Canadian Journal of Anesthesia, Vol 16, 508-518, Copyright © 1969 by Canadian Anesthesiologists' Society

Simulated Subarachnoid Haemorrhage in Monkeys Under Pentobarbital-Halothane Anaesthesia, with Particular Reference to Monitoring During Cerebral Angiography

¹ Departments of Anaesthesia, Neurosurgery, and Radiology, Surgical Medical Research Institute, University of Alberta, Edmonton

There are at least four reported cases of subarachnoid haemorrhage taking place during a neuroradiologic procedure. It is of interest to consider what changes may be expected during subarachnoid haemorrhage under pentobarbitalhalothane anaesthesia with artificial ventilation. Experiments were performed on female Rhesus monkeys at varying temperatures and acid-base status. Parameters observed were lead 2 ecg, systemic arterial blood pressure, and csf pressure. Subarachnoid haemorrhage was simulated by injecting fresh autogenous blood through a needle the point of which was placed in a position in the midline about 0.75 cm anterior to the tuberculum sellae, dorsal to the planum sphenoidale. The conclusions reached were that under the conditions of the experiments the monitoring of csf pressure at the time of haemorrhage provides evidence of haemorrhage, but that this increase in pressure is of varying amount, and transient. Systemic arterial pressure changes are small. The sudden development of t-wave or st changes, nodal rhythm, or tachycardia from foci of impulse formation in the a-v node or ventricle in the absence of other causes can be accepted as evidence that subarachnoid haemorrhage has occurred, though the absence of obvious ecg changes apparently cannot permit the assumption that a haemorrhage has not occurred.

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Supported in part by MRC grant no. 2835.