Weaning from ventilatory support.

PURPOSE OF REVIEW

In intubated patients, mechanical ventilation offers essential ventilatory support, while the respiratory system recovers from acute respiratory failure. Yet, invasive mechanical ventilation is associated with risks and complications that prolong the duration of mechanical ventilation and increase the risk for death. Therefore, safely weaning the patient from the ventilator as soon as possible is paramount. Recent randomized trials have addressed a number of key areas of interest.

RECENT FINDINGS

Determining readiness for spontaneous breathing, the first step in weaning, is best achieved using liberal oxygenation criteria; does not require routine use of weaning predictors; and can be conducted, in certain patient populations, using protocols driven by respiratory therapists or ICU nurses. Spontaneous breathing trials can be conducted on low levels of pressure support, continuous positive airway pressure, or T-piece. Weaning failure often results from an imbalance between respiratory load and capacity. There is increasing appreciation that cardiac dysfunction can limit weaning. Recent randomized trials suggest that noninvasive ventilation (in patients with chronic obstructive pulmonary disease) and computer-driven approaches show promise as weaning strategies. New techniques have been employed to identify patients at increased risk for extubation failure. Noninvasive ventilation, when used in high-risk patients, can decrease extubation failure.

SUMMARY

Weaning from mechanical ventilation continues to be an area of considerable importance. Recent randomized controlled trials provide high-level evidence for the best approaches to weaning and extubation.