Arterial pCO₂ Effect at Various Levels of Intracranial Pressure

Abstract

Although hyperventilation has long been known to reduce intracranial pressure, the limits of application are still not defined. As early as 1894, Mosso [1] reported that hyperventilation reduced the tension of the brain in 2 patients with skull defects. Hyperventilation has long been used for brain relaxation during surgery. Recent reports have stated beneficial effects from a lowered arterial partial pressure of carbon dioxide (pCO₂) in patients with head injuries [2, 3]. Some have cautioned the use of hyperventilation because of the possible danger of reduced cerebral blood flow [4, 5]. Also, patients in certain stages of decompensation are known not to respond to reduction in arterial pCO₂ [6]. This study was undertaken to further define the effect of varying arterial pCO₂ at various base levels of intracranial pressure.

Supported by a gift of Mrs. Arvella Bentley to the neurosurgical research fund.