Mechanical ventilation in traumatic brain injury

Abstract

Mechanical ventilation is frequently required in the management of brain-injured patients. Common indications include pulmonary contusions, acute respiratory distress syndrome, neurogenic pulmonary edema, pneumonia, fluid overload, airway compromise from depressed mental status, and need for sedatives to facilitate procedures and control intracranial pressure. Cautious management of mechanical ventilation is required to avoid secondary injury from hypoxemia, hypo-or hypercarbia, or decreases in cerebral perfusion pressure. Optimal ventilator management utilizes a “lung protective " strategy that emphasizes adequate positive end expiratory pressure in concert with low tidal volumes and plateau pressures to prevent ventilator-induced lung injury. This strategy can be safely applied in the majority of brain-injured patients. Patients with concurrent severe acute respiratory distress syndrome and traumatic brain injury present a significant therapeutic challenge, as it may be difficult to maintain adequate oxygenation and an appropriate carbon dioxide level without injurious ventilator settings. Strategies that have been successfully applied in this patient population include airway pressure release ventilation, prone positioning, and extracorporeal lung support techniques, although none of these methods have been validated in prospective trials in this specific population.