Weaning from Mechanical Ventilation: Which Weaning Test for Critically Ill Patients?

Abstract

Decision making process aiming at separate patients from mechanical ventilation relies with others issues, on the interpretation of patient’s clinical tolerance during a weaning attempt, so-called spontaneous breathing trial. Several modalities of spontaneous breathing trial are available for clinicians (T piece, minimal pressure support with/without positive end expiratory pressure, no pressure support, no positive end expiratory pressure). From a physiological point of view, T piece reflects better spontaneous breathing without assistance as compared to others methods and ventilation without any support seems equivalent. Any support provided by modern ventilators underestimates work of breathing. In a non-selected population where the weaning success probability is high, the choice of the first spontaneous breathing trial modality takes into account several issues (feasibility, decision not to underestimate the probability success). In a population selected by a first weaning attempt failure, it is logical to repeat further trial with T piece (or without ventilatory support) in order to avoid underestimation of a potential next failure.