Hyperkalemia

Severe: above 6.5 mmol/l carry
Risk of cardiac stand still in diastole
c/p: progressive muscular weakness or no symptoms

Of Hyperkalemia Causes

1.(spurious) Pseudohyperkalemia
2.Excessive intake (diet, iv therapy..)
3.Redistribution out of cells
4.Endogenous increase K Load
( 5.Medications(ACEI,B-BLOCKER,K-sparingD
: 6.Renal retention of K
(Renal failure or Tubular secretary failure)

1.Spurious Hyperkalemia

Hemolysis (in tube )
Delay in processing of blood
Severe leukocytosis or thrombocytosis

2. Redistribution out of cells

1.Metabolic acidosis
2.Insulin deficiency
3.B-BLOCKERS
4.Hyperkalemic periodic paralysis

3. Exogenous(diet,K therapy)

4. Endog enous K load
Rhabdomyolysis
Hemolysis
Tumor lysis syndrome
Severe exercise

: 5. Renal Retention of K

In renal failure(especially when S.Cr >500 mic mol/L) ie with decrease GFR
A. Sever Acute Renal Failure , esp with Hemolysis , Rhabdomyolysis , Acidosis))
B. Chronic Renal Failure(Advanced)
(esp with oliguria /K load)

Conditions with Hyperkalemia due to Renal Tubular Secretary Failure ie with preserved GFR

1.Addison disease
2.Congenital adrenal enzyme defect
3. Drugs : ACEIs , B-blockers ,NSAIDs and K Sparing Diuretics..Amiloride,Spironolactone
4.Tubulointerstial disease…no response to the Aldosteron by tubules..(SLE , transplant (,Amyloidosis, Obstructive Uropathy

Investigations

Serum Electrolytes

Renal Function tests (B. urea ,S. Cr ), bicarbonate level

ECG

Treatment of Hyperkalemia

1- Stabilize myocardial membrane
2- Drive extracellular potassium into the cells
3- Removal of Potassium from the body

Stabilize myocardial cell membrane

Calcium Gluconate  10 ml 10% IV. Over 2-3 min ,repeated if no reversal changes in ECG within 5-10 min

Drive extracellular potassium into the cells

1- Inhaled 2 Agonists: or 5-10mg nibulized Salbutamol inhaler over 10 min, it will lower K by 0.5-1.5 mmol/L started after 30 min ,action remain for 2-4 hours.
2-Soluble Insulin 5-10 u with 25 gm of Glucose(Glucose50ml of 50% concentration) infusion within 10 min :
it will lower K by 0.5-1.5 mmol/L started after 15-30 min ,action remain for several hours.
*infusion of10-20%Dextrose 500ml within4-6hrs to minimize rebound increase in K
3- If Acidosis , IV Sodium Bicarbonate 100ml of 8.4%.

Removal of Potassium from the body

1.Frusemide IV with Normal Saline if renal function is normal
2.Ion Exchange Resin(eg. Calsium Resonium binds K+ in exchange for Ca++) given orally 15-30 g or rectally 30g, which remove K from GIT.
* K-Resin Exchanges Na+ for K+ and binds it in gut, primarily in large intestine, decreasing total body potassium
3.Dialysis if significant renal impairment