2 Distribution of potassium The intracellular concentration of potassium ranges from 140 to 150 meq/L.The extracellular concentration of potassium meq/L.
3 Electrolyte disorders of potassium Hyperkalemia is the most dangerous acute electrolyte abnormality Serum K level > 5.0 meq/LHypokalemia is the most common electrolyte abnormality Serum K level < 3.5 meq/L
4 Five Most Common Causes of Hypokalemia Renal lossesDiuretic use, drugs, steroid use, metabolic acidosis, hyperaldosteronism, renal tubular acidosis, diabetic ketoacidosis, alcohol consumptionIncreased nonrenal lossesSweating, diarrhea, vomiting, laxative useDecreased intakeEthanol, malnutritionIntracellular shiftHyperventilation, metabolic alkalosis, drugsEndocrineCushing’s disease, Bartter’s syndrome,insulin therapy
10 Management of hypokalemia Increasing the intake of foods high in potassium contentOral potassium supplementsGiving potassium intravenously when rapid replacement is needed.
11 Oral replacementOral 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
12 ManagementTransient, 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.
13 IV Management cardiac monitoring is necessary in patients with profound hypokalemia (< 2.5 meq/L), orif cardiac arrhythmias are present, orif 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.
14 IV infusion rate for severe or symptomatic hypokalemia Standard IV replacement ratemeq/hSerum potassium < 2.5 meq/L, orModerate-severe symptomsmeq/hSerum potassium < 2.0 Meq/L, orLife-threatening symptoms> 40 meq/h.
15 Management of hypokalemia Potassium replacement therapy is immediately indicated for:Severe hypokalemia (< 2.5 meq/L), orIf the hypokalemia is causing muscle paralysis, orMalignant cardiac arrhythmias .
16 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.
17 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 plateletsRenal failureAcute or chronicAcidosisDiabetic ketoacidosis, Addison’s disease, adrenal insufficiency, type 4 renal tubular acidosisCell deathRhabdomyolysis, tumor lysis syndrome, massive hemolysis or transfusion, crush injury, burnDrugsBeta-blockers, acute digitalis overdose, succinylcholine, angiotensin-converting enzyme inhibitors, angiotension receptor blockers, nonsteroidal anti-inflammatory drugs, spironolactone, amiloride, potassium supplementation
18 Clinical features Cardiovascular Neuromuscular: GI: 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 paralysisGI:nausea, vomiting, and diarrhea
20 Hyperkalemia with QRS widening merging into T wave, absent P wave.
21 Hyperkalemia after potassium-lowering therapy has begun Hyperkalemia after potassium-lowering therapy has begun. Tall peaked T waves, decreased P wave.
22 The same patient after dialysis. The electrocardiogram is now normal.
23 Treatment of Hyperkalemia MEDICATIONFEATURESStabilize cardiac membraneCalcium chloride (10 mL, maximum 20 mL) or calcium gluconate (10-30 mL), IV pushFor wide QRS, restores the electrical gradient; does not decrease serum PotassiumShift potassium into cellsInsulin, 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 mLIf severely acidotic In conjunction with nephrologist if dialysis dependentRemove potassium from the bodyHemodialysis Normal saline and furosemide Ion exchange resinEmergently 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