Tetsuhiro Sone

“Deep-forehead” temperature correlates well with blood temperature

Purpose: To evaluate the accuracy and precision of “deep-forehead” temperature with rectal, esophageal, and tympanic membrane temperatures, compared with blood temperature.Methods: We studied 41 ASA physical status 1 or 2 patients undergoing abdominal and thoracic surgery scheduled to require at least three hours. “Deep-forehead” temperature was measured using a Coretemp® thermometer (Terumo, Tokyo, Japan). Blood temperature was measured with a thermistor of a pulmonary artery. Rectal, tympanic membrane, and distal esophageal temperatures were measured with thermocouples. All temperatures were recorded at 20 min intervals after the induction of anesthesia. We considered blood temperature as the reference value. Temperatures at the other four sites were compared with blood temperature using correlation, regression, and Bland and Altman analyses. We determined accuracy (mean difference between reference and test temperatures) and precision (standard deviation of the difference) of 0.5°C to be clinically acceptable.Results: “Deep-forehead” temperature correlated well with blood temperature as well as other temperatures, the determination coefficients (r2) being 0.85 in each case. The bias for the “deep-forehead” temperature was 0.0°C which was the same as tympanic membrane temperature and was smaller than rectal and esophageal temperatures. The standard deviation of the differences for the “deep-forehead” temperature was 0.3°C, which was the same as rectal temperature.Conclusions: We have demonstrated that the “deep-forehead” temperature has excellent accuracy and clinically sufficient precision as well as other three core temperatures, compared with blood temperature.RésuméObjectif: Évaluer l’exactitude et la précision de la température frontale «cutanée profonde» et les températures rectale, œsophagienne et tympanique, comparées à la température du sang.Méthode: L’étude a porté sur 41 patients d’état physique ASA I ou II devant subir une intervention chirurgicale abdominale et thoracique d’au moins deux heurs. La température «cutanée profonde» a été mesurée à l’aide du thermomètre Coretemp® (Terumo, Tokyo, Japon). Celle du sang a été prise avec une thermistance d’une artère pulmonaire et les températures rectale, tympanique et œsophagienne distale, avec des thermocouples. Elles ont toutes été enregistrées à 20 min d’intervalle après l’induction de l’anesthésie. La température du sang a servi de référence. Les températures des quatre autres sites ont été comparées avec celle du sang à l’aide d’analyses de corrélation, de régression et des analyses de Bland et Altman. Nous avons reconnu une exactitude (différence moyenne entre la température de référence et les autres) et une précision (écart type de la différence) de 0,5 °C près comme une différence acceptable en clinique.Résultats: La température «cutanée profonde» était en corrélation avec celle du sang, et avec celle des autres sites, le cofficient de détermination (r2) étant de 0,85 dans chaque cas. Le biais de la température «cutanée profonde» était de 0,0 °C, comme celui de la température tympanique, et plus faible que ceux des températures rectale et œsophagienne. L’écart type de la différence pour la température «cutanée profonde» était de 0,3 °C, comme pour la température rectale.Conclusion: Nous avons démontré que la température frontale pronfonde présentait une grande exactitude et une précision utile suffisante, autant que les trois autres températures centrales, comparée à la température du sang.

Thyroid Storm Due to Functioning Metastatic Thyroid Carcinoma in a Burn Patient

Thyroid storm as a result of functioning metastatic thyroid carcinoma is exceedingly rare. 1 We describe a patient with functioning distant metastases from adenocarcinoma of the thyroid in whom thyroid storm developed in the course of care for extensive burns.

Evaluation of a New, Improved Deep Body Thermometry System

Patients can easily be subject to hypothermia in an operating room.1,2 Thus, monitoring a patient’s body temperature is one of the most important tasks during anesthesia. Although the esophageal and the tympanic membrane thermometry are the most reliable sites for this purpose, their thermometry may be associated with trauma.1,2 In contrast, a newly developed deep body thermometry system, CTM-205™ (Terumo, Tokyo), can be used to measure body temperature by simply placing a probe on the skin surface.3 The principle of this method, originally proposed by Fox and Solman is to create a region of zero heat flow under the probe.4 We evaluated the accuracy and precision of this system during major surgery, using pulmonary arterial blood temperature as a standard.

Effects of surgical site and inspired gas warming devices on body temperature during lower abdominal and thoracic surgery.

To evaluate the effects of surgical site and inspired gas warming and humidifying devices on body temperature, we studied rectal, tympanic membrane, and esophageal temperature changes in 48 patients. The patients were divided into 4 groups (n=12), according to surgical site, lower abdominal surgery and thoracic surgery, and according to the warming device used, heat and moisture exchanger (ThermoVent 600) and heated humidifier (Cascade 1). The heated humidifier was controlled to warm inspired gases to about 35°C. All body temperatures fell significantly during surgery. There was no difference in the tympanic membrane and esophageal temperature declines between the two surgical sites, but the decline in rectal temperature was larger in the lower abdominal surgery than in the thoracic surgery. At the end of surgery, all temperatures returned to the value before surgery, and the rectal and tympanic membrane temperatures even exceeded them. There was no difference between the effects of the ThermoVent 600 and Cascade 1. These results suggest that rectal temperature is influenced by the ambient temperature during lower abdominal surgery and that warming and humidifying devices for inspired gases do not prevent, but can restore the decline in body temperature during lower abdominal and thoracic surgery. The heated humidifier showed no advantage over the heat and moisture exchanger in our study.