General anaesthesia for neurosurgery.

Anaesthesia for neurosurgery, especially intracranial operations, requires conditions which maintain the perfusion of the brain with blood. This perfusion results from the cerebral perfusion pressure: the difference between the arterial and the intracranial pressures. Anaesthesia must also facilitate surgical access by reducing brain volume and minimizing surgical haemorrhage. Other common problems arising in the conduct of neurosurgical anaesthesia include the diagnosis of neurological damage and the treatment of haemorrhage during operation. In the past decade, anaesthetic techniques have evolved which are designed to provide the necessary conditions for intracranial surgery, and incorporate the physiological information gained from the wealth of research on the effects of anaesthetic drugs and techniques on intracranial pressure, cerebral blood flow and cerebral metabolism. Many reviews and monographs reflecting the current interest in neuroanaesthesia have appeared in recent years (for example Hunter, 1964; Bozza Marrubini, 1965; Gilbert, Brindle and Salindo, 1966; Michenfelder, Gronert and Rehder, 1969; McComish and Bodley, 1971; Smith and Wollman, 1972; Gordon, 1975; Shapiro, 1975a, b). The particular hazards of intracranial hypertension, and of intracranial vascular surgery, have been stressed, as these form special risk groups.