Ventilación mecánica en el paciente con lesión cerebral aguda / Mechanical ventilation in patients with acute brain injury

ABSTRACT

In about20 percent of patients admitted to an Intensive Care Unit (ICU) the indica-tion of mechanical ventilation (MV) is a neurological disease. These patients have a prolonged MV stay and high mortality. The appropriate use of MV in patients with acute brain injury (ABI) is critica! considering that MV by itself is oble to induce or worsen an underlying lung injury. Patients with ABI have a higher risk to develop pulmonary complications. During endotracheal intubation the activation of airway reflexes should beprevented, because they may increase intracranialpressure. Tracheostomy is indicated to improve airway management and it is performed in about 33 percent of these patients. Indications for MV are loss of spontaneous respira-tory effort, changes in lung compliance, gas exchange impairment and ventilatory failure due to muscle fatigue or neuromuscular junction dysfunction. During MV, hypoxemia should be avoided. The pC0(2) level has a critica! role in cerebral blood flow regulation; therefore a normal pCO must be maintained in order to guarantee an optimal cerebral blood flow. Despite that, hypocapnia has been used in patients with increased intracranial pressure, at the present it is not recommended. Its use should be limited to the emergency management of intracranial hypertension, while the underlying cause is beingtreated. Non-conventional ventilatory modes asprone position ventilation, high-frequency oscillatory ventilation and extracorporeal C02 removal can be used in patients with ABI. All ofthem have specific risks and should be employed cautiously This paper reviews upper airway management and MV in patients with acute brain injury.