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

The Effects of Body composition (Percent Fat) On Acclimatization to Heat

1981 ◽  
Vol 25 (1) ◽  
pp. 774-778
Author(s):  
Alex Loewenthal ◽  
David J. Cochran ◽  
Michael W. Riley
Keyword(s):  
Heart Rate ◽  
Weight Loss ◽  
Body Composition ◽  
Skin Temperature ◽  
Heat Exposure ◽  
Temperature Differential ◽  
Mean Skin Temperature ◽  
Physiological Variables ◽  
The Core ◽  
Rate Of Decay

Nine fully acclimatized men falling in the lean, medium and obese categories of body composition were observed during heat exposure periods for four days following acclimatization decay periods of various lengths in order to determine the effects of body composition on the decay and reinduction of acclimatization. The physiological variables taken into consideration were core temperature, “DuBois” mean skin temperature, heart rate, weight loss due to perspiration and the temperature differential between the core and surface. All of the men were subjected to an acclimatization schedule of twelve daily sessions in order to insure that they were all fully acclimatized. Three decay, or non-exposure, periods of four, eight and twelve days were each followed by four days of reinduction. It was determined that body composition does not affect the rate of decay or reinduction of acclimatization, although this parameter as well as the extent of decay and the duration of the reinduction period does affect the physiological variables monitored in this study.

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.

scholarly journals Thermal Behavior Augments Heat Loss Following Low Intensity Exercise

2019 ◽  
Vol 17 (1) ◽  
pp. 20 ◽  
Author(s):  
Nicole T. Vargas ◽  
Christopher L. Chapman ◽  
Blair D. Johnson ◽  
Rob Gathercole ◽  
Matthew N. Cramer ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Skin Temperature ◽  
Heat Loss ◽  
Core Temperature ◽  
Sweat Rate ◽  
Upper Body ◽  
Mean Skin Temperature ◽  
Thermal Discomfort ◽  
Low Intensity ◽  
Low Intensity Exercise

We tested the hypothesis that thermal behavior alleviates thermal discomfort and accelerates core temperature recovery following low intensity exercise. Methods: In a 27 ± 0 °C, 48 ± 6% relative humidity environment, 12 healthy subjects (six females) completed 60 min of exercise followed by 90 min of seated recovery on two occasions. Subjects wore a suit top perfusing 34 ± 0 °C water during exercise. In the control trial, this water continually perfused throughout recovery. In the behavior trial, the upper body was maintained thermally comfortable by pressing a button to receive cool water (3 ± 2 °C) perfusing through the top for 2 min per button press. Results: Physiological variables (core temperature, p ≥ 0.18; mean skin temperature, p = 0.99; skin wettedness, p ≥ 0.09; forearm skin blood flow, p = 0.29 and local axilla sweat rate, p = 0.99) did not differ between trials during exercise. Following exercise, mean skin temperature decreased in the behavior trial in the first 10 min (by −0.5 ± 0.7 °C, p < 0.01) and upper body skin temperature was reduced until 70 min into recovery (by 1.8 ± 1.4 °C, p < 0.05). Core temperature recovered to pre-exercise levels 17 ± 31 min faster (p = 0.02) in the behavior trial. There were no differences in skin blood flow or local sweat rate between conditions during recovery (p ≥ 0.05). Whole-body thermal discomfort was reduced (by −0.4 ± 0.5 a.u.) in the behavior trial compared to the control trial within the first 20 min of recovery (p ≤ 0.02). Thermal behavior via upper body cooling resulted in augmented cumulative heat loss within the first 30 min of recovery (Behavior: 288 ± 92 kJ; Control: 160 ± 44 kJ, p = 0.02). Conclusions: Engaging in thermal behavior that results in large reductions in mean skin temperature following exercise accelerates the recovery of core temperature and alleviates thermal discomfort by promoting heat loss.

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.

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.

Thermoregulatory Vasoconstriction Impairs Active Core Cooling

1995 ◽  
Vol 82 (4) ◽  
pp. 870-876. ◽  
Author(s):  
Andrea MD Kurz ◽  
Daniel I. Sessler ◽  
Franz Birnbauer ◽  
Udo M. Illievich ◽  
Christian K. Spiss
Keyword(s):  
Skin Temperature ◽  
Core Temperature ◽  
Neurosurgical Procedures ◽  
Air Cooling ◽  
Target Temperature ◽  
Active Cooling ◽  
The Core ◽  
Forced Air ◽  
Time Required ◽  
Core Cooling

Background Many clinicians now consider hypothermia indicated during neurosurgery. Active cooling often will be required to reach target temperatures &lt; 34 degrees C sufficiently rapidly and nearly always will be required if the target temperature is 32 degrees C. However, the efficacy even of active cooling might be impaired by thermoregulatory vasoconstriction, which reduces cutaneous heat loss and constrains metabolic heat to the core thermal compartment. The authors therefore tested the hypothesis that the efficacy of active cooling is reduced by thermoregulatory vasoconstriction. Methods Patients undergoing neurosurgical procedures with hypothermia were anesthetized with either isoflurane/nitrous oxide (n = 13) or propofol/fentanyl (n = 13) anesthesia. All were cooled using a prototype forced-air cooling device until core temperature reached 32 degrees C. Core temperature was measured in the distal esophagus. Vasoconstriction was evaluated using forearm minus fingertip skin-temperature gradients. The core temperature triggering a gradient of 0 degree C identified the vasoconstriction threshold. Results In 6 of the 13 patients given isoflurane, vasoconstriction (skin-temperature gradient = 0 degrees C) occurred at a core temperature of 34.4 +/- 0.9 degree C, 1.7 +/- 0.58 h after induction of anesthesia. Similarly, in 7 of the 13 patients given propofol, vasoconstriction occurred at a core temperature of 34.5 +/- 0.9 degree C, 1.6 +/- 0.6 h after induction of anesthesia. In the remaining patients, vasodilation continued even at core temperatures of 32 degrees C. Core cooling rates were comparable in each anesthetic group. However, patients in whom vasodilation was maintained cooled fastest. Patients in whom vasoconstriction occurred required nearly an hour longer to reach core temperatures of 33 degrees C and 32 degrees C than did those in whom vasodilation was maintained (P &lt; 0.01). Conclusions Vasoconstriction did not produce a full core temperature "plateau," because of the extreme microenvironment provided by forced-air cooling. However, it markedly decreased the rate at which hypothermia developed. The approximately 1-h delay in reaching core temperatures of 33 degrees C and 32 degrees C could be clinically important, depending on the target temperature and the time required to reach critical portions of the operation.

scholarly journals A case report: Glycopyrrolate for treatment of exercise-induced hyperhidrosis

2017 ◽  
Vol 5 ◽  
pp. 2050313X1772160
Author(s):  
Matthew Negaard ◽  
Christopher Anthony ◽  
Daniel Bonthius ◽  
Matthew Jepson ◽  
Britt Marcussen ◽  
...  
Keyword(s):  
Case Report ◽  
Core Temperature ◽  
Perceived Exertion ◽  
Sweat Rate ◽  
Case Reports ◽  
Return To Sport ◽  
Exercise Intolerance ◽  
Anticholinergic Medication ◽  
Sweat Production ◽  
Exercise Induced

Objective: Hyperhidrosis can cause dehydration and exercise intolerance. There are several case reports of extremely high sweat rates in athletes. We present as case report of a 17-year-old male with the highest sweat rate recorded in the literature (5.8 L/h). Our goal was to determine if glycopyrrolate, an anticholinergic medication with primarily anti-muscarinic effects that is known to decrease sweat production, would reduce the sweat rate of our subject in a controlled exercise setting. Methods: Our patient and a control subject were subjected to an exercise protocol consisting of running on a treadmill (5.4–6.7 mile/h at 1° of incline) in a warm climate-controlled chamber after receiving 0, 2, or 4 mg of glycopyrrolate. Core temperature, heart rate, rater of perceived exertion, and sweat rate were monitored in both subjects. Results: Glycopyrrolate dose was not significantly correlated with decreased sweat rate and maximal core temperature. However, the clinical effect of reducing the sweat rate was very strong. The improvement of the subject’s sweat rate allowed him to successfully return to sport. Conclusion: Our findings suggest that low-dose glycopyrrolate may be a safe and effective method of controlling exertional hyperhidrosis.

scholarly journals Effects of Casein Hydrolysate Ingestion on Thermoregulatory Responses in Healthy Adults during Exercise in Heated Conditions: A Randomized Crossover Trial

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 867
Author(s):  
Yasuyuki Sakata ◽  
Chikako Yoshida ◽  
Yuka Fujiki ◽  
Yutaka Matsunaga ◽  
Hirohiko Nakamura ◽  
...  
Keyword(s):  
Amino Acid ◽  
Skin Temperature ◽  
Core Temperature ◽  
Acid Concentration ◽  
Crossover Trial ◽  
Sweat Rate ◽  
Casein Hydrolysate ◽  
Amino Acid Concentration ◽  
Body Core Temperature ◽  
Body Core

Food ingestion has been shown to affect thermoregulation during exercise, while the impact of protein degradant consumption remains unclear. We investigated the effects of casein hydrolysate ingestion on thermoregulatory responses during exercise in the heat. In a randomized, placebo-controlled, double-blind, crossover trial, five men and five women consumed either 5 g of casein hydrolysate or placebo. Thirty minutes after ingestion, participants cycled at 60% VO2max until voluntary exhaustion wearing a hot-water (43 °C) circulation suit. Exercise time to exhaustion, body core temperature, forearm sweat rate, and forearm cutaneous vascular conductance did not differ different between the conditions. However, chest sweat rate and mean skin temperature increased upon casein hydrolysate ingestion compared with placebo during exercise. Increased chest sweat rate upon casein hydrolysate ingestion was associated with elevated sudomotor sensitivity to increasing body core temperature, but not the temperature threshold for initiating sweating. A positive correlation was found between chest sweat rate and plasma total amino acid concentration during exercise. These results suggest that casein hydrolysate ingestion enhances sweating heterogeneously by increasing peripheral sensitivity of the chest’s sweating mechanism and elevating skin temperature during exercise in the heat. However, the physiological link between plasma amino acid concentration and sweat rate remains unclear.

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