By Lori Kleinfield, RD, LDE, CDE

Potassium is a vital nutrient everyone needs to keep their heart, nerves and muscles working properly. For kidney disease patients – especially those on dialysis – having too much or too little potassium in the body can be a serious problem. Either condition can cause muscle weakness, nausea, numbness, hallucinations and other conditions – even sudden heart failure. In other words, you have to stay within the potassium safety zone.

Hemodialysis patients are at particular risk of having excess potassium. As the kidneys fail, they lose the ability to expel potassium. Although dialysis removes potassium from the body, it can build up during longer periods between treatment sessions. Peritoneal dialysis patients are at less risk than hemodialysis patients because they dialyze daily. However, they still need to monitor their potassium levels regularly.

What is the potassium safety zone?
Typically, a hemodialysis patient’s diet should include 2,000-3,000 milligrams (mg)  of potassium per day. A peritoneal dialysis patient, on the other hand, can typically have 3,000-4,000 mg of potassium per day.

When your blood is tested for potassium, the safety zone is generally in the range of 3.5-5.5 milliEquivalents per liter (mEq/L) of blood, although each person has his or her own individual potassium safety zone. With hemodialysis patients, potassium levels are tested before the dialysis treatment, when levels are highest. In fact, it is not uncommon for the potassium level to go up to 6.0 mEq/L in these tests, as it will immediately start coming down when treatment begins. Less than 3.5 or more than 6.0 mEq/L is definitely outside the potassium safety zone.

How can you keep your potassium level from getting too high?
First, meet with your renal dietitian to determine your personal potassium allowance. The dietitian can work with you to set up a reasonable diet plan that will keep you within normal limits. It should also be easy for you to follow over the long term.

The best rule of thumb for a low-potassium diet is to eat a balanced diet with meat, fruit, vegetables and grains. You should aim for 7-10 ounces, or two medium servings of meat, fish, poultry and eggs per day and also include about six daily servings of low-potassium fresh fruit and vegetables (See Chart 1). Also, grain products such as bread, rice, pasta, cereals and crackers are very low in potassium, although whole grains have slightly more potassium.

Be sure to avoid or limit high-potassium foods such as:
• Melon
• Dairy products
• Nuts
• Orange juice
• Potatoes (especially baked)
• Salt substitutes containing potassium
• Spinach

The best diets are the ones that let you eat as many of your favorite foods as possible. It is important to track your potassium levels on a monthly basis. Don’t hesitate to discuss your individual potassium levels and dietary preferences with your physician. Your renal dietitian can also help you work out a potassium safety zone diet plan that includes some of your favorite highpotassium highpotassium foods – chocolate, anyone? – in small portions. You may even discover some new “favorite foods” along the way (See recipe on page 7).

Chart 1
Low Potassium Fruits and Vegetables Fruits Vegetables

• Apples
• Berries
• Cherries
• Grapes
• Peaches
• Pineapple
• Plums
• Tangerines
• Broccoli
• Cauliflower
• Cucumbers
• Green beans
• Lettuce
• Peppers
• Summer squash
• Zucchini

References:
“Blood tests for people on dialysis: Understandingthe results,” www.mayoclinic.com/health/dialysis/DA00133

Pocket Guide to Nutrition Assessment of the Patient with Chronic Kidney Disease, 3rd Edition, 2002, Council on Renal Nutrition of the National Kidney Foundation

Lori Kleinfield is a Registered and Licensed Dietitian and Certified Diabetes Educator with Fresenius Medical Care North America. She has been a renal dietitian since 1984. Originally from New York and a graduate of Cornell University, she currently practices at two Fresenius Medical Care dialysis clinics in the greater Dallas area.

This article originally appeared in the March 2008 issue of aakpDelicious!

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