After the kidney transplant you can let the water flow! Your drinking quantity restrictions from the times during dialysis no longer apply. Now it is usually important to drink enough fluids for your new kidney. Particularly in the first period after the transplantation, a so-called balance sheet is prepared to better control your fluid balance and the function of your new kidney. This is an overview of the fluid you excrete and the fluid you consume. In this article you will learn exactly how this works and what you need to keep in mind.
Transplantation is a true miracle! Your transplant team takes an organ from another human body and places it in your own. Here it takes over the function of an organ that no longer functions for various reasons. Today, this works with some of the most important organs of all: the heart, the lungs, the liver and, of course, the kidney.
The function of the new organ depends, of course, on the exact organ that is transplanted. The lungs supply your body with important oxygen, your heart pumps this oxygen in your blood through your circulation and the liver plays an important role in your metabolism and the detoxification of your body.
The kidney has several vital roles. It produces important hormones such as erythropoietin (=EPO), which stimulates the formation of new red blood cells in your body. It also keeps important electrolytes such as sodium, potassium or phosphate in your blood in balance. In addition, it cleanses your blood of important pollutants and waste products, removes excess fluid from your body and thus keeps your blood pressure in balance.
So your kidney is a true all-rounder! After the transplant, all these functions should of course be checked to make sure your new kidney is doing a good job. Various tests are used for this purpose. In addition to laboratory checks and imaging methods (e.g. ultrasound), so-called balancing also plays a role here.
What does my excretion say about my kidney function?
A decrease in urine output is often a sign of a lack of fluids. This means that you have simply taken in too little fluid, which is why you now also excrete less fluid. The cause can also be diarrhea, warm weather, or intense exercise, for example. In this case, you may be supplying your body with enough fluid in principle, but you are losing more of it through your stool or sweat. As a result, it is again too little.
Especially in the case of chronic kidney failure and after transplantation, a decrease in the amount of urine you produce can also be an indication of poor kidney function. This is because urine is produced when your kidney cleans your blood. If it is not able to do this, no urine is produced. A very simple calculation!
If you also experience pain when urinating or over the transplant, low excretion can also be a sign of rejection or a urinary tract infection (UTI). Both of these pose a risk to your kidney. Therefore, if you have been drinking enough and your excretion does not increase after increased fluid intake, you should contact your transplant team directly.
What is balancing?
A balance sheet is - simply put - a sheet on your fluid balance. Maybe you already know this word from another context. In the financial world, a balance sheet is made to contrast inputs and outputs and to see what remains of your money at the end.
In medicine, it's relatively similar. In a balance, the fluid you take in is compared to the fluid your body excretes. In a neutral balance, these two values are almost the same. Your fluid balance is then in equilibrium.
What are a positive and negative balance?
If this is not the case, however, it is called a positive or negative balance.
- Positive balance: A positive balance is when you take in more fluid through food or infusions ( fluid through the vein) than you excrete. The reason for this is often heart or kidney failure. Subsequently, this water accumulates in your body (=overhydration). Your blood pressure rises, fluid deposits form and these become noticeable as weight gain.
- Negative balance: With a negative balance, your body excretes more fluid than you take in. Causes for this can be, for example, diarrhea, vomiting or sweating at high temperatures. A strongly increased urine production can also lead to a negative balance
How does a balance work?
Of course, to perform a balance, your medical team must first determine how much fluid you are taking in and how much you are excreting. To do this, you need to understand how both fluid intake and fluid output occur.
1. How much fluid do I take in?
The most important way of fluid intake is drinking. It is here that a big change takes place after transplantation. The drinking quantity restrictions from dialysis are lifted and it is important that your drinking quantity is sufficiently high. Your medical team will tell you exactly how much you should drink after transplantation. Typically, the recommended amount to drink is between 2 and 3 liters per day. You will also often take in a little fluid through your diet.
If you are still in the hospital, you may also receive fluids through infusions. These are liquid medications that drip directly into your bloodstream. Your medical and nursing team will tell you the exact amount of fluid contained in the infusion. At home, of course, this type of fluid intake is not necessary.
Finally, your body also produces water itself as part of the natural build-up and breakdown of substances in your body (=metabolism). You do not need to measure this amount yourself, because it is relatively constant at 200 to 300 milliliters per day.
2. How much fluid does my body give off?
You lose most of your fluid through your urine after your kidneys have cleansed your blood. The exact amount, of course, depends on the function of your new kidney. If the total amount of your urine is very high or low, it may indicate poor kidney function. On average, the amount of urine is between 1,000 and 1,500 milliliters per day. However, fluctuations in urine production are completely normal, especially shortly after transplantation. Your medical team will explain to you which values are appropriate for your current situation.
To measure your exact urine output, your medical team at the transplant center may place a urinary catheter in your bladder to collect your urine in a bag. Here, your doctors can read exactly how much urine your new kidney is producing. When you return home, you can measure the exact amount of urine using a collection canister. You will receive this from your medical team and simply collect all the urine you pass in the course of a full day (24 hours).
In addition to your urine, your stool also contains fluid. For normal bowel movements, this is between 150 and 200 milliliters per day. In the case of diarrhea, of course, it can be considerably more. Of course, you do not have to measure this value exactly.
Another value that you can generally count as part of your fluid excretion is the excretion of fluid through your skin, mucous membranes and respiratory tract. You do not notice this fluid loss yourself and therefore cannot measure it. Usually, a flat 800 milliliters per day is added for this.
A final individual point is your sweat. This plays an important role, especially at high temperatures and strong physical exertion. However, you can only estimate the exact amount. Weighing yourself before and after sweating (e.g. sports or sauna) can help you to develop a sense for it.
How do I calculate the balance at home?
So you see: Some values you can measure very well, others are a pure estimation. A balance is always somewhat imprecise and does not need to be checked to the milliliter.
In the clinic, your balance will always be determined by your transplant team. You may be asked to keep a drinking diary to accurately determine your fluid intake through drinks. Your urine volume will be determined through a bladder catheter, especially in the first few days. Afterwards, a collection canister is often used. You can roughly add the remaining values - as indicated above - to your intake or excretion. When you get home, you can continue to determine your urine volume using a collection canister. You can continue to keep your drinking diary at home, just as you did in the hospital.
Subsequently, you subtract your excreted fluid (urine, stool, loss via skin or respiratory tract, etc.) from the absorbed fluid (drinking, infusions, metabolism, etc.):
- Final balance = fluid absorbed - fluid excreted.
If your fluid intake is significantly higher than your fluid excretion, the value is clearly positive and is called a positive balance. Fluid remains in the body. If the value of the absorbed fluid is clearly below the excretion, the value becomes negative and one speaks of a negative balance. Your body loses more fluid than it takes in.
Much more important than an exact balance, however, are the clear symptoms of a positive or negative balance. In the case of a positive balance, these are water retention or high blood pressure. In the case of a negative balance, these are a drop in performance, a fast heartbeat (=pulse) and low blood pressure. How exactly you should carry out your balance and which values you should aim for is always best discussed with your transplant team.
