Hyperventilation in neurological patients

Purpose of review Hyperventilation is commonly used in neurological patients to decrease elevated intracranial pressure (ICP) or relax a tense brain. However, the potentially deleterious effects of hyperventilation may limit its clinical application. The aim of this review is to summarize the physiological and outcome evidence related to hyperventilation in neurological patients. Recent findings Physiologically, hyperventilation may adversely decrease cerebral blood flow (CBF) and the match between the cerebral metabolic rate and CBF. In patients with severe traumatic brain injury (TBI), prolonged prophylactic hyperventilation with arterial carbon dioxide tension (PaCO2) less than 25 mmHg or during the first 24 h after injury is not recommended. Most patients (>90%) with an aneurysmal subarachnoid hemorrhage undergo hyperventilation (PaCO2