Discontinuing mechanical ventilation: the role of a 'respiratory acute care unit'

摘要

The timing of discontinuing mechanical ventilation is important. Premature extubation of the trachea may lead to catastrophic complications such as the failure to re-establish an airway. More frequently, inability to sustain spontaneous ventilation manifests itself within 12 - 72 h and may be associated with hypoxemia, CO_2 narcosis, haemodynamic instability, and aspiration of gastric contents. Conversely, unnecessary prolongation of mechanical ventilation is associated with an increased chance of development of nosocomial pneumonia and of laryngeal damage. Hence, the appropriate timing of tracheal extubation is the subject of debate both at the patient's bedside and in a number of clinical investigations. In the present review, we will first examine some of the studies looking at strategies of weaning from mechanical ventilation. We will then look at the problem of the patient with prolonged acute respiratory failure (ARF), its principal physiological issues, possible treatment approaches, and the use of a dedicated respiratory acute care unit.