Abstract
In six patients of total aortic arch replacement, we evaluated the cerebral oxygen dynamics under unilateral carotid perfusion by means of near infra-red spectrophotometry (NIRS). Alteration of total, oxygenated and deoxygenated homoglobin concentration in cerebral tissue were estimated by measuring the reflectance of rediated three different wavelengths of near infra-red light. Probes of NIRS were fixed on the left forehead of the patient. Cerebral low perfusion pattern (decresed oxygenated and increased deoxygenated hemoglobin) was observed in all patients. Three out of the six patients revealed progression of this change (group S) and others revealed balance of the change (group M). Mean perfusion rate was 6.7ml/kg/min in group S and 7.2ml/kg/min in group M. Mean rectal temperature of group S and M were 28.4 and 26.0°C and mean arterial blood temperature were 34.4 and 25.7°C respectively.
There was no statistical difference in these parameters but arterial blood temperature of group S was relatively higher than group M. According to these result, unilateral carotid perfusion under relatively high arterial blood temperature lead to progressive cerebral ischemia. NIRS is a simple, non-invasive and sensitive monitor of cerebral oxygen dynamics and we could present the suitable conditions of unilateral carotid perfusion by NIRS measurement.
