Approach to potassium disorder, causes, investigation, ecg changes, management

quick description regarding hypo and hyperkalemia

1. Approach to potassium disorder CME Guide: Dr. B. D. Jha Dr. Praveen Kumar Giri Dr . Sahana Tamrakar Presented by: Gaurav Thakuri MBBS (NEPALESE ARMY INSTITUTE OF HEALTH SCIENCES)

2. Potassium homeostasis

3. Serum potassium level HYPOKALEMIA NORMAL HYPERKALEMIA < 3.5 mEq /L ( mmol /L) 3.5 – 5.5 mEq /L ( mmol /L) > 5.5 mEq /L ( mmol /L)

4. Hypokalemia CAUSE OF HYPOKALEMIA PSEUDO HYPOKALEMIA INTRACELLULAR SHIFT INADEQUATE INTAKE EXCESSIVE LOSS GI LOSS RENAL LOSS

5. PSEUDOHYPOKALEMIA A LAB ARTIFACT BLOOD SAMPLE OF LEUKEMIA (AML) PATIENTS

6. INTRACELLULAR SHIFT TRANSIENT SHIFT OF POTASSIUM FROM EXTRACELLULAR COMPARTMENT INTO CELLS MEDICATIONS HYPOKALEMIC PERIODIC PARALYSIS ALKALOSIS SYMPATHOMIMETIC AGENTS : SALMETEROL PHOSPHODIESTERASE INHIBITOR : THEOPHYLLINE INSULIN

7. INADEQUATE INTAKE OF POTASSIUM VERY RARE PROLONGED STARVATION ANOREXIA

8. Excessive loss of potassium GI loss Vomiting Nasogastric aspiration/drainage Diarrhea Laxative abuse Ureterosigmoidostomy

9. Excessive loss of potassium Renal loss Increased sodium delivery to distal nephron Increased mineralocorticoid activity Diuretics Primary hyperaldosteronism High- dose penicillin Renin- secreting tumors Renal tubular acidosis (Type 2 proximal) Cushing syndrome 3 genetic syndromes (Liddle, Bartter, and Gitelman) Causes of volume depletion

10. Clinical manifestations Asymptomatic until serum potassium < 3 mEq /l Symptoms/signs are usually limited to: 1. Muscles- weakness (legs > arms), cramps, ileus RESPIRATORY PARALYSIS 2. Cardiac conduction abnormalities: arrhythmias ( eg :   premature ventricular contractions, ventricular fibrillation, atrial fibrillation, and torsade de pointes. )

11. Diagnostic evalutaion

12. POTASSIUM REPLETION FOR PATIENT WITH HYPOKALEMIA IN THE SETTING OF ESSENTIAL DIURETIC USE AS IN HEART FAILURE OR HYPERALDOSTERONISM, POTASSIUM-SPARING DIURETIC IS USUALLY MORE EFFECTIVE THAN CHRONIC POTASSIUM REPLETION INDICATION MAX DOSE/ REPLETION RATE MAJOR SIDE EFFECT ORAL KCL THOSE WHO TOLERATE FEEDS 40 mEq at a time every 2 to 4 HRLY GI upset IV KCL NPO 10 mEq / hr via peripheral vein 20 mEq / hr via central line Burning pain Proximal to IV site

13. Hyperkalemia

14. Pseudohyperkalemia False rise in potassium levels Cellular release of potassium during venipuncture due to hemolysis or prolonged torniquet use Also occur with significant leukocytosis or thrombocytosis

15. Extracellular shift Transient shift of potassium from cells into extracellular compartment Medications Increased cell turnover ACIDOSIS DIGOXIN TUMOR LYSIS SYNDROME SUCCINYLCHOLINE RHABDOMYOLYSIS BETA BLOCKERS ACUTE LEUKEMIA

16. Increased intake of potassium Rare KCl infusion

17. Decreased excretion of potassium Renal failure Any condition that inhibits aldosterone release or aldosterone action

18. Cause of hypoaldosteronism Renin Aldosterone Etiologies Hyporeninemic Hypoaldosteronism Low Low Diabetic nephropathy NSAID Non- hyoporeninemicy hypoaldosteronism Normal or High low ACE INH CHRONIC HEPARIN USE PRIMARY ADRENAL INSUFFICIENCY Aldosterone resistance Normal or High Normal or High Aldosterone receptor antagonist

19. Clinical manifestations Patients are almost always without significant manifestation until serum potassium >6.5 mEq /l Symptoms/signs are usually limited to: 1. muscles- weakness ( legs > arms) 2. Arrhythmias: sinus bradycardia , heart block CARDIAC ARREST

20. ECG CHANGES K + ECG CHANGES 5.5-6.5 NO OR TALL T WAVES >6.5 TALL PEAKED T WAVES 7 - 8 PROLONGED PR INTERVAL FLAT P WAVES >8 WID E QRS, SINE WAVE VF ASYSTOLE

21. Management Exclude pseudohyperkalemia Evaluate renal function and medication list Evaluate for hypoaldosteronism by checking renin, aldosterone and cortisol

22. Treatment of underlying cause TIME TO ONSET DURATION AMOUNT OF K + REDUCED IV CALCIUM <5MIN 10 TO 30 MIN NONE INSULIN + GLUCOSE 15MIN 2 HOURS 0.5-1.2 SALBUTAMOL 30MIN 2HOURS 0.5-1.2

23. OTHERS Diuretics: loop diuretics +/- saline hydration used to treat hyperkalemia Dialysis: when hyperkalemia is associated with ESRD HYPERKALEMIA INDUCED ARRYTHMIAS REFRACTORY HYPERKALEMIA

24. ANY QESTIONS?????

25. Refrence •Harrison's Principles of Internal Medicine, 18th edition, Anthony S.Fauci , MD, Eugene Braunwald , MD, Dennis L. Kasper, MD, Stephen L . Standard treatment protocol of emergency health service package 2078 A step-wise approach vol II second edition Guyton and hall textbook of medical physiology 13 th edition http:// www.kidney-international.org All images are copyright to their respective owners. All product names, logos and brands used are properties of their respective owners.