Increasing Mean Skin Temperature Linearly Reduces the Core- temperature Thresholds for Vasoconstriction and Shivering in Humans 

1995 ◽  
Vol 82 (5) ◽  
pp. 1160-1168 ◽  
Author(s):  
Christi Cheng ◽  
Takashi Matsukawa ◽  
Daniel I. Sessler ◽  
Ozaki Makoto ◽  
Andrea Kurz ◽  
...  
Keyword(s):  
Skin Temperature ◽  
Core Temperature ◽  
Central Venous ◽  
Men And Women ◽  
Ringer’S Solution ◽  
The Core ◽  
Temperature Thresholds ◽  
Venous Infusion ◽  
Lactated Ringer's Solution ◽  
Skin Temperatures

Background The contribution of mean skin temperature to the thresholds for sweating and active precapillary vasodilation has been evaluated in numerous human studies. In contrast, the contribution of skin temperature to the control of cold responses such as arteriovenous shunt vasoconstriction and shivering is less well established. Accordingly, the authors tested the hypothesis that mean skin and core temperatures are linearly related at the vasoconstriction and shivering thresholds in men. Because the relation between skin and core temperatures might vary by gender, the cutaneous contribution to thermoregulatory control also was determined in women. Methods In the first portion of the study, six men participated on 5 randomly ordered days, during which mean skin temperatures were maintained near 31, 34, 35, 36, and 37 degrees C. Core hypothermia was induced by central venous infusion of cold lactated Ringer's solution sufficient to induce peripheral vasoconstriction and shivering. The core-temperature thresholds were then plotted against skin temperature and a linear regression fit to the values. The relative skin and core contributions to the control of each response were calculated from the slopes of the regression equations. In the second portion of the study, six women participated on three randomly ordered days, during which mean skin temperatures were maintained near 31, 35, and 37 degrees C. At each designated skin temperature, core hypothermia sufficient to induce peripheral vasoconstriction and/or shivering was again induced by central venous infusion of cold lactated Ringer's solution. The cutaneous contributions to control of each response were then calculated from the skin- and core-temperature pairs at the vasoconstriction and shivering thresholds. Results There was a linear relation between mean skin and core temperatures at the response thresholds in the men: r = 0.90 +/- 0.06 for vasoconstriction and r = 0.94 +/- 0.07 for shivering. Skin temperature contributed 20 +/- 6% to vasoconstriction and 19 +/- 8% to shivering. Skin temperature in the women contributed to 18 +/- 4% to vasoconstriction and 18 +/- 7% to shivering, values not differing significantly from those in men. There was no apparent correlation between the cutaneous contributions to vasoconstriction and shivering in individual volunteers. Conclusions These data indicate that skin and core temperatures contribute linearly to the control of vasoconstriction and shivering in men and that the cutaneous contributions average approximately 20% in both men and women. The same coefficients thus can be used to compensate for experimental skin temperature manipulations in men and women. However, the cutaneous contributions to each response vary among volunteers; furthermore, the contributions to the two responses vary within volunteers.

Sweating responses to central and peripheral heating in spinal man

1976 ◽  
Vol 40 (5) ◽  
pp. 701-706 ◽  
Author(s):  
J. A. Downey ◽  
C. E. Huckaba ◽  
P. S. Kelley ◽  
H. S. Tam ◽  
R. C. Darling ◽  
...  
Keyword(s):  
Core Temperature ◽  
Rapid Decrease ◽  
Central Temperature ◽  
Ambient Temperatures ◽  
The Core ◽  
Central Heating ◽  
Temperature Thresholds ◽  
Skin Cooling ◽  
Skin Temperatures

Studies of central and peripheral heating of a resting spinal man (T6) were performed under various ambient temperatures (20–34 degrees C). It was found that at a constant core temperature, sweating could not be initiated by sentient skin heating alone, but skin cooling alone did produce a rapid decrease in sweating response. Central heating alone induced sweating responses and the central temperature thresholds of sweating were inversely related to the ambient (sentient skin) temperatures. The local and mean sweating rates were found to be linearly related to the core temperature. The slopes of local sweating rates versus the core temperature vary increasingly with the following locations: chest, forearm, and forehead; but the slopes of mean sweating rates versus core temperature were essentially constant.

Propofol Linearly Reduces the Vasoconstriction and Shivering Thresholds 

1995 ◽  
Vol 82 (5) ◽  
pp. 1169-1180 ◽  
Author(s):  
Takashi Matsukawa ◽  
Andrea Kurz ◽  
Daniel I. Sessler ◽  
Andrew R. Bjorksten ◽  
Benjamin Merrifield ◽  
...  
Keyword(s):  
Skin Temperature ◽  
Core Temperature ◽  
Response Curves ◽  
Target Concentration ◽  
The Core ◽  
Temperature Thresholds ◽  
Cutaneous Temperature ◽  
Response Thresholds ◽  
Temperature Manipulation ◽  
Sweating Threshold

Background Skin temperature is best kept constant when determining response thresholds because both skin and core temperatures contribute to thermoregulatory control. In practice, however, it is difficult to evaluate both warm and cold thresholds while maintaining constant cutaneous temperature. A recent study shows that vasoconstriction and shivering thresholds are a linear function of skin and core temperatures, with skin contributing 20 +/- 6% and 19 +/- 8%, respectively. (Skin temperature has long been known to contribute approximately 10% to the control of sweating). Using these relations, we were able to experimentally manipulate both skin and core temperatures, subsequently compensate for the changes in skin temperature, and finally report the results in terms of calculated core-temperature thresholds at a single-designated skin temperature. Methods Five volunteers were each studied on 4 days: (1) control; (2) a target blood propofol concentration of 2 micrograms/ml; (3) a target concentration of 4 micrograms/ml; and (4) a target concentration of 8 micrograms/ml. On each day, we increased skin and core temperatures sufficiently to provoke sweating. Skin and core temperatures were subsequently reduced to elicit peripheral vasoconstriction and shivering. We mathematically compensated for changes in skin temperature by using the established linear cutaneous contributions to the control of sweating (10%) and to vasoconstriction and shivering (20%). From these calculated core-temperature thresholds (at a designated skin temperature of 35.7 degrees C), the propofol concentration-response curves for the sweating, vasoconstriction, and shivering thresholds were analyzed using linear regression. We validated this new method by comparing the concentration-dependent effects of propofol with those obtained previously with an established model. Results The concentration-response slopes for sweating and vasoconstriction were virtually identical to those reported previously. Propofol significantly decreased the core temperature triggering vasoconstriction (slope = -0.6 +/- 0.1 degrees C.micrograms-1.ml-1; r2 = 0.98 +/- 0.02) and shivering (slope = -0.7 +/- 0.1 degrees C.micrograms -1.ml-1; r2 = 0.95 +/- 0.05). In contrast, increasing the blood propofol concentration increased the sweating threshold only slightly (slope = 0.1 +/- 0.1 degrees C.micrograms -1.ml-1; r2 = 0.46 +/- 0.39). Conclusions Advantages of this new model include its being nearly noninvasive and requiring relatively little core-temperature manipulation. Propofol only slightly alters the sweating threshold, but markedly reduces the vasoconstriction and shivering thresholds. Reductions in the shivering and vasoconstriction thresholds are similar; that is, the vasoconstriction-to-shivering range increases only slightly during anesthesia.

scholarly journals Nefopam and Alfentanil Additively Reduce the Shivering Threshold in Humans whereas Nefopam and Clonidine Do Not

2009 ◽  
Vol 111 (1) ◽  
pp. 102-109 ◽  
Author(s):  
Pascal Alfonsi ◽  
Andrea Passard ◽  
Valérie Gaude–Joindreau ◽  
Bruno Guignard ◽  
Daniel I. Sessler ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Therapeutic Hypothermia ◽  
Core Temperature ◽  
Individual Effect ◽  
Mean Skin Temperature ◽  
Ringer’S Solution ◽  
The Core ◽  
Individual Effects ◽  
Lactated Ringer's Solution ◽  
The Individual

Background Induction of therapeutic hypothermia is often complicated by shivering. Nefopam reduces the shivering threshold with minimal side effects. Consequently, nefopam is an attractive component for induction of therapeutic hypothermia. However, nefopam alone is insufficient; it will thus need to be combined with another drug. Clonidine and alfentanil each reduce the shivering threshold. This study, therefore, tested the hypothesis that nefopam, combined either with clonidine or alfentanil, synergistically reduces the shivering threshold. Methods For each combination, ten volunteers were studied on 4 days. Combination 1: (1) control (no drug); (2) nefopam (100 ng/ml); (3) clonidine (2.5 microg/kg); and (4) nefopam plus clonidine (100 ng/ml and 2.5 microg/kg, respectively). Combination 2: (1) control (no drug); (2) nefopam (100 ng/ml); (3) alfentanil (150 ng/ml); and (4) nefopam plus alfentanil (100 ng/ml and 150 ng/ml, respectively). Lactated Ringer's solution (approximately 4 degrees C) was infused to decrease core temperature. Mean skin temperature was maintained at 31 degrees C. The core temperature that increased oxygen consumption to more than 25% of baseline identified the shivering threshold. Results With nefopam and clonidine, the shivering thresholds were significantly lower than on the control day. The shivering threshold decreased significantly less than would be expected on the basis of the individual effects of each drug (P = 0.034). In contrast, the interaction between nefopam and alfentanil on shivering was additive, meaning that the combination reduced the shivering threshold as much as would be expected by the individual effect of each drug. Conclusions Nefopam and alfentanil additively reduce the shivering threshold, but nefopam and clonidine do not.

Meperidine and Alfentanil Do Not Reduce the Gain or Maximum Intensity of Shivering 

1998 ◽  
Vol 88 (4) ◽  
pp. 858-865 ◽  
Author(s):  
Takehiko Ikeda ◽  
Daniel I. Sessler ◽  
Farzin Tayefeh ◽  
Chiharu Negishi ◽  
Minang Turakhia ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Core Temperature ◽  
Maximum Intensity ◽  
Intensity Increase ◽  
Temperature Deviation ◽  
Kappa Agonist ◽  
Target Plasma ◽  
Opioid Administration ◽  
Venous Infusion ◽  
Lactated Ringer's Solution

Background Thermoregulatory shivering can be characterized by its threshold (triggering core temperature), gain (incremental intensity increase with further core temperature deviation), and maximum intensity. Meperidine (a combined mu- and kappa-agonist) treats shivering better than equianalgesic doses of pure mu-opioid agonists. Meperidine's special antishivering action is mediated, at least in part, by a disproportionate decrease in the shivering threshold. That is, meperidine decreases the shivering threshold twice as much as the vasoconstriction threshold, whereas alfentanil (a pure mu-agonist) decreases the vasoconstriction and shivering thresholds comparably. However, reductions in the gain or maximum shivering intensity might also contribute to the clinical efficacy of meperidine. Accordingly, we tested the hypothesis that meperidine reduces the gain and maximum intensity of shivering much more than alfentanil does. Methods Ten volunteers were each studied on three separate days: (1) control (no drug); (2) a target total plasma meperidine concentration of 1.2 microg/ml; and (3) a target plasma alfentanil concentration of 0.2 microg/ml. Skin temperatures were maintained near 31 degrees C, and core temperatures were decreased by central-venous infusion of cold lactated Ringer's solution until maximum shivering intensity was observed. Shivering was evaluated using oxygen consumption and electromyography. A sustained increase in oxygen consumption identified the shivering threshold. The gain of shivering was calculated as the slope of the oxygen consumption versus core temperature regression, and as the slope of electromyographic intensity versus core temperature regression. Results Meperidine and alfentanil administration significantly decreased the shivering thresholds. However, neither meperidine nor alfentanil reduced the gain of shivering, as determined by either oxygen consumption or electromyography. Opioid administration also failed to significantly decrease the maximum intensity of shivering. Conclusions The authors could not confirm the hypothesis that meperidine reduces the gain or maximum intensity of shivering more than alfentanil does. These results suggest that meperidine's special antishivering effect is primarily mediated by a disproportionate reduction in the shivering threshold.

scholarly journals Enhancing sweat rate using a novel device for the treatment of congestion in heart failure

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
D Aronson ◽  
Y Nitzan ◽  
S Petcherski ◽  
E Bravo ◽  
M Habib ◽  
...  
Keyword(s):  
Heart Failure ◽  
Weight Loss ◽  
Adverse Events ◽  
Skin Temperature ◽  
Core Temperature ◽  
Sweat Rate ◽  
Interquartile Range ◽  
Private Company ◽  
The Core ◽  
Sweat Production

Abstract Background Current treatment of fluid retention in heart failure (HF) relies primarily on diuretics. However, adequate decongestion is not achieved in many patients. Purpose To study the feasibility and short-term performance of a novel approach to remove fluids and sodium directly from the interstitial compartment by enhancing sweat rate. Methods We used a device designed to enhance fluid and salt loss via the eccrine sweat glands. Skin temperature in the lower body was increased to 35–38°, where the slope of the relationship between temperature and sweat production is linear. With this wearable device, the sweat evaporates instantaneously, thus avoiding the awareness of perspiration. The primary efficacy endpoint was the ability to increase skin temperature to the desired range without elevating the core temperature above normal range. A secondary efficacy endpoint was a clinically meaningful hourly sweat output, defined as ≥150 mL/h. The primary safety endpoint was any procedure-related adverse events. Results We studied 6 normal subjects and 10 HF patients with clinical evidence of congestion and median NT-proBNP of 602 pg/mL [interquartile range 427 to 1719 pg/mL]. Participants underwent 3 treatment sessions of up to 4h. Skin temperature increased to a median of 37.5°C (interquartile range 37.1–37.9°C) with the core temperature remaining unchanged. The median total weight loss during treatment was 219±67 g/h (Figure) with a range of 100–338 g/h. In 77% of cases, the average sweat rate was ≥150 mL/h. Systolic (P=0.25) and diastolic (P=0.48) blood pressure and heart rate (P=0.11) remained unchanged during the procedure. There were no significant changes in renal function and no procedure-related adverse events. Conclusion Enhancing sweat rate was safe and resulted in a clinically meaningful fluid removal and weight loss. Further evaluation of this concept is warranted. FUNDunding Acknowledgement Type of funding sources: Private company. Main funding source(s): AquaPass Inc Weight loss due to sweat

Core Cooling by Central Venous Infusion of Ice-cold (4°C and 20°C) Fluid

2000 ◽  
Vol 93 (3) ◽  
pp. 629-637 ◽  
Author(s):  
Angela Rajek ◽  
Robert Greif ◽  
Daniel I. Sessler ◽  
James Baumgardner ◽  
Sonja Laciny ◽  
...  
Keyword(s):  
Therapeutic Hypothermia ◽  
Core Temperature ◽  
Heat Balance ◽  
Heat Content ◽  
Partial Recovery ◽  
Central Venous ◽  
Metabolic Heat ◽  
Cold Fluid ◽  
Venous Infusion ◽  
Body Heat

Background Central venous infusion of cold fluid may be a useful method of inducing therapeutic hypothermia. The aim of this study was to quantify systemic heat balance and regional distribution of body heat during and after central infusion of cold fluid. Methods The authors studied nine volunteers, each on two separate days. Anesthesia was maintained with use of isoflurane, and on each day 40 ml/kg saline was infused centrally over 30 min. On one day, the fluid was 20 degrees C and on the other it was 4 degrees C. By use of a tympanic membrane probe core (trunk and head) temperature and heat content were evaluated. Peripheral compartment (arm and leg) temperature and heat content were estimated with use of fourth-order regressions and integration over volume from 18 intramuscular thermocouples, nine skin temperatures, and "deep" hand and foot temperature. Oxygen consumption and cutaneous heat flux estimated systemic heat balance. Results After 30-min infusion of 4 degrees C or 20 degrees C fluid, core temperature decreased 2.5 +/- 0.4 degrees C and 1.4 +/- 0.2 degrees C, respectively. This reduction in core temperature was 0.8 degrees C and 0.4 degrees C more than would be expected if the change in body heat content were distributed in proportion to body mass. Reduced core temperature resulted from three factors: (1) 10-20% because cutaneous heat loss exceeded metabolic heat production; (2) 50-55% from the systemic effects of the cold fluid per se; and (3) approximately 30% because the reduction in core heat content remained partially constrained to core tissues. The postinfusion period was associated with a rapid and spontaneous recovery of core temperature. This increase in core temperature was not associated with a peripheral-to-core redistribution of body heat because core temperature remained warmer than peripheral tissues even at the end of the infusion. Instead, it resulted from constraint of metabolic heat to the core thermal compartment. Conclusions Central venous infusion of cold fluid decreases core temperature more than would be expected were the reduction in body heat content proportionately distributed. It thus appears to be an effective method of rapidly inducing therapeutic hypothermia. When the infusion is complete, there is a spontaneous partial recovery in core temperature that facilitates rewarming to normothermia.

Reduction in the Shivering Threshold Is Proportional to Spinal Block Height

1996 ◽  
Vol 84 (6) ◽  
pp. 1327-1331 ◽  
Author(s):  
Kate Leslie ◽  
Daniel I Sessler
Keyword(s):  
Skin Temperature ◽  
Spinal Anesthesia ◽  
Skin Surface ◽  
Intravenous Fluid ◽  
Upper Body ◽  
Spinal Block ◽  
Cooling Rates ◽  
Ambient Temperatures ◽  
Ringer’S Solution ◽  
Lactated Ringer's Solution

Background Hypothermia is nearly as common, and may be as severe, during spinal and epidural anesthesia as during general anesthesia. The authors have proposed that thermoregulatory failure results when regional anesthesia increases apparent leg skin temperature to a level far exceeding actual leg skin temperature. Extensive dermatomal blocks will alter thermal input to the hypothalamus from a greater skin-surface area more than less extensive ones and thus might be expected to impair central thermoregulatory control more. Accordingly, they tested the hypothesis that reduction in the shivering threshold is directly related to the number of dermatomes blocked during spinal anesthesia. Methods Eleven men, aged 62 +/- 6 yr (mean +/- SD), undergoing urologic surgery were studied. Ice-cold lactated Ringer's solution was administered intravenously before spinal blockade and the shivering threshold (triggering core temperature) was established. Spinal anesthesia then was induced using a randomly assigned dose of 0.5% bupivacaine (2-4 ml). Again, sufficient cold lactated Ringer's solution was given to induce shivering. Tympanic membrane, ambient and skin temperatures were measured, and extent of block was defined by loss of temperature discrimination. Presence of shivering was evaluated by a blinded observer. Mean upper-body skin and ambient temperatures, cooling rates and intravenous fluid volumes at the two thresholds were compared using paired, two-tailed t tests (P < 0.05). Linear regression defined the relationship between reduction in shivering threshold and the number of dermatomes blocked. Results There were no significant differences between mean upper-body skin and ambient temperatures, cooling rates or intravenous fluid volumes at the control and spinal shivering thresholds. Spinal anesthesia reduced the shivering threshold in direct relation to the number of dermatomes blocked: delta threshold = 0.74 - 0.06 (dermatomes blocked); r2 = 0.58, P < 0.006. Conclusions Extensive spinal blockade impairs central thermoregulatory control more than less extensive blockade. Clinicians can thus anticipate more core hypothermia during extensive than during restricted spinal blockade.

Influence of Thermoregulatory Vasomotion and Ambient Temperature Variation on the Accuracy of Core-temperature Estimates by Cutaneous Liquid-crystal Thermometers

1997 ◽  
Vol 86 (3) ◽  
pp. 603-612 ◽  
Author(s):  
Takehiko Ikeda ◽  
Daniel I. Sessler ◽  
Danielle Marder ◽  
Junyu Xiong
Keyword(s):  
Liquid Crystal ◽  
Ambient Temperature ◽  
Skin Temperature ◽  
Temperature Variation ◽  
Core Temperature ◽  
Temperature Difference ◽  
Capillary Flow ◽  
The Core ◽  
Neck Temperature ◽  
Body Heat

Background Recently, liquid crystal skin-surface thermometers have become popular for intraoperative temperature monitoring. Three situations during which cutaneous liquid-crystal thermometry may poorly estimate core temperature were monitored: (1) anesthetic induction with consequent core-to-peripheral redistribution of body heat, (2) thermoregulatory vasomotion associated with sweating (precapillary dilation) and shivering (minimal capillary flow), and (3) ambient temperature variation over the clinical range from 18-26 degrees C. Methods The core-to-forehead and core-to-neck temperature difference was measured using liquid-crystal thermometers having an approximately 2 degrees C offset. Differences exceeding 0.5 degree C (a 1 degree C) temperature range) were a priori deemed potentially clinically important. Seven volunteers participated in each protocol. First, core-to-peripheral redistribution of body heat was produced by inducing propofol/desflurane anesthesia; anesthesia was then maintained for 1 h with desflurane. Second, vasodilation was produced by warming unanesthetized volunteers sufficiently to produce sweating; intense vasoconstriction was similarly produced by cooling the volunteers sufficiently to produce shivering. Third, a canopy was positioned to enclose the head, neck, and upper chest of unanesthetized volunteers. Air within the canopy was randomly set to 18, 20, 22, 24, and 26 degrees C. Results Redistribution of body heat accompanying induction of anesthesia had little effect on the core-to-forehead skin temperature difference. However, the core-to-neck skin temperature gradient decreased approximately 0.6 degree C in the hour after induction of anesthesia. Vasomotion associated with shivering and mild sweating altered the core-to-skin temperature difference only a few tenths of a degree centigrade. The absolute value of the core-to-forehead temperature difference exceeded 0.5 degree C during approximately 35% of the measurements, but the difference rarely exceeded 1 degree C. The core-to-neck temperature difference typically exceeded 0.5 degree C and frequently exceeded 1 degree C. Each 1 degree C increase in ambient temperature decreased the core-to-fore-head and core-to-neck skin temperature differences by less than 0.2 degree C. Conclusions Forehead skin temperatures were better than neck skin temperature at estimating core temperature. Core-to-neck temperature differences frequently exceeded 1 degree C (a 2 degrees C range), whereas two thirds of the core-to-forehead differences were within 0.5 degree C. The core-to-skin temperature differences were, however, only slightly altered by inducing anesthesia, vasomotor action, and typical intraoperative changes in ambient temperature.

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