General care of mechanically ventilated pts is reviewed in Chap. 4. Principles of Critical Care Medicine, along with weaning from mechanical ventilation. A cuffed endotracheal tube is often used to provide positive pressure ventilation with conditioned gas. A protective ventilation approach is generally recommended, including the following elements: (1) target tidal volume of ~6 mL/kg of ideal body weight; (2) avoid plateau pressures >30 cm H₂O; (3) use the lowest fraction of inspired oxygen (FIO₂) to maintain arterial oxygen saturation ≥90%; and (4) apply PEEP to maintain alveolar patency while avoiding overdistention. This approach may result in a permissible degree of hypercapnia. After an endotracheal tube has been in place for an extended period of time, tracheostomy should be considered, primarily to improve pt comfort, reduce needs for sedative medications, and provide a more secure airway. No absolute time frame for tracheostomy placement exists, but pts who are likely to require mechanical ventilatory support for >2 weeks should be considered for a tracheostomy.

A variety of complications can result from mechanical ventilation. Barotrauma—overdistention and damage of lung tissue—can cause pneumomediastinum, subcutaneous emphysema, and pneumothorax. Ventilator-related pneumothorax typically requires treatment with tube thoracostomy. Ventilator-associated pneumonia is a major complication in intubated pts; common pathogens include Pseudomonas aeruginosa and other gram-negative bacilli, as well as Staphylococcus aureus.