Managing fluids and diet as a patient on peritoneal dialysis

Managing your diet

Specific dietary restrictions for dialysis differ from person to person. However, there are some general guidelines all patients should follow, whether on haemodialysis (HD) or peritoneal dialysis (PD).

Woman making a smoothie and referencing her phone for the toolkit.

PD gives you the opportunity to choose from a wide variety of foods.

Your optimal dialysis diet is determined by your age, weight, level of kidney function, and what type of dialysis you are on, as well as whether you have other health conditions, such as, hypertension, high cholesterol or diabetes. Dietary requirements are mostly the same for people being treated with peritoneal dialysis (PD) and haemodialysis (HD). However, there are a few key differences to keep in mind.

Broschure "Essen und Peritonealdialyse - einfacher als gedacht" Once a Month We Post a Recipe for a Delicious and Healthy Meal

General & individual recommendations

With declining kidney performance, less protein should be eaten than is normally the case in Germany. What does that mean in concrete terms? Nothing other than to follow what the German Nutrition Society recommends for the normal population: 0.8 g protein per kilogram of body weight. That is almost a third less than is eaten on average. This targeted reduction is therefore only an approximation to the desirable normal intake.

The situation is different for patients starting renal replacement therapy. On haemodialysis, the protein requirement increases for various reasons, and the same applies to peritoneal dialysis. The recommendation now is to eat at least 1.2 g of protein per kilogram of body weight daily. These are amounts that now again correspond to the actual protein intake in the population... You see how different recommendations can be for an underlying disease.

There are no differences when it comes to table salt. Less is more is the motto for everyone. 6 g of table salt per day would be optimal. With this reduction, you can positively influence your high blood pressure and prevent water retention in the body. Not to forget thirst, which automatically arises with salt consumption and is a challenge especially for haemodialysis patients, whose drinking quantity is often limited. Those who decide to eat less salt will probably find the food tastes too bland at first. This change in taste takes a few weeks, after which a pleasant taste sets in even with lower amounts of salt. Use lemon juice in combination with less salt to enhance the taste of the food.

The amount of water drunk and also the water content in food plays a rather minor role for patients with impaired kidney function and for most peritoneal dialysis patients. For patients on haemodialysis, however, drinking quantity is a major issue.

In the case of potassium and phosphate, the situation is clear and applies to all sufferers: if the values rise, you will be advised to replace foods rich in potassium or to eat smaller amounts. In this case, about 2000 mg of potassium per day should be taken in with food. Replacing or reducing phosphate-rich foods is one way to control elevated phosphate levels. These values can also be effectively lowered by the correct intake of phosphate binders. The aim should be to consume about 1200 mg of phosphate with food and drink. Phosphate intake is directly related to protein intake: if more protein is eaten, the amount of phosphate automatically increases. However, under no circumstances should dialysis patients avoid protein-rich foods in order to reduce phosphate levels. The targeted selection of foods that are rich in protein and at the same time low in phosphate is the right way to go in this case.

Managing fluids

Fluid weight is the liquid part of your body. Body weight may change daily depending on what you eat and drink.

It is important to keep fluids in balance. Your healthy kidneys were able to balance the amount of fluid in your body. PD will help remove some extra fluid but you need to pay attention to the amount of fluids taken in and removed from your body. Your weight and how you feel also depend on your fluid balance.

Fluid balance and types of dialysis

Your dialysis treatment plays a significant role in how much fluid you can include in your diet. If you are on peritoneal dialysis, you may not have the same fluid restrictions as someone who is receiving in-center hemodialysis.

In PD, fluid is removed daily. Patients may also continue to have urine output, which provides additional removal of water from the body.

In-center hemodialysis implies that most patients receive dialysis three times a week for four hours per treatment. This means fluid builds up between treatments and as a result, patients must be careful with how much liquid they consume.

Fluid and your kidneys¹

One of the kidneys’ major functions is to maintain the fluid balance in your body. When your kidneys are not working well, they are not able to remove water as effectively. If you take in more fluids than your body is able to get rid of, this can lead to a buildup of excess fluid, or “edema.” Excess fluid can be dangerous, as it puts a great strain on your heart.²

For patients on dialysis, it can be challenging to know what amount of fluid is right for their individual needs. Too much or too little fluid can result in a fluid imbalance; this is not only uncomfortable, but may also put your health at risk. It is very important that you know how to recognize if you are not in a healthy balance. Your registered dietitian will work with you to determine your fluid needs.

Possible signs and symptoms of fluid imbalance:*

Overhydration (too much fluid)

High blood pressure
Swelling (edema)
Cramping
Shortness of breath
Sudden increase in weight

Dehydration (too little fluid)

Low blood pressure
Feeling dizzy, weak, faint, or lightheaded
Cramping
Dry mouth
Vomiting, diarrhea

*Your healthcare team monitors your fluid status on a regular basis. Knowing the signs and symptoms of having too much or too little fluid in your body enables you to work with your team to come up with a plan that keeps you as healthy as possible

How to manage your fluid

Managing your fluid can be challenging when you are on dialysis but it is possible. There are steps you can take to minimize fluid buildup and control your thirst.

1) Know your limit (and stay within it)

Rule of thumb when setting daily fluid targets is to aim for four cups plus the amount equal to how much urine you are making. If you have a larger body mass, your registered dietitian may calculate your fluid allowance based on 5% of your weight.

2) You are what you eat (and drink)

Next to dialysis, food and fluid play the greatest role in keeping your water gains to a minimum.

Sodium
High sodium (salt) intake can make you feel thirsty and lead to increased fluid intake. Sodium also causes your body to hold on to extra water. Both can result in excess fluid buildup. Speak to your registered dietitian to learn how you can reduce sodium in your diet.

Fluid
Everything that is liquid at room temperature is considered a fluid and must be counted towards your daily allowance.

Common fluids

Water
Juices/fruit drinks
Tea/Coffee
Alcohol
Ice cream/sherbet
Soup
Ice
Pop
Milk
Nutritional supplements
Popsicles
Jello

Hidden fluid
You may also take in more fluid than you think. Hidden fluid can be found in all foods, which contain water; some have more than others. While you do not count this as part of your daily fluid allowance, you may need to limit the portion size of foods with higher water content.

Question:

Which food has the greatest amount of hidden fluid?

Green peas
Celery
Watermelon

Answer: 2) Celery. It contains 95% fluid. Watermelon contains 91% fluid and peas contain 79% fluid.³

3) Tips for controlling fluid intake

Plan ahead

Measure how much liquid your favorite cups hold to help plan your fluid for the day.
Avoid drinking simply out of habit; save your fluid for when it is important to you.
Spread your fluid intake throughout the day.

Track your fluid

Keep a daily fluid diary. Measure and mark down each time you have a fluid. Remember: small portions such as ice cubes add up quickly.

Be strategic

Take your medication with soft foods such as applesauce. Save your fluid for liquids you enjoy. Important: Check with your healthcare team to learn which pills you can have with your meals.
Replace liquids with frozen fruit when possible.
Choose foods that are liquid at room temperature less often.

Did you know?

For every cup of liquid you drink beyond your daily fluid target, you will see ½ pound of weight gain. ²

4) Tips for controlling thirst

Limit salt, spicy food, caffeine and alcohol.
Add lemon or mint to cold water.
Replace water with plain or flavored ice cubes. It lasts longer and the options are endless.
Drink slowly and take small sips to make your fluid last longer.
Fruit including grapes and berries taste great frozen and help relieve thirst.
Use candy (hard or sour), gum or mints to increase saliva in your mouth. Speak to your dietitian for options that are right for you.
Ask your pharmacist about using breath spray or strips.

5) Other strategies

Dry mouth?
Brush your teeth and rinse out your mouth with water or non-alcoholic mouthwash.
High blood sugar?
This could make you feel thirstier. If you have diabetes, it is important to keep your blood sugar under control.
Dry air in your home?
Use a humidifier to add moisture.
Hot summer day?
Stay indoors when possible or spray cold mist on your face and body to keep cool

How much fluid can I have?
The amount of fluid you can include each day will be different for everyone. Your dialysis treatment, urine output and other factors such as medications, body size and physical activity will be considered. Your registered dietitian will work with you to determine your fluid needs.

What should you do each day to balance your fluids?

How do you know if you have too much fluid?

What can you do if you have too much fluid?

How do you know if you have too little fluid?

What can you do if you have too little fluid?

References

Adapted from the original by Christine Nash, MSc(C), RD, CDE and Antonia Zettas, RD, CDE. Both authors are registered dietitians at the home peritoneal dialysis unit at the Toronto General Hospital (UHN). Christine Nash is the co-chair of the Canadian Association of Nephrology Dietitians (CAND).

²Canadian Association of Nephrology Dietitians. Essential guide for renal dietitians; 3rd edition, 2010.

³Canadian Nutrient File 2016