1. July 1

2. Fluids and electrolytes Joel Topf, MD Nephrology Attending St. John Hospital

3. http:// PBFluids .com

6. Question: What is 100%?

7. Answer: The percentage of hospital days that patients get electrolytes drawn

8. Question: What is 100%?

9. Fluids and electrolyte issues are ubiquitous The ability to screw up is ubiquitous 132 4.4 108 17 106 34 3.8

10. Fluids: Total body water

11. Ideal weight : Females: 45 kg Males: 50 kg Adjusted weight : ideal weight + 0.4 (actual body weight – ideal weight) + 2.3 kg for every inch over 5 feet

12. 67% 28 L 25% 11 L 8% 3 L Blood volume = 5 L

14. Intravenous fluids Dextrose Saline Ringers Lactate Plasma expanders Crystalloids

19. Dextrose Saline Ringers Lactate Plasma expanders

32. Loop diuretic resistance Situation Mechanism of diminished response Therapeutic response Renal failure Impaired delivery to tubular fluid Increased dose Nephrotic Syndrome Protein binding in the urine. Sodium avid nephron Increased dose Heart Failure Sodium avid nephron Increased frequency Cirrhosis Sodium avid nephron Increased frequency

35. Electrolyte Emergencies

47. Urine Osmolality 50 1200 Healthy Kidneys Concentrated urine Na + Dilute urine Na +

48. isosthenuria Urine Osmolality 50 1200 Healthy Kidneys 150 900 Chronic Kidney Disease 600 900 Excess ADH: • SIADH • CHF • Volume depletion 50 150 Absence of ADH: Diabetes insipidis 300 ESRD or acute renal failure

49. Concentrated urine Na + 600 900 Excess ADH: • SIADH • CHF • Volume depletion

54. Implications of hyponatremia

55. Adrogué and Madias NEJM 2000;342:1581.

56. The response to hyponatremia Low sodium concentration causes water to move into the cells. In the brain this causes an increase in ICP. Compensated chronic hyponatremia is essentially asymptomatic.

57. The problem with compensation The starting point is after compensation has reduced the amount of intracellular solute and the ICP Now, an over-eager intern sees the low sodium and starts an infusion of 3% NaCl to raise the sodium to normal. Sodium 108 The sodium draws water from the inside of the cells causing the brain to shrivel. The problem with interns This causes osmotic brain damage. Central pontine myelinolysis. This is lethal. Sodium 134

62. Clock and calendar are unreliable measures of chronicity

66. Renneboog B, Musch W, Et al. Am J Med 2006; 119: 71 e1-8.

69. 9% of patients had overly rapid (>12 mmol/L in 24 hours) correction of hyponatremia Potent CYP3A4 inhibitor: Caution with ketoconazole, itraconazole, clarithromycin, ritonavir and indinavir Placebo (n=21) Conivaptan 40mg/d (n=18) Baseline sodium 124.3 mmol/l 123.6 mmol/l Sodium at 48 hours 125.1 mmol/l 129.4 mmol/l Sodium at 96 hours 126.7 mmol/l 130.0 mmol/l Number with a Na rise of ≥ 6 mmol/L at 48 hours 0 (0%) 7 (38.9%) Number with a Na rise of ≥ 6 mmol/L at 96 hours 6 (28.6%) 12 (66.7%)

74. Sodium < 130 Sodium 130-134

76. 12 Increase Na 12 mmol/L in the first 24 hours. Increase Na 12 mmol/L in the first 24 hours.

80. Fluids: Total body water

81. 100 kg 70 kg Ideal weight : Females: 45 kg Males: 50 kg Adjusted weight : ideal weight + 0.4 (actual body weight – ideal weight) + 2.3 kg for every inch over 5 feet 60% H 2 O 45% H 2 O

85. Consequences and compensation