scholarly journals Body temperature depression and peripheral heat loss accompany the metabolic and ventilatory responses to hypoxia in low and high altitude birds

2008 ◽  
Vol 211 (8) ◽  
pp. 1326-1335 ◽  
Author(s):  
G. R. Scott ◽  
V. Cadena ◽  
G. J. Tattersall ◽  
W. K. Milsom
Keyword(s):  
Body Temperature ◽  
High Altitude ◽  
Heat Loss ◽  
Ventilatory Responses ◽  
Temperature Depression

Comparison of the effect of isopropyl alcohol and chlorhexidine solution rinses on body temperature of female cats undergoing sterilization surgery

2021 ◽  
pp. 1098612X2097956
Author(s):  
Rachael E Kreisler ◽  
Michelle L Douglas ◽  
Karissa N Harder
Keyword(s):  
Body Temperature ◽  
Heat Loss ◽  
Isopropyl Alcohol ◽  
Body Condition Score ◽  
High Volume ◽  
Veterinary Students ◽  
Reversal Agents ◽  
Duration Of Surgery ◽  
Chlorhexidine Solution ◽  
Recovery Temperature

Objectives Isopropyl alcohol 70% as a rinse agent for chlorhexidine scrub has been shown to decrease body temperature more quickly than chlorhexidine solution in mice prepared aseptically prior to surgery. For this reason, some high-quality, high-volume (HQHV) surgical sterilization clinics use chlorhexidine solution rather than alcohol. We sought to determine if temperature upon entry to recovery, heat loss per kg and rate of temperature decline during surgery were different between cats rinsed with chlorhexidine solution vs 70% isopropyl alcohol following surgical scrub, and if there were significant predictors of recovery temperature. Methods Female cats admitted for surgery to trap–neuter–return (TNR) clinics at a veterinary college were assigned chlorhexidine solution or alcohol rinse agents via block randomization. Veterinary students and veterinarians performed spay surgeries using HQHV techniques. In recovery, heat support and reversal agents were available for cats with a low body temperature or that were slow to recover. Baseline values, outcome variables and duration of each stage (preparation, surgery, recovery) were assessed using Wilcoxon rank-sum and t-tests. Recovery temperature was evaluated using random effects multiple linear regression. Results The recovery temperature, heat loss per kg, heat loss per min, need for reversal and need for heat support in recovery were not significantly different between rinse groups. Weight <2.3 kg, body condition score <4, duration of surgery and postinduction temperature were predictors of recovery temperature. The rate of heat loss in the first 30 mins of surgery was slightly lower for cats in the alcohol rinse group and the recovery duration was shorter for cats weighing less <2.3 kg in the alcohol rinse group. Conclusions and relevance There were no clinically meaningful differences in body temperature between chlorhexidine and alcohol rinses. Both chlorhexidine solution and isopropyl alcohol 70% are appropriate rinse agents for aseptic preparation of feline spay surgeries.

Frostbite and Hypothermia

2015 ◽  
Author(s):  
Jeffrey I. Schneider
Keyword(s):  
Body Temperature ◽  
Heat Loss ◽  
Pleural Cavity ◽  
The Body ◽  
Ice Crystals ◽  
Homeless Population ◽  
Outdoor Sports ◽  
Increased Risk ◽  
Long Term Consequences

Frostbite and hypothermia are becoming increasingly common as the popularity of extreme and outdoor sports rises and the homeless population increases. Advanced age is also associated with an increased risk of frostbite and hypothermia; thus, their incidence will likely continue to increase as the population ages. Frostbite occurs when there is sufficient heat loss to produce ice crystals within either superficial or deep flesh. Hypothermia is defined as an involuntary drop in body temperature to below 35°C, but a useful functional definition is a decrease in temperature that results in an inability of the body to maintain its natural functions. This review details the assessment and stabilization, diagnosis, and treatment and disposition for frostbite and hypothermia. Figures show factors that may predispose individuals to developing frostbite, long-term consequences of severe frostbite, and an approach for pleural cavity lavage. Tables list factors that increase the risk of frostbite, degrees of frostbite, three phases of frostbite, and staging of hypothermia. This review contains 3 highly rendered figures, 4 tables, and 71 references.

Fetal and maternal temperatures in rabbits

1965 ◽  
Vol 20 (4) ◽  
pp. 737-741 ◽  
Author(s):  
Frederick M. Hart ◽  
J. Job Faber
Keyword(s):  
New Zealand ◽  
Body Temperature ◽  
Heat Loss ◽  
Abdominal Cavity ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
Sodium Pentobarbital ◽  
Deep Body Temperature ◽  
New Zealand White Rabbits ◽  
Deep Body

The differences between fetal deep body temperature and maternal aortic temperature were measured in 10 New Zealand white rabbits of 22—29 days gestation with thermocouples thrust into the fetuses immediately after the animals had been killed by a warmed overdose of sodium pentobarbital. Fetal temperatures exceeded maternal temperatures by —2.51 + 0.099.X °C, where X is the gestational age in days. There is 95% confidence that fetal temperatures exceeded maternal temperature by at least 0.25 °C at a fetal age of 29 days. Permanently implanted thermocouples in six nonpregnant rabbits showed that the ventral surface of the abdominal cavity is colder than the aorta, and that the dorsal surface is slightly warmer. Fetal heat loss is partly via the umbilical circulation and partly via the fetal body surface. tissue temperatures in rabbits; fetal heat loss Submitted on September 28, 1964

Light masking of circadian rhythms of heat production, heat loss, and body temperature in squirrel monkeys

1999 ◽  
Vol 276 (2) ◽  
pp. R298-R307 ◽  
Author(s):  
Edward L. Robinson ◽  
Charles A. Fuller
Keyword(s):  
Body Temperature ◽  
Heat Loss ◽  
Heat Production ◽  
Whole Body ◽  
Direct Calorimetry ◽  
Set Point ◽  
Subjective Night ◽  
Timing System ◽  
Circadian Timing System ◽  
Body Heat

Whole body heat production (HP) and heat loss (HL) were examined to determine their relative contributions to light masking of the circadian rhythm in body temperature (Tb). Squirrel monkey metabolism ( n = 6) was monitored by both indirect and direct calorimetry, with telemetered measurement of body temperature and activity. Feeding was also measured. Responses to an entraining light-dark (LD) cycle (LD 12:12) and a masking LD cycle (LD 2:2) were compared. HP and HL contributed to both the daily rhythm and the masking changes in Tb. All variables showed phase-dependent masking responses. Masking transients at L or D transitions were generally greater during subjective day; however, L masking resulted in sustained elevation of Tb, HP, and HL during subjective night. Parallel, apparently compensatory, changes of HL and HP suggest action by both the circadian timing system and light masking on Tb set point. Furthermore, transient HL increases during subjective night suggest that gain change may supplement set point regulation of Tb.

Effect of heating rate on evaporative heat loss in the microwave-exposed mouse

1982 ◽  
Vol 53 (2) ◽  
pp. 316-323 ◽  
Author(s):  
C. J. Gordon
Keyword(s):  
Body Temperature ◽  
Heat Loss ◽  
Heat Dissipation ◽  
Dew Point ◽  
Whole Body ◽  
Evaporative Heat Loss ◽  
Heat Absorption ◽  
Deep Body Temperature ◽  
The Difference ◽  
Body Heat

Male CBA/J mice were administered heat loads of 0–28 J X g-1 at specific absorption rates (SARs) of either 47 or 93 W X kg-1 by exposure to 2,450-MHz microwave radiation at an ambient temperature of 30 degrees C while evaporative heat loss (EHL) was continuously monitored with dew-point hygrometry. At an SAR of 47 W X kg-1 a threshold heat load of 10.5 J X g-1 had to be exceeded before EHL increased. An approximate doubling of SAR to 93 W X kg-1 reduced the threshold to 5.2 J X g-1. Above threshold the slopes of the regression lines were 1.15 and 0.929 for the low- and high-SAR groups, respectively. Thus the difference in threshold and not slope attributes to the significant increase in EHL when mice are exposed at a high SAR (P less than 0.02). In separate experiments a SAR of 47 W X kg-1 raised the deep body temperature of anesthetized mice at a rate of 0.026 degrees C X s-1, whereas 93 W X kg-1 raised temperature at 0.049 degrees C X s-1. Hence the sensitivity of the EHL mode of heat dissipation is directly proportional to the rate of heat absorption and to the rate of rise in body temperature. These data contradict the notion that mammals have control over whole-body heat exchange only (i.e., thermoregulation) but instead indicate that the EHL system is highly responsive to the rate of heat absorption (i.e., temperature regulation).

Perfusions of the posterior hypothalamus of cats with various ions and saccharides: effects on body temperature

1978 ◽  
Vol 56 (4) ◽  
pp. 571-577 ◽  
Author(s):  
D. L. Jones ◽  
W. L. Veale ◽  
K. E. Cooper
Keyword(s):  
Body Temperature ◽  
Heat Loss ◽  
Posterior Hypothalamus ◽  
Body Temperatures ◽  
Vasomotor Tone ◽  
Hypothalamic Area ◽  
Hypothalamic Region ◽  
Energy Substrate ◽  
Available Energy ◽  
Perfusion Solution

Alterations of the ionic constituents of solutions perfused through the tissue of the posterior hypothalamic region in conscious cats elicited changes in body temperatures. Increasing the [Ca2+] to [Na+] ratio of the perfusion solution elicited falls in body temperature which were accompanied by changes in posture and vasomotor tone which assisted the heat loss. The magnitude of the fall was dependent on the ratio of [Ca2+] to [Na+] and was not related to the osmolarity of perfusion solution. The addition of dextrose to the perfusion solution attenuated or abolished the response produced by an increase in the [Ca2+] to [Na+] ratio. This dextrose effect could be attributed to its role as an energy substrate. These data are consistent with and extend previous suggestions that the set point for body temperature may be dependent on the inherent ratio of the ionic constituents of the posterior hypothalamic area. Further, they suggest that these ionically induced alterations can be overriden by increasing the available energy substrate.

scholarly journals Do small precocial birds enter torpor to conserve energy during development?

2020 ◽  
Vol 223 (21) ◽  
pp. jeb231761
Author(s):  
Yaara Aharon-Rotman ◽  
Gerhard Körtner ◽  
Chris B. Wacker ◽  
Fritz Geiser
Keyword(s):  
Body Temperature ◽  
Metabolic Rate ◽  
Surface Temperature ◽  
Heat Loss ◽  
Body Mass ◽  
Infrared Thermometer ◽  
Common Strategy ◽  
Energy Conserving ◽  
Altricial Birds ◽  
Precocial Birds

ABSTRACTPrecocial birds hatch feathered and mobile, but when they become fully endothermic soon after hatching, their heat loss is high and they may become energy depleted. These chicks could benefit from using energy-conserving torpor, which is characterised by controlled reductions of metabolism and body temperature (Tb). We investigated at what age the precocial king quail Coturnix chinensis can defend a high Tb under a mild thermal challenge and whether they can express torpor soon after achieving endothermy to overcome energetic and thermal challenges. Measurements of surface temperature (Ts) using an infrared thermometer showed that king quail chicks are partially endothermic at 2–10 days, but can defend high Tb at a body mass of ∼13 g. Two chicks expressed shallow nocturnal torpor at 14 and 17 days for 4–5 h with a reduction of metabolism by >40% and another approached the torpor threshold. Although chicks were able to rewarm endogenously from the first torpor bout, metabolism and Ts decreased again by the end of the night, but they rewarmed passively when removed from the chamber. The total metabolic rate increased with body mass. All chicks measured showed a greater reduction of nocturnal metabolism than previously reported in quails. Our data show that shallow torpor can be expressed during the early postnatal phase of quails, when thermoregulatory efficiency is still developing, but heat loss is high. We suggest that torpor may be a common strategy for overcoming challenging conditions during development in small precocial and not only altricial birds.

Hypocapnia and sustained hypoxia blunt ventilation on arrival at high altitude

1984 ◽  
Vol 56 (3) ◽  
pp. 602-606 ◽  
Author(s):  
S. Y. Huang ◽  
J. K. Alexander ◽  
R. F. Grover ◽  
J. T. Maher ◽  
R. E. McCullough ◽  
...  
Keyword(s):  
High Altitude ◽  
Ventilatory Response ◽  
Minute Ventilation ◽  
Ventilatory Responses ◽  
Low Altitude ◽  
Arterial O2 Saturation ◽  
Sustained Hypoxia

Hypoxia at high altitude stimulates ventilation, but inhibitory influences in the first days after arrival limit the ventilatory response. Possible inhibitory influences include hypocapnia and depression of ventilation during sustained hypoxia. Our approach was to compare hypoxic ventilatory responses at low altitude with ventilation at high altitude. In 12 subjects we compared responses both to isocapnic hypoxia and poikilocapnic (no CO2 added) hypoxia during acute (less than 10 min) and sustained (30 min) hypoxia in Denver (1,600 m) with ventilations measured on each of 5 days on Pikes Peak (4,300 m). On Pikes Peak, day 1 ventilation [minute ventilation = 10.0 1/min, BTPS; arterial O2 saturation (Sao2) = 82%] was less than predicted by either acute isocapnic or poikilocapnic tests. However, sustained poikilocapnic hypoxia (Sao2 approximately = 82%) in Denver yielded ventilation similar to that on Pikes Peak on day 1. By Pikes Peak days 4 and 5, endtidal PCO2, pHa, and Sao2 approached plateaus, and ventilation (12.4 1/min, BTPS) on these days was as predicted by the acute isocapnic test. Thus the combination of hypocapnia and sustained hypoxia may have blunted the ventilatory increase on Pikes Peak day 1 but apparently not after 4 or 5 days of acclimatization.

scholarly journals Reduction of Heat Loss during Transurethral Resection of the Prostate

1986 ◽  
Vol 14 (1) ◽  
pp. 12-16 ◽  
Author(s):  
P. M. Dyer ◽  
P. S. Heathcote
Keyword(s):  
Body Temperature ◽  
Blood Loss ◽  
Heat Loss ◽  
Spinal Anaesthesia ◽  
Transurethral Resection ◽  
Marked Decrease ◽  
Prospective Trial ◽  
Bladder Irrigation ◽  
Number Of Patients ◽  
Irrigation Solution

A prospective trial was performed on 100 patients to determine whether using a reflective blanket (Space Blanket) and heated glycine 1.5% bladder irrigation solution would decrease the fall in body temperature associated with transurethral resection of the prostate under spinal anaesthesia. Patients who received a combination of reflective blanket and heated glycine 1.5% solution had their fall in body temperature significantly reduced when compared with those patients managed without a reflective blanket and/or heated 1.5% glycine. There was a marked decrease in the number of patients shivering and no increase in blood loss was seen when heated bladder irrigation solution was used.

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