endocrine and metabolic disorders
Hyperkalemia
Treatment of Hyperkalemia
Treatment of the cause For mild hyperkalemia,sodium polystyrene sulfonate,patiromer, orsodium zirconium cyclosilicate For moderate or severe hyperkalemia, IVinsulinand glucose, an IV calcium solution, possibly an inhaled beta 2-agonist, and usually hemodialysis Patients with serum potassium<6 mEq/L (< 6 mmol/L) and no ECG abnormalities may respond to diminished potassium intake or stopping potassium-elevating drugs. The addition of a loop diuretic enhances renal potassium excretion as long as volume depletion is not present. is used, sodium overload (see Hypernatremia ) may occur, particularly in patients with oliguria and preexisting volume overload. ) is generally all that is needed. In patients who need ACE inhibitors and angiotensin receptor blockers (eg, patients with chronic Heart Failure (HF) or Serum potassium between 6 and 6.5 mEq/L (6 and 6.5 mmol/L) needs prompt attention, but the actual treatment depends on the clinical situation. If no ECG changes are present and renal function is intact, maneuvers as for mild hyperkalemia are usually effective. Follow-up serum potassium measurements are needed to ensure that the hyperkalemia has been successfully treated. If serum potassium is>6.5 mEq/L (>6.5 mmol/L), more aggressive therapy is required. Administration ofregular insulin5 to 10 units IV is followed immediately by or administered simultaneously with rapid infusion of 50 mL 50% glucose. Infusion of 10%dextrosein water should follow at 50 mL/hour to prevent hypoglycemia. The effect on serum potassium peaks in 1 hour and lasts for several hours. If ECG changes include the loss of P-wave or widening of the QRS complex, treatment with IV calcium as well asinsulinand glucose is indicated; 10 to 20 mL of 10%calcium gluconate(or 5 to 10 mL of 22% calcium gluceptate) is given IV over 5 to 10 minutes. If the ECG shows a sine wave pattern or asystole,calcium gluconatemay be given more rapidly (5 to 10 mL IV over 2 minutes). Calcium antagonizes the effect of hyperkalemia on cardiac muscle. Calcium should be given with caution to patients takingdigoxinbecause of the risk of precipitating hypokalemia-related arrhythmias.Calcium chloridecan also be used but can be irritating to peripheral veins and cause tissue necrosis if extravasated.Calcium chlorideshould be given only through a correctly positioned central venous catheter. The benefits of calcium occur within minutes but last only 20 to 30 minutes. Calcium infusion is a temporizing measure while awaiting the effects of other treatments or initiation of hemodialysis and may need to be repeated. A high-dose beta 2-agonist, such asalbuterol10 to 20 mg inhaled over 10 minutes (5 mg/mL concentration), can lower serum potassium by 0.5 to 1.5 mEq/L (0.5 to 1.5 mmol/L) and may be a helpful adjunct. The peak effect occurs in 90 minutes. However, beta 2-agonists are contraindicated in patients with unstable angina or acute myocardial infarction. Administration of IVsodium bicarbonate(NaHCO3) is frequently used to treat hyperkalemia, but evidence supporting its use is limited. It may lower serum potassium over several hours. Reduction may result from alkalinization or from the hypertonicity due to the concentrated sodium in the preparation. The amount of sodium contained in the infusion may be harmful for dialysis patients who also may have volume overload. Another possible complication of IVsodium bicarbonateis that it acts to acutely lower the ionized calcium concentration, which further exacerbates the cardiotoxicity of hyperkalemia. Whensodium bicarbonateis given, the typical dose is 3 ampules of 7.5%sodium bicarbonatein one liter 5%dextrosein water infused over 2 to 4 hours. Bicarbonate therapy has little effect when used by itself in patients with severe renal insufficiency unless acidemia is also present. In addition to strategies for lowering potassium by shifting it into cells, maneuvers to remove potassium from the body should also be done early in the treatment of severe or symptomatic hyperkalemia. Potassium can be removed via the gastrointestinal tract by Mild hyperkalemia , but because the rate of potassium removal is somewhat unpredictable, close monitoring is needed. Patiromerand sodium zirconium silicate are not recommended for use as an emergency treatment to acutely lower potassium because of these drugs' delayed onset of action. Hemodialysis should be instituted promptly when emergency medical treatment is ineffective especially in patients with severe chronic kidney disease and/or acute kidney injury. Dialysis should be considered early in patients with end-stage renal disease and hyperkalemia because they are at increased risk of progression to more severe hyperkalemia and serious cardiac arrhythmias. Peritoneal dialysis is relatively inefficient at removing potassium acutely. 