The main job of kidneys is to clean blood of excess fluids and waste products. When they are working they can filter 130 to 170 litres of blood each day producing 1 to 2 litres of urine. This helps to keep electrolytes like potassium, sodium, and phosphate at stable levels.
Unfortunately, in people living with kidney failure, this is not possible. So you have to find ways to help the body keep the levels of these electrolytes at a stable level. If you don’t then you can end up with difficulty breathing, chest pain, or heart palpitations. This condition is called hyperkalemia: if you experience these symptoms, call for emergency help immediately as it requires immediate medical care.
How do I minimise potassium build up?
To minimise potassium build up, the best way is to make dietary changes. This is where I had been doing well, but then had made a near-fatal error recently.
You have to know which foods are high in potassium and should be avoided and which are not and may be consumed. Also, even if it is low in potassium, if you eat too much of it your potassium levels can spike.
Foods to add to your diet
Some low-potassium foods include:
- berries including strawberries and blueberries,
- grapefruit (though I can’t have this due to the Blood pressure tablets),
- cranberries and cranberry juice,
- green beans,
- white rice,
- white pasta
- white bread,
- egg whites
- canned tuna in water
Foods to limit or avoid
You should limit high-potassium foods including:
- prunes and prune juice,
- oranges and orange juice (this is where I went wrong recently),
- tomatoes, tomato juice, and tomato sauce,
- Brussels sprouts,
- potatoes (regular and sweet),
- dried apricots,
- bran products,
- Cola drinks.
Reduce potassium from fruit and vegetables
It is best to swap tinned fruit and vegetables for their fresh or frozen counterparts. The potassium in tinned goods leaches into the water or the juice in the can. You have to throw out this water to prevent a spike in potassium levels if you use it.
There are ways of reducing the level of potassium in vegetables. The two ways that I have been told to do by the dietician are:
- Boil it in water and then throw the water out, and boil in fresh water; or
- Boil in 10 times the volume of water to the volume of vegetable.
How much potassium is safe?
Healthy men and women over the age of 19 should consume at least 3,400 mg and 2,600 mg of potassium per day, respectively. Of course, people with reduce kidney function who are on potassium-restricted diets should keep this well below 2,000 mg per day.
People with kidney disease will have their potassium checked at least monthly by their renal team. This blood test will determine the level of potassium millimoles per litre of blood (mmol/L).
There are three levels:
- safe zone: 3.5 to 5.0 mmol/L;
- caution zone: 5.1 to 6.0 mmol/L; and
- danger zone: 6.0 mmol/L or higher.
Danger zone level yesterday
Yesterday, my potassium level was 7 mmol/L, which you can see from above list is in the danger zone. Fortunately, I was beginning dialysis and so they could clean the blood. So now, I have to really make sure that I avoid anything that may raise the potassium level.
I’ve just remembered that I have been having some potato wedges as well recently, those are also to be limited in the diet. So, if I do go to the local garage for some food, I had better make some better choices: stick to the chicken rolls, leave out the wedges. And find an alternative to orange juice to drink. Perhaps try the cranberry juice.
So, I shall have to take a fresh look at the Truly Tasty cook book that I got given when I transferred from Tallaght to Tullamore hospital. I have made a few things from it including the beef dish in the picture above. I shall limit the orange juice that I drink and will revert to cranberry juice instead for now. Of course, I am not allowed to drink more than 1 litre of fluid in a day anyway, so that limits everything all the time.