Hyperventilation in neurosurgery.

An outline of the nature and varieties of hyperventilation is presented together with a discussion on the role of artificial hyperventilation in the management of neurosurgical patients. Attention is called to the value of gasometric investigations in the ventricular cerebrospinal fluid for evaluation of disturbances in pH of the intracranial environment and possible effectiveness of hyperventilation. The results of our measurements of cerebrospinal fluid pressure are presented in 21 cases of supratentorial cerebral tumours in which controlled ventilation with hyperventilation was conducted. In 19 cases, the cerebrospinal fluid pressure fell by a mean of 44.3% with a simultaneous fall of PaCO2 by 29.3%. In the conclusions the authors stress the role of hyperventilation in the lowering of raised cerebrospinal fluid pressure and prevention of cerebral oedema.