Conservative Approach to Blood Transfusions in Cardiac Surgery Safe for Kidney

By Bridget M. Kuehn

More conservative use of blood transfusions during cardiac surgery is safe for the kidneys, suggests results from the Transfusion Requirements in Cardiac Surgery-III (TRICS-III) trial presented at Kidney Week 2018 in San Diego, CA.

The 20 million cardiac surgeries done worldwide each year consume about 20% of the world’s blood supply, said Amit Garg, MD, PHD, nephrologist at the London Health Sciences Center in Ontario, Canada. Blood transfusions are often used during such surgeries to prevent hypoxia caused by low blood supply to the organs, particularly the kidneys, which are easily injured by low blood flow. But blood transfusions themselves can also cause kidney injury as well as other adverse effects. Safely reducing the number of transfusions needed for such surgeries would not only help conserve the blood supply and reduce health care costs, but also reduce adverse effects of the blood transfusion itself, he said. As a result, the National Institutes of Health Heart Lung and Blood Institute has made funding randomized trials of red cell blood cell transfusions a priority.

“It is balancing [the risk and benefit of transfusion] where you are trying to figure out the cause and effect and that is where an RCT is very helpful in trying to tease out the right trigger for a blood transfusion,” said Garg, who presented the kidney results of the TRICS-II.  

The TRICS-III study enrolled 4531 patients undergoing cardiac surgery with cardiopulmonary bypass from 73 centers in 19 countries between January 2014 and March 2017. Patients were randomized to a conservative or liberal threshold for blood transfusion during or after surgery through day 28 or discharge. Patients in the conservative threshold only received a red blood cell transfusion if their hemoglobin fell below 7.5 gram per deciliter (g/dL), while those in the liberal group received a transfusion if hemoglobin was less than 9.5 g/dL in the operating room or intensive care unit or less than 8.5 g/dL while in nonintensive care. The percentage of patients who developed AKI did not significantly differ between the two groups (27.7% in the conservative group vs 27.9% in the liberal group).

“We found no higher risk of AKI when we looked at it multiple ways so that was reassuring,” Garg said. “It’s safe from a kidney perspective to use less blood.” 

Category:
Subcategory:
Author:
Bridget M. Kuehn
Article Image:
Body:

More conservative use of blood transfusions during cardiac surgery is safe for the kidneys, suggests results from the Transfusion Requirements in Cardiac Surgery-III (TRICS-III) trial presented at Kidney Week 2018 in San Diego, CA.

The 20 million cardiac surgeries done worldwide each year consume about 20% of the world’s blood supply, said Amit Garg, MD, PHD, nephrologist at the London Health Sciences Center in Ontario, Canada. Blood transfusions are often used during such surgeries to prevent hypoxia caused by low blood supply to the organs, particularly the kidneys, which are easily injured by low blood flow. But blood transfusions themselves can also cause kidney injury as well as other adverse effects. Safely reducing the number of transfusions needed for such surgeries would not only help conserve the blood supply and reduce health care costs, but also reduce adverse effects of the blood transfusion itself, he said. As a result, the National Institutes of Health Heart Lung and Blood Institute has made funding randomized trials of red cell blood cell transfusions a priority.

“It is balancing [the risk and benefit of transfusion] where you are trying to figure out the cause and effect and that is where an RCT is very helpful in trying to tease out the right trigger for a blood transfusion,” said Garg, who presented the kidney results of the TRICS-II.  

The TRICS-III study enrolled 4531 patients undergoing cardiac surgery with cardiopulmonary bypass from 73 centers in 19 countries between January 2014 and March 2017. Patients were randomized to a conservative or liberal threshold for blood transfusion during or after surgery through day 28 or discharge. Patients in the conservative threshold only received a red blood cell transfusion if their hemoglobin fell below 7.5 gram per deciliter (g/dL), while those in the liberal group received a transfusion if hemoglobin was less than 9.5 g/dL in the operating room or intensive care unit or less than 8.5 g/dL while in nonintensive care. The percentage of patients who developed AKI did not significantly differ between the two groups (27.7% in the conservative group vs 27.9% in the liberal group).

“We found no higher risk of AKI when we looked at it multiple ways so that was reassuring,” Garg said. “It’s safe from a kidney perspective to use less blood.” 

Date:
Saturday, October 27, 2018