Balanced crystalloid solution versus saline in deceased donor kidney transplantation (BEST-Fluids): a pragmatic, double-blind, randomised, controlled trial

Global Kidney Trials Insights: A Guide for Everyone

Balanced crystalloid solution versus saline in deceased donor kidney transplantation (BEST-Fluids): a pragmatic, double-blind, randomised, controlled triaL

Global Kidney Trials Insights: A Guide for Everyone

1. The question for investigation?

Do two different kinds of fluids given at time of kidney transplantation produce different outcomes in people with kidney failure who receive a kidney transplant?

Simply put, scientific investigators wanted to know “When people with kidney failure get a kidney transplant, does using two different types of fluids during surgery and up until 48 hours after transplantation lead to different results?”

To answer this question, research scientists conducted a big study with over 800 people. These study participants all received a new kidney from someone who had passed away, who is known as a “deceased donor.” Fluids are usually given to help the new kidney work as well as possible. Scientists wanted to find out which of the following two types of fluid helps the new kidney work better.

  1. Normal saline solution: It contains primarily salty water. It is commonly used during and early after the transplant surgery; and
  2. Balanced crystalloid solution: This contains the electrolytes commonly found in our bodies. It has extra minerals like potassium and magnesium that are important to help keep our bodies healthy.

For the first few days after a kidney transplant, fluids are given to patients through their veins. In this study, 808 children and adults from Australia and New Zealand, were randomly given one of the two types of fluids at the time of the transplant surgery and for the first 48 hours (about two days), after their kidney transplant.

Sometimes, a newly transplanted kidney needs a little extra help to start working properly. When a transplanted kidney does not start working right away and needs additional support with dialysis to help remove excess fluid and waste from the blood, this is called “delayed graft function”. Delayed graft function can be linked to several problems, including the need for ongoing dialysis until the kidney works well enough, longer hospital stays, a higher risk of kidney failure, and death. In this study, delayed graft function, defined as needing dialysis within seven days after kidney transplantation, was the “outcome” of primary interest. “Outcome” refers to an event over time that is measured to monitor the impact of a treatment in a given population.

This study compared the two different types of fluids to see if one is better than the other in reducing delayed graft function. The investigators were also interested in looking at the length of hospital stay, overall mortality, kidney function, kidney rejection and safety outcomes (like high potassium levels or fluid overload).

2. The findings of the study

People who received the “balanced crystalloid solution” after the transplant surgery had a lower risk of delayed graft function than people who received “normal saline solution.” Thirty percent of people (121 of 404) receiving the “balanced crystalloid solution experienced delayed graft function, compared to forty percent of people (160 of 403) receiving normal saline. This means that for every ten people receiving balanced crystalloid solution instead of normal saline, one case of delayed graft function could be avoided.

There were no differences in the other outcomes of interest, such as kidney function, kidney failure or death within the first year after kidney transplantation, rejection of the kidney, duration of hospitalization, or safety outcomes.

Additional information about patient reported outcomes is expected to report how people felt, and so is information about costs, as dialysis is very expensive and the difference in cost between the two types of fluid is small. These two aspects are important for policy makers and clinicians.

Overall, this is a well-done large-scale study in people receiving a kidney transplant from a “deceased donor”. It shows that the choice of fluid given during and shortly after kidney transplantation has an impact on the occurrence of delayed graft function. Based upon these study findings, it is recommended that the standard-of-care, (i.e., the best way to take care of patients) is to use the fluid called balanced crystalloid solution. This fluid should be entered into the veins of patients who receive a deceased donor kidney transplantation.

This edition was edited by Andrea Viecelli, ISN-ACT Committee member and Glenda Roberts, ISN-ACT Patient Engagement in Renal Trials subgroup member, supported by members of the ISN Patient Engagement in Renal Trials subgroup and members of the Patient Liaison Advisory Group.

Read the GTF editorial team’s original review of the BEST-Fluids trial here.
Access the complete study here.
Any questions? Contact us at research@theisn.org

Glossaries

Glossaries

Adrenal glands are small glands that sit on top of the kidneys.

Efficacy refers to how well a medication or treatment works in achieving its intended effect.

Aldosterone is a hormone produced by your adrenal glands, which sit on top of your kidneys. It's kind of like a chemical messenger that helps regulate the amount of water and salt in your body.

Semaglutide is a medication used to treat type 2 diabetes and help with weight loss. It works by mimicking a hormone (called GLP-1) in the body that helps control blood sugar and appetite. It's usually given as an injection.

Random assignment (or randomisation) is a way of putting people into different groups in a study by chance, like flipping a coin. This helps make sure the groups are similar at the start of the study, so researchers can better tell if a treatment is really working.

Cardiovascular disease refers to diseases that affect the heart and blood vessels. This includes problems like heart attacks, strokes, and heart failure. Diabetes, high cholesterol, high blood pressure, and being overweight can damage the blood vessels and cause cardiovascular disease.

refers to the best way to take care of patients

refers to an event over time that is measured to monitor the impact of a treatment in a given population.

Delayed graft function happens when a transplanted kidney does not start working right away and needs additional support with dialysis to help remove excess fluid and waste from the blood, Delayed graft function can be linked to several problems, including the need for ongoing dialysis until the kidney works well enough, longer hospital stays, a higher risk of kidney failure, and death.

This contains the electrolytes commonly found in our bodies. It has extra minerals like potassium and magnesium that are important to help keep our bodies healthy.

It contains primarily salty water. It is commonly used during and early after the transplant surgery; and

Arteriovenous fistula (AVF): irregular connection between an artery and a vein

Hemodiafiltration, is combining this process with direct fluid removal by adding many tiny holes, also called pores, to the membrane. These pores allow fluid and waste to be passed through more easily, including larger wastes that might not otherwise be removed through dialysis. As this process involves much more fluid being removed, some replacement waste-free fluid is added to the filtered blood before it returns to the body. It is unclear if this approach improves heart health and survival. 

In hemodialysis, wastes are removed from the blood by travelling through a barrier (called a membrane) in the filter of the dialysis machine, which allows wastes to pass through but aims to keep important parts of the blood, like blood cells and protein, in the bloodstream. One challenge of this approach is that some larger wastes (called middle-molecular-weight molecules), do not pass through the barrier very well. The build-up of these wastes may increase the risk of health problems, including for heart health.