The Effect of Nitrous Oxide and Halothane Upon the Intracranial Pressure in Hypocapnic Patients With Intracranial Disorders

Abstract

In nine patients with severe intracranial disease causing increased intracranial pressure (ICP), the effects on ICP and cerebral perfusion pressure (CPP) of the following manoeuvres were studied: (1) endotracheal intubation, (2) addition of 50% nitrous oxide to the inspired gas after hyperventilation with oxygen and thereafter (3) addition of halothane to the nitrous oxide/oxygen mixture. The mean "peak" increase in ICP during endotracheal intubation was 16.6 mm Hg. Critically small CPP values were prevented by an increase in arterial pressure. Nitrous oxide caused only a minor increase in ICP. Halothane caused a mean increase in ICP of 7.6 mm Hg and critically small CPP values in three patients.

Nitrous oxide is a potent cerebrovasodilator in humans when added to isoflurane. A transcranial Doppler study

“…Nitrous oxide is an almost universal component of anesthesia including neuroanesthesia. Its use for neurosurgical procedures, however, has been repeatedly questioned (3, 4); there is accumulating evidence that nitrous oxide increases CBF (5,6), cerebral blood volumc (7) and intracranial pressure (ICP) (8,9) in susccptible patients. Many investigations have focused on the role of nitrous oxide as a cerebrovascular dilatator.…”

¿Anestesia halogenada o anestesia total endovenosa en neurocirugía?

“…La magnitud de los cambios en la fisiología cerebral es afectada por la administración concomitante de otros anestésicos, de manera que, asociado a la anestesia con barbitúricos, opioides, benzodiacepinas y propofol, se han reportado mínimos incrementos en FSC, mientras que la administración concomitante con anestésicos volátiles produce un aumento sustancial del FSC. En general no confiere beneficios adicionales en este escenario, por lo cual su uso es desaconsejado para los procedimientos neuroquirúrgicos [37], [38], [39], [40], [41].…”