Decreased red cell deformability following open-heart surgery.

Red blood cell deformability is essential for a normal microcirculation. The effect of extracorporeal circulation on red cell deformability was evaluated with a filtration technique in 25 patients undergoing open-heart surgery. During extracorporeal circulation there was a significant decrease in deformability, by on average 31% (p less than 0.001). No correlation was found between decrease in deformability and duration of the extracorporeal circulation procedure. In a subgroup of patients, deformability was followed also postoperatively. During the first postoperative day there was a further decrease of 17%. By the second to third postoperative days, deformability had decreased by another 23%, so that now it was less than half of the preoperative value. On the fifth to sixth postoperative days the values remained equally low. A reduction in red blood cell damage during extracorporeal circulation may be an important factor for improving nutritional blood flow. This in turn could reduce the number of complications in various organs following open-heart surgery.