Reexamination of tympanic membrane temperature as a core temperature

1996 ◽  
Vol 80 (4) ◽  
pp. 1233-1239 ◽  
Author(s):  
K. T. Sato ◽  
N. L. Kane ◽  
G. Soos ◽  
C. V. Gisolfi ◽  
N. Kondo ◽  
...  

Controversies surrounding tympanic temperature (Tty) itself and techniques for measuring it have dampened the potential usefulness of Tty in determining core temperature (operationally defined here as the body temperature taken at a deep body site). The present study was designed to address the following questions. 1) Can a tympanic membrane probe be made that is safer and more reliable than its predecessors? 2) Why is the effect of facial cooling and heating on Tty so inconsistent in reports from different laboratories? 3) Is Tty still useful as a measure of core temperature? Data from this study, obtained with a modified thermocouple probe, suggest that the widely reported facial skin cooling effect on Tty is most probably due to thermal contamination from the surrounding ear canal wall and/or suboptimal contact of the probe sensor with the tympanic membrane because 1) Tty that fell during facial cooling was increased to the precooling level by the repositioning of the probe sensor; 2) Tty determined by using a probe with a larger sensor area (the sensor soldered to a steel wire ring)tended to fall in response to facial cooling, whereas Tty determined with a thermally insulated probe ring did not; and 3) Tty obtained under careful positioning of the insulated probe was relatively insensitive to facial cooling or heating. Because Tty was practically identical to esophageal temperature (Tes) in the steady state, i.e., 36.83 +/- 0.20 (SD) degrees C for Tty and 36.87 +/- 0.16 degrees C for Tes at room temperature (n = 11), and because facial cooling had little effect on both Tty and Tes (36.86 +/- 0.17 degrees C for Tty and 36.86 +/- 0.26 degrees C for Tes during facial or scalp skin cooling), we support the postulate that Tty is a good measure of core temperature. The temperature transient in response to foot warming was detected 5 min (n = 2) faster with Tty than with Tes. Thus, with further improvements in the design of the probe. Tty can become a standard for determination of core body temperature.

1997 ◽  
Vol 6 (1) ◽  
pp. 46-51 ◽  
Author(s):  
KA Thomas ◽  
MV Savage ◽  
GL Brengelmann

BACKGROUND: In clinical practice, tympanic temperature is used as an estimate of body temperature. Theoretically, temperature recorded directly from the tympanum reflects the temperature of arterial blood circulating to the brain. However, some studies do not support this connection. Ear-based thermometers in clinical use, commonly called tympanic thermometers, detect heat emission from the aural canal and tympanum. Dissociation of core body temperature and tympanic temperature would suggest that factors other than arterial blood perfusion affect tympanic temperature. METHODS: In a controlled laboratory experiment with four adult volunteers, esophageal and tympanic temperatures were recorded repeatedly at 2-minute intervals during whole-body heating and cooling. Facial cooling, produced by a small electrical fan, was used in three subjects. RESULTS: The gradient between tympanic and esophageal temperature was inconsistent across subjects, with tympanic temperature both higher and lower than esophageal temperature. Correlations between esophageal and tympanic temperature varied widely across subjects. Fanning the face produced a decrease in tympanic temperature without an accompanying decline in esophageal temperature. CONCLUSIONS: Facial cooling in the form of fanning altered the relationship between tympanic and esophageal temperature. This result suggests the possible lowering of tympanic temperature by cooled facial venous blood flow. Use of tympanic temperature in circumstances in which facial temperature may be different from that of other regions of the body deserves further study.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Dikmen S ◽  
Davila KMS ◽  
Rodriquez E ◽  
Scheffler TL ◽  
Oltenacu PA ◽  
...  

In cattle, core body temperature can be used as an important indicator of heat stress level. However, accurately recording core body temperature can be difficult and labor intensive. The objectives of the current study were 1) to compare the recorded tympanic and tail body temperature measurements in steers and 2) to determine the body temperature change of Angus and Brahman steers in a hot and humid environment. Data was analyzed using a repeated measure model where repeated measures were hourly tympanic and tail temperatures and their difference for individual steers during the day of the experiment. There was a significant breed effect (P=0.01), hour (P<0.0001) and breed by hour interaction (P<0.0001) for the tympanic temperature. Brahman steers, which are known to have superior thermotolerance, maintained a lower body temperature than the Angus steers during the afternoon under grazing conditions. In the Brahman steers there was only a minimal increase in the body temperature throughout the day, an evidence of the thermotolerance ability of the breed. In the Angus steers, which experienced an increase in their body temperature from hour to hour with a peak around 1600 hour; there was a significant difference between the tympanic and tail temperature during the times when the body temperature as measured by the tympanic recordings was the highest (1300 to 1700 hour). Our results indicate that the tympanic temperature can be used to accurately and continuously monitor core body temperature in a natural environment for up to several days and without disturbing the animal.


2017 ◽  
Vol 60 (3) ◽  
pp. 19-25
Author(s):  
Sławomir Kujawski ◽  
Joanna Słomko ◽  
Monika Zawadka-Kunikowska ◽  
Mariusz Kozakiewicz ◽  
Jacek J. Klawe ◽  
...  

Abstract Changes observed in the core body temperature of divers are the result of a multifaceted response from the body to the change of the external environment. In response to repeated activities, there may be a chronic, physiological adaptation of the body’s response system. This is observed in the physiology of experienced divers while diving. The purpose of this study is to determine the immediate and delayed effects of hyperbaric exposure on core temperature, as well as its circadian changes in a group of three experienced divers. During compression at 30 and 60 meters, deep body temperature values tended to increase. Subsequently, deep body temperature values showed a tendency to decrease during decompression. All differences in core temperature values obtained by the group of divers at individual time points in this study were not statistically significant.


2017 ◽  
Vol 312 (5) ◽  
pp. R779-R786 ◽  
Author(s):  
Domenico Tupone ◽  
Georgina Cano ◽  
Shaun F. Morrison

To maintain core body temperature in mammals, the normal central nervous system (CNS) thermoregulatory reflex networks produce an increase in brown adipose tissue (BAT) thermogenesis in response to skin cooling and an inhibition of the sympathetic outflow to BAT during skin rewarming. In contrast, these normal thermoregulatory reflexes appear to be inverted in hibernation/torpor; thermogenesis is inhibited during exposure to a cold environment, allowing dramatic reductions in core temperature and metabolism, and thermogenesis is activated during skin rewarming, contributing to a return of normal body temperature. Here, we describe two unrelated experimental paradigms in which rats, a nonhibernating/torpid species, exhibit a “thermoregulatory inversion,” which is characterized by an inhibition of BAT thermogenesis in response to skin cooling, and a switch in the gain of the skin cooling reflex transfer function from negative to positive values. Either transection of the neuraxis immediately rostral to the dorsomedial hypothalamus in anesthetized rats or activation of A1 adenosine receptors within the CNS of free-behaving rats produces a state of thermoregulatory inversion in which skin cooling inhibits BAT thermogenesis, leading to hypothermia, and skin warming activates BAT, supporting an increase in core temperature. These results reflect the existence of a novel neural circuit that mediates inverted thermoregulatory reflexes and suggests a pharmacological mechanism through which a deeply hypothermic state can be achieved in nonhibernating/torpid mammals, possibly including humans.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
K Kimura

Abstract Background Maintaining a core temperature of 37.0 °C is important for autoimmunity, but reports in recent years show a declining trend in body temperature in Japan. The present study aimed to identify the factors leading to hypothermia by examining the relationship between dietary composition. Methods The subjects were 80 healthy females (average age: 18.2±1.0 years). We used a questionnaire format to survey the dietary pattern of the subjects. The dietary patterns were assessed by examining the average meal content consumed per week over the last 1-2 months and meal consumption, including nutritional content and other factors, using analysis software. The subjects measured their tympanic temperature using a thermometer after waking up. Correlation coefficient was calculated to determine correlations between tympanic temperature and each item. Results A significant correlation was observed between tympanic membrane temperatures upon waking up and iodine intake (r = 0.301,P&lt;0.05) as well as the adequacy ratio of iodine reference intake (ratio of iodine intake to the Dietary Reference Intakes for Japanese, r = 0.301,P&lt;0.05). A comparison between the group with tympanic membrane temperatures of ≥ 36.0 °C upon waking up and that with temperatures of &lt; 36.0 °C showed a significant difference in iodine intake (732±518μg vs 422±248μg,P&lt;0.05) and the adequacy ratio of iodine reference intake (5.6±4.0 vs 3.2±1.9,P&lt;0.05). Conclusions We examined the association of body temperature in Japanese women in their teens with their dietary composition and found a correlation between iodine intake and the adequacy ratio of iodine reference intake. Iodine is a substance essential for the production of the thyroid hormones thyroxine and triiodothyronine. Thyroid hormones regulate biochemical reactions, such as protein synthesis and enzyme activity, and play an important role in regulating metabolic activity. Therefore, iodine may influence body temperature via these hormones. Key messages Regular body temperature monitoring is recommended for the prevention of infectious diseases. When there is a decrease in the body temperature, dietary composition of the individual should be checked.


Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2885 ◽  
Author(s):  
Hsuan-Yu Chen ◽  
Andrew Chen ◽  
Chiachung Chen

Many types of thermometers have been developed to measure body temperature. Infrared thermometers (IRT) are fast, convenient and ease to use. Two types of infrared thermometers are uses to measure body temperature: tympanic and forehead. With the spread of COVID-19 coronavirus, forehead temperature measurement is used widely to screen people for the illness. The performance of this type of device and the criteria for screening are worth studying. This study evaluated the performance of two types of tympanic infrared thermometers and an industrial infrared thermometer. The results showed that these infrared thermometers provide good precision. A fixed offset between tympanic and forehead temperature were found. The measurement values for wrist temperature show significant offsets with the tympanic temperature and cannot be used to screen fevers. The standard operating procedure (SOP) for the measurement of body temperature using an infrared thermometer was proposed. The suggestion threshold for the forehead temperature is 36 °C for screening of fever. The body temperature of a person who is possibly ill is then measured using a tympanic infrared thermometer for the purpose of a double check.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2316
Author(s):  
Daniel Mota-Rojas ◽  
Dehua Wang ◽  
Cristiane Gonçalves Titto ◽  
Jocelyn Gómez-Prado ◽  
Verónica Carvajal-de la Fuente ◽  
...  

Body-temperature elevations are multifactorial in origin and classified as hyperthermia as a rise in temperature due to alterations in the thermoregulation mechanism; the body loses the ability to control or regulate body temperature. In contrast, fever is a controlled state, since the body adjusts its stable temperature range to increase body temperature without losing the thermoregulation capacity. Fever refers to an acute phase response that confers a survival benefit on the body, raising core body temperature during infection or systemic inflammation processes to reduce the survival and proliferation of infectious pathogens by altering temperature, restriction of essential nutrients, and the activation of an immune reaction. However, once the infection resolves, the febrile response must be tightly regulated to avoid excessive tissue damage. During fever, neurological, endocrine, immunological, and metabolic changes occur that cause an increase in the stable temperature range, which allows the core body temperature to be considerably increased to stop the invasion of the offending agent and restrict the damage to the organism. There are different metabolic mechanisms of thermoregulation in the febrile response at the central and peripheral levels and cellular events. In response to cold or heat, the brain triggers thermoregulatory responses to coping with changes in body temperature, including autonomic effectors, such as thermogenesis, vasodilation, sweating, and behavioral mechanisms, that trigger flexible, goal-oriented actions, such as seeking heat or cold, nest building, and postural extension. Infrared thermography (IRT) has proven to be a reliable method for the early detection of pathologies affecting animal health and welfare that represent economic losses for farmers. However, the standardization of protocols for IRT use is still needed. Together with the complete understanding of the physiological and behavioral responses involved in the febrile process, it is possible to have timely solutions to serious problem situations. For this reason, the present review aims to analyze the new findings in pathophysiological mechanisms of the febrile process, the heat-loss mechanisms in an animal with fever, thermoregulation, the adverse effects of fever, and recent scientific findings related to different pathologies in farm animals through the use of IRT.


2008 ◽  
Vol 109 (2) ◽  
pp. 318-338 ◽  
Author(s):  
Daniel I. Sessler ◽  
David S. Warner ◽  
Mark A. Warner

Most clinically available thermometers accurately report the temperature of whatever tissue is being measured. The difficulty is that no reliably core-temperature-measuring sites are completely noninvasive and easy to use-especially in patients not undergoing general anesthesia. Nonetheless, temperature can be reliably measured in most patients. Body temperature should be measured in patients undergoing general anesthesia exceeding 30 min in duration and in patients undergoing major operations during neuraxial anesthesia. Core body temperature is normally tightly regulated. All general anesthetics produce a profound dose-dependent reduction in the core temperature, triggering cold defenses, including arteriovenous shunt vasoconstriction and shivering. Anesthetic-induced impairment of normal thermoregulatory control, with the resulting core-to-peripheral redistribution of body heat, is the primary cause of hypothermia in most patients. Neuraxial anesthesia also impairs thermoregulatory control, although to a lesser extent than does general anesthesia. Prolonged epidural analgesia is associated with hyperthermia whose cause remains unknown.


Author(s):  
Rajnandini Singha ◽  
Amazing Grace Siangshai ◽  
Jashlyn Lijo

Hypothermia, described as a core body temperature of < 95%, is associated with ECG alteration abnormalities. Sinus bradycardia occurs when the body temperature drops below 90°F, and is correlated with gradual prolongation of the PR interval, QRS complex, QT interval. It can progress to ventricular and atrial fibrillation at a temperature reaching 89°F, which can lead to left ventricular dysfunction. Hypothermia is connected to the osborn waves, which at the end of the QRS complex consist of additional deflection. The inferior and lateral precordial leads are seen by Osborn waves, also known as J waves, Camel hump waves and hypothermic waves. As the body temperature decreases, it becomes more pronounced and a gradual expansion of the QRS complex raises the likelihood of ventricular fibrillation causing ventricle dysfunction.


2004 ◽  
Vol 5 (2) ◽  
pp. 27-30
Author(s):  
J. Hegarty

The regulation of body temperature is one of a variety of mechanisms, which play a part in maintaining a stable internal environment in the body thus enabling the body to function optimally. It is crucial that the core body temperature is maintained within a narrow (36–37.5°C) range [Luckmann, 1997]. Thermoregulation in the operating theatre and post anaesthetic care unit is often an underemphasized concern for surgical patients. Anaesthesia and surgery commonly cause substantial alterations in the temperature of surgical patients.Unnecessary heat loss, hypothermia, the typical variation, results from a combination of anaesthetic-induced impairment of thermoregulatory control, a cool, operating room environment and other factors exclusive to surgery and anaesthesia. Estimates of the incidence of inadvertent perioperative hypothermia range from 60% to 90% of all surgical cases [Bernthal, 1999, Litwack, 1995], when this condition is defined as a body temperature below 36°C (degrees Celsius) 96.8°F (degrees Fahrenheit) (Arndt, 1999). Hypothermia apart from causing a very unpleasant sensation of cold, places the patient at risk of developing life-threatening events, which include altered cardiac performance, delayed emergence from anaesthesia and increased rates of morbidity and mortality. Although the aim of temperature management by intraoperative medical and nursing staff is prevention of heat loss, the objective of post anaesthetic recovery room staff is usually the restoration of normothermia. Thus, perioperative nurses need to be aware of the need to monitor patient's temperature, be familiar with different patient warming/rewarming methods and be alert for potential problems that can arise from hypothermia.


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