Disorders of potassium(Hypokalaemia, Hyperkalaemia)
- 1. Disorders of Potassium -M.Mohan -B.Sc Renal Dialysis -P.E.S Institute
- 3. What is potassium?? • • • • • • • Potassium is a mineral that your body needs to work properly. It is a type of electrolyte. It helps your nerves to function and muscles to contract. It helps your heartbeat stay regular. It also helps move nutrients into cells and waste products out of cells. A diet rich in potassium helps to offset some of sodium's harmful effects on blood pressure. Many people get all the potassium they need from what they eat and drink. Sources of potassium in the diet include: Leafy greens, such as spinach and collards Fruit such as grapes and blackberries Root vegetables, such as carrots and potatoes Citrus fruits, such as oranges and grapefruit Your kidneys help to keep the right amount of potassium in your body. If you have chronic kidney disease, your kidneys may not remove extra potassium from the blood. Some medicines also can raise your potassium level. You may need a special diet to lower the amount of potassium that you eat.
- 4. Introduction:- - K + is the second most abundant cation in the body (3.5mol). -Dietary K + amounts to 80 – 150mmol/day. Only around 65mmol is present in the ECF, with the great majority (98%) found within cells in muscle (and, to a lesser extent, liver, red cells, and bone -Total body K + balance is regulated by renal excretion: K + is freely filtered at the glomerulus (700mmol/day) and is reabsorbed by the PCT (75%), the loop of Henle (15%), and the A-intercalated cells of the collecting duct.
- 5. Conti...... - K + secretion is responsible for most urinary potassium loss and is tightly controlled by aldosterone in the DCT and the principal cells of the collecting duct. -In health, around 1 – 1.5mmol/kg/day is excreted in urine, with a small fraction ( 7- 10mmol) in faeces -Obligate urinary K + loss (10 – 15mmol/day) will always occur, no matter how low the serum K + -Aldosterone secretion is increased directly by hyperkalaemia (and hypovolaemia) and suppressed by hypokalaemia controlling K + in the normal range (3.5 – 5.0mmol/L).
- 6. Hyperkalemia:- -True hyperkalaemia is either due to increased release from cells or decreased excretion by the kidney. Since the release of important trials using spironolactone or eplerenone (in addition to ACE inhibitors) in the treatment of heart failure, dangerous hyperkalaemia has become more common in those with better renal function
- 7. - Increased K + is often spurious: always recheck result. Traumatic venepuncture leads to cellular K + leakage and false hyperkalaemia. -This leads to 1 – 2mmol/L rise in the apparent K +. Fine-bore needles, tourniquets, and fi st clenching can all induce mechanical release of K + from cells, as can cold temperature. Psudohypokalemia:-
- 8. Common causes include:- •CKD •K + -rich diets (bananas, other fruits) with CKD. •Drug-induced (esp. combinations of the following): -ACE inhibitors/ARB. -K + -sparing diuretics (spironolactone, eplerenone, amiloride). -NSAIDs. -Heparin and LMW heparins (inhibit normal aldosterone release). - Ciclosporin. -High-dose trimethoprim. - Digoxin toxicity (but not therapeutic levels of digoxin). -B-blockers.
- 9. Conti...... • Hypoaldosteronism •Addison’s. •Increased release from cells: -Acidosis (lactic). -Insulin defi ciency (DKA). - strenuous exercise, or tumour lysis. -Massive haemolysis. -Succinylcholine use.
- 10. Conti...... Other rare causes -Hyperkalaemic periodic paralysis: mutations in skeletal Na + channel -Type 1 pseudohypoaldosteronsim: presents in infancy
- 11. Hypokalaemia;- -One of the most common electrolyte abnormalities seen, esp. in patients on diuretics -Although K + of 3 – 3.5mmol/L is generally well tolerated hypokalaemia of <2.5mmol/L can be life-threatening (esp. in the presence of digitalis(used to treat heart failure)
- 12. Causes:- Causes • Inadequate intake <25mmol/day (either dietary or IV). •Increased gut losses: -Vomiting -Diarrhoea or laxative abuse. -Zollinger – Ellison syndrome(a rare condition in which one or more tumors . form in your pancreas or the upper part of your duodenum • Redistribution into cells: -B-agonism (any cause of ⬆sympathetic drive, e.g. delirium tremens). -B-agonist drugs (bronchodilators, decongestants) -Insulin, theophylline, or caffeine (activate Na + /K + -ATPase pump). • Alkalosis. • Vigorous exercise
- 13. Contin..,..., •-1°hyperaldosteronism: adrenal adenoma (Conn’s syndrome), bilateral adrenal hyperplasia — plasma aldosterone:renin ratio -Renin-secreting tumours ( i BP in the young) -Cushing’s disease.(Cushing's syndrome is a hormonal disorder caused by high levels of the hormone cortisol(ACTHACTH) in your body) -2° hyperaldosteronism(Liver failure, heart failure, nephrotic syndrome)
- 14. Conti.... -Renal losses: • Diuretics (esp. thiazides, loops), including abuse of diuretics. • Acquired renal tubular disease -Other drugs: • Amphotericin and aminoglycosides (tubular toxicity). • Glucocorticoids (esp. at high dose) or mineralocorticids. -Hypomagnesaemia
- 15. Symptoms and signs:- -See previous list of causes for specific associations — usually picked up on U&E. -Take a full drug history, particularly for diuretics. Exclude diarrhoea -Fatigue -constipation - proximal muscle weakness, and ⬇tone -Cardiac arrhythmias, esp. if underlying heart disease -⬇urinary concentrating ability -Increased blood pressure
- 16. Investigations:- -U&E *Mg+2 *calculate the anion gap(measures the difference between the negatively charged and positively charged electrolytes in your blood. If the anion gap is too high, your blood is more acidic than normal) - Either perform 24-hour urinary K + or do spot u-K + and u-Cr. -Calculate the urinary K/Cr ratio (KCR) -Digoxin level if on drug. -If 24-hour u-K + <15mmol/L, losses are EXTRARENAL.
- 17. -depending on the KCR, focus attention as shown in Table - Check the ECG: small T waves, U wave (after T), PR interval ⬆, ST segments ⬇
- 18. Treatment:- -Is the patient on digoxin? Will potentiate digoxin’s arrhythmogenicity. -Note that diuretic-induced hypokalaemia is exacerbated if dietary Na +intake is high. Always aim to treat the underlying cause over time. Mild (>2.5mmol/L): -Oral slow-release potassium chloride 50 – 150mmol/day in divided doses •⬆dietary K + and ? switch to K + -sparing diuretic.
- 19. Contin.... -Severe or symptomatic hypokalaemia (K <2.5mmol/L, arrhythmias, liver failure, or extreme weakness) • Cardiac monitor. • Check Mg 2+ , and correct if need be . • Avoid glucose-containing solutions or sodium bicarbonate. • IV 0.9% saline 1L with 20 – 40mmol KCl at no more than 10-20mmol KCl/h through peripheral cannula. If ⬇K + with hyperchloraemic acidosis, avoid 0.9% saline, and rather use KCl
- 20. Contin.... • In volume-restricted patients KCl can be given into a central vein as 20 – 40mmol/100mL 0.9% saline (NOT glucose, risk of hypokalaemia) at not > 40mmol/h using a volumetric pump
- 21. Potassium in dialysis:- -Potassium is a mineral that controls nerve and muscle function. The heart beats at a normal rhythm because of potassium. Potassium is also necessary for maintaining fluid and electrolyte balance and pH level. Low potassium:- Potassium comes from the foods we eat. Healthy kidneys remove excess potassium in the urine to help maintain normal levels in the blood. -Because most foods have potassium, low potassium (hypokalemia) is uncommon in people who eat a healthy diet.
- 22. Hyperkalaemia • • When kidneys fail they can no longer remove excess potassium, so the level builds up in the body. High potassium in the blood is called hyperkalemia, which may occur in people with advanced stages of chronic kidney disease (CKD) For people with stage 5 CKD (also known as end stage kidney disease or ESKD), dialysis is necessary to help regulate potassium. Between dialysis treatments, however, potassium levels rise and high-potassium foods must be limited.
- 23. Effects of hyperkalaemia:- -Nausea -Feeling tired or weakness -Muscle pain or Muscle cramps -Trouble breathing -,unusual heartbeat, -chest pain
- 24. Consequences of potassium:- • • Managing high potassium is important if you want to protect heart function • Having too much potassium in your blood can be dangerous. High potassium can even cause a heart attack or death!
- 25. High potassium foods :- Foods:- -Banaana 🍌🍌 -kiwi 🥝🥝🥝 -Mango 🥭🥭🥭🥭 -oranges 🍊🍊🍊 - Papaya Vegetables:- - Dried beans - Pumpkins🎃🎃🎃 - Potatoes 🥔🥔🥔 - Sweet potato - Tomatoes 🍅🍅🍅
- 26. Low potassium foods :- • Foods:- -Apples🍎🍎🍎 -Berries -Grapes 🍇🍇🍇 - Lemon 🍋🍋🍋 - Pine apple - watermelon🍉🍉 Vejitables:- - Carrot🥕🥕🥕 -Cabbage -Cauliflower -Green beans - Onion🧅🧅
- 27. Thank you for listening to