Fluid and electrolytes

Dr. Ram Yadav, Max Fac Surgeon, BPKIHS

1. F luid E lectrolyte

2. Introduction

3. Body Fluid Distribution

4. Body Fluid Regulation For Input --- thirst Stimuli– Dehydration, Fall in BP and Increased solute concentration (osmolality)

5. For output -- kidneys Antidiuretic hormone (ADH) Aldosterone-Renin-Angiotensin mechanism Atrial Natriuretic Peptide

6. ↓Blood volume or ↓BP Volume receptor Atria and great veins Hypothalamus ↓ Posterior pituitary gland Osmoreceptors in hypothalamus ↑ Osmolarity ↑ADH Kidney tubules ↑H2O reabsorption ↑vascular volume and ↓osmolarity Narcotics, Stress, Anesthetic agents, Heat, Nicotine, Antineoplastic agents, Surgery ANTIDIURETIC HORMONE REGULATION MECHANISMS

7. ALDOSTERONE-RENIN-ANGIOTENSIN SYSTEM

8. ANP opposite to Aldosterone

9. Fluid Balance Input Output

10. If Output/ fluid loss is more is more = Fluid defecit occurs. To correct fluid defecit = Fluid therapy

11. The fluids used in clinical practice are usefully classified into colloids , crystalloids and blood products Colloid Solutions that contain large molecules that don't pass the cell membranes. When infused, they remain in the intravascular compartment and expand the intravascular volume and they draw fluid from extravascular spaces via their higher oncotic pressure Types of Fluid

12. Colloid solutions How does it work? It expand the intravascular volume by drawing fluid from the interstitial spaces into the intravascular compartment through their higher oncotic pressure . The same effect as hypertonic crystalloids solutions but it requires administration of less total volume and have a longer duration of action because the molecules remain within the intravascular space longer. Its effect can last for several days if capillary wall linings are intact and working properly.

13. BEFORE STARTING COLLOID THERAPY ONE SHOULD COLLECT BLOOD SAMPLES FOR ABO-RH GROUPING AS BLOOD LOADED WITH COLLOIDS INTERFERS WITH CROSSMATCHING.

14. Colloid solutions Examples : 1- 5 % albumin (Human albumin solution ) - The most commonly utilized colloid solutions. - It contains plasma protein fractions obtained from human plasma and works to rapidly expand the plasma volume used for : volume expansion moderate protein replacement achievement of hemodynamic stability in shock states. - considered a blood transfusion product and requires all the same nursing precautions used when administering other blood products.

15. Colloid solutions Albumin Contraindications: a) Severe anemia b) Heart failure c ) Known sensitivity to albumin d ) Angiotensin-converting enzyme inhibitors ( ACEI) should be withheld for at least 24 hours before administering albumin because of the risk of atypical reactions, such as flushing and hypotension  

16. What to do if you suspect transfusion reaction Sings of transfusion reaction may include: fever, flank pain, vital sign changes, nausea, headache, urticaria , dyspnea , and broncho spasm. If you suspect a transfusion reaction, take these immediate actions: Stop the transfusion. Keep the I.V. line open with normal saline solution. Notify the physician and blood bank. Intervene for signs and symptoms as appropriate. Monitor the patients vital signs.

17. 2- Hydroxy-ethalstarches   Another form of hypertonic synthetic colloids used for volume expansion C ontain sodium and chloride and used for hemodynamic volume replacement following major surgery and to treat major burns Less expensive than albumin and their effects can last 24 to 36 hours

18. Precautions when using Colloid solutions: The patient is at risk for developing fluid volume overload As for blood products, use an 18-gauge or larger needle to infuse colloids. Monitor the patient for signs and symptoms of hypervolemia, including: Increased BP Dyspnea or crackles in the lungs Edema.

19. Precautions ……. Closely monitor intake and output. Colloid solutions can interfere with platelet function and increase bleeding times , so monitor the patient's coagulation indexes. Elevate the head of bed unless contraindicated. Anaphylactoid reactions are a rare but potentially lethal adverse reaction to colloids. Take a careful allergy history from patients receiving colloids (or any other drug or fluid), asking specifically if they've ever had a reaction to an I.V. infusion

20. 2.Crystalloid Solutions that contain small molecules that flow easily across the cell membranes , allowing for transfer from the bloodstream into the cells and body tissues. This will increase fluid volume in both the interstitial and intravascular spaces (Extracellular) It is subdivided into: * Isotonic * Hypotonic * Hypertonic Types of Fluid

21. Types of isotonic solutions include: 0.9 % sodium chloride (0.9% NaCl ) lactated Ringer's solution 5% dextrose in water (D5W) Ringer's solution Isotonic Fluids

22. A- 0.9% sodium chloride (Normal Saline) Simply salt water that contains only water, sodium (154 mEq /L), and chloride (154 mEq /L). It's called "normal saline solution " because the percentage of sodium chloride in the solution is similar to the concentration of sodium and chloride in the intravascular space . Isotonic Fluids Solutions Na + K + Ca 2+ Mg 2+ Cl - HCO 3 - Dextrose mOsm/L 0.9% NaCl 154 154 308

23. When to be given? 1- to treat low extracellular fluid, as in fluid volume deficit from - Hemorrhage - Severe vomiting or diarrhea - Heavy drainage from GI suction, fistulas, or wounds 2- Shock 3- Mild hyponatremia 4- Metabolic acidosis (such as diabetic ketoacidosis) 5- It’s the fluid of choice for resuscitation efforts. 6- it's the only fluid used with administration of blood products. A- 0.9% sodium chloride (Normal Saline)

24. TAKE CARE: Because 0.9% sodium chloride replaces extracellular fluid, it should be used cautiously in certain patients (those with cardiac or renal disease) for fear of fluid volume overload. A- 0.9% sodium chloride (Normal Saline)

25. is the most physiologically adaptable fluid because its electrolyte content is most closely related to the composition of the body's blood serum and plasma. Another choice for first-line fluid resuscitation for certain patients, such as those with burn injuries. B- Ringer's lactate or Hartmann solution

26. When to be used? To replace GI tract fluid losses ( Diarrhea or vomiting ) Fistula drainage Fluid losses due to burns and trauma Patients experiencing acute blood loss or hypovolemia due to third-space fluid shifts. B- Ringer's lactate or Hartmann solution

27. In liver Lactate -------------------------> bicarbonate . Used in metabolic acidosis. Don't give LR to patients with liver disease as they can't metabolize lactate - used cautiously in patients with severe renal impairment because it contains some potassium - LR shouldn't be given to a patient whose pH is greater than 7.5 B- Ringer's lactate or Hartmann solution

28. Like LR, contains sodium, potassium, calcium, and chloride doesn't contain lactate . Ringer's solution is used in a similar fashion as LR, but doesn't have the contraindications related to lactate . C -Ringer's solution

29. It is considered an isotonic solution, but when the dextrose is metabolized, the solution actually becomes hypotonic and causes fluid to shift into cells. D- Dextrose 5%

30. How does it work? D5W provides free water that pass through membrane pores to both intracellular and extracellular spaces. Its smaller size allows the molecules to pass more freely between compartments, thus expanding both compartments simultaneously It provides 170 calories per liter, but it doesn't replace electrolytes. The supplied calories doesn't provide enough nutrition for prolonged use. But still can be added to provide some calories while the patient is NPO. D- Dextrose 5%

31. Take Care ! - Not good for patients with renal failure or cardiac problems since it could cause fluid overload. - patients at risk for intracranial pressure should not receive D5W since it could increase cerebral edema - D5W shouldn't be used in isolation to treat fluid volume deficit because it dilutes plasma electrolyte concentrations - Never mix dextrose with blood as it causes blood to hemolyze . - Not used for resuscitation , because the solution won't remain in the intravascular space . D- Dextrose 5%

32. Be aware that patients being treated for hypovolemia can quickly develop hypervolemia (fluid volume overload) following rapid or over infusion of isotonic fluids. Document baseline vital signs, edema status, lung sounds, and heart sounds before beginning the infusion, and continue monitoring during and after the infusion. Precautions in usage of Isotonic solutions

33. Frequently assess the patient's response to I.V. therapy, monitoring for signs and symptoms of hypervolemia such as: hypertension / bounding pulse / pulmonary crackles / peripheral edema / dyspnea/ shortness of breath / jugular venous distention (JVD) Monitor intake and output Elevate the head of bed at 35 to 45 degrees, unless contraindicated . If edema is present, elevate the patient's legs. Precautions …….

34. monitor for signs and symptoms of continued hypovolemia, including: urine output of less than 0.5 mL/kg /hour poor skin turgor tachycardia weak, thready pulse hypotension Educate patients and their families about signs and symptoms of volume overload and dehydration instruct patients to notify if they have trouble breathing or notice any swelling. Instruct patients and families to keep the head of the bed elevated (unless contraindicated).

35. B- HYPOTONIC FLUIDS Compared with intracellular fluid (as well as compared with isotonic solutions), hypotonic solutions have a lower concentration of solutes (electrolytes). And osmolality less than 250 mOsm /L . Hypotonic crystalloid solutions lowers the serum osmolality within the vascular space, causing fluid to shift from the intravascular space to both the intracellular and interstitial spaces . These solutions will hydrate cells, although their use may deplete fluid within the circulatory system.

36. TYPES OF HYPOTONIC FLUIDS 0.45% sodium chloride (0.45% NaCl ), 0.33% sodium chloride , 0.2% sodium chloride , and 2.5% dextrose in water Hypotonic fluids are used to treat patients with conditions causing intracellular dehydration, when fluid needs to be shifted into the cell , such as: Hypernatremia Diabetic ketoacidosis Hyperosmolar hyperglycemic state.

37. Precautions with hypotonic solutions Never give hypotonic solutions to patients who are at risk for increased ICP because it may exacerbate cerebral edema D on't use hypotonic solutions in patients with liver disease , trauma , or burns due to the potential for depletion of intravascular fluid volume

38. Precautions …… The decrease in vascular bed volume can worsen existing hypovolemia and hypotension and cause cardiovascular collapse Monitor patients for signs and symptoms of fluid volume deficit In older adult patients, confusion may be an indicator of a fluid volume deficit. Instruct patients to inform the doctor/ sisters if they feel dizzy or just "don't feel right."

39. C- HYPERTONIC SOLUTIONS What is hypertonic solution? Solution that have a higher tonicity or solute concentration. Hypertonic fluids have an osmolarity of 375 mOsm /L or higher The osmotic pressure gradient draws water out of the intracellular space, increasing extracellular fluid volume, so they are used as volume expanders.

40. HYPERTONIC SOLUTIONS Some examples and Indications: 1- 3% sodium chloride ( 3% NaCl ): May be prescribed for patients in critical situations of severe hyponatremia . Patients with cerebral edema may benefit from an infusion of hypertonic sodium chloride 2- 5% Dextrose with normal saline (D5NS): which replaces sodium, chloride and some calories

41. Precautions with hypertonic fluids: Hypertonic sodium chloride solutions should be administered only in high acuity areas with constant nursing surveillance for potential complications . Maintain vigilance when administering hypertonic saline solutions because of their potential for causing intravascular fluid volume overload and pulmonary edema. shouldn't be given for an indefinite period of time. Prescriptions for their use should state the specific hypertonic fluid to be infused, the total volume to be infused and infusion rate, or the length of time to continue the infusion .

42. Isolyte - G (Gastric Replacement) - hypertonic Provides all electrolyte lost by gastric Juice , corrects alkalosis, provides calories Only IV Fluid which directly corrects alkalosis of any nature Isolyte - M ( Maintenance solution with 5% Dextrose) - hypertonic Richest source of K (35mEq/L ), so used to correct hypokalemia secondary to diarrhoea , bilious vomiting, prolonged infusion of potassium free IV fluids etc. Isolyte - P (Pediatric maintenance) - hypotonic Provides double water but same amount of electrolyte as isolyte -M Isolyte - E (Extracellular replacement solution) - isotonic Similar to ECF, but double potassium and acetate (converts to bicarbonate), so used in metabolic acidosis, diarrhoea and in maintenance of ECF volume pre-operatively. Only IV fluid available which will correct magnesium deficiency A small note on - Isolytes

43. FLUIDS Dextr Na K Cl Acetate Special constt. mOsm/L Iso-G 50 63 17 150 - NH 4 Cl -70 580 Iso-M 50 40 35 40 20 HPO 4 - 15 410 Iso-P 50 25 20 22 23 HPO 4 - 3. Citrate-3. 368 Iso-E 50 140 10 103 47 Ca-5. Mg-3. Citrate-8. 595

44. Initial selection of intravenous fluids for various clinical disorders

45. Initial selection of intravenous fluids for various clinical disorders

46. Components of fluid therapy Maintenance therapy: replaces normal ongoing losses 2. Fluid Resuscitation: corrects any existing water and electrolyte deficits.

47. Components of fluid therapy Maintenance therapy Maintenance therapy is usually undertaken when the individual is not expected to eat or drink normally for a longer time ( eg ; perioperatively or patient on a ventilator)

48. Maintenance therapy How to calculate maintenance fluid flow rates? The most commonly used formula is (4/2/1) rule a.k.a ( Weight+40), which is used for both adults and pediatrics. 4/2/1 rule 4 ml/kg/ hr for first 10 kg (=40ml/ hr ) then 2 ml/kg/ hr for next 10 kg (=20ml/ hr ) then 1 ml/kg/ hr for any kgs over that This always gives 60ml/ hr for first 20 kg then you add 1 ml/kg/ hr for each kg over 20 kg So: Weight in kg + 40 = Maintenance IV rate/hour For any person weighing more than 20kg

49. Fluid Resuscitation B) Fluid Resuscitation : Correction of existing abnormalities in volume status or serum electrolytes (as in hypovolemic shock)

50. Fluid Resuscitation How to know that the patient has Hypovolemic Shock? The patient has the following sings and symptoms: 1- Anxiety or agitation 2- Cool, Pale skin 3- Confusion 4- Decreased or no urine output 5- Rapid breathing 6- Disturbed consciousness 7- Low blood pressure 8- Low body temperature 9- Rapid pulse, often weak and thready

51. Fluid Resuscitation Rate of Repletion of Fluid deficit: 1- Severe volume depletion or hypovolemic shock: Rapid infusion of 1-2L of isotonic saline (0.9% NS) as rapidly as possible to restore tissue perfusion 2- Mild to moderate hypovolemia: Choose a rate that is 50-100mL/h greater than estimated fluid losses. Calculating estimated fluid loss as follows: Urine output = 50ml/h Insensible losses = 30ml/h Additional loss such as Vomiting or Diarrhea or high fever (additional 100- 150 ml/day for each degree of temp >37 C)

52. How to calculate IV flow rates ! What is a drop factor? Drop factor is the number of drops in one milliliter used in IV fluid administration (also called drip factor). A number of different drop factors are available but the commonest are: 10 drops/ml (blood set) 15 drops / ml (regular set) 60 drops / ml ( microdrip )

53. How to calculate IV flow rates ? The formula for working out flow rates is: Example: 1500 ml IV Saline is ordered over 12 hours. Using a drop factor of 15 drops / ml, how many drops per minute need to be delivered? volume (ml) X drop factor ( gtts / ml )  --------------------------------------------- time (min) = gtts / min (flow rate ) 1500 (ml) X 15 (drop / ml)  --------------------------------------------------- 12 x 60 (gives us total minutes) = 31 drop/ minute

54. Blood Loss Intra-operatively and fluid therapy post-operatively

55. Allowable Blood Loss estimated blood volume =weight (kg) X average blood volume Hi = initial hematocrit Hf = final acceptable hematocrit . The final acceptable hematocrit usually is 30% less than the initial hematocrit (estimated blood volume X [Hi – Hf ]) Hi ABL=

56. Ongoing losses from nasogastric tubes, fistulae, and drains can be measured directly. Blood-soaked sponges One gram = 1 mL of blood. Laparotomy sponges =100 mL of blood Ray-Tec sponge =10 to 20 mL of blood and X 4 sponges =10 mL of blood. Suction canister volume (after subtraction of irrigation) also assists in blood loss assessment. Measuring Intra-operative blood loss

57. Causes Pre-op inadequate correction of hydration status with proper fluid or inadequate Intraop maintenance by fluid infusion. Inappropriate calculation of required fluid volume. Intra-op blood loss replaced with equal volume of crystalloid. Fluid lost from naso -gastric tubes, fistulae, drains if not considered. Excessive loss due to hypermetabolism , pyrexia, hyperventilation. In early post-op period if there is hypotension, disproportionate anaemia …think of internal bleeding unless proved otherwise & inadequate fluid replacement. Post-Operative Hypovolemia

58. BEFORE PRESCRIBING POST-OP FLUIDS, ONE SHOULD CONSIDER:- Age, Weight, Vital data, Hydration status, Urine output of the patient. Pre-op diagnosis, Nature of surgery, Intra-op blood loss. Nature & Volume of fluid / blood used intra-op. Drain output, Nasogastric feeding tube output, Fluid loss at wound site. Associated illness if any- eg . Protein losing Nephropathy, Chronic HTN, DM, CHF etc. Insensible losses due to ambient temperature, pyrexia, hyperventilation, obese/lean & thin body mass. Pre-Requisites

59. AIM – To maintain reasonable blood pressure (>100/70 mmHg) Pulse rate <120/min Hourly Urine output of 30-50ml/hour Normal temperature Warm skin Normal respiration Normal sensation. Post-Operative Fluids

60. 1) WHY MAINTAINENCE FLUIDS ON 1 ST POST-OP DAY ARE LESS IN SALT & OF LOW TOTAL VOLUME ? GA & Post-op pain leads to increase secretion of ADH & Aldosterone . (response to stretch & stress) Thus, salt & water are retained by the kidney. To avoid, overloading of either salt/water, fluids low in their sodium content, and of low total volume are used. Choice of fluids

61. To infuse salt rich fluids is not a routine in all patients. Special conditions are:- a) Elderly patients with salt losing nephropathy. b) Patients on simultaneous treatment with diuretics & mannitol . c) To replace nasogastric aspiration & drainage output. d) After major surgeries, wherein intestinal/renal handling has been significant, saline is transfused to replace third space losses. 2 ) IN WHICH CASES ON 1 ST POST-OP DAY, SALT CONTAINING FLUIDS ARE TO BE USED ?

62. Patients may have oliguria / azotemia . So, till urine output is established & normal renal status ensured, potassium supplementation can be risky. Post-op tissue trauma causes release of K+ from intracellular to extracellular compartment, which may cause hyperkalemia. Intra-op / Post-op transfusion of stored or haemolysed blood may add large amounts of K+. Post-op metabolic acidosis will shift intracellular K+ extracellularly . So, as body has large stores of intracellular K+, non replacement for first 2-3 days will not cause hypokalemia . WHY USUALLY POTASSIUM IS AVOIDED IN FLUIDS FOR 1 ST TWO POST-OP DAYS ?

63. Prolonged Vomiting/ Nasogastric Suction- Ideal fluid is NS. If urine output is adequate, K+ added after 2 nd day. After initial two days, even Iso -G can be added in amounts similar to upper GI loss, provided the urine output & renal status are normal. Decision to add K+ in fluid therapy should be guided by Serum K+ estimation & bedside ECG. Fluid loss due to small bowel fistulas causing diarrhoea - RL is ideal for replacement , may need additional HCO3- & K+ supplementation. Blood loss- to be replaced with two times the volume of NS or RL. For larger losses, should be replaced with blood at the earliest. WHICH FLUIDS TO BE USED TO REPLACE ADDITIONAL LOSSES ?

64. It’s a wrong method to infuse the entire volume over 8-12 hours. Maintenance fluids are to be given at a steady rate over 24 hours. If given at a fast rate & over a short period- CHF, Lung oedema , may develop Renal excretion of excess salt & water will cause fluid-electrolyte imbalance. HOW TO INFUSE FLUIDS POST OPERATIVELY ?

65. It is commonly believed that intravascular losses require 3–4 times volume replacement with crystalloid fluids compared with colloids. A recent systematic review of the use of HES in surgical, emergency, and intensive care patients reported that the crystalloid to colloid ratio for volume resuscitation was lower, 2:1 Hartog CS, Kohl M, Reinhart K. A systematic review of third generation hydroxyethyl starch (HES 130/0.4) in resuscitation: safety not adequately addressed. Anesth Analg 2011; 112: 635–45

66. FLUID STRATEGIES ‘Liberal’ vs. ‘restrictive’ fluid strategy Recent meta-analyses of published studies have shown that restrictive fluid administration strategies may improve patient- centred outcomes when compared to liberal regimens. ‘M. BUNDGAARD-NIELSEN, N. H. SECHER and H. KEHLET.1Liberal’ vs. ‘restrictive’ perioperative fluid therapy – a critical assessment of the evidence. Acta Anaesthesiol Scand 2009; 53: 843–851 Glassford NJ ,  Myles P ,  Bellomo R .The Australian approach to peri -operative fluid balance. Curr Opin Anaesthesiol .  2012 Feb;25(1):102-10 Joshi GP. Intraoperative fluid restriction improves outcome after major elective gastrointestinal surgery. Anesth Analg 2005; 101:601. Chappell D, Jacob M, Hofmann-Kiefer K, et al. A rational approach to perioperative fluid management. Anesthesiology 2008; 109:723

67. ‘Liberal’ vs. ‘restrictive’ perioperative fluid therapy The range of the liberal intraoperative fluid regimen was from 2750 to 5388 ml compared with 998 to 2740ml for the restrictive fluid regimen. Three studies found an improved outcome (morbidity/hospital stay) with a restrictive fluid regimen whereas two studies found no difference and two studies found differences in the selected outcome parameters. ‘M. BUNDGAARD-NIELSEN, N. H. SECHER and H. KEHLET.1Liberal’ vs. ‘restrictive’ perioperative fluid therapy – a critical assessment of the evidence. Acta Anaesthesiol Scand 2009; 53: 843–851 Recent meta-analyses of published studies have shown that restrictive fluid administration strategies may improve patient- centred outcomes when compared to liberal regimens. This approach will likely open the door for a large multicentre study called RELIEF ( REstrictive versus LIbEral Fluid Therapy in Major Abdominal Surgery), which should begin in 2013 and achieve completion in 2016. Glassford NJ ,  Myles P ,  Bellomo R .The Australian approach to peri -operative fluid balance. Curr Opin Anaesthesiol .  2012 Feb;25(1):102-10

68. For routine surgery, when post op fluid therapy is limited, for 1-2 days, low calorie input poses no problem. But, a patient having Diabetes, Thyroid toxicosis , Obesity, Chronic malnutrition etc. need careful monitoring of serum glucose levels, and adequate calorie replacement . In routine 500ml of 5% dextrose will give 100calories. CALORIE REPLACEMENT

69. IN POST OP CONDITIONS WHERE EARLY ENTERAL FLUID THERAPY CAN’T BE STARTED, REPLACEMENT OF ADEQUATE CALORIES SHOULD BE DEALT PROPERLY, SO THAT PATIENT DOESN’T DEVELOP HYPOGLYCEMIA, ACIDOSIS, AZOTEMIA, BODY PROTEIN LOSES VIA GLUCONEOGENESIS.

70. Clinical judgement of degree of hydration/ dehydration. Pulse rate, Blood Pressure monitoring. Strict recording of input- volume of fluid, type of fluid, Strict recording of sensible fluid loss i.e urine output, sweating(temperature), vomitings , diarrhoea , drains output, nasogastric aspiration etc. Serum electrolytes estimation should be done. Monitoring of iv fluid therapy

71. Haematocrit . Blood urea & Serum creatinine . Urinary Na excretion estimation. Metabolic acidosis (urine pH with litmus paper test) CVP or PAWP.

72. If input is more??? Input Output

73. FLUID OVERLOAD (HYPERVOLEMIA) It is excessive accumulation of fluid in the body, due to: 1- Excessive parenteral infusion 2- Deficiencies in cardiovascular or renal fluid volume regulation

74. FLUID OVERLOAD (HYPERVOLEMIA) Signs and Symptoms They are not always typical but most commonly are: 1- Edema (swelling) - particularly feet, and ankles 2- Difficulty breathing while lying down 3- Crackles on auscultation 4- High blood pressure 5- Irritated cough 6- Jugular vein distension 7- Shortness of breath (dyspnea) 8- Strong, rapid pulse

75. FLUID OVERLOAD (HYPERVOLEMIA) Management of Hypervolemia 1- Prevention is the best way 2- Sodium restriction 3- Fluid restriction 4- Diuretics 5- Dialysis

76. Remember ! Treat IV fluids as “prescription” like any other medication Determine if patient needs maintenance or resuscitation Choose fluid type based on co-existing electrolyte disturbances Don’t forget about additional IV medications patient is receiving Choose rate of fluid administration based on weight and minimal daily requirements Avoid fluids in patients with ECF volume excess Always reassess whether the patient continues to require IV fluid

77. Fluid and fluid therapy is over……… Electrolytes ??????

78. 78 Distribution of Major Electrolytes

79. Sodium (Na+) 135-145 mEq /liter Normal physiologic function Maintains ECF volume Maintenance of ECF osmolality. Initiation of skeletal muscle contraction Initiation of cardiac contractility Transmission of neuronal impulses Maintenance of renal urine-concentration system

80. Renal regulation of sodium and potassium balance

81. Sodium Imbalance

82. SODIUM DEFICIT: HYPONATREMIA Sodium level below 135 mEq /L Causes Losses from excessive sweating, vomiting, diarrhea Use of certain diuretic drugs combined with low-salt diets Hormonal imbalances Insufficient aldosterone Adrenal insufficiency Excess ADH secretion Diuresis Excessive water intake

83. CLINICAL MANIFESTATIONS OF HYPONATREMIA Muscle Weakness APATHY Postural hypotension Nausea and Abdominal Cramps Weight Loss In severe hyponatremia : mental confusion, delirium, shock and coma

84. Treatment of Hyponatremia Hyponatremia caused by excessive dilution Treat with loop diuretics to cause an isotonic diuresis Hyponatremia caused by sodium loss Treat with oral sodium chloride or intravenous fluids containing salt Normal saline Lactated Ringers

85. 85 Hypernatremia Sodium level above 145 mEq /L Most commonly caused by kidney disease Sodium accumulates Decreased excretion High, net water loss (watery diarrhea, fever, burns) High doses of glucocorticoids or estrogens Insufficient ADH (diabetes insipidus ) Results in large volume of dilute urine Loss of the thirst mechanism Prolonged periods of rapid respiration Ingestion of large amounts of sodium without enough water

86. CLINICAL MANIFESTATIONS Dry, sticky mucous membranes Firm, rubbery tissue turgor Manic excitement Tachycardia DEATH

87. Treatment Can be treated with low-salt diet Acute hypernatremia treated with hypotonic intravenous fluids or diuretics

88. Potassium (K+) 3.5 to 5.5 mEq /L Major cation in the ICF Affects cardiac muscle concentration, electrical conductivity, & cell excitability Aids neuromuscular transmission of nerve impulses. Regulation of protein synthesis Regulation of glucose use & storage Alteration in K+ balance will result in acid-base imbalance

89. Hypokalemia K + <3.5 mEq /l diarrhea ileostomy drainage Diuretics Inadequate intake Hyperaldosteronism Causes

90. Clinical Features

91. Diagnostic Tests: ↓ K+ Serum potassium is less than 3.5 mEq /L Arterial Blood Gases (ABG) - Metabolic alkalosis ECG: FLAT “T” waves, or inverted T waves, depressed ST segment and presence of the “U” wave and prolonged PR interval.

92. Treatment: ↓ K+ Oral potassium supplements Oral: dilute liquid K+ in fruit or vegetable juice or cold water Never give K+ if pt is not voiding Chill to increase palatability Give with food to minimize GI effects Parental potassium supplements Infuse parenteral potassium supplement. Always dilute the K in the IVF solution and administer with a pump. IVF with potassium should be given no faster than 10-20-mEq/ hour! NEVER administer K by IV bolus or IM – can cause cardiac arrhythmias.

93. Hyperkalemia: K+>5.0 mEq /L Causes Tissue damage (K goes out of cell) Renal failure Potassium sparing diuretics Excess potassium intake Adrenal insufficiency Aged blood

94. Clinical features

95. Diagnostic Tests Serum potassium is more than 5 mEq /L Arterial Blood Gases (ABG) - Metabolic acidosis 1. Peaked and narrow T waves 2. ST segment depression and shortened QT interval 3. Prolonged PR interval 4. Prolonged QRS complex 5. Disappearance of P wave

96. Management: ↑ K+ Medications Calcium gluconate (emergency) Regular insulin & 50g of glucose (emergency) Sodium bicarbonate (acidosis) (emergency) Diuretics Restrict dietary sources Decrease dose of potassium-sparing diuretics Administer calcium to counteract potassium toxicity on heart Administer polystyrene sulfonate ( Kayexalate ) and sorbitol to decrease potassium levels

97. Chloride ( Cl -) 95 to 108 mEq /liter Formation of hydrochloric acid in stomach Cl - and Na + levels usually change in direct proportion to one another. Works with Na + to maintain ECF osmotic pressure & water balance Chloride imbalances Hypochloremia Usually associated with alkalosis Early stages of vomiting – loss of hydrochloric acid Hyperchloremia Excessive sodium chloride intake

98. 98 HYPOCHLOREMIA Risk Factors a. Diuresis b. Metabolic alkalosis c. Hyponatremia, prolonged D5W IV d. Addison’s disease Clinical Manifestation Slow, shallow respirations (met. Alkalosis) Hypotension ( Na & water loss ) Collaborative Management 1. Administer IV or Oral : KCl , NaCl 2. Diet: high Cl (& usually Na)

99. 99 HYPERCHLOREMIA Risk Factors / Cause a. Metabolic acidosis b. Usually noted in hyper Na, hyper K Clinical Manifestation Deep, rapid respirations (met. Acidosis) Similar signs of hyper K, hyperN a Collaborative Management 1. Diuretics 2. Hypotonic solutions, D5W to restore balance 3. Diet: low Cl (& usually Na) 4. Treat acidosis

100. Calcium (Ca++) 8.5 – 10.5 mEq /dl (4-5.5 mEq /L) Functions Enhances activity of enzymes or reactions Skeletal muscle contraction Cardiac contractility Helps activate steps in blood coagulation. Bone strength & density Regulation of neural impulse transmission

101. CAUSES AND EFFECTS OF HYPOCALCEMIA Decreased Ionized Ca Large tranfusion with citrated blood Excess Loss Kidney Disease Draining fistula Decrease in GI Tract and Bone Absorption ↑Magnesium ↑Calcitonin ↓Vitamin D ↓Parathyroid Hormone HYPOCALCEMIA Bones Osteoporosis leading to Fractures CNS Tingling ↓ convulsions Other Abnormal deposits of calcium in body tissues Muscles Muscle spasm ↓ Tetany Cardiovascular System Dysrhythmias ↓ Cardiac arrest Inadequate Intake Dietary Deficit

102. TESTS USED TO ELICIT SIGNS OF CALCIUM DEFICIENCY Trousseau’s sign (inflate BP cuff 20mm above systole for 3 min = carpopedal spasm) Chvosteks Sign: When the  facial nerve  is tapped at the angle of the jaw (i.e.  masseter muscle ), the facial muscles on the same side of the face will contract momentarily (typically a twitch of the nose or lips) 

103. Management 1. Calcium gluconate 10% IV 2. Calcium chloride 10% IV 3. Both usually given by Doctor, very slowly; venous irritant; cardiac problems 4. Oral: calcium citrate, lactate, carbonate; Vit D supplements 5. Diet: high calcium 6. Watch out for tetany , seizures, laryngospasm , respiratory & cardiac arrest 7. Seizure precautions

104. HYPERCALCEMIA:Causes and Effects Loss from bones Immobilization, Carcinoma with bone metastases, Multiple myeloma Excess Intake ↑ Calcium diet (esp. milk) Antacids containing calcium Increase in factors Causing Mobilization from bone ↑PTH, ↑ Vitamin D, steroid therapy HYPERCALCEMIA Kidneys Stones ↓ Kidney Damage CNS ↓Deep-tendon reflexes ↓ Lethargy ↓ Coma Bones Bone pain ↓ Osteoporosis ↓ Fractures Muscles Muscle fatigue, hypotonia ↓ ↓ GI motility CV System Depressed activity ↓ Dysrhythmias ↓ Cardiac Arrest

105. MANAGEMENT 1. If parathyroid tumor = surgery 2. Diet: low Ca, stop taking Ca Carbonate antacids, increase fluids 3. IV flushing (usually NaCl ) 4. Loop diuretics 5. Corticosteroids 6.Biphosphonates, like etidronate ( Calcitonin ) & alendronate 7. Plicamycin – inhibits bone resorption 8. Calcitonin – IM or intranasal 9. Dialysis (severe case) 10. Watch out for digitalis toxicity 11. Prevent fractures, handle gently

106. Phosphorus 2.5 – 4.5 mEq /dl Vital for intracellular activities Activation of B complex vitamins Plays major role in acid-base balance through its action as a urinary buffer Cell division Plays essential role in muscle, RBC, neurological function Aids in carbohydrate, protein and fat metabolism

107. Hypophosphatemia Decreased Vit D absorption, sunlight exposure Hyperparathyroidism (increased PTH) c. Aluminum & Mg-containing antacids (bind P) d. Severe vomiting & diarrhea Hyperphosphatemia a. Acidosis b. Cytotoxic agents/chemotherapy in cancer c. Renal failure d. Hypocalcemia e. Massive Blood Transfusions (P leaks out of cells during storage of blood) f. Hyperthyroidism Cause

108. Clinical Manifestations Hypophosphatemia (as of hypercalcemia ) Anemia, bruising (weak blood cell membrane) Seizures, coma Muscle weakness, paraesthesias Constipation, hypoactive bowel sounds Hyperphosphatemia (as of hypocalcemia ) Calcification of kidney, cornea, heart Muscle spasms, tetany , hyper- reflexia

109. Management Hypophosphatemia (as of hypercalcemia ) Sodium phosphate or potassium phosphate IV (give slowly, no faster than 10 mEq /hr) Sodium & potassium phosphate orally– give with meals to prevent gastric irritation Avoid P-binding antacids Diet: high Mg, milk Monitor joint stiffness, arthralgia , fractures,bleeding Hyperphosphatemia (as of hypocalcemia ) Aluminum antacids as phosphate binders: Al carbonate, Al Hydroxide Ca carbonate for hypocalcemia /Avoid phosphate laxatives/enemas Increase fluid intake / Diet: low P, non carbonated drinks

110. Magnesium (Mg++) 1.5-2.5 mEq /l Muscle contractility Carbohydrate and protein metabolism. Affects neuromuscular irritability & contractility of cardiac and skeletal muscle. Facilitates transport of Na+ and K+ across cell membranes. DNA & Protein synthesis

111. Magnesium Imbalance Hypo- magnesemia Muscle weakness & tremors Dysphasia Tachycardia, HTN Mood & personality changes Hypermagnesemia Hyporeflexia Hypotension, bradycardia, arrhythmia Flushing Weakness, lethargy, coma Decreased RR & respiratory paralysis

112. MANAGEMENT of Hypomagnesia Recognition of people at risk: people taking loop diuretics and digoxin should be encouraged to eat foods rich in magnesium, such as fruits, vegetables, cereals, and milk Magnesium is essential for potassium resorption , so if hypokalemia does not respond to potassium replacement, hypomagnesemia should be suspected Severe: parenteral magnesium replacement is indicated

113. MANAGEMENT of Hypermagnesia Any patient receiving parenteral magnesium therapy should be assessed frequently for signs of hyper- magnesemia Mild hypermagnesemia : withholding magnesium-containing medications may suffice Severe: may require treatment with calcium gluconate (10-20 mL of 10% Ca Gluconate administered over 10 minutes) If cardio-respiratory collapse is imminent, the patient may require temporary pacemaker and ventilator support

114. A cid B ase Few slides on

115. 3 Systems that maintain pH Buffers - first line (takes seconds) -Moves or release hydrogen ions Respiratory system - 2nd line (takes minutes) -Regulate carbonic acid by eliminating or retaining CO2 Renal system - 3rd line (takes hours-days) -Long term regulation of acid-base in body

116. Interpretation Arterial Blood Gases Step 1 Look at the pH - Is it up or down? If it is up - it reflects alkalosis If it is down - it reflects acidosis Step 2 Look at the PCO2 - Is it up or down? If it reflects an opposite response as the pH, then you know that the condition is a respiratory imbalance If it does not reflect an opposite response as the pH - move to step III Step 3 Look at the HCO3- Does the HCO3 reflect a corresponding response with the pH If it does then the condition is a metabolic imbalance

117. Anion Gap =Na + - (Cl - + HCO 3 - ) ; usually <12 If >12, Anion Gap Acidosis : Common causes Lactic acidosis Metabolic disorders Renal failure

118. Acid-Base Imbalances Metabolic Alkalosis pH > 7.45 HCO3- > 26 mEq /L Caused by diarrhea, steroid or diuretic therapy. Respiratory Alkalosis pH >7.45 PaCO2 <35 mmHg Caused by hyperventilation Metabolic Acidosis Ph < 7.35 HCO3- < 22 mEq /L Common in cases of kidney disease and diabetes Respiratory Acidosis pH <7.35 PaCO2 > 45 mmHg Caused by hypoventilation Normal bicarbonate 22-26 mEq /L Normal PaCO2 = 35- 45 mmHg

119. RESPIRATORY ACIDOSIS Signs and Symptoms Compensation: kidneys respond by generating and reabsorbing bicarbonate ions, so HCO3 >26 mm Hg Respiratory: hypoventilation, slow or shallow respirations Neuro : headache, blurred vision, irritability, confusion Respiratory collapse leads to unconsciousness and cardiovascular collapse

120. Management 1. Restore ventilation and gas exchange; CPR for respiratory failure with oxygen supplementation; intubation and ventilator support if indicated 2. Treatment of respiratory infections with bronchodilators, antibiotic therapy 3. Reverse excess anesthetics and narcotics with medications such as naloxone .

121. 4. Chronic respiratory conditions Treat with no higher than 2 liters O 2, because patients are adjusted to high carbon dioxide level through metabolic compensation. So, they cannot receive high levels of oxygen, or will have no trigger to breathe; will develop carbon dioxide narcosis 5. Continue respiratory assessments, monitor further arterial blood gas results