scholarly journals Temperature Monitoring and Perioperative Thermoregulation

2008 ◽  
Vol 109 (2) ◽  
pp. 318-338 ◽  
Author(s):  
Daniel I. Sessler ◽  
David S. Warner ◽  
Mark A. Warner
Keyword(s):  
Body Temperature ◽  
General Anesthesia ◽  
Core Temperature ◽  
Core Body Temperature ◽  
Neuraxial Anesthesia ◽  
General Anesthetics ◽  
The Core ◽  
Core Body ◽  
Dose Dependent ◽  
Body Heat

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.

Monitoring of the core body temperature of cows using implantable wireless thermometers

2019 ◽  
Vol 163 ◽  
pp. 104849 ◽  
Author(s):  
Wataru Iwasaki ◽  
Shuichi Ishida ◽  
Daisuke Kondo ◽  
Yuichi Ito ◽  
Jun Tateno ◽  
...  
Keyword(s):  
Body Temperature ◽  
Core Body Temperature ◽  
The Core ◽  
Core Body

scholarly journals Skipping Breakfast for 6 Days Delayed the Circadian Rhythm of the Body Temperature without Altering Clock Gene Expression in Human Leukocytes

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2797 ◽  
Author(s):  
Hitomi Ogata ◽  
Masaki Horie ◽  
Momoko Kayaba ◽  
Yoshiaki Tanaka ◽  
Akira Ando ◽  
...  
Keyword(s):  
Gene Expression ◽  
Body Temperature ◽  
Clock Gene ◽  
Core Body Temperature ◽  
The Core ◽  
Clock Gene Expression ◽  
Meal Timing ◽  
Dim Light ◽  
Core Body ◽  
Skipping Breakfast

Breakfast is often described as “the most important meal of the day” and human studies have revealed that post-prandial responses are dependent on meal timing, but little is known of the effects of meal timing per se on human circadian rhythms. We evaluated the effects of skipping breakfast for 6 days on core body temperature, dim light melatonin onset, heart rate variability, and clock gene expression in 10 healthy young men, with a repeated-measures design. Subjects were provided an isocaloric diet three times daily (3M) or two times daily (2M, i.e., breakfast skipping condition) over 6 days. Compared with the 3M condition, the diurnal rhythm of the core body temperature in the 2M condition was delayed by 42.0 ± 16.2 min (p = 0.038). On the other hand, dim light melatonin onset, heart rate variability, and clock gene expression were not affected in the 2M condition. Skipping breakfast for 6 days caused a phase delay in the core body temperature in healthy young men, even though the sleep–wake cycle remained unchanged. Chronic effects of skipping breakfast on circadian rhythms remain to be studied.

scholarly journals The Effects of Hyperbaric Exposure on Immediate and Delayed Changes in Core Temperature and Its Circadian Fluctuations

2017 ◽  
Vol 60 (3) ◽  
pp. 19-25
Author(s):  
Sławomir Kujawski ◽  
Joanna Słomko ◽  
Monika Zawadka-Kunikowska ◽  
Mariusz Kozakiewicz ◽  
Jacek J. Klawe ◽  
...  
Keyword(s):  
Body Temperature ◽  
Core Temperature ◽  
Core Body Temperature ◽  
The Body ◽  
Physiological Adaptation ◽  
Deep Body Temperature ◽  
Delayed Effects ◽  
Hyperbaric Exposure ◽  
Core Body ◽  
Deep Body

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.

scholarly journals The Use of Percutaneous Thermal Sensing Microchips for Body Temperature Measurements in Horses Prior to, during and after Treadmill Exercise

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2274
Author(s):  
Hyungsuk Kang ◽  
Rebeka R. Zsoldos ◽  
Solomon M. Woldeyohannes ◽  
John B. Gaughan ◽  
Albert Sole Guitart
Keyword(s):  
Body Temperature ◽  
Core Body Temperature ◽  
Central Venous ◽  
Exertional Heat Illness ◽  
The Core ◽  
Thermal Sensing ◽  
Positive Correlations ◽  
The Right ◽  
Nuchal Ligament ◽  
Core Body

Accurately measuring body temperature in horses will improve the management of horses suffering from or being at risk of developing postrace exertional heat illness. PTSM has the potential for measuring body temperature accurately, safely, rapidly, and noninvasively. This study was undertaken to investigate the relation between the core body temperature and PTSM temperatures prior to, during, and immediately after exercise. The microchips were implanted into the nuchal ligament, the right splenius, gluteal, and pectoral muscles, and these locations were then compared with the central venous temperature, which is considered to be the “gold standard” for assessing core body temperature. The changes in temperature of each implant in the horses were evaluated in each phase (prior to, during, and immediately postexercise) and combining all phases. There were strong positive correlations ranging from 0.82 to 0.94 (p < 0.001) of all the muscle sites with the central venous temperature when combining all the phases. Additionally, during the whole period, PTSM had narrow limits of agreement (LOA) with central venous temperature, which inferred that PTSM is essentially equivalent in measuring horse body temperature. Overall, the pectoral PTSM provided a valid estimation of the core body temperature.

scholarly journals Is Oral Temperature an Accurate Measurement of Deep Body Temperature? A Systematic Review

2011 ◽  
Vol 46 (5) ◽  
pp. 566-573 ◽  
Author(s):  
Stephanie M. Mazerolle ◽  
Matthew S. Ganio ◽  
Douglas J. Casa ◽  
Jakob Vingren ◽  
Jennifer Klau
Keyword(s):  
Body Temperature ◽  
Key Words ◽  
Core Temperature ◽  
Core Body Temperature ◽  
Ambient Air ◽  
Controlled Vocabulary ◽  
Cochrane Library ◽  
Original Research ◽  
Oral Temperature ◽  
Core Body

Context: Oral temperature might not be a valid method to assess core body temperature. However, many clinicians, including athletic trainers, use it rather than criterion standard methods, such as rectal thermometry. Objective: To critically evaluate original research addressing the validity of using oral temperature as a measurement of core body temperature during periods of rest and changing core temperature. Data Sources: In July 2010, we searched the electronic databases PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), SPORTDiscus, Academic Search Premier, and the Cochrane Library for the following concepts: core body temperature, oral, and thermometers. Controlled vocabulary was used, when available, as well as key words and variations of those key words. The search was limited to articles focusing on temperature readings and studies involving human participants. Data Synthesis: Original research was reviewed using the Physiotherapy Evidence Database (PEDro). Sixteen studies met the inclusion criteria and subsequently were evaluated by 2 independent reviewers. All 16 were included in the review because they met the minimal PEDro score of 4 points (of 10 possible points), with all but 2 scoring 5 points. A critical review of these studies indicated a disparity between oral and criterion standard temperature methods (eg, rectal and esophageal) specifically as the temperature increased. The difference was −0.50°C ± 0.31°C at rest and −0.58°C ± 0.75°C during a nonsteady state. Conclusions: Evidence suggests that, regardless of whether the assessment is recorded at rest or during periods of changing core temperature, oral temperature is an unsuitable diagnostic tool for determining body temperature because many measures demonstrated differences greater than the predetermined validity threshold of 0.27°C (0.5°F). In addition, the differences were greatest at the highest rectal temperatures. Oral temperature cannot accurately reflect core body temperature, probably because it is influenced by factors such as ambient air temperature, probe placement, and ingestion of fluids. Any reliance on oral temperature in an emergency, such as exertional heat stroke, might grossly underestimate temperature and delay proper diagnosis and treatment.

scholarly journals Thermoregulatory inversion: a novel thermoregulatory paradigm

2017 ◽  
Vol 312 (5) ◽  
pp. R779-R786 ◽  
Author(s):  
Domenico Tupone ◽  
Georgina Cano ◽  
Shaun F. Morrison
Keyword(s):  
Body Temperature ◽  
Core Temperature ◽  
Neural Circuit ◽  
Core Body Temperature ◽  
Normal Body Temperature ◽  
Dorsomedial Hypothalamus ◽  
Pharmacological Mechanism ◽  
Brown Adipose ◽  
Skin Cooling ◽  
Core Body

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.

Decrease of Core Body Temperature in Mice by Dehydroepiandrosterone

2002 ◽  
Vol 227 (6) ◽  
pp. 382-388 ◽  
Author(s):  
Fernando Catalina ◽  
Leon Milewich ◽  
William Frawley ◽  
Vinay Kumar ◽  
Michael Bennett
Keyword(s):  
Body Temperature ◽  
Receptor Antagonist ◽  
Food Restriction ◽  
Serotonin Receptor ◽  
Biological Effects ◽  
Core Body Temperature ◽  
The Body ◽  
Serotonin Receptor Antagonist ◽  
Core Body ◽  
Dose Dependent

Dietary dehydroepiandrosterone (DHEA) reduces food intake in mice, and this response is under genetic control. Moreover, both food restriction and DHEA can prevent or ameliorate certain diseases and mediate other biological effects. Mice fed DHEA (0.45% w/w of food) and mice pair-fed to these mice (food restricted) for 8 weeks were tested for changes in body temperature. DHEA was more efficient than food restriction alone in causing hypothermia. DHEA injected intraperitoneally also induced hypothermia that reached a nadir at 1 to 2 hr, and slowly recovered by 20 to 24 hr. This effect was dose dependent (0.5–50 mg). Each mouse strain tested (four) was susceptible to this effect, suggesting that the genetics differ for induction of hypophagia and induction of hypothermia. Because serotonin and dopamine can regulate (decrease) body temperature, we treated mice with haloperidol (dopamine receptor antagonist), 5,7-dihydroxytryptamine (serotonin production inhibitor), or ritanserin (serotonin receptor antagonist) prior to injection of DHEA. All of these agents increased rather than decreased the hypothermic effects of DHEA. DHEA metabolites that are proximate (5-androstene-3β, 17β-diol and androstenedione) or further downstream (estradiol-17β) were much less effective than DHEA in inducing hypothermia. However, the DHEA analog, 16α-chloroepiandrosterone, was as active as DHEA. Thus, DHEA administered parentally seems to act directly on temperature-regulating sites in the body. These results suggest that DHEA induces hypothermia independent of its ability to cause food restriction, to affect serotonin or dopamine functions, or to act via its downstream steroid metabolites.

scholarly journals Heterothermy is associated with reduced fitness in wild rabbits

2017 ◽  
Vol 13 (12) ◽  
pp. 20170521 ◽  
Author(s):  
Shane K. Maloney ◽  
Maija K. Marsh ◽  
Steven R. McLeod ◽  
Andrea Fuller
Keyword(s):  
Body Temperature ◽  
Oryctolagus Cuniculus ◽  
Reproductive Output ◽  
Core Body Temperature ◽  
The Body ◽  
The Core ◽  
Temperature Rhythm ◽  
Body Temperature Rhythm ◽  
Core Body ◽  
Growth And Reproduction

An increase in variation in the 24 h pattern of body temperature (heterothermy) in mammals can be induced by energy and water deficits. Since performance traits such as growth and reproduction also are impacted by energy and water balance, we investigated whether the characteristics of the body temperature rhythm provide an indication of the reproductive success of an individual. We show that the amplitude of the daily rhythm of body temperature in wild rabbits ( Oryctolagus cuniculus ) prior to breeding is inversely related to the number of pregnancies in the subsequent seven months, while the minimum daily body temperature is positively correlated to the number of pregnancies. Because reproductive output could be predicted from characteristics of the core body temperature rhythm prior to the breeding season, we propose that the pattern of the 24 h body temperature rhythm could provide an index of animal fitness in a given environment.

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