1. 10/5/2009 0 FLUIDS AND ELECTROLYTES Dr. Tanuj Paul Bhatia MBBS,MS

2. Fluid compartments 10/5/2009 1

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4. Total body water varies with… Age Gender Body fat (Fat contains less water) 10/5/2009 3

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6. Intracellular fluid 60% of body fluid Rich in : Potassium Magnesium proteins 10/5/2009 5

7. Extracellular fluid 40 % of body fluid Rich in : Sodium Chloride Bicarbonate Interstitial fluid : between cells, low in protein Intravascular fluid(Plasma) : High in protein Transcellular fluids – CSF, intraocular fluids, serous membranes (third space) 10/5/2009 6

8. Spacing First space: normal Second Space: interstitial - edema; Third Space: in places not normally found 10/5/2009 7

9. Fluid compartments are separated by membranes that are freely permeable to water. Movement of fluids due to: Hydrostatic pressure Osmotic pressure Examples: Capillary filtration (hydrostatic) pressure Capillary colloid osmotic pressure Interstitial hydrostatic pressure Tissue colloid osmotic pressure 10/5/2009 8

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11. Fluid balance 10/5/2009 10 Total for both is 2550ml

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13. Balance Fluid and electrolyte homeostasis is maintained in the body Neutral balance: input = output Positive balance: input > output Negative balance: input < output 10/5/2009 12

14. Regulators: organs & hormones Kidneys: regulates fluid volume, electrolytes, pH, waste; influenced by ADH & aldosterone Lungs: remove 500 cc fluid. Heart & blood vessels: regulate pressure. 10/5/2009 13

15. Aldosterone: REGULATES SODIUM and potassium balance. INCREASED ALDOSTERONE TO RETAIN SODIUM & excrete potassium in kidneys. ADH - CONTROLS WATER. ADH release causes kidney tubules to retain water 10/5/2009 14

16. Solutes – dissolved particles Electrolytes – charged particles Cations – positively charged ions Na+, K+ , Ca++, H+ Anions – negatively charged ions Cl-, HCO3- , PO43- Non-electrolytes - Uncharged Proteins, urea, glucose, O2, CO2 10/5/2009 15

17. MW (Molecular Weight) = sum of the weights of atoms in a molecule mEq (milliequivalents) = MW (in mg)/ valence mOsm (milliosmoles) = number of particles in a solution 10/5/2009 16

18. Solutes determine the tonicity of a solution 10/5/2009 17

19. tonicity 10/5/2009 18

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21. 20 Cell in a hypertonic solution

22. 21 Cell in a hypotonic solution

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24. 23 Movement of body fluids “ Where sodium goes, water follows.” Diffusion – movement of particles down a concentration gradient.Osmosis – diffusion of water across a selectively permeable membraneActive transport – movement of particles up a concentration gradient ; requires energy

25. Regulation of body water ADH – antidiuretic hormone + thirst Decreased amount of water in body Increased amount of Na+ in the body Increased blood osmolality Decreased circulating blood volume Stimulate osmoreceptors in hypothalamusADH released from posterior pituitaryIncreased thirst 24

26. 25 Result: increased water consumption increased water conservation Increased water in body, increased volume and decreased Na+ concentration

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28. Different components of renal function occur along thenephron. A normal glomerular filtration rate of 125 mL/minwould generate 180 L/day of filtrate containing 27,000 mmolofsodium. 10/5/2009 27

29. Approximately two thirds of the filtered sodium is absorbed in the PCT, 20% in the LOH, 7% in the DCT, and 3%in the CD; the net excretion of urinary sodium per day, as a fraction of the total sodium filtered load, is less than 1%. 10/5/2009 28

30. Disturbances of fluid and electrolyte balance 10/5/2009 29

31. Volume depletion Pure volume deficits – RARE Causes : 1. Comatosed patients with increased insensible loss (e.g. fever) 2. Diabetes insipdus Reflected biochemicalyby hypernatremia. 10/5/2009 30

32. Clinical features Due to depressed nervous system Lethargy Muscle rigidity Seizures Coma 10/5/2009 31

33. Treatment Replacement of adequate water by 5% Dextrose 10/5/2009 32

34. Volume and electrolyte depletion Due to extrarenal loss of body fluid Causes : Vomiting Diarrohoea Nasogastric suction Intestinal fistulae Intestinal obstruction Peritonitis 10/5/2009 33

35. Effects 10/5/2009 34

36. Effects 10/5/2009 35

37. Clinical features Sunken eyes Tongue – Dry and Coated Low urinary output Lab: Normal or Slightly reduced Serum Sodium Low urinary sodium 10/5/2009 36

38. Treatment Replacement of sodium deficit in addition to volume deficit by infusion of Isotonic saline, or Ringer’s lactate Depending on the severity of hyponatremia 10/5/2009 37

39. Volume overload Conservation of sodium and water following stress like surgery If fluid intake is excessive in immediate post op  fluid overload may occur. 10/5/2009 38

40. Tendency of fluid overload increases in patients with : Heart disease Liver disease Kidney disease 10/5/2009 39

41. Clinical features Peripheral edema Jugular venous distension Tachypnoea ( due to pulmonary edema) 10/5/2009 40

42. Treatment Mild overload: Restriction of sodium and water Severe overload : Diuretics 10/5/2009 41

43. Specific electrolyte disorders 10/5/2009 42

44. Hyponatremia Always associated with volume depletion Clinical features and treatment as discussed before 10/5/2009 43

45. Hypernatremia Serum Na levels > 150Mmol/l Causes: Renal dysfunction Cardiac failure Drug induced (NSAIDS, corticosteroids) 10/5/2009 44

46. Types of hypernatremia Euvolemic (pure water loss) Hypovolemic (more water lost than sodium) Hypervolemic (both gained but more sodium gained) 10/5/2009 45

47. Clinical features Pitting edema Puffiness of face Increased urination Dilated jugular veins Features of pulmonary edema 10/5/2009 46

48. Treatment Restriction of sodium and saline. Treatment of pulmonary edema. 10/5/2009 47

49. Hypokalemia Serum potassium levels <3.5 mEq/L Causes : Diarrhoea Villous tumor of rectum After trauma or surgery Gastric outlet obstruction Duodenal fistula 10/5/2009 48

50. Clinical features Slurred speech Muscular hypotonia Depressed reflexes Paralytic ileus Weakness of respiratory muscles Cardiac arrhythmias ECG shows prolonged QT interval , depessed ST segment and inversion of T waves 10/5/2009 49

51. Treatment Oral potassium 2g 6th hourly Intravenous KCl 40 mmol/litre given in 5% dextrose of normal saline, under ECG monitoring Max dose per hour = 20 mmol 10/5/2009 50

52. Hyperkalemia Normal range of K = 3.5-5 mEq/L Hyperkalemia >6 mEq/L Causes Renal failure Rapid infusion of potassium Massive blood transfusion Diabetic ketoacidosis Potassium sparing diuretics 10/5/2009 51

53. Dangerous condition, can cause sudden cardiac arrest. High serum potassium levels Peaked ‘T’ waves in ECG 10/5/2009 52

54. Treatment IV admin. Of 50 ml of 50% glucose with 10 units of soluble insulin, slowly. Hemodialysis if life threatening. Correction of acidosis. 10/5/2009 53

55. Hypermagnesimia It is rare Occurs because of renal failure or during treatment of pre eclampsia for which magnesium sulfate is given. 10/5/2009 54

56. Hypomagnesimia Causes : Malnutrition Large GI fluid loss Patients on Total Parenteral Nutrition 10/5/2009 55

57. Clinical features Hyperreflexia Muscle spasm Paraesthesia Tetany It mimics hypocalcemia Often associated with hypokalemia and hypocalcemia IV/Oral magnesium is needed. 10/5/2009 56

58. Hypocalcemia Causes Hypoparathyroidism Severe pancreatitis Severe trauma Crush injuries 10/5/2009 57

59. Clinical features Circumoralparasthesia Hyperactive DTRs Carpopedal spasm Adbdominal cramps Rarely, convulsions ECG shows prolonged Q-T interval 10/5/2009 58

60. Treatment Treatment of alkalosis, if present Intravenous calcium gluconate Vitamin D Oral calcium suplements 10/5/2009 59

61. Hypercalcemia Causes : Hyperparathyroidism Cancer with bony metastasis Sarcoidosis Prolonged immobilization 10/5/2009 60

62. Clinical features Fatigue Muscle weakness Depression Anorexia Constipation 10/5/2009 61

63. Treatment Expand ECF by IV normal saline Also increases urinary output and thus increasing calcium excretion. Hemodialysis in case of renal failure. 10/5/2009 62

64. THANK YOU 10/5/2009 63