the blood
is known as the known as the extracellular fluid, is contained in blood vessels as plasma and in tissue spaces. The body water may therefore be conveniently described as existing in three compartments; the blood vessels containing plasma; the tissue spaces containing interstitial fluid (including lymph); and the cells containing intracellular fluid (Gamble, 1942). The distribution of water in the different compartments in a man weighing 70 kg. (11 stones) is approximately as follows :?
including
intracellular fluid.
corpuscles, The rest,
Per cent of )f body bod; iirnirrTif
weight
Intracellular
(litres)
50
35
15
11
Extracellular? Tissue fluid
..
Plasma Total
3
..
70
49
(11 gallons)
Notes
Therapeutic notes
Water passes freely through the cell membrane and capillary wall which divide these compartments one from another, its direction and magnitude being determined by the amount of protein and salts in the various compartments. A dynamic osmotic equilibrium is maintained. There is an interchange of fluids between the gastro-intestinal tract and the blood, between the blood and interstitial fluid, and between the latter and the intracellular fluid. If the plasma volume is reduced, it is promptly restored from the interstitial fluid. The extracellular fluid constitutes what is called the internal environment of the body; it serves to transport nutrient and waste materials and to maintain an approximate constancy in hydrogen-ion concentration and osmotic pressure. It is this fluid which is primarily affected in dehydration.
on some remedies
XXIX.?DEHYDRATION
AND ITS TREATMENT,* Part I
hy R- N. CHAUDHURI, t.d.d.
^
m.b.
(Cal.),
m.k.c.p.
(Edin.),
(Wales)
>ofcssor of Tropical Medicine, School of Tropical Medicine, Calcutta
y considerations Physiological ?V ater constitutes 70 Water per cent of the body Weight. The portion contained within the cells, 'v
v cu us u t/L/u-i/
better understanding of the treatment, the i?l?gy ancj symptomatology are first described.
,.
^or
The body derives its water from beverages, from water contained in foods and from the water of oxidation of proteins, fats and carbohydrates. The average daily water intake in a temperate climate is about 2,600 ml. The output is also the same, consisting of 1,500 ml. in the urine, 600 ml. in perspiration (insensible), 350 ml. in The the expired air and 150 ml. in fasces. amounts lost depend greatly on the environment and on the fluid intake, but it should be noted that even if all water intake stops, the skin and lungs continue closing the usual amount, i.e. nearly 1,000 ml., while the amount excreted by the kidneys is reduced to about 500 ml. The
THE INDIAN MEDICAL GAZETTE
300
latter is the minimum urinary volume required for excretion of waste products. This unavoidable loss of 1,500 ml. may be an important factor in the sBtiology of dehydration. The water intake and output are greater in the tropics; a man doing muscular work may lose The as much as 10 litres of sweat in a day. body tends to keep its water content at a constant level by variations in the intake in response to thirst, and by variations in the urine volume to counterbalance changes in the water-loss by skin and lungs. Death occurs when the loss of water reaches approximately 15 per cent of body weight or 20 to 22 per cent of body water. The body's retention and distribution of water mainly depends on salts; in their absence it is not possible to maintain its volume. The extracellular fluid has sodium as the predominant basic ion (90 per cent) and chloride as the main acid ion (70 per cent); plasma differs from the interstitial fluid mainly in its high protein
The intracellular fluid has a different composition; its main ions are kations and phosphate anions. A proper concentration of sodium and chloride ions in the extracellular fluid is the main factor in maintaining its osmotic equilibrium with the fluid in the cells; of these two ions sodium is the If the concentration rises water most important. passes from the cells to the extracellular fluid and if it falls, a reverse movement of water takes place. Another function of sodium and chloride is that they play principal parts in the acid-base balance of the extracellular fluid. One of the important functions of the kidney is to regulate the volume and composition of the extracellular fluid. content.
electrolyte potassium
Sodium chloride is then the principal salt which the body requires. An adult needs 5 gm. a day, but it should be higher in hot climate. Any excess of salt above requirements is excreted mostly by way of urine. We get our salt from food and what is added during cooking and taken as a condiment. The total salt content of the body is about 1/400 of the body weight or about 6 oz. in a 70 kg. man, two-thirds of which are in plasma and tissue fluid, and nearly all the rest in alimentary The secretions, sweat and urine. body economizes salt more efficiently than water, for if no salt is taken, the kidneys practically stop excreting salt as soon as the plasma level falls below normal. But if in addition to the stoppage of salt intake there is abnormal loss of sodium chloride by vomiting, etc., a state of '
.
hypochlorsemia develops. General causes oj dehydration.?Dehydration refers to depletion of water and salt and is caused by excessive loss of body fluids without adequate intake of food, chloride and water to
make up for the loss. If a person does not take fluids, he may lose considerable amounts of water through the lungs and skin, even
[July,
1949
though its excretion in the urine is reduced. The losses are increased if sweating is profuse as at high environmental temperature (e.g. heat cramps, heat exhaustion) or if the respiration rate is rapid as in acute febrile diseases like pneumonia. Patients sometimes refuse to take water or other drink, may be too weak to ask for it, or may not be given any at all if in states of coma. After operation a patient may lose fluid through sweat which is promoted by extra blankets or hot water bottles. More serious dehydration occurs from persistent vomiting and acute or chronic diarrhoea. In acute poisoning with violent vomiting and diarrhoea serious salt and water deficiency may develop?a fact which is apt to be forgotten in treatment. A rare but important cause is gastric or intestinal suction drainage, in itself a valuable method of treatment, which can cause withdrawal of a large amount of sodium and chloride ions. In Addison's disease there is failure of the cortical hormone of the suprarenal gland causing excessive secretion of sodium chloride and water in the urine. Shock is often associated with dehydration. Clinical manifestations.?It is now recognized that dehydration may arise from primary loss of water or be secondary to a reduction in the salt content of the body. Although in clinical practice, the two conditions are often more or less combined, it is important to know which deficiency is predominant, as the mechanism of production and treatment differ in each case. Water
deficiency
This occurs from inability to swallow or obtain food and water owing to great weakness, coma or other causes. Ship-wrecked men in boats and men lost in desert suffer from this kind of defiStarvation is a well-known cause. ciency. Water is lost through the lungs, skin and urine, but there is no significant loss of sodium The extracellular fluid therefore chloride. becomes hypertonic, but tends to maintain itself by withdrawing water from the cells. Because of this cellular desiccation thirst is pronounced; the voice is husky and dryness of mouth makes swallowing difficult. The patient looks ill and has a peculiar pinched The urine is conappearance of the face. centrated, low in volume with a specific gravity above 1030 and has sodium chloride in it. Although weakness is progressive, the circulation is "well maintained and there is no reduction of blood volume and no renal failure until late, when mental power becomes impaired and there may be confusion and hallucinations. The patient retains the power of absorbing water and may recover rapidly after water ingestion. In this form of deficiency the water loss is twice as much from the intracellular as from the extracellular fluid
(Black, 1945).
is known as the known as the extracellular fluid, is contained in blood vessels as plasma and in tissue spaces. The body water may therefore be conveniently described as existing in three compartments; the blood vessels containing plasma; the tissue spaces containing interstitial fluid (including lymph); and the cells containing intracellular fluid (Gamble, 1942). The distribution of water in the different compartments in a man weighing 70 kg. (11 stones) is approximately as follows :?
including
intracellular fluid.
corpuscles, The rest,
Per cent of )f body bod; iirnirrTif
weight
Intracellular
(litres)
50
35
15
11
Extracellular? Tissue fluid
..
Plasma Total
3
..
70
49
(11 gallons)
Notes
Therapeutic notes
Water passes freely through the cell membrane and capillary wall which divide these compartments one from another, its direction and magnitude being determined by the amount of protein and salts in the various compartments. A dynamic osmotic equilibrium is maintained. There is an interchange of fluids between the gastro-intestinal tract and the blood, between the blood and interstitial fluid, and between the latter and the intracellular fluid. If the plasma volume is reduced, it is promptly restored from the interstitial fluid. The extracellular fluid constitutes what is called the internal environment of the body; it serves to transport nutrient and waste materials and to maintain an approximate constancy in hydrogen-ion concentration and osmotic pressure. It is this fluid which is primarily affected in dehydration.
on some remedies
XXIX.?DEHYDRATION
AND ITS TREATMENT,* Part I
hy R- N. CHAUDHURI, t.d.d.
^
m.b.
(Cal.),
m.k.c.p.
(Edin.),
(Wales)
>ofcssor of Tropical Medicine, School of Tropical Medicine, Calcutta
y considerations Physiological ?V ater constitutes 70 Water per cent of the body Weight. The portion contained within the cells, 'v
v cu us u t/L/u-i/
better understanding of the treatment, the i?l?gy ancj symptomatology are first described.
,.
^or
The body derives its water from beverages, from water contained in foods and from the water of oxidation of proteins, fats and carbohydrates. The average daily water intake in a temperate climate is about 2,600 ml. The output is also the same, consisting of 1,500 ml. in the urine, 600 ml. in perspiration (insensible), 350 ml. in The the expired air and 150 ml. in fasces. amounts lost depend greatly on the environment and on the fluid intake, but it should be noted that even if all water intake stops, the skin and lungs continue closing the usual amount, i.e. nearly 1,000 ml., while the amount excreted by the kidneys is reduced to about 500 ml. The
THE INDIAN MEDICAL GAZETTE
300
latter is the minimum urinary volume required for excretion of waste products. This unavoidable loss of 1,500 ml. may be an important factor in the sBtiology of dehydration. The water intake and output are greater in the tropics; a man doing muscular work may lose The as much as 10 litres of sweat in a day. body tends to keep its water content at a constant level by variations in the intake in response to thirst, and by variations in the urine volume to counterbalance changes in the water-loss by skin and lungs. Death occurs when the loss of water reaches approximately 15 per cent of body weight or 20 to 22 per cent of body water. The body's retention and distribution of water mainly depends on salts; in their absence it is not possible to maintain its volume. The extracellular fluid has sodium as the predominant basic ion (90 per cent) and chloride as the main acid ion (70 per cent); plasma differs from the interstitial fluid mainly in its high protein
The intracellular fluid has a different composition; its main ions are kations and phosphate anions. A proper concentration of sodium and chloride ions in the extracellular fluid is the main factor in maintaining its osmotic equilibrium with the fluid in the cells; of these two ions sodium is the If the concentration rises water most important. passes from the cells to the extracellular fluid and if it falls, a reverse movement of water takes place. Another function of sodium and chloride is that they play principal parts in the acid-base balance of the extracellular fluid. One of the important functions of the kidney is to regulate the volume and composition of the extracellular fluid. content.
electrolyte potassium
Sodium chloride is then the principal salt which the body requires. An adult needs 5 gm. a day, but it should be higher in hot climate. Any excess of salt above requirements is excreted mostly by way of urine. We get our salt from food and what is added during cooking and taken as a condiment. The total salt content of the body is about 1/400 of the body weight or about 6 oz. in a 70 kg. man, two-thirds of which are in plasma and tissue fluid, and nearly all the rest in alimentary The secretions, sweat and urine. body economizes salt more efficiently than water, for if no salt is taken, the kidneys practically stop excreting salt as soon as the plasma level falls below normal. But if in addition to the stoppage of salt intake there is abnormal loss of sodium chloride by vomiting, etc., a state of '
.
hypochlorsemia develops. General causes oj dehydration.?Dehydration refers to depletion of water and salt and is caused by excessive loss of body fluids without adequate intake of food, chloride and water to
make up for the loss. If a person does not take fluids, he may lose considerable amounts of water through the lungs and skin, even
[July,
1949
though its excretion in the urine is reduced. The losses are increased if sweating is profuse as at high environmental temperature (e.g. heat cramps, heat exhaustion) or if the respiration rate is rapid as in acute febrile diseases like pneumonia. Patients sometimes refuse to take water or other drink, may be too weak to ask for it, or may not be given any at all if in states of coma. After operation a patient may lose fluid through sweat which is promoted by extra blankets or hot water bottles. More serious dehydration occurs from persistent vomiting and acute or chronic diarrhoea. In acute poisoning with violent vomiting and diarrhoea serious salt and water deficiency may develop?a fact which is apt to be forgotten in treatment. A rare but important cause is gastric or intestinal suction drainage, in itself a valuable method of treatment, which can cause withdrawal of a large amount of sodium and chloride ions. In Addison's disease there is failure of the cortical hormone of the suprarenal gland causing excessive secretion of sodium chloride and water in the urine. Shock is often associated with dehydration. Clinical manifestations.?It is now recognized that dehydration may arise from primary loss of water or be secondary to a reduction in the salt content of the body. Although in clinical practice, the two conditions are often more or less combined, it is important to know which deficiency is predominant, as the mechanism of production and treatment differ in each case. Water
deficiency
This occurs from inability to swallow or obtain food and water owing to great weakness, coma or other causes. Ship-wrecked men in boats and men lost in desert suffer from this kind of defiStarvation is a well-known cause. ciency. Water is lost through the lungs, skin and urine, but there is no significant loss of sodium The extracellular fluid therefore chloride. becomes hypertonic, but tends to maintain itself by withdrawing water from the cells. Because of this cellular desiccation thirst is pronounced; the voice is husky and dryness of mouth makes swallowing difficult. The patient looks ill and has a peculiar pinched The urine is conappearance of the face. centrated, low in volume with a specific gravity above 1030 and has sodium chloride in it. Although weakness is progressive, the circulation is "well maintained and there is no reduction of blood volume and no renal failure until late, when mental power becomes impaired and there may be confusion and hallucinations. The patient retains the power of absorbing water and may recover rapidly after water ingestion. In this form of deficiency the water loss is twice as much from the intracellular as from the extracellular fluid
(Black, 1945).
