Common carotid blood temperature

¹ Department of Medicine, Stanford University School of Medicine, Stanford; and Departments of Clinical Physiology and Neurosurgery, Community Hospital of San Mateo County, San Mateo, California

Common carotid artery blood temperature was measured by means of a needle thermistor in seven subjects under thiopental-nitrous oxide anesthesia. In each subject the blood temperature was within 0.2°C of the oral temperature. In the one subject so tested, the breathing of air chilled to 4°C had no effect on the common carotid blood temperature. In four out of five subjects the common carotid artery temperature was lowered (0.2°–0.5°C) by applying cold packs to the homolateral side of the anterior aspect of the face and forehead for 5–20 minutes. In the fifth subject there was no change. The probable mechanism of this cooling is heat exchange between the artery and the internal jugular vein which drains the chilled structures through the common facial vein. Rewarming the face and forehead had no significant effect on the common carotid blood temperature.