FLUID AND ELECTROLYTE BALACE IN HUMANSpptx

Introduction to fluid and electrolytes, characteristics of specific fluids and electrolytes, abnormalities of electrolyte disturbances

1. Fluid & Electrolyte Balance ABHITOSH DEBATA , Dept of OMFS

2. CONTENTS HOMEOSTASIS TERMINOLOGIES BRIEF INTRODUCTION TO FLUID AND ELECTROLYTES CHARACTERISTICS OF SPECIFIC FLUIDS AND ELECTROLYTES ELECTROLYTE ABNORMALITIES CONCLUSION REFERENCES

3. Is defined as maintenance of static or constant conditions in the internal environment. - Guyton HOMEOSTASIS

4. 4

5. Electrolyte : Is a substance containing free ions that behaves as an electrically conductive medium… Osmosis : Net movement of the solvent across the semi permeable membrane from a region of high solute potential to an area of low solute potential.

6. Osmotic Pressure : Force per unit area or pressure required to prevent the passage of water through a selectively permeable membrane & into a solution of greater or equivalent concentration Reverse Osmosis : Solvent moving from a region of high solute conc to a region of low solute concentrate by applying pressure in excess of the osmotic pressure.

7. Osmolarity  is defined as the number of osmoles of solute per liter (L) of solution. NaCl solution has an osmolarity of 2 osmol /L. Osmolality  is defined as the number of osmoles of solute per kilogram of solvent. It is expressed in terms of osmol /kg or Osm /kg .

8. Body fluids Water constitutes an average 50% to 70% of the total body weight Young males - 60% of total body weight Older males – 52% Young females – 50% of total body weight Older females – 47% Variation of ±15% in both group is normal Obese have 25 to 30% less body water than lean people. Infants - 75 to 80% Child - 65% at one year of age

9. Daily loss of body water Insensible water loss Cannot be precisely regulated

10. D istribution of body fluids

11. Difference betwEEn ecf & icf EXTRACELLULAR INTRACELLULAR Main constituent – Na+ K+ , MG , sulfate , phosphate Chief anion – CL- Hpo2 , sulfate ions Traces of k , ca , mg , ph,s Traces of NA+ ,CL- , no CA 15 - 20 litre in an avg adult(70kgs) 25 – 40 litre in an avg adult(70kgs)

12. To summarize in 70Kg male TBW – 42 lts ICF – 28 lts Extra vascular fluid – 10.5lts ECF – 14 lts Intravascular fluid – 3.5lts Blood volume = Plasma volume + RBC volume = 8% of BW = 5.6 lt approx.

13. MOVEMENT OF BODY FLUIDS - Diffusion - Osmosis - Active transport

14. Water balance Intake Regulation Driving force for intake .........thirst  of 10% plasma volume ↓ D ry mouth ↓ hypothalamic thirst centre ↓ Drink

15. Anti-diuretic hormone (vasopressin)

16. Inappropriate Stimuli of ADH Rele ase Narcotics Nicotine Vincristine Carbamazepine Chlorpropamide

17. 19

18. Input & Output of water

19. Sodium –Potassium Pump

20. Clinical Evaluation Changes in BW… Water loss Degree of Dehydration 4% of body wt Mild 6% “ “ Moderate 8% “ “ Severe Normal urinary output Adult 0.5-2cc/kg/hr Child 2cc/kg/hr

21. FLUID THERAPY

22.  0.9% NaCl (normal saline)  isotonic  0.25% NaCl  hypotonic  0.45% NaCl  hypotonic  2.5% dextrose  hypotonic  Lactated Ringer's solution  isotonic  D5W (acts as a hypotonic solution in body)  isotonic   D5 NaCl  hypertonic  D5 in Lactated Ringer's  hypertonic  D5 0.45% NaCl  hypertonic    

23. Fluid therapy Route……

24. Fluid types Crystalloids and colloids 3ml of crystalloids = 1ml of colloid (blood for intravascular replacement) Crystalloids 1. Molecular wt <8000 daltons 2.      Replaces mainly extracellular volume E.g. a.    Normal saline. b.     5% dextrose c.     Ringer’s lactate 3. Shorter intravascular half life 4. In trauma it stabilizes the haemodyNamics in 3 hrs

25. Colloids 1.    Molecular wt > 8000 daltons 2.    Replace intravascular volume E.g. a.    Serum albumin. b.     Human plasma. c.     Synthetic plasma expanders. i .           Gelatin solution ii.         Dextrans 3. Longer intravascular half life 4. In trauma it stabilizes the haemodyNamics in 2 hrs

26. IV fluids 0.9% Sodium Chloride – iso osmolar with plasma and ECF hence Called normal saline… serves a good replacement solution for ECF volume deficient… chloride content - higher than that of plasma infusion → too much of normal saline may produce hyperchloraemic acidosis… IndiCation : ECF def in the presence of hyperNatremia , hypochloremia & metabolic alkylosis …

27. Dextrose 5% in water It provides 50gms of dextrose / l . It is slightly hypertonic to plasma after infusion dextrose is metabolized → water is left in the ECF… too much of 5% dextrose may Cause dilution and hypotonicity of ECF and water loading, if kidneys are not functioning normally. 100ml --- dextrose 5gm Dextrose 5% with 0.9% of saline . Its twice as hypertonic as plasma… However within a few hours glucose is used and there is no signifiCant change in the plasma tonicity… 100ml ----dextrose 5 gm, NaCl .9 gm, water

28. Lactated ringers solution . This is slightly hypo osmolar compared to plasma & contains Na, K, Ca, Cl & Lactate... Its good substitute for gastrointestiNal and other ECF fluid deficits in the absence of gross abnormalities of concentration Used in correcting metabolic acidosis…. Should not be given in patients with liver diseases and in presence of lactic acidosis.

29. Ringers acetate solution . - slightly hypo osmolar to plasma… - main use is as a replacement for ECF deficits in patients with damaged liver or lactic acidosis.. - helps in correction of mild to moderate metabolic acidosis. 0.45% sodium chloride in 5% dextrose solution - It is used as mainteNance fluid in postoperative period. - Provides sodium for reNal adjustment of sodium concentration in the serum. - Potassium may be added to be used for mainteNance requirements in uncompliCated pt requiring only a short period of parenteral fluids.

30. Hypertonic saline solution 1.8 % sodium chloride - Indicated in correction of pts with symptomatic hyponatraemia who Can not be given too much of water volume due to oliguria or anuria . 7.2-7.5 % sodium chloride - Studies have shown that even with 50% blood loss a small volume of 7.2-7.5% NaCl restores the Cardiac output and blood pressure within one minute. - This saline is given through a peripheral vein very fast over 2 to 5 mins . And this results in rise in the plasma sodium level and plasma osmolality Causing a shift of body water in the vascular tree

31. Colloid solutions Human plasma Used for resuscitation of shock patient and for mainteNance of I.V. fluid therapy it has a composition and osmolality similar to ECF. Human Albumin 20% purified human albumin is commercially available. Its volume expansion Capacity is 400 per cent. Rarely, aNaphylactoid reaction has been reported with albumin and may Cause post resuscitation hypotension.

32. The usual volume of fluid intake necessary. The choice of IV fluid type. Three electrolytes considered when choosing an IV solution.

33. In general after dentoalveolar surgery IN otherwise healthy patient requires a relatively physiologic IV solution with some calories during and after surgery, which can be provided IN combination WITH crystalloid solutions, such as 5% dextrose in a 0.45% sodium chloride solution to which 20 mEq of potassium chloride per liter MAY BE added.

34. ClassifiCation of Body Fluid Changes/disorders Disorders in the fluid balance are Classified in three general Categories. Disturbances of - Volume. - Concentration. - Composition.

35. Causes of ECF deficit 1. Loss of GI fluids due to: a. Vomiting. b. Diarrhea. c. Nasogastric suction. d. Fistular draiNage . 2. soft tissue injuries and infections. 3. IntraabdomiNal and Intraperitoneal inflammatory processes. 4. Burns. 5. Insensible losses 6. Sweat.

36. Causes of ECF excess Iatrogenic Secondary to reNal insufficiency Cirrhosis Sodium retention Mineralocorticoids NSAIDS

37. CAUSES OF VOLUME DEFICIT Failure to absorb or reabsorb water. Complete sudden cessation of intake. Prolonged diminished intake. Difficulty or inability to take orally. Loss from GIT via vomiting and kidneys. Soft tissue injuries burns.

38. SIGNS OF MODERATE VOLUME DEFICIT : ECF LOSS EARLY SIGNS CNS : Sleepiness,cessation in usual activity, anorexia, thirst CVS : Orthostatic hypotension, Tachycardia, weak thready pulse GIT : progressive decrease in food consumption, AFTER 24 HOURS TISSUE SIGNS : Soft ,small tongue with longitudinal wrinkling, Dry mucus membrane , dry cracked lips

39. SIGNS OF SEVERE VOLUME DEFICIT : EARLY SIGNS CNS : decreased tendon reflexes, anesthesia of extremeties , stupor, coma CVS: hypotension, distant heart sounds, absent peripheral pulse GIT : nausea , vomiting refusal to eat AFTER 24 HOURS TISSUE SIGNS: Eyeballs sunken , atonic muscles

40. SPECIFIC MANAGEMENT……

41. CAUSES OF FLUID LOSS IN SURGICAL PATIENTS Increased loss from lungs after anesthesia Fistulae In soft tissue injuries & infections Burns External loss of fluids internal redistribution of ECF in nonfunctional spaces

42. CLINICAL MANIFESTATION Skin pallor Cold extremities Weak and rapid pulse Hypotension Oliguria Decreased levels of consiousness

43. MANAGEMENT Treat the cause For burns and tissue injuries large volume of isosmolar IV fluid is administered Albumin is administered for protein deficit IV fluid intake is maintained after major surgery to maintain kidney perfusion Pericardiocentesis if pericarditis is the cause Paracentesis for ascitis

44. Concentration changes The serum sodium level/Conc. is used to estimate the total body fluid osmolality . Even though the sodium ions are largely confined to the extra cellular compartment, its level/Conc. reflects total body osmolality .

45. Compositional changes Compositional abnormalities of importance include changes in Acid – base balance and concentration changes of calcium, Potassium and magnesium.

46. Methods to calculate the rate of fluid infusion

47. 4/2/1 Rule Maintenance of fluids for 24 hours : 100/50/20 rule

48. The Electrolyte abnormalities include – Sodium abnormalities Potassium abnormalities Calcium abnormalities Magnesium abnormalities

49. Na + (Sodium) Function: Most important ion in regulating ECF volume and thereby maintaining BP Important in nerve and muscle function

50. Serum Na+ Normal daily intake: 100 mEq / lt Causes of Hyponatremia

51. Causes of hyponatremia with increased extracellular volume Heart failure. Liver failure. Oliguric renal failure Hypoalbuminaemia Hyperglycemia Hyperlipidemia Each 100mg/dl raise in blood glucose results in decrease in serum sodium concentration of about 1.6 to 3mEq /Lt

52. Clinical Signs and Symptoms Symptoms rarely develop unless serum sodium drops 120 to 125mEq/Lt

53. Treatment Determine if hyponatremia acute Chronic Acute serum sodium <110-115meq/ lt Symptomatic - seizures coma Rapid correction- Till serum sodium 120-125meq/ lt If it is asymptomatic gradual correction over 48 hrs

54. Hypernatremia Clinical manifestations of hypernatremia Thirst Lethargy Neurological dysfunction due to dehydration of brain cells Decreased vascular volume

55. Correction of Hypernatremia Asymptomatic: 5% dextrose in H 2 O 0.45% saline preferable in coma. Very large volumes of 5litres a day may be needed to be given. Symptomatic: 0.9% saline to correct volume deficit Correct over a period of 48 hrs as rapid correction may lead to cerebral edema.

56. Potassium Functions : Regulates fluid, ion balance inside cell Ph balance Maintains cell integrity

57. Serum Potassium 98% located in intracellular compartment. Normal daily intake 40-60mEq/Lt. Over 85% is excreted in urine and stool.

58. Hypokalemia Persistent reduction of serum potassium below 3.5 meq /l . Causes Decreased intake of k + Increased k + loss: renal / non renal chronic diuretics acid/base imbalance trauma and stress increased aldosterone redistribution between icf and ecf Metabolic alkalosis

59. Hypokalemia in surgical patients Excessive renal secretion Movement of potassium in cells Prolonged administration of k- free parentaral fluids Continued loss of k through urine Loss of GIT secretions

60. Clinical manifestations Gradual onset of drowsiness, with difficulty in rousing and slow opening of the eye Slow slurred speech Neuromuscular disorders Weakness, flaccid paralysis, respiratory arrest, constipation Dysrhythmias Postural hypotension Cardiac arrest

61. Clinical features BP is low and slow pulse rate Warm and dry skin Reddish flushed face Increased thirst

62. Treatment Increase k + intake, but slowly, preferably by foods Oral administration of potassium salt Potassium chloride effervescent tab 2gm 8 th hrly In case of coma patients and severe vomiting- Administration of IV fluids- ISOLYTE G, ISOLYTE M Maintain within 7 mEq /L Assure adequate urine out put

63. HYPERKALEMIA Serum k+ > 5.5 meq / L

64. Clinical signs and symptoms Cardiac Peaked T wave QRS widening. St depression Bradycardia Ventricular fibrillation Neuromuscular Weakness Paresthesia Respiratory failure

65. Treatment: I mmediate If potassium levels greater than 7mEq/L Protect myocardium 10ml of 10% calcium gluconate given over 2-3 minutes in the presence of ECG changes   In potassium level in 1hr If no response second dose can be repeated

66. 2. Drive potassium into the cells 10 units of insulin + 5% dextrose in water I.v . administered over 5 minutes decreases serum potassium levels in 30 mins and last for several hours. Regular check of blood glucose and potassium Repeat as necessary 3. 1.26% Sodium bicarbonate – Can be given with 5% dextrose in water. If ECG changes still present – repeat dose 15 mins after first dose

67. CALCIUM Normal serum level : 9.5 – 11 mg/dl 1000 -1200 gm found in bones Daily intake : 1- 3 gm Excretion : git,renal

68. HYPERCALCEMIA Ca > 15 mg/ml Results from: Hyperparathyroidism Hypothyroid states Renal disease Excessive intake of vitamin D Milk-alkali syndrome Certain drugs Malignant tumors – hypercalcemia of malignancy Tumor products promote bone breakdown Tumor growth in bone causing ca ++ release

69. EFFECTS: Initially GI symptoms Nausea, abdominal cramps Diarrhea / constipation Many nonspecific – vague pain Fatigue, weakness, lethargy Muscle cramps Bradycardia , cardiac arrest Metastatic calcification Increases formation of kidney stones and pancreatic stones Finally stupor & coma

70. Treatment A.Measures to↑ urinary execretion of ca 0.9 % nacl followed by frusemide cautiously Haemodialysis B. Measures to ↓ ca reabsorption Biphosphontes , calcitonin C. Meassures to ↓ intestinal absorption Glococorticosteroids , oral phosphates

71. Hypocalcemia Numbness tingling sensation in the circumoral region and the tip of the fingers and toes Convulsions in severe cases Diagnosis: Chvostek’s sign Trousseau’s sign Treatment Iv calcium for acute Oral calcium and vitamin d for chronic cases

72. Acute management- 10 % ca gluconate 10 to 20 ml slow i.V . Over 10 mins If i.V . Ca doesn’t relieve tetany , rule out hypomagnesemia Long term management- Rx underlying etiology Ca supplements Vitamin d supplements

73. MAGNESIUM 4 th most common cation in ecf 2 nd most common cation in icf Serum level : 1.8 to 3 mg/l Function: normal contractility of muscle and excitability of neuronal tissues Normal daily intake is 20 to 25 meq / day 8 meq /day is absorbed and excreted in urine

74. Hypomagnesemia Signs and sypmtoms : muscular tremors, hyperactive deep tendon reflexes Magnesium deficiency Parenteral administration of magnesium chloride or sulphate solution Monitor heart rate, BP, respiration and ECG for signs of toxicity Followed by 10 to 20 mEq of 50% of magnesium sulphate solution daily IM or IV

75. Hypermagnesemia Hypermagnecaemia is extremely rare and is only seen in severe renal insufficiency more so when renal dialysis is carried out Occurs when magnesium containing antacids and laxatives are used in patients with impaired renal function Burns and massive trauma Clinical features Hypoactive deep tendon reflexes, shallow and slow respirations lethargy, weakness Ecg changes – increased pr interval, widened qrs complex and elevated t wave. Gradual muscular paralysis fallowed by coma---death due to cardiac or respiratory arrest

76. TREATMENT Withhold administration of exogenous magnesium Slow administration of 5 to 10 mEq of calcium chloridE . Haemodialisis .

77. ACID BASE BALANCE

78. Metabolic acidosis  A pH under 7.1 is an emergency, due to the risk of cardiac arrhythmias, and may warrant treatment with intravenous bicarbonate. Bicarbonate is given at 50-100  mmol at a time under scrupulous monitoring of the arterial blood gas readings.  Dialysis may clear both the intoxication and the acidosis .

79. Metabolic alkalosis The management of metabolic alkalosis depends primarily on the underlying etiology and on the patient’s volume status. In the case of vomiting, administer antiemetics , if possible. If continuous gastric suction is necessary, gastric acid secretion can be reduced with H2-blockers or more efficiently with proton-pump inhibitors. In patients who are on thiazide or loop diuretics, the dose can be reduced or the drug can be stopped if appropriate. Alternatively, potassium-sparing diuretics or acetazolamide can be added.

80. CONSIDERATIONS FOR SURGICAL PATIENT PRIME GOAL

81. Depends on the 1.Preoperative hydration status 2.Length of npo 3.Normal maintenance needs 4.Replacement of “third space” losses (open belly, hot lights, extensive dissection of tissues) 5.Replacement of blood loss 6. Fluid shift

82. EFFECT OF ANESTHESIA ON FLUID BALANCE General anesthesia produces vasodilation and some degree of myocardial contractility (usually overcome by sympathetic drive induced by the surgical stimulus) Mechanical ventilation can increase evaporative loss if gases are not adequately humidified, which is often the case during long Operating procedures. Other factors, including increased intrathoracic pressure brought about by mechanical ventilation, a stress response to surgical stimulus, or the prone position, may lead to increased ADH production and decreased urine output.

83. Monitor : Vital signs Urine output Acid-base status

84. PREOPERATIVE CORRECTIONS 1 ) correction of hypovolemia 2 ) correction of other disorders CORRECTION OF HYPOVOLEMIA Causes : vomiting , blood loss, nasogastric suction, fever, hyperventilation, diuretic therapy, etc Problems : ↓ o₂ carrying capacity, ↑ ed risk of tissue hypoxia & development of organ failure , risk of severe hypotension.

85. INTRAOPERATIVE FLUID MANAGEMENT Roughly calculated as- Correction of fluid deficit due to starvation + Maintenece required for period of surgery + Loss due to tissue dissection or haemorrhage

86. CORRECTION OF FLUID DEFICIT Volume to be replaced = duration of starvation ( hrs) * 2ml/kg body weight Usually corrected by – 5% dextrose Half of calculated dose in 1 st hr followed by remaining half over next 2 hrs

87. MAINTENCE VOLUME calculated as – duration of surgery ( hrs) *2 ml/kg body weight or rate of infusion = 2ml/kg /hr INTRAOPERATIVE FLUID LOSS fluid loss d/t tissue dissection & haemorrhage in different types of surgeries : Type Fluid volume (ml/kg/hr) Least trauma nil Minimal trauma 4 Moderate trauma 6 Severe trauma 10

88. Least trauma : Hypotonic maintence fluid, dextrose , 2ml/kg/hr Minimal trauma : Tonsillectomy, nasal septal repair,plastic surgery 6 ml/kg/hr; balanced salt solution for period of surgery Moderate trauma procedures of extermities etc 8 ml/kg/hr of ringer’s lactate or isotonic saline Severe trauma Radical neck dissection etc 12 ml/kg/hr ringer’s lactate or isotonic saline

89. CAUSES OF HYPOVOLEMIA IN POST OPERATIVE PATIENTS Inadequate correction of starvation Inadequate maintenance in intra operative period Intra operative blood loss & fluid loss Excessive loss due to hyperventilation, hypermetabolism & pyraxia Lengthy operation Environmental factors - summer

90. ROUTINE POST OPERATIVE IV FLUID FOR FIRST THREE DAYS First 24 hrs – 2 liters 5% dextrose or 1.5 lit 5% dextrose + 500 isotonic saline Second post op day - 2 liters 5% dextrose + 1lit 0.9 % saline Third post op day – similar fluid + 40 – 60 mEq potassium/day may require modifications depending upon clinical situations

91. Thank you Thank you