How to prevent hyperkalemia in patients with chronic kidney disease?

Article by Pharmacist Nguyen Thu Giang - Faculty of Pharmacy - Vinmec Times City International General Hospital

Hyperkalemia is one of the complications of impaired kidney function and causes many health complications. Taking measures to prevent hyperkalemia, especially in patients with chronic kidney disease, is essential. Refer to the article below to help readers find useful answers to prevent hyperkalemia.

Potassium is a positive ion located mainly in cells that plays an important role in maintaining the normal functioning of cells. Potassium helps maintain water balance in the body, maintaining the normal functioning of the heart, nerves and muscles.
To maintain normal functioning, the extracellular potassium concentration (blood potassium concentration) is 3.5 - 5 mmol/l, the intracellular potassium concentration (the intracellular potassium concentration) is 120-140 mmol/l. The result of the blood potassium test is the value of the extracellular potassium concentration.
Hyperkalemia is when the potassium level in the blood is higher than 5mmol/l. Hyperkalemia may be asymptomatic or present with some nonspecific symptoms such as fatigue, weakness, palpitations, paresthesias...
Emergency hyperkalemia is when one of the following occurs: status: high blood potassium level above 7mmol/l, hyperkalemia with symptoms such as paralysis or muscle weakness, arrhythmia or changes in the electrocardiogram.
Potassium is regulated through 2 mechanisms. The mechanism of potassium balance in the cell, potassium is transported from the extracellular environment into the intracellular environment. Mechanism of balancing potassium in the blood or extracellularly, absorbed potassium is excreted by the kidneys and intestines. Every day, when our body absorbs 100mmol of potassium from the diet, the kidneys will be responsible for excreting 90-95mmol, the intestines are responsible for eliminating 5-10mmol.
In patients with impaired renal function, especially those with end-stage chronic kidney disease, the intestinal excretion of potassium is increased but not commensurate with the renal elimination. Therefore, hyperkalemia is common mainly in patients with impaired renal function due to a decreased ability to excrete potassium in the urine. In particular, patients who use drugs that increase blood potassium or diet, dietary supplements containing a lot of potassium will often face this condition.
Table 1- Grading of glomerular filtration rate in adults [KDIGO 2012]

Several measures can be applied to prevent hyperkalemia in patients with chronic kidney disease, especially in patients with end-stage CKD. Depending on the severity of chronic kidney disease and hyperkalemia, your treating doctor and nutritionist will advise you on appropriate measures.
2.1 Low Potassium Diet The average person's diet needs at least 4700mg of potassium a day. People with moderate to severe chronic kidney disease with a glomerular filtration rate (GFR) less than 45ml/min should have a daily diet containing less than 3000mg of potassium. A diet containing 2000-3000mg of potassium per day is called a reduced potassium diet.
When your kidneys don't work as well anymore, it becomes more difficult to excrete potassium to maintain potassium balance in the blood. Following a low-potassium diet will help reduce your risk of hyperkalemia. In particular, this would be beneficial for people taking medications that can increase blood potassium such as ACE inhibitors (eg, perindopril, lisinopril...), angiotensin 2 receptor blockers (eg. valsartan, telmisartan, irbesartan...), potassium-sparing diuretics (eg spironolactone), non-selective beta-blockers (eg propranolol, labetalol)... or those with a history of repeated hyperkalemia , chronic hyperkalemia.
Potassium-rich foods are often foods rich in fiber, good for the cardiovascular system, and contain many vitamins and minerals. Therefore, you need to know about foods that are high in potassium, how to measure portion sizes guided by a nutritionist, as well as how to prepare foods to ensure a potassium-restricted diet. does not remove fiber, vitamins and minerals.
Foods with the most potassium include cantaloupe, watermelon, grapefruit, dried fruit and fruit juices, avocados, tomatoes, potatoes, sweet potatoes, Brussels sprouts, milk, yogurt, lentils, most nuts except peanuts (peanuts). You should avoid or use only very small amounts of these foods. High-potassium foods are those that contain more than 200mg of potassium per serving (usually around 100 grams or according to the recommended serving size for certain foods). You can share your eating habits and commonly used foods so that your doctor and nutritionist can advise and assist you in building a suitable menu.
For vegetables high in potassium (e.g. bamboo shoots, beets, broccoli, cabbage, Brussels sprouts, spinach, carrots, kohlrabi, potatoes, sweet potatoes, pumpkin, eggplants) sour...), you can remove some of the potassium by soaking vegetables in warm water for at least 2 hours before cooking. Vegetables should be peeled (if any), cut into bite-sized chunks or pieces and soaked in large amounts of water (1 part vegetables, 10 parts warm unsalted water) for at least 2 hours or overnight. Before cooking, you rinse again with warm water. When processing, you should also use a large amount of water (1 part vegetables, 5 parts water) and should not use more broth for these potassium-rich vegetables in the diet. You should also not eat these potassium-rich vegetables too often (eg daily use) and should not be used too much in one serving (eg more than 1 serving ~ 100 grams).
2.2 Avoid starvation To prevent hyperkalemia, patients need to avoid being hungry for too long, which leads to an increase in the amount of potassium that moves from the cell to the outside of the cells and increases the concentration of potassium in the blood. This may be partly due to the body's reflex to reduce insulin secretion when hungry. According to a study of 10 patients with chronic kidney disease on stable hemodialysis, fasting for 18 hours increased serum potassium levels by 0.6 mmol/l. Therefore, patients with end-stage renal disease (without diabetes) require elective surgery and should receive an overnight infusion to avoid excessively prolonging the fast.
2.3 Avoid using drugs that can increase potassium Some drugs can increase potassium such as ACE inhibitors (eg enalapril, perindopril, lisinopril...), angiotensin 2 receptor blockers (eg. such as valsartan, telmisartan, irbesartan...), potassium-sparing diuretics (eg, spironolactone), non-selective beta-blockers (eg, propranolol, labetalol)...
Physicians need careful monitoring and evaluation Be extra careful when using these drugs if you have chronic kidney disease. Usually, your doctor will check your blood potassium levels before starting treatment with drugs that can increase potassium, re-evaluate after 1 week of medication and re-evaluate each dose increase, and then reassess periodically. as other patients with chronic kidney disease. Your doctor may start you at a lower dose, increase your dose more slowly, and leave the maximum dose lower than in patients without chronic kidney disease.
If you have chronic kidney disease with high blood pressure or heart failure or arrhythmia, do not change the dose of your medicine without consulting your doctor. In particular, do not follow the medicine of friends and relatives to avoid possible unwanted side effects, including hyperkalemia.
Doctors generally avoid prescribing you drugs that can cause hyperkalemia when your pre-treatment potassium level is higher than 5.5 mmol/l. Patients should discuss their hyperkalemia with their specialist physicians in the case of multiple doctor visits.
Patients always need to comply with the drug treatment prescribed by the doctor, have regular check-ups and evaluations or follow the instructions to receive the most effective and safe treatment.