Factors associated with withdrawal of mechanical ventilation in a neurology/neurosurgery intensive care unit

Objective, The objective of this study was to identify factors associated with the decision to withdraw mechanical ventilation from patients in a neurology/neurosurgery intensive care unit. Specifically, the following factors were considered: the severity of the neurologic illness, the healthcare delivery system, and social factors. Design., Retrospective analysis of prospectively collected clinical database. Setting. Neurology/neurosurgery intensive care unit of a large academic tertiary care hospital. Patients: Patients were 2,109 nonelective admissions to the neurology/neurosurgery intensive care unit who received mechanical ventilation over a period of 82 months. Interventions: None. Measurements and Main Results: The average age was 56 +/- 19.7 yrs, 53% were male, and 81% were functionally normal before admission. The median Glasgow Coma Scale score was 14, the average Acute Physiology and Chronic Health Evaluation 11 severity of illness score was 13.5 +/- 8.3, and probability of death was 18.2 +/- 22.0%. Mechanical ventilation was withdrawn from 284 (13.5%). Factors that were independently associated with withdrawal of mechanical ventilation were as follows: more severe neurologic injury [admission Glasgow Coma Scale score (odds ratio 0.86/point, confidence interval 0.82-0.90), diagnosis of subarachnoid hemorrhage (odds ratio 2.44, confidence interval 1.50-3.99), or ischemic stroke (odds ratio 1.72, confidence interval 1.13-2.60)], older age (odds ratio 1.04/yr, confidence interval 1.03-1.05), and higher Acute Physiology and Chronic Health Evaluation 11 probability of death (odds ratio 1.03/%, confidence interval 1.02-1.04). Mechanical ventilation was less likely to be withdrawn if patients were African-American (odds ratio 0.50, confidence interval 0.36-0.68) or had undergone surgery (odds ratio 0.44, confidence interval 0.2-0.67). Marital status, premorbid functional status, clinical service (neurology vs. neurosurgery), attending status (private vs. academic), and type of health insurance were not associated with decisions to withdraw mechanical ventilation. Conclusions: We conclude that decisions to withdraw mechanical ventilation in the neurology/neurosurgery intensive care unit are based primarily on the severity of the acute neurologic: condition and age but not on characteristics of the healthcare delivery system. Care is less likely to be withdrawn from African-American patients or those who had surgery.