Avoid These Common Mistakes in Treating Hyperkalemia

Hyperkalemia tends to cause panic in healthcare professionals, and rightfully so. On a good day, it causes weakness in the legs; on a bad day, it causes cardiac arrest.

It makes sense that a high potassium level causes clinicians to feel a bit jumpy. This anxiety tends to result in treating the issue by overly restricting potassium in the diet. The problem with this method is that it should be temporary but often isn't. There are only a few concerns that justify long-term potassium restriction.

As a dietitian, I have seen numerous patients with varying disease states who are terrified of potassium because they were never properly educated on the situation that required restriction or were never notified that their potassium was corrected. 

I've seen patients whose potassium level hasn't been elevated in years refuse banana bread because they were told that they could never eat a banana again. I've worked with patients who continued to needlessly restrict, which eventually led to hypokalemia.

Not only does this indicate ineffective education — banana bread is actually a low-potassium food at about 80 mg per slice — but also poor follow-up. 

Potassium has been designated by the United States Department of Agriculture as a nutrient of public health concern due to its underconsumption in the general population. Although there is concern in the public health community that the current guidelines for potassium intake (3500-4700 mg/d) are unattainable, with some professionals arguing for lowering the standard, there remains a significant deficiency in the general population. This deficiency has also been connected to increasing rates of hypertension and cardiovascular disease. 

Nondietary Causes of Hyperkalemia 

There are many causes of hyperkalemia, of which excessive potassium intake is only one, and an uncommon one at that. A high potassium level should resolve during the course of treatment for metabolic acidosis, hyperglycemia, and dehydration. We may also see resolution with medication changes. But the question remains: Are we relaying this information to patients?

Renal insufficiency is a common cause of hyperkalemia, but it is also a common cause of chronic constipation that can cause hyperkalemia as well. Are we addressing bowel movements with these patients? I often work with patients who aren't having their bowel movements addressed until the patient themselves voices discomfort. 

Depending upon the urgency of treatment, potassium restriction may be the most effective and efficient way to address an acutely elevated value. However, long-term potassium restriction may not be an appropriate intervention for all patients, even those with kidney conditions.

As a dietitian, I have seen many patients who overly restrict dietary potassium because they had one elevated value. These patients tend to view potassium as the enemy because they were never educated on the actual cause of their hyperkalemia. They were simply given a list of high-potassium foods and told to avoid them. A lack of follow-up education may cause them to avoid those foods forever. 

Benefits of Potassium

The problem with this perpetual avoidance of high potassium foods is that a potassium-rich diet has been shown to be exceptionally beneficial. 

Potassium exists in many forms in the Western diet: as a preservative and additive, a salt substitute, and naturally occurring in both animal and plant products. My concern regarding blanket potassium restriction is that potassium-rich plant and animal products can actually be beneficial, even to those with kidney and heart conditions who are most often advised to restrict its intake. 

Adequate potassium intake can: 

• Decrease blood pressure by increasing urinary excretion of sodium
• Improve nephrolithiasis by decreasing urinary excretion of calcium
• Decrease incidence of metabolic acidosis by providing precursors to bicarbonate that facilitate excretion of potassium
• Increase bone density in postmenopausal women
• Decrease risk for stroke and cardiovascular disease in the general population

One study found that metabolic acidosis can be corrected in patients with stage 4 chronic kidney disease, without hyperkalemia, by increasing fruit and vegetable intake when compared with those treated with bicarbonate alone, thus preserving kidney function.

Do I suggest encouraging a patient with acute hyperkalemia to eat a banana? Of course not. But I would suggest finding ways to work with patients who have chronic hyperkalemia to increase intake of potassium-rich plant foods to maintain homeostasis while liberalizing diet and preventing progression of chronic kidney disease. 

When to Refer to a Dietitian

In patients for whom a potassium-restricted diet is a necessary long-term treatment of hyperkalemia, education with a registered dietitian can be beneficial. A registered dietitian has the time and expertise to address the areas in the diet where excessive potassium exists without forfeiting other nutritional benefits that come from whole foods like fruits, vegetables, lean protein, legumes, nuts, and seeds in a way that is both realistic and helpful. A dietitian can work with patients to reduce intake of potassium-containing salt substitutes, preservatives, and other additives while still encouraging a whole-food diet rich in antioxidants, fiber, and healthy fats.

Dietitians also provide education on serving size and methods to reduce potassium content of food.

For example, tomatoes are a high-potassium food at 300+ mg per medium-sized tomato. But how often does a patient eat a whole tomato? A slice of tomato on a sandwich or a handful of cherry tomatoes in a salad are actually low in potassium per serving and can provide additional nutrients like vitamin C, beta-carotene, and antioxidants like lycopene, which is linked to a decreased incidence of prostate cancer.

By incorporating the assistance of a registered dietitian into the treatment of chronic hyperkalemia, we can develop individualized restrictions that are realistic for the patient and tailored to their nutritional needs to promote optimal health and thus encourage continued compliance.