Abstract

The dangers of mechanical ventilation make it critical to wean patients at the earliest time possible. However, premature weaning trials trigger significant respiratory distress, which can cause setbacks in a patient's clinical course. Premature extubation is also a known risk. To reduce delayed weaning and premature extubation, a three-step diagnostic strategy has been suggested: 1) measurement of weaning predictors; 2) a trial of unassisted breathing (T-tube trial); and 3) a trial of extubation. It is imperative not to defer this first step by waiting for a more difficult diagnostic test, such as a T-tube trial. To increase the likelihood that a patient will tolerate extubation, a positive result on a screening test (weaning predictor test) is followed by a confirmatory test (weaning trial). Many difficult aspects of pulmonary pathophysiology encroach on weaning management. Accordingly, weaning commands sophisticated individualised care. Few other responsibilities of an intensivist require a more analytical effort and carry more promise for improving a patient's outcome than the application of physiological principles in the weaning of patients.