Liberation from Mechanical Ventilation in Acutely Brain-injured Patients

Endotracheal intubation and mechanical ventilation are required for the majority of critically ill patients suffering from acute brain injury. While these patients certainly may develop cardiopulmonary complications, many of them receive mechanical ventilation because of a decreased level of consciousness and subsequent inability to protect the airway and clear secretions, rather than because of primary respiratory failure. Indeed in a large observational study of mechanical ventilation practices around the world, coma was the primary reason for initiation of ventilatory support in close to 20% of cases [1]. In addition, many brain-injured patients will need ventilatory support as part of the management of raised intracranial pressure (ICP) [2]. For example, severe stroke patients may not have underlying respiratory insufficiency but up to 25% of them require mechanical ventilation [3]. Like all patients receiving invasive ventilation, patients with acute brain injury are at risk of complications including airway injury and ventilator-associated pneumonia (VAP); as usual our goal is to discontinue ventilatory support as soon as it is safe to do so. However, the approach to weaning and discontinuation of mechanical ventilation in this patient population remains a challenge to clinicians as these patients have been understudied and because the usual cardiopulmonary markers of liberation readiness may not be applicable. In this chapter, we will discuss what is currently known about weaning and discontinuation from mechanical ventilation, as well as tracheostomy, in brain-injured patients.