A 58-year-old hypertensive man is evaluated in the emergency department after being found on the floor in his home with left hemiparesis, a left frontotemporal scalp laceration, and somnolence. Because the patient does not remember the onset of symptoms and the mechanism of injury is uncertain, a rigid cervical collar is placed by emergency medical services in the field. Computed tomography (CT) of the head demonstrates a right thalamic intracerebral and intraventricular hemorrhage involving the right lateral and third ventricles. There is no skull fracture, cervical spine injury, or gross cervical misalignment. Initially, he is interactive and speaks clearly. The blood pressure is rapidly controlled, and preparations are made for transfer to the intensive care unit (ICU). But before transfer occurs he becomes progressively obtunded, with a symmetric increase in bilateral lower-extremity tone. He begins to struggle with respiration, making grunting sounds and activating accessory muscles on inspiration. It is not known when he last ate, and examination of the oropharynx reveals a blunted gag reflex and weak cough.
Does this patient need to be intubated?
Yes, for several reasons. He is in a period of acute neurologic decline, with an inadequate airway to provide for oxygenation and ventilation. He has dangerously dulled airway protective reflexes and could have a full stomach, putting him at risk for large-volume gastric aspiration. He will require an urgent invasive procedure (ventriculostomy placement), will be transported between units, and will undergo further imaging studies, requiring flat positioning on the bed. All of these factors suggest he should be intubated. Of interest is that a patient with the same neurologic examination can sometimes be safely extubated in the recovery period—safely monitored in an ICU, with no procedures or transfers planned, an empty stomach, and no clinical decline anticipated.
Neurocritical care patients include trauma victims with facial or cervical spinal injuries and patients in whom bleeding, seizures, or anatomic complications may cause progression from a state of relative stability to brain herniation and/or cardiopulmonary arrest in a matter of minutes. Furthermore, hypoxemia, hypoventilation, and hyperventilation are all powerful mediators of cerebral blood flow and tissue perfusion, so maintenance of a state of respiratory homeostasis is critical to preventing secondary brain injury.
Finally, aspiration before or during intubation can lead to fever, pneumonia, acute respiratory distress syndrome, and systemic inflammation, each associated with worse neurologic outcomes and increased mortality rate. These concerns, which suggest that intubation may be required for many acutely ill neurology patients, are balanced by the principles of preserving an accurate neurologic examination and avoiding the complications of intubation whenever possible.
Indications for endotracheal intubation in the neurocritically ill are often categorized according to three general criteria1:
Failure to maintain or protect the airway
Failure of oxygenation or ventilation
An anticipated course of clinical deterioration
These principles are discussed further below.