title: Cardiac vagal tone predicts outcome in neurosurgical patients.
abstract: OBJECTIVE
  To evaluate the relationship between presurgical levels of cardiac vagal tone and outcome in neurosurgical patients.
  
  
  METHODS
  Prospective series.
  
  
  METHODS
  Respiratory ICU in a university hospital.
  
  
  METHODS
  Fifty-one adults admitted to the respiratory ICU between 1982 and 1985. Forty-two patients were scheduled for elective neurosurgery, and nine patients suffered from head trauma.
  
  
  METHODS
  Ten minutes of electrocardiographic (EKG) data were recorded before medical intervention. Neurosurgical patients scheduled for surgery had EKG data recorded 24 hrs before their operation. Trauma patients had EKG data recorded immediately after arrival in the respiratory ICU.
  
  
  RESULTS
  Cardiac vagal tone was evaluated using a vagal tone index, quantified from the EKG. Cardiac vagal tone monitored before surgical intervention significantly distinguished between the outcome groups only for the elective neurosurgical patients. Age, gender, heart rate, Glasgow Coma Scale scores, and tumor location, size, and malignancy were not related to outcome in the elective neurosurgery group. However, within the trauma group, low Glasgow Coma Scale scores were significantly related to poor outcome.
  
  
  CONCLUSIONS
  Cardiac vagal tone may offer important predictive value by alerting the physician to the functional consequence of head injury. Information relating to autonomic nervous system functioning, such as the vagal tone index used in this study, may provide additional information that will complement the computed tomography scan results. This study demonstrates that the vagal tone index is a predictive factor that may be efficiently extracted from the heart rate pattern routinely monitored in ICUs.
authors.affiliation: Department of Anesthesia, Hadassah University Hospital, Jerusalem, Israel.
authors.forename: Y
authors.initials: Y
authors.lastname: Donchin
authors.forename: S
authors.initials: S
authors.lastname: Constantini
authors.forename: A
authors.initials: A
authors.lastname: Szold
authors.forename: E A
authors.initials: EA
authors.lastname: Byrne
authors.forename: S W
authors.initials: SW
authors.lastname: Porges
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001930:Brain Injuries / Q000503:physiopathology / Q000601:surgery*; D001932:Brain Neoplasms / Q000601:surgery*; D004562:Electrocardiography; D005260:Female; D015600:Glasgow Coma Scale; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011184:Postoperative Period; D011446:Prospective Studies; D014630:Vagus Nerve / Q000502:physiology*