Hypokalemia

electrolytes imbalance

1. HYPOKALEMIA

2. Definition Hypokalemia is defined as persistently low levels of serum potassium lower than 3.5mEq/L. Normal serum levels are 3.5-5mEq/L. 98% of body potassium is intracellular(150mEq/L)whereas only 2% of it is intracellular(3.5-5mEq/L)

3. CAUSES

4. CLINICAL FEATURES Non severe hypokalemia is usually asymptomatic. Common acute manifestations are muscle weakness and ecg changes. Profound hypokalemia causes arrythmias,rhabdomyolisis,renal abnormalities. Cardiac arrythmias like sinus bradycardia, premature beats, ventricular fibrillation. Skeletal muscle weakness or paralysis usually do not develop unless hypokalemia develops slowly and levels are <2.5 mEq/L.

5. Diagnostic Approach History( drugs,diet,diarrhea,vomiting ) Physical examination(BP,S/O Hyperthyroidism,Cushings ) Lab tests( Sr.electrolytes,BUN,sr.creatinine,urinary Ph) ECG

6. Investigaions Sr.elecrolyter,BUN,,creatinine ECG Urine electrolytes ABGS Urinanalysis and urine Ph Urinary calcium Aldosterone suppression test CT abdomen

7. ECG CHANGES

8. PREVENTION Especially important in patients on digitalis, hepatic failure, previous MI,DM. Normal daily intake of 60mEq?day Supplementation in patients on digitalis, diuretics and long erm steroids, hepatic failure.

9. WHEN TO TREAT 3.4-5 mEq/L: No supplement needed, Potassium rich foods,Change diuretics. 3-3.5:Treatment needed in High risk patients(h/o MI,CHF) <3mEq/L: Needs definitive treatment.

10. TREATMENT The management of hypokalemia should be focused on preventing or treating the acute complications of low potassium levels, replacing the potassium deficit and treating the underlying cause and preventing further wasting if possible. For mild asymptomatic hypokalemia potassium supplements should be used (10 to 20 mEq orally, two to four times a day, with meals). If potassium supplements are not enough, potassium sparing diuretics may be used as well, with careful monitoring of serum potassium

11. Severe or symptomatic hypokalemia can be treated promptly with oral and IV potassium. The oral potassium should be used in the dose 20-40 mEq three to four times a day. The IV potassium can be given in a solution with normal saline (not glucose) in a concentration of 20-60 mEq/L and a rate around 10-20 mEq/h to avoid phlebitis and hyperkalemia (a central vein is a better option for a rate higher than 10 mEq/h). Dosing forms: Potassium chloride: Extended release capsules: KLOR-CON SPRINKLE, MICRO-K or generic – 8 or 10mEq capsules. Extended release tablets: K-TAB (8, 10 or 20mEq tablets), KLOR-CON or generic (8, 10, or 20 mEq tablets) Solution PO: K-SOL 20 or 40mEq/15mL (10 or 20%); generic 20 mEq/15mL (10%).