The Utility of Tracheal Temperature Monitoring

Abstract

Tracheal temperature--the temperature of the tracheal wall--is believed to reflect the core temperature. The trachea reacts quickly to temperature changes because it is surrounded by various large arteries and veins. Using the blood temperature from the cardiopulmonary bypass (CPB) and the jugular vein temperature as standards for core temperature, we evaluated the utility of monitoring the tracheal temperature during cardiac surgery. The tracheal temperature was measured by a thermistor which was attached to the anterior inner surface of the cuff of a tracheal tube. The tracheal temperature had correlation coefficients more than 0.99 with both blood temperature from the CPB (r = 0.993, P < 0.001) and jugular vein temperature (r = 0.993, P < 0.001) during CPB. Because the blood from the CPB draining into the ascending aorta and the jugular vein temperature might reflect the hypothalamic temperature directly, the tracheal temperature, which correlates with both of these quite closely, may reflect the core value directly. The monitoring of the tracheal temperature is not only valuable in monitoring the core value, but is also convenient during general anesthesia.

Comparison of distal oesophageal temperature with “deep” and tracheal temperatures

“…The critical innovation in tracheal temperature monitoring was to position the temperature sensor on the tracheal cuff periphery, thus keeping it in continuous contact with tracheal tissue while simultaneously shielding it from the cooling effects of tracheal gases. 21 In the absence of respiratory gas heating and humidification, and at the 6 L.min -l fresh gas flow rate used in our analysis, the accuracy of tracheal temperature was relatively poor whereas precision was adequate. Our data suggest that tracheal temperatures may not be an adequate substitute for conventional core-temperature monitoring sites.…”

The Usefulness of an Earphone-Type Infrared Tympanic Thermometer for Intraoperative Core Temperature Monitoring

“…Although measurements of those temperatures have been reported to be reliable for core temperature monitoring (14), it is difficult to follow sudden core temperature changes by such measurements (15) and, therefore, these measurements are not reliable in the case of malignant hyperthermia or sudden decline in body temperature. Rectal or bladder measurements are even less reliable during lower abdominal surgery because they are influenced by operating room temperature (11).…”

Deep temperature monitoring using a zero-heat-flow method

“…On the other hand, in patients undergoing cardiac surgery with CPB [20] or with malignant hyperthermia, in which the body temperature can change very quickly (at a rate of more than 1.0°C·30 min Ϫ1 ), deep temperature monitoring does not seem to be as reliable as measurement of the blood temperature from the CPB or jugular vein temperature.…”