HyperKalemia - Potassium increase - Causes, level, diagnosis and Rx:

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Hyperkalemia - increase in the level of potassium
Causes, level, diagnosis and Rx:
s-K> 5.5mmol/l
requires emergency management:

  1. ECG, repeat bloods, 
  2. stop exogenous potassium and potassium retaining medications
  3. Assess potential causes of transcellular shift
  4. estimate the GFR


  • Drugs: ACE inhibitors, Potassium sparing drugs, digitalis toxicity (blocks the Na/K ATPase, Succinylcholine, B-Blockers
  • Potassium Supliments - Potassium Chloride suppliments or KCl IVI
  • PEN G - antibioltics
  • Breakup of cells: Rhabdomyolysis, tumour lysis syndrome, Hemolysis - the intracellular K leaks out to the extracellular space - increasing potassium in the blood
  • Metabolic Acidosis (except for keto and lactic acidosis) and Insulin deficiency - DKA - both acidosis and insulin deficiency
  • Potassium can not be  excreated
    • decreased GFR
    • renal failure
    • decreased effective circulating volume
    • NSAID in renal insufficiency
    • HYPOALDOSTERONISM
  • Causes of Hyerkalemia with Normal GFR
    • Low renin and low aldosterone
      • associated with DM2, NSAID, Chronic interstitial nephritis, HIV
    • Normal renin and low aldosterone
      • Adrenal insufficiency - Addisons disease, AIDS, metastatic Ca
      • ACE inhibitors
      • Angiotensin II receptor blockers
      • heparin
      • Congenital adrenal hyperplasia with 21-hydroxylase deficiency
    • Aldosterone resistance
      • K-sparing diuretics: spironolactone, amiloride, trimeterne
      • Drugs that mimic K-sparing diuretics: pantamide, trimetoprim, cyclosporin, tracrolimus
      • Psudohypoaldosteronism
So what do you do?



Symptoms
Nausea, Muscle weakness, fatigue, anesthesia, palpitation, cardiac arrhythmia, areflexia, asending weakness, and hypoventilation
Renal metabolic acidosis - impaired amonia genesis


  • EKG - deepening T waves - peaked and narrow T waves.
  • low amplitude p waves or loss of P waves
  • Prolonged PR interval
  • QRS wave complex widening
  • Ventricluar fibrillation, asystole
  • Death
  • EKG is not sensitive enough to measure progress in management
Goal of treatment to protect the heart with calcium gluconate, shift K into cells and enhance K removal from the Body
  • Protect the heart: 
  • Give calcium - antagonises the effects of potassium on the heart (but has no effect on the K levels)
Use calcium gluconate, 1 to 2 Amps (10ml of 10% solution) IVI except if there is digitalis toxicity.

  • stabilize the membrane potential - Shift K into the cells - Send the potassium in the cell 
    • Use Insulin - 10 to 20 units IV- also give dextrose 50%  - D50W - 1 to 2 amps to prevent hypoglycemia
      • Review s-glucose q1h
      • Infusion at a rate of 1 unit per hour
    • NaHCO3 1-3 amps (given as 3 amps NaHCO3 in 1L D5W)
      • drives K intracellular in exchange for H+
    • Use salbutamol inhalations 
      • B2 Agonist (Ventolin) in nabulised form (2cc or 10mg inhaled) or 0.5mcg IV
      • stimulates NaK ATPase, may result in tachycardia - use with caution
Increase the excretion of potassium
    • via the urine
      • furosimide (>40mg IV) with IV fluids to prevent dehydration
      • fludrocortisone (symthetic miralocorticoid) if suspect aldosterone deficiency
    • via gut
      • using Kayexelate - 20 to 50 mg 
        • cation resins - Kayexelate plus Sorbitol po to avoid constipation 
        • Kayexelate enemas with TAP WATER (not sorbitol)
    • dialysis - renal failure, life threatening, hyperkalemia unresponsive to Rx



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