Water balance

Abstract

1. 1. Water metabolism and salt metabolism are the chief factors in water balance. 2. 2. No water is available to the kidneys until the requirements of vaporization are satisfied. 3. 3. Normal kidneys need a urinary output of only 500 c.c. if they concentrate to maximum capacity, while severely damaged kidneys with low concentrating capacity (1.010 – 1.014) require nearly 1,500 c.c. of urine to excrete the same amount of solids. 4. 4. The average daily sodium chloride requirement of an adult is about 4.5 Gm. 5. 5. The loss of the chloride ion causes an alkalosis. The loss of the sodium ion causes an acidosis. 6. 6. The parenteral administration of fluids during the course of operations is a rational procedure. Such fluid should not be considered in calculating daily volume of fluid to be given but the salt content should be considered. 7. 7. A simple test of hydration is to measure the twenty-four hour urinary output, which should be approximately 1,500 c.c. 8. 8. In case of serious dehydration the water loss amounts to 6 per cent of the body weight. 9. 9. The clinical rule of Bartlett for determining the amount of sodium chloride required to bring the blood chlorides to normal in cases of hypochloremia is satisfactory. 10. 10. The indiscriminate use of hypotonic and hypertonic solutions is to be condemned. The routine use of 5 per cent glucose in physiologic salt solution is not physiologic in principle. 11. 11. The average patient unable to take fluids by mouth should receive 500 to 1,000 c.c. of physiologic salt solution. The balance of the water requirement should be given as 5 per cent glucose in distilled water. 12. 12. Patients with hyperthyroidism and liver damage may be given 10 per cent glucose in distilled water.