was defined as breathing without mechanical ventilatory assistance on discharge from the hospital. Six (35%) of 17 patients had electrocardiographic evidence of myocardial ischemia at the time of entry into the study. The presence of ischemia was associated with failure to wean from mechanical ventilation (p < .05; relative risk 3.05).
  
  
  CONCLUSIONS
  Myocardial ischemia (as detected by a 24-hr, continuous Holter monitor) occurs frequently in ventilator-dependent patients. The occurrence of ischemia was associated with failure to wean from mechanical ventilation in this patient population.
authors.affiliation: Department of Anesthesia, Harvard Medical School, Massachusetts General Hospital, Boston, USA.
authors.forename: W E
authors.initials: WE
authors.lastname: Hurford
authors.forename: F
authors.initials: F
authors.lastname: Favorito
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003422:Critical Care; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications / Q000401:mortality / Q000503:physiopathology*; D011446:Prospective Studies; D012131:Respiratory Insufficiency / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D017211:Treatment Failure; D015300:Ventilator Weaning