Protection of total body water content and absence of hyperthermia despite 2% body mass loss ('voluntary dehydration') in soldiers drinking ad libitum during prolonged exercise in cool environmental conditions

2010 ◽  
Vol 45 (14) ◽  
pp. 1106-1112 ◽  
Author(s):  
H. W. Nolte ◽  
T. D. Noakes ◽  
B. van Vuuren
1992 ◽  
Vol 119 (3) ◽  
pp. 419-422 ◽  
Author(s):  
A. A. Degen ◽  
M. Kam

SUMMARYDorper sheep are raised in extreme desert areas. Body mass loss and body fluid shifts were measured in Dorper rams denied water for 4 days and offered only wheat straw. The rams lost 16·3% body mass, 22·0% total body water volume, 35·1 % extracellular fluid volume and 41·7% plasma volume. On first drinking following dehydration, Dorpers were able to consume 19·7% of their dehydrated body mass and 100·3 % of their body mass loss. It was concluded that Dorpers can survive in harsh deserts through their ability to withstand dehydration and quickly replenish body mass losses when water becomes available.


PEDIATRICS ◽  
1968 ◽  
Vol 41 (6) ◽  
pp. 1146-1147
Author(s):  
W. Burmeister

I would like to comment on the article by J. C. Sinclair, et al. (Pediatrics, 39:724, 1967), "Metabolic Reference Standards for the Neonate." In the course of my work on the composition of the human organism, I also found the difference weight-extracellular fluid (= W-ECF). The fact that the composition of W-ECF is a rather constant one may be seen from the following calculation: if total body water content is assumed to be 71% of body mass with newborn and 61% with male adults, it follows that the proportion of intracellular water in W-ECF remains almost unchanged during growth.


2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S20-S21
Author(s):  
Sandrine O Fossati ◽  
Beth A Shields ◽  
Renee E Cole ◽  
Adam J Kieffer ◽  
Saul J Vega ◽  
...  

Abstract Introduction Nutrition is crucial for recovery from burn injuries, as severe weight (wt.) loss can lead to impaired immunity and wound healing, infections, skin graft failure, and mortality. Previous studies recommended avoiding more than 10% wt. loss, as this level resulted in increased infection rates. However, wt. loss is often not quantifiable during the critical illness phase, with severe edema masking non-fluid related body wt. changes. Energy (kcal) deficits can be used to estimate wt. loss until the edema has resolved, but previous studies in non-burn patients indicate that actual wt. loss is less than the commonly used 3500 kcal per pound of fat (7700 kcal per kg of fat). The objective of this performance improvement project was to evaluate nutritional intake and the resulting dry wt. change in severely burned patients. Methods This performance improvement project was approved by our regulatory compliance division. We performed a retrospective evaluation on patients with at least 20% total body surface area (TBSA) burns admitted for initial burn care to our intensive care unit over a 7-year period. Patients who died or who had major fascial excisions or limb amputations were excluded. Patients who did not achieve a recorded dry wt. after wound healing were not included in this analysis. Retrospective data were collected, including sex, age, burn size, kcal intake, kcal goal per the Milner equation using activity factor of 1.4, admission dry wt., dry wt. after wound healing (defined as less than 10% TBSA open wound), and days to dry wt. after wound healing. Descriptive statistics and linear regression were performed using JMP. Significance was set at p< 0.05. Results The 30 included patients had the following characteristics: 90% male, 30 ± 11 years old, 45% ± 15% TBSA burn. They received 2720 ± 1092 kcal/day, meeting 68% ± 24% kcal goal, and took approximately 53 ± 30 days from injury to achieve dry wt. after wound healing. These patients had wt. loss of 8 ± 8 kg from the kcal deficit of 69,819 ± 51,704 during this time period. The kcal deficit was significantly associated with wt. change [p < 0.001, R2 = 0.49, wt. change in kg = (-0.000103 x kcal deficit) – 1]. This translates to one kg of body wt. loss resulting from 9709 kcal deficit. Conclusions This performance improvement project found that an energy deficit of approximately 9700 kcal in our patients equates to 1 kg of body mass loss (4400 kcal deficit equates to 1 pound of body mass loss). These findings are similar to wt. loss studies in other patient populations and contrary to the commonly used 3500 kcal per pound of fat (7700 kcal per kg of fat).


2020 ◽  
Vol 87 (9-10) ◽  
pp. 84-88
Author(s):  
R. I. Vynogradov ◽  
O. S. Tyvonchuk ◽  
K. O. Nadiein ◽  
V. V. Moskalenko

Objective. To study metabolic changes and peculiarities of mineral balance depending on the common loop length while constructing of the simulated model of gastric shunting with one anastomosis during 60 days. Materials and methods. Experimental simulation of gastric minishunting with one anastomosis of various length of bilio-pancreatic loop was constructed on the rats. In 10 rats the anastomosis was formatted on level of half of total length of small intestine (Group I), and also in 10 - a third part of general length of small intestine (Group II). Control Group consisted of 5 rats. The indices of the extra body mass loss and metabolic changes were compared. Results. In the rats of Group I the index of the body mass loss have constituted 16.6% (41.7 gm), and of the Group II -20.6% (53.2 gm). Lowering of indices of mineral and prion metabolism, comparing preoperative values, was observed in both Groups. Dystrophic changes in osseous tissue of vertebral bodies of lumbar vertebral column were noted in animals of both Groups, more pronounced - in Group II. Conclusion. The protein and mineral metabolism disorders may be observed not only in large resection volume, but in exclusion of half and more segment of small bowel from general transit, using gastric shunting, what lacks significant advantages in the extra body mass loss, but leads to more profound metabolic disorders.


1969 ◽  
Vol 72 (1) ◽  
pp. 31-40 ◽  
Author(s):  
W. R. McManus ◽  
R. K. Prichard ◽  
Carolyn Baker ◽  
M. V. Petruchenia

SUMMARYThe use of tritiated water to estimate total body-water content of animals experiencing recovery from under-nutrition was studied.The time for equilibration of tritiated water (TOH), given intraperitoneally, with total body water (TBW) was determined in rabbits and in rats. As judged by the specific activity of blood water, equilibration had occurred by 76–125 min in the rabbit and did not appear to be affected by the plane of nutrition. However, between slaughter groups the specific activity of water obtained from the liver 180 min after injection of TOH was significantly different from the specific activity of water simultaneously obtained from the blood plasma. It is concluded that the liver is not a suitable tissue to use for testing achievement of equilibration.As judged by the specific activity of blood water compared to that of water from the whole body macerate, equilibration in mature rats either in stable body condition or undergoing rapid compensatory growth occurred in less than 60 min.A trial comparing TOH-space (corrected by 3% body weight) and actual TBW (by desiccation) was conducted on thirty rabbits which experienced under-nutrition followed by compensatory growth.Prior to under-nutrition the agreement between actual and estimated TBW was satisfactory and within 2·3%. During compensatory growth the agreement was poor— the TOH values over-estimating actual TBW by about 12%.A trial with mature rats confirmed the findings with rabbits. For rats in stable body weight the mean estimated TOH-space for fourteen animals was within 1·2% of the actual TBW. For fourteen rats undergoing compensatory growth the mean estimated TOH-space (corrected by 3% body weight) overestimated actual TBW by 6·2%.


2002 ◽  
Vol 138 (2) ◽  
pp. 221-226 ◽  
Author(s):  
A. ALLAN DEGEN ◽  
B. A. YOUNG

Body mass was measured and body composition and energy requirements were estimated in sheep at four air temperatures (0 °C to 30 °C) and at four levels of energy offered (4715 to 11785 kJ/day) at a time when the sheep reached a constant body mass. Final body mass was affected mainly by metabolizable energy intake and, to a lesser extent, by air temperature, whereas maintenance requirements were affected mainly by air temperature. Mean energy requirements were similar and lowest at 20 °C and 30 °C (407·5 and 410·5 kJ/kg0·75, respectively) and increased with a decrease in air temperature (528·8 kJ/kg0·75 at 10 °C and 713·3 kJ/kg0·75 at 0 °C). Absolute total body water volume was related positively to metabolizable energy intake and to air temperature. Absolute fat, protein and ash contents were all affected positively by metabolizable energy intake and tended to be related positively to air temperature. In proportion to body mass, total body water volume decreased with an increase in metabolizable energy intake and with an increase in air temperature. Proportionate fat content increased with an increase in metabolizable energy intake and tended to increase with an increase in air temperature. In contrast, proportionate protein content decreased with an increase in metabolizable energy intake and tended to decrease with an increase in air temperature. In all cases, the multiple linear regression using both air temperature and metabolizable energy intake improved the fit over the simple linear regressions of either air temperature or metabolizable energy intake and lowered the standard error of the estimate. The fit was further improved and the standard error of the estimate was further lowered using a polynomial model with both independent variables to fit the data, since there was little change in the measurements between 20 °C and 30 °C, as both air temperatures were most likely within the thermal neutral zone of the sheep. It was concluded that total body energy content, total body water volume, fat and protein content of sheep of the same body mass differed or tended to differ when kept at different air temperatures.


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