A COMPARISON BETWEEN DEHYDRATION FROM SALT LOSS AND FROM WATER DEPRIVATION

Abstract

In 1935 Kerpel-Fronius (1) demonstrated in rabbits that there are two distinct types of dehydration , depending upon whether the condition is associated with (1) a primary loss of salt or (2) a shortage of water not accompanied by a corresponding loss of salt. He pointed out that the former is characterized by circulatory disturbances , while the latter is characterized by thirst. In a later paper (2) Kerpel-Fronius referred to the two conditions as " Durstexsikkose und Salz-mangelexsikkose " and emphasized the fact that in animals dehydrated by loss of salt the principal loss of fluid is from tfie extracellular portion, including the blood, whereas in thirsting animals the water loss is distributed among all fluid compartments of the body, including the large intra-cellular portion. It is our impression that most physicians, including ourselves, have not been sufficiently aware of this important distinction and its therapeutic implications. The present report concerns itself with a study of these two types of dehydration in normal human subjects. The first two experiments (IA and IB) deal with abnormal loss of salt while the water intake is adequate. The other two experiments (IIA and IIB) deal with water deprivation with no abnormal loss of salt. PROCEDURE Experiment IA. Abnormal loss of salt; water intake adequate. Subject W. M., a healthy male, aged 26, was weighed and placed upon a salt-poor diet (containing approximately 1 gram of NaCl per day) for 6 days. After this preliminary period a Miller-Abbott tube (3) was passed to the proximal jejunum, the position of the tube was verified by x-ray examination, and constant suction was applied for 4 days. During this 4-day period no food was allQwed, but water was administered daily, either orally or in the form of intravenous 5 per cent dextrose in distilled water, in amounts sufficient to insure a normal urinary output. Also, the tube was irrigated frequently with measured amounts of tap water which 1 Aided by a grant from the Horace H. Rackham School of Graduate Studies. were figured in as part of the total oral intake. After removal of the Miller-Abbott tube, the subject was allowed salt-free water orally and intravenously for a period of 24 hours. On the following day he was given 3675 cc. of Ringer's solution (containing 33.1 grams of NaCl) intravenously. On the 2 final days he was allowed water ad libitum and a salt-poor diet. Each morning after voiding the subject was weighed. Daily measurements were made of the urine volume and of the losses of sodium and chloride in the urine and from the jejunal drainage.2 Frequent determinations 2 were also made of the hematocrit, plasma proteins, serum sodium, plasma chlorides, plasma carbon dioxide combining power, and of the arterial blood pressure. The subject was watched closely for any signs of dehydration. Experiment IB. Abnormal loss of salt; water intake adequate. Subject E. B., aged 21, was a normal male except for the presence of an orthostatic albuminuria. The procedure was identical to that in Experiment IA with the following exceptions. The Miller-Abbott tube suction was continued for 5 days instead of 4. Distilled water was used in place of tap water throughout the experiment. The salt-poor diet was resumed as soon as the Miller-Abbott tube had been removed. Three thousand cubic centimeters of Ringer's solution (containing 27 grams of NaCl) were administered on the second day following removal of the tube. Experiment IIA. Water deprivation; no abnormal loss of salt. Subject E. B. at the conclusion of Experiment IB was studied further. He continued on a salt-poor diet for 2 days and had water ad libitum. Then the dehydration period began and all fluids were eliminated for 4 days. On the 5th day his mouth was so dry he could not eat, so 600 cc. of distilled water were allowed. During the recovery period distilled water was allowed ad libi-tum, the diet remaining salt-poor as before. Blood studies and other measurements were carried out as in Experiments IA and IB. Also several determinations were made of the blood non-protein nitrogen. Experiment IIB. Water deprivation by means of total 2The chemical determinations were run in duplicate and standard methods were