Amount Of Fluid Intake Research Articles

Effect of intrauterine growth retardation on postnatal weight change in preterm infants

To investigate the cause or causes of early postnatal weight change, we measured total body water and fluid and energy balances in 14 preterm infants who were appropriate in size for gestational age (AGA) and in 5 weight-matched, preterm, small-for-gestational-age (SGA) infants. On the first day of life, AGA and SGA infants had the same weight and total body water content. At 6 +/- 2 days (mean +/- SD), AGA infants had had significant weight loss (94 +/- 45 gm) and body water loss (67 +/- 80 ml), whereas weight and total body water content in the SGA infants at the same age (5 +/- 1 days) did not differ from the values at birth. Loss of weight and total body water in AGA infants was accompanied by a greater diuresis than in SGA infants at the same amount of fluid intake. At the end of week 1, AGA and SGA infants had the same total energy expenditure (184 +/- 33 vs 171 +/- 17 kJ.kg-1 x day-1); energy intake, which had exceeded total energy expenditure from the third day of life and beyond, already provided 188 +/- 46 (AGA) or 209 +/- 109 kJ.kg-1 x day-1 (SGA), respectively, for energy storage. Nitrogen balance was positive. Subsequent weight gain occurred at the same rate in AGA and SGA infants; both total body water and solids increased. Energy intake, total energy expenditure, and the amount of energy stored (measured during stable weight gain on a regimen of full enteral feedings) had significantly increased compared with week 1, but both groups maintained similar energy storage.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of diuretics, hormonal derangements, and clinical setting of hyponatremia in medical patients.

Because hyponatremia is frequently associated with preceding diuretic treatment and unrestricted fluid intake--conditions which have not been addressed sufficiently in published literature--we studied the pathophysiology and the clinical setting of such hyponatremia in a large group of internal medicine patients. We observed: a) Of an initial 310 patients with chemical hyponatremia only 204 (64%) had an associated plasma hypoosmolality. Since a normal plasma osmolality excludes a disturbance of water metabolism only the 204 patients with hypoosmolar hyponatremia were included in the study. This data shows that plasma osmolality is an essential measurement in any evaluation of hyponatremia. b) In 204 consecutive patients with hypoosmolar hyponatremia the electrolyte disturbance was related to advanced congestive cardiac failure in 25%, decompensated liver cirrhosis in 18%, volume contraction in 28%, syndrome of inappropriate antidiuretic hormone secretion in 19% and renal insufficiency in 4%. c) Plasma vasopressin was measurable in 90% of the 204 patients. It is known that radioimmunoassays to measure vasopressin fail to reliably detect low concentrations of circulating vasopressin (less than 0.5 pg/ml). It may therefore be stated that hypoosmolar hyponatremia was generally characterized by a failure of antidiuretic hormone suppression. d) Mean daily fluid intake of hyponatremic patients was 2.35 +/- 0.15 l. In the presence of stimulated vasopressin this large a fluid intake is bound to worsen the severity of hyponatremia. e) Of 204 patients 126 were treated with diuretics at the time of study. In these patients hyponatremia worsened during such treatments and was associated with evidence of prerenal azotemia. However there were no significant differences between diuretic-treated and -untreated patients with respect to plasma vasopressin stimulation and amount of fluid intake.(ABSTRACT TRUNCATED AT 250 WORDS)

Osmotic factors in restitution from thermal dehydration in rats

The degree of voluntary dehydration after thermal dehydration was assessed while supplying drinking water of varying NaCl concentrations. Adult male albino rats were exposed to a hot-dry environment (dry bulb temp 36 degrees C; relative humidity 20%) for 6-8 h, and dehydration of 7% body wt was induced. After dehydration the rats were divided into three groups, and distilled water and 0.45 or 0.9% NaCl solution was given ad libitum. The amount of fluid intake reached an equilibrium in 6-12 h; the 0.45 and 0.9% NaCl groups regained almost all lost water, whereas the distilled water group regained only half. During rehydration the 0.45 and 0.9% NaCl groups gained Na by approximately 430-650 mueq and lost K by 90-130 mueq, whereas the distilled water group lost Na slightly and K by 80 mueq/100 g body wt. As for the electrolyte balance during thermal dehydration, rats excreted Na and K into urine and saliva. Na loss was 200 mueq/100 g, almost all of which was derived from the interstitial space of skin and skeletal muscle, and K loss was 230 mueq/100 g, almost all of which was derived from intracellular space of skeletal muscle. Total cation loss (Na, K) during thermal dehydration, including K excretion during rehydration, was 510-560 mueq/100 g, which was almost identical to the Na gained by rats given 0.45 or 0.9% NaCl solution. These results suggest that voluntary dehydration is caused by the dilutional inhibition of drinking due to loss of electrolytes during thermal dehydration.

The use of X rays as the unconditioned stimulus in five-hundred-day-old rats.

Attempts were made to resolve conflicting reports on the threshold dose for the unconditioned stimulus (US) of ionizing radiation as an aversion to saccharin. Earlier studies employed both the simultaneous presentation of conditioned stimulus (CS) and US and the trace conditioning technique, and although some investigators have been unable to demonstrate the conditioned aversion with doses lower than 200 r, others were able to show it with total doses as low as 10 r of gamma radiation over a wide variety of dose rates. These investigations, however, were limited to animals ranging in age from 60 to 120 days. Since effects of x irradiation on rats have been shown to be a function of age, the present study was undertaken in an attempt to condition an aversion to saccharin fluid with x rays as the US in rats older than those used in previous studies. In addition, the strength of the saccharin aversion was studied as a function of both dose and amount of saccharin fluid (CS) ingested prior to irradiation. Male Wistar rats, 500 days old, were whole-body irradiated with 50- to 350-r doses of 250-kv x rays at 30 r/min, and control rats were sham- irradiated. On themore » day of irradiation, 0.1% saccharin fluid was offered the animals. Twenty-four hr after irradiation, two bottles were attached to each cage, one containing tap water and the other containing saccharin fluid. At the end of a 48-hr preference test the bottles were removed and the total fluid consumption and the S score were determined. The S score is equal to the proportion of the total fluid consumption that was saccharin. There was no significant difference between the S scores or total fluid intake for the 6 irradiated groups conditions gave rise to significantiy different consumption of saccharin fluid presented as a CS, the deprivation condition has no apparent effect on the amount of fluid intake or the S score for a postirradiation test. When the groups are reconstituted on the basis of the amount of saccharin fluid consumed in the CS, again no effect is noted on the two postirradiation measures. The threshold for the conditioned aversion was between 0 and 50 r and an increase in the roentgen dose up to 350 r had no effect. Conditioned aversion can be obtained as readily with mature animals as with young animals. The threshold for this effect is close to that found earlier in 60- to 120-day-old rats ( approximates 10 r). (BBB)« less

Recent observations in the study of asthma due to food allergy

An allergic individual responding to the ingestion of codfish with an asthmatic reaction was kept under close observation for a short time and the following was revealed: 1. 1. When the patient was on a ketogenic diet with a fair amount of fluid intake, no protection against the asthmatic attacks was obtained. A high carbohydrate diet gave very little protection. 2. 2. When the water intake was low in connection with the ketogenic diet, the reaction was worse and the same is true in case of the high carbohydrate diet. 3. 3. When the patient was on a high fluid intake in connection with the relatively high carbohydrate diet, full protection was obtained while the patient was up and about indoors, but this failed when the patient became quite active outdoors, and later developed an upper respiratory infection. The administration of a solution of glucose was just as effective in controlling the allergic reactions in this case as adrenalin. Severe asthmatic attacks required intravenous glucose, while the mild attacks could be taken care of with glucose which was given orally. The effect of glucose is most interesting in that adrenalin which has long been used to control allergic reactions also raises the blood sugar. No definite conclusions can be drawn from the observations in this one case, but the results are significant enough to warrant further study in a more extensive way with other cases of food allergy. Further work will soon be in progress.