Presentation on theme: "Hypokalemia & Hyperkalemia LAILA TAVAZO, REM. Distribution of potassium The intracellular concentration of potassium ranges from 140 to 150 meq/L. "— Presentation transcript:
Hypokalemia & Hyperkalemia LAILA TAVAZO, REM
Distribution of potassium The intracellular concentration of potassium ranges from 140 to 150 meq/L. The extracellular concentration of potassium meq/L.
Electrolyte disorders of potassium Hyperkalemia is the most dangerous acute electrolyte abnormality. Serum K level > 5.0 meq/L Hypokalemia is the most common electrolyte abnormality Serum K level < 3.5 meq/L
Five Most Common Causes of Hypokalemia Renal lossesDiuretic use, drugs, steroid use, metabolic acidosis, hyperaldosteronism, renal tubular acidosis, diabetic ketoacidosis, alcohol consumption Increased nonrenal lossesSweating, diarrhea, vomiting, laxative use Decreased intakeEthanol, malnutrition Intracellular shiftHyperventilation, metabolic alkalosis, drugs EndocrineCushing’s disease, Bartter’s syndrome, insulin therapy
Clinical features Non specific complaint: Palpitations, Skeletal muscle weakness or cramping, Depression, Easy fatigue ability Neuromuscular: Paralysis, paresthesia fasciculation, decreased tendon reflexes, confusion, respiratory failure Cardiovascular: Heart block, AF, VF, Asystole, Cardiac arrest, ↑sensitivity to digoxin toxicity GI: Constipation4, nausea or vomiting, anorexia, abdominal cramp, paralytic ileus Renal: polyuria, nocturia, or polydipsia,
Diagnostic strategy Clinical presentation Measurement of serum K level ECG
Management of hypokalemia Increasing the intake of foods high in potassium content Oral potassium supplements Giving potassium intravenously when rapid replacement is needed.
Oral replacement Oral replacement is available in liquid, powder, and tablet form. Potassium chloride is the most commonly used supplementation, and 40 to 60 mEq orally every 2 to 4 hours is typically well tolerated. it is easy to administer, safe, inexpensive, and readily absorbed from the GI tract
Management Transient, asymptomatic, or mild hypokalemia may resolve spontaneously or may be treated with enteral potassium supplements. Outpatient therapy and follow-up in hours may be acceptable for mild hypokalemia patients with no underlying heart disease.
IV Management cardiac monitoring is necessary in patients with profound hypokalemia (< 2.5 meq/L), or if cardiac arrhythmias are present, or if IV potassium is going to be rapidly administered. IV potassium should normally be diluted in saline solution so that the maximum concentration is 40 meq/L (peripheral lines) or 60 meq/L (central lines) and IV potassium.
IV infusion rate for severe or symptomatic hypokalemia. Standard IV replacement rate Standard IV replacement rate meq/h Serum potassium < 2.5 meq/L, or Serum potassium < 2.5 meq/L, or Moderate-severe symptoms Moderate-severe symptoms meq/h Serum potassium < 2.0 Meq/L, or Serum potassium < 2.0 Meq/L, or Life-threatening symptoms Life-threatening symptoms > 40 meq/h
Potassium replacement therapy is immediately indicated for: Severe hypokalemia (< 2.5 meq/L), or If the hypokalemia is causing muscle paralysis, or Malignant cardiac arrhythmias. Management of hypokalemia
Magnesium Replacement Therapy Magnesium replacement therapy is often necessary in malnourished alcoholics with hypokalemia. Hypomagnesemia should be suspected if the serum potassium does not increase within ~ 96 hours of the commencement of potassium supplementation therapy.
Five Most Common Causes of Hyperkalemia Spurious elevationHemolysis due to drawing or storing of the laboratory sample or post–blood sampling leak from markedly elevated white blood cells, red blood cells, or platelets Renal failureAcute or chronic AcidosisDiabetic ketoacidosis, Addison’s disease, adrenal insufficiency, type 4 renal tubular acidosis Cell deathRhabdomyolysis, tumor lysis syndrome, massive hemolysis or transfusion, crush injury, burn DrugsBeta-blockers, acute digitalis overdose, succinylcholine, angiotensin-converting enzyme inhibitors, angiotension receptor blockers, nonsteroidal anti-inflammatory drugs, spironolactone, amiloride, potassium supplementation
Clinical features Cardiovascular cardiac arrhythmia heart blocks, Brady dysrhythmias, pseudo infarction ST segment elevation, and the classic “sine wave” pattern. Neuromuscular: Muscle cramps, generalized weakness, paresthesia, tetany, and focal or global paralysis GI: nausea, vomiting, and diarrhea
Hyperkalemia with QRS widening merging into T wave, absent P wave.
Hyperkalemia after potassium-lowering therapy has begun. Tall peaked T waves, decreased P wave.
The same patient after dialysis. The electrocardiogram is now normal.
Treatment of Hyperkalemia TREATMENTMEDICATIONFEATURES Stabilize cardiac membrane Calcium chloride (10 mL, maximum 20 mL) or calcium gluconate (10-30 mL), IV push For wide QRS, restores the electrical gradient; does not decrease serum Potassium Shift potassium into cells Insulin, 10 units, IV push, combined with 100 mL of 50% dextrose, IV push High-dose nebulized albuterol by face mask (15-25 mg by continuous inhalation) Bicarbonate mL Normal saline mL If severely acidotic In conjunction with nephrologist if dialysis dependent Remove potassium from the body Hemodialysis Normal saline and furosemide Ion exchange resin Emergently in cardiac arrest, urgently in renal failure; may delay if renal function is normal In patients with rhabdomyolysis or tumor lysis syndrome with intact urine output Not effective acutely