Weaning from mechanical ventilation

Use of mechanical ventilation is associated with several major complications despite its lifesaving potential. Timely discontinuation of mechanical ventilation is critical to control of duration of intensive care unit stay and reduction of complications associated with mechanical ventilation. Difficulty in discontinuation (or weaning) of patients from mechanical ventilatory support is in part attributable to inadequate understanding of the mechanisms responsible for unsuccessful outcome and a lack of guidelines regarding the optimal approach to the process of discontinuation of mechanical ventilation. For the first time, results from prospective, randomized, multicenter trials are available comparing common means of discontinuation of mechanical ventilation. In addition, the physiologic basis for a weaning strategy in mechanical ventilation is also coming into better focus. Two recent trials of weaning suggest different optimal modes, one favoring T-piece trials and the other supporting the use of pressure support ventilation. In either case, the above weaning techniques appear to be superior to intermittent mandatory ventilation in separating patients from mechanical ventilatory support. Based on available clinical trials, pressure support ventilation or T-piece trials appear to be the preferred methods for discontinuation of mechanical ventilatory support. A method using a simple T-piece trial technique is described.