Perioperative Intracranial Hypertension in Patients with Supratentorial Tumors: Role of CBF Changes vs Importance of Mass Effect
Intracranial hypertension is a well-recognized complication in the perioperative management of patients with malignant supratentorial brain tumors of every cell-type, and this always is a serious concern with regard to optimal anesthetic care (Bedford et al. 1982). The compromised intracranial compliance caused by these tumors could be based on at least two possible mechanisms. One possibility is that the tumor causes an expanding mass lesion that gradually exhausts the pressure-volume reserves of the cranial compartment such that a relatively small increase in cerebral blood volume within normal brain can produce a large increase in ICP. An alternative possibility is that impaired cerebrovascular reactivity in the tumor mass might result in large increases in cerebral blood flow and consequent intracranial hypertension whenever arterial blood pressure or CO2 tension increases. To our knowledge the relative role of these two possible mechanisms for intracranial hypertension have not been studied in a systematic fashion, although both are often invoked whenever ICP problems are discussed in managing malignant supratentorial tumors.