The Role of Noninvasive Mechanical Ventilation in Facilitating Weaning and Extubation

Abstract

As correctly stated recently,“the physician should distinguish between liberation (no need for the ventilator) and extubation (no need for endotracheal tube),” so that after a patient has successfully undergone a trial of unassisted breathing, a second judgment must be made about whether the artificial airway is still required [1]. The term “weaning success” should, in our opinion, be used only after both of the two conditions have been met. Another crucial point in the definition of weaning success, never systematically addressed, is the minimum time a patient must remain disconnected from a ventilator in order to be considered “weaned”. If we considered weaning from mechanical ventilation purely as a matter of numbers, we could easily conclude that it is not a major clinical problem, since about 75%–80% of patients admitted to an ICU and mechanically ventilated because of acute respiratory failure resume spontaneous breathing quite easily [2, 3]. The presence of a respiratory disorder is, however, strongly associated with mechanical ventilation lasting longer than 15 days [4]. Once these chronically ill patients have recovered from the most acute phase of their critical illness, they are still likely to require intensive nursing and/or physiotherapy for several weeks before they can be weaned [5]. In one study these “chronically critically ill” patients, representing only 3% of the total number of patients admitted to the ICUs, used almost 40% of the total patient days of care [6]. Endotracheal intubation and invasive mechanical ventilation are often accompanied by complications that carry their own morbidity and mortality. Long-term sequelae may develop after complications directly related to intubation, while the possible need for heavy sedation or curarization during the first few days of ventilation may lead to generalized myopathy [7].