Withdrawal of mechanical ventilation in anticipation of death in the intensive care unit.

BACKGROUND

In critically ill patients who are receiving mechanical ventilation, the factors associated with physicians' decisions to withdraw ventilation in anticipation of death are unclear. The objective of this study was to examine the clinical determinants that were associated with the withdrawal of mechanical ventilation.

METHODS

We studied adults who were receiving mechanical ventilation in 15 intensive care units, recording base-line physiological characteristics, daily Multiple Organ Dysfunction Scores, the patient's decision-making ability, the type of life support administered, the use of do-not-resuscitate orders, the physician's prediction of the patient's status, and the physician's perceptions of the patient's preferences about the use of life support. We examined the relation between these factors and withdrawal of mechanical ventilation, using Cox proportional-hazards regression analysis.

RESULTS

Of 851 patients who were receiving mechanical ventilation, 539 (63.3 percent) were successfully weaned, 146 (17.2 percent) died while receiving mechanical ventilation, and 166 (19.5 percent) had mechanical ventilation withdrawn. The need for inotropes or vasopressors was associated with withdrawal of the ventilator (hazard ratio, 1.78; 95 percent confidence interval, 1.20 to 2.66; P=0.004), as were the physician's prediction that the patient's likelihood of survival in the intensive care unit was less than 10 percent (hazard ratio, 3.49; 95 percent confidence interval, 1.39 to 8.79; P=0.002), the physician's prediction that future cognitive function would be severely impaired (hazard ratio, 2.51; 95 percent confidence interval, 1.28 to 4.94; P=0.04), and the physician's perception that the patient did not want life support used (hazard ratio, 4.19; 95 percent confidence interval, 2.57 to 6.81; P<0.001).

CONCLUSIONS

Rather than age or the severity of the illness and organ dysfunction, the strongest determinants of the withdrawal of ventilation in critically ill patients were the physician's perception that the patient preferred not to use life support, the physician's predictions of a low likelihood of survival in the intensive care unit and a high likelihood of poor cognitive function, and the use of inotropes or vasopressors.