Dyselectrolytemia in icu

Lecture By:
By: Dr. Muhammad Asim Fazal
ICU Doctor.Meeqat Hospital,Madina, KSA

1. Dyselectrolytemia in ICU By: Dr. Muhammad Asim Fazal

2. Definition An electrolyte disorder is an imbalance of certain ionized salts (i.e., bicarbonate, calcium, chloride, magnesium, phosphate, potassium, and sodium) in the blood.

3. Electrolytes Electrolytes are ionized molecules found throughout the blood, tissues, and cells of the body.   ·         Cations                       + ve ·         Anions                        - ve

4. General Functions of Electrolytes •     Help to balance pH and acid-base levels in the body. •     Facilitate the passage of fluid between and within cells through osmosis •     Play a part in regulating the function of the neuromuscular, endocrine, and excretory systems.

5. Specific Electrolytes – Functions •     Sodium (Na) •     Helps to balance fluid levels in the body and •     Facilitates neuromuscular functioning. •     Potassium (K) •     Main component of cellular fluid •     Helps to regulate neuromuscular function and osmotic pressure.

6. •     Calcium (Ca) •     Affects neuromuscular performance and •     Contributes to skeletal growth •     Blood coagulation. •     Magnesium (Mg) •     Influences muscle contractions and •     Intracellular activity

7. •     Chloride (CI-) •     Regulates blood pressure.   •     Phosphate (HPO4) •     Impacts metabolism and •     regulates acid-base balance and •     calcium levels.   •     Bicarbonate (HCO3) •     Assists in the regulation of blood pH levels

8. Normal levels of electrolytes •     Sodium.                       135-145 mEq /L (serum) •     Potassium.                       3.5-5.5 mEq /L (serum) •     Calcium(Serum)            8.8-10.4 mg/ dL (total Ca) •     Magnesium (Plasma)       1.4-2.1 mEq /L •     Chloride(Serum)          100-108 mEq /L •     Phosphate (Plasma)         2.5-4.5 mg/ dL (adults)

9. Sodium •     Normal : 135-145 mEq /L   •     Sodium helps the kidneys to regulate the amount of water the body retains or excretes.

10. HYPERNATREMIA (Serum sodium > 145 mEq /L) •     Inadequate water intake •     Increased sodium intake •     Excessive free water loss: •     Extra-renal •     Burns •     Sweating •     Tachypnoea

11. •     Renal •     Central diabetes insipidus •     Nephrogenic diabetes insipidus •     Craniophariangioma •     Post-operative

12. Symptoms of hypernatremia •     Non-specific , •     Restlessness, •     Irritability, •     Muscular twitching, •     Hyperreflexia , •     Spasticity, and •     Seizures •     With hypotonic losses  - signs of volume loss •     Tachycardia, •     Hypotension, •     Decreased JVP, •     Dry mucosa, •     Reduced skin turgor and •     Thick doughy skin

13. Treatment of Hypernatremia Acute Hypernatremia can be corrected rapidly Chronic Hypernatremia (more than 48 hours) should be corrected slowly. If hypernatremia is rapidly corrected, the osmotic imbalance may cause cerebral edema and potentially severe neurologic impairment. Aim for serum sodium correction of approximately 12 mol/L/24h (0.5 mmol /L/h)

14. Volume in (L) to be replaced = Current TBW × [Na] – 140 / 140 where TBW is typically 50% of total mass in women and 55% of total mass in men.

15. Hypernatremia with hypovolemia Patients should receive isotonic 0.9% normal saline to restore euvolemia and to treat hyperosmolality After adequate volume resuscitation with normal saline, 0.45% saline or 5% dextrose (or both) can be used to replace any remaining free water deficit.

16. Hypernatremia with euvolemia Water ingestion or intravenous 5% dextrose will result in the excretion of excess sodium in the urine.

17. Hypernatremia with hypervolemia Furosemide (1mg/kg) to get rid of sodium + Free water replacement as 5% D/W •     (* furosemide alone will aggravate the hypernatremia •     Dialysis may be required for patients with oliguric renal failure

18. HYPONATREMIA (Serum sodium less than 135 mEq /L) Up to 1% of all hospitalized patients develop hyponatremia , making it one of the most common electrolyte disorders. Hyponatremia usually reflects excess water retention relative to sodium rather than sodium deficiency. The clinician should be wary about hyponatremia since mismanagement can result in neurologic catastrophes from cerebral osmotic demyelination .

19. Symptoms and Signs Whether hyponatremia is symptomatic depends on its severity and acuity. Chronic disease can be severe (sodium concentration < 110 mEq /L), yet remarkably asymptomatic because the brain has adapted by decreasing its tonicity over weeks to months. Acute disease that has developed over hours to days can be severely symptomatic with relatively modest hyponatremia .

20. Nausea •     Abdominal cramping, and/or vomiting •     Headache •     Edema (swelling) •     Muscle weakness and/or tremor •     Paralysis •     Disorientation •     Slowed breathing •     Seizures •     Coma

21. Complications The most serious complication of hyponatremia is iatrogenic cerebral osmotic demyelination from overly rapid sodium correction. Also called central pontine myelinolysis . Demyelination may occur days after sodium correction or initial neurologic recovery from hyponatremia . The neurologic effects are generally catastrophic and irreversible.

22. Correction of Hyponatremia Treatment depends on: Etiology and types of hyponatremia Clinical Condition Serum Na level Ongoing loss

23. Regardless of the patient’s volume status, another common feature is to restrict free water and hypotonic fluid intake, since these solutions will exacerbate hyponatremia . Free water intake from oral intake and intravenous fluids should generally be < 1–1.5 L/d.

24. Hypovolemic patients Require adequate fluid resuscitation from isotonic fluids (either normal saline or lactated Ringer solution) to suppress the hypovolemic stimulus for ADH release. Patients with cerebral salt wasting may require hypertonic saline to prevent circulatory collapse; some may respond to fludrocortisone .

25. Hypervolemic patients May require loop diuretics or dialysis, or both, to correct increased total body water and sodium. To treat the basic CAUSE.

26. Euvolemic patients May respond to free water restriction alone.

27. Formula for Correction

28. For Example a non edematous, severely symptomatic 70 kg woman with a serum sodium of 122 mEq /L should have her serum sodium corrected to approximately 132 mEq /L in the first 24 hours. Her sodium deficit is calculated as:

29. 3% hypertonic saline has a sodium concentration of 514 mEq /1000 mL. The delivery rate for hypertonic saline can be calculated as:

30. Hypertonic saline in hyper- volemic patients can be hazardous, resulting in worsening volume overload, pulmonary edema, and ascites .

31. Potassium •     Normal : 3.5-5.5 mEq /L Main component of cellular fluid •     Helps to regulate neuromuscular function and osmotic pressure

32. Hyperkalemia S. Potassium > 5.5 m Eq/L Signs and Symptoms •     Fatigue •     Weakness •     Tingling, numbness, or other unusual sensations •     Paralysis •     Palpitations •     Difficulty breathing

33. ECG Changes ECG changes in hyperkalemia include bradycardia , PR interval prolongation, peaked T waves, QRS widening, and biphasic QRS–T complexes. Conduction disturbances, such as bundle branch block and atrioventricular block, may occur. Ventricular fibrillation and cardiac arrest are terminal events.

34. Hyperkalemia - Etiology What Causes It? •     Inadequate Excretion : •     Renal failure •     Addison’s disease •     Excessive intake •     Diet high in potassium (bananas, oranges, tomatoes, dates, high protein diets, salt substitutes, potassium supplements)

35. •     Shifting of potassium from tissues •     Trauma, especially crush injuries or burns •     Hemolysis •     Acidosis •     Insulin deficiency •     Drugs •     Digoxin , scuuinyl choline , beta agonists, potassium sparing diuretics

36. Treatment of Hyperkalemia Mild: (Serum K+  = 5.5 to 6.0 m Eq /L) •     Stop intake of potassium •     Stop offending drugs Restrict potassium rich diet

37. Moderate to Severe:  (in addition to above..) •     (Serum K+  = 6.0 to 8.0 m Eq /L or peaked T waves) •     Glucose Insulin Infusion : (0.5g/kg with 0.3 U regular insulin / g of glucose) •     Sodabicarb infusion (2 mEq /kg of NaHCO3 over 5 – 10 min)

38. IV Calcium gluconate 0.5 mEq /kg – to reverse cardiac effects •     Dialysis in cases of resistant hyperkalemia •     Nebulized salbutamol   •     Sodium polyesterene sulphate   - ion exchange resin for long term management

39. Hypokalemia (Serum K+ < 3.5 mEq /L) Increased Potassium Loss:   •     Extrarenal – Diarrhoea •     Renal – RTA, polycystic kidneys, Drugs •     Endocrine – Cushing’s disease, hyperaldosteronism •     Decreased Stores •     Malnutrition •     Shift into intracellular compartment •     Alkalosis •     hyperinsulinemia

40. Symptoms and Signs Muscular weakness, fatigue, and muscle cramps are frequent complaints in mild to moderate hypokalemia . Gastrointestinal smooth muscle involvement may result in constipation or ileus . Flaccid paralysis, hyporeflexia , hypercapnia , tetany , and rhabdomyolysis may be seen with severe hypokalemia (< 2.5 mEq /L).

41. Laboratory Findings Urinary potassium concentration is low (< 20 mEq /L) as a result of extrarenal loss ( eg , diarrhea, vomiting) and inappropriately high (> 40 mEq /L) with renal loss ( eg , mineralocorticoid excess, Bartter syndrome, Liddle syndrome)

42. Electrocardiogram The electrocardiogram (ECG) shows decreased amplitude and broadening of T waves, prominent U waves, premature ventricular contractions, and depressed ST segments.

43. Treatment of Hypokalemia Oral potassium supplementation is the safest and easiest treatment for mild to moderate deficiency. Intravenous potassium is indicated for patients with severe hypokalemia and for those who cannot take oral supplementation. For severe deficiency, potassium may be given through a peripheral intravenous line in a concentration up to 40 mEq /L and at rates up to 10 mEq /h.

44. Concentrations of up to 20 mEq /h may be given through a central venous catheter. Continuous ECG monitoring is indicated, and the serum potassium level should be checked every 3–6 hours. Magnesium deficiency should be corrected, particularly in refractory hypokalemia .

45. Formula for correction of Potassium Required K+ in mmol = 0.3 × Weight × [ Desired K+ level – Measured K+ level] Deficit corrected over 24 hour period.

46. HYPERCALCEMIA (Serum Ca++ > 12 mg/dL) Parathyroid excess  •     Multiple myeloma, •     Vitamin D excess •     Sarcoidosis •     Subcutaneous fat necrosis •     William’s syndrome •     Thyrotoxicosis •     Prolonged immobilization

47. Metastatic cancer, •     Multiple bone fractures, •     Milk-alkali syndrome, and •     Paget's disease. •     Drugs •     Excessive use of calcium-containing supplements •     Certain over-the-counter medications (i.e., Antacids) may also cause hypercalcemia .

48. HYPERCALCEMIA - Symptoms Nonspecific •     fatigue •     constipation •     depression •     confusion •     muscle pain •     nausea and vomiting •     dehydration •     increased urination •     irregular heartbeat (arrhythmia) •     Urinary stones •     Nephrocalcinosis •     Stupor & coma – S.Ca > 15 mg/ dL )

49. HYPERCALCEMIA - Management Forced saline diuresis with fruesemide •     Treat primary cause Bisphosphonates are the treatment of choice for hypercalcemia of malignancy. Although they are safe, effective, and normalize calcium in > 70% of patients, bisphosphonates may require up to 48–72 hours before reaching full therapeutic effect. Calcitonin may be helpful in the short-term until bisphosphonates reach therapeutic levels.

50. In emergency cases, dialysis with low calcium dialysate may be needed.

51. HYPOCALCEMIA (Serum Calcium < 8 mg/dL) Vitamin D deficiency •     Malabsorption •     Abnormal metabolism •     Prolonged phynetoin medication •     Increased Losses •     Idiopathic hypercalcuria •     Renal tubular necrosis •     Frusemide therapy •     Hypomagnesemia •     Hyperphosphatemia

52. •     Metabolic causes •     Hypoparathyroidism •     Pseudohyperthyroidism •     Hypoprotenemia •     Acute pancreatitis

53. HYPOCALCEMIA - Symptoms Muscle cramps and spasms •     Tetany and/or convulsions •     Mood changes (depression, irritability) •     Dry skin •     Brittle nails •     Facial twitching •     Latent Tetany •     Trousseu’s sign •     Chvostek’s sign

54. HYPOCALCEMIA - Management Tetany , laryngospasm , seizures •     2 ml/kg of 10 5 Calcium gluconate slow IV under cardiac monitoring •     Later •     Oral calcium supplementation – 40 to 80 mg/kg/d •     Treat Vit . D def.

55. HYPERMAGNESEMIA End-stage renal disease, •     Addison's disease, or •     An overdose of magnesium salts.

56. Lethargy •     Hypotension •     Decreased heart and respiratory rate •     Muscle weakness •     Diminished tendon reflexes

57. Treatment Exogenous sources of magnesium should be discontinued. Calcium antagonizes Mg 2+ and may be given intravenously as calcium chloride, 500 mg or more at a rate of 100 mg (4.1 mmol ) per minute. Hemodialysis or peritoneal dialysis may be necessary to remove magnesium, particularly with severe kidney disease.

58. HYPOMAGNESEMIA Inadequate dietary intake •     Chronic alcoholism •     Malnutrition •     Malabsorption syndromes, •     Pancreatitis, •     Aldosteronism , •     Burns, •     Hyperparathyroidism, •     Digestive system disorders, and •     Diuretic use.

59. Signs and symptoms Leg and foot cramps •     Weight loss •     Vomiting •     Muscle spasms, twitching, and tremors •     Seizures •     Muscle weakness •     Arrthymia

60. Treatment Symptomatic hypomagnesemia requires intravenous magnesium sulfate 1–2 g over 5–60 minutes mixed in either dextrose 5% or 0.9% normal saline.

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