Decreased oxygen concentration in the blood, hypoxia, and increase in the carbon dioxide concentration in the blood, hypercapnia, are potent vasodilators in the cerebral vasculature, and should be avoided in those with cerebral edema. It is recommended that persons with decreased levels of consciousness be intubated for airway protection and maintenance of oxygen and carbon dioxide levels. However, the laryngeal instrumentation involved in the intubation process is associated with a acute, brief rise in intracranial pressure. Pretreatment with a sedative agent and neuromuscular blocking agent to induce unconsciousness and motor paralysis has been recommended as part of standard Rapid Sequence Intubation (RSI). Intravenous lidocaine prior to RSI has been suggested to reduce the rise in ICP but there is no supporting data at this time.