Hemolysis is the rupture of red blood cells, and it has multiple causes, can happen at any time, both in vivo and in vitro.
Hemolysis can certainly impact study results, and has a particularly well-documented impact on potassium concentration measurements. It can also impact measurements of other analytes, such as aminotransferase and lactate dehydrogenase.
When red blood cells are ruptured or damaged, the components of those cells are released into the extracellular space in the blood. In addition to affecting the measurement of certain analytes, hemolysis releases proteases that can degrade some proteins, including insulin and cardiac troponin. The hemoglobin and other components of red blood cells can also interfere with accurate spectrophotometric measurements.
There are several causes of hemolysis, and they can occur in vitro or in vivo, so it’s important that your samples are carefully examined and hemolyzed samples discarded.
The most common causes of hemolysis happen at the time blood is drawn. The wrong gauge needle, too much suction, leaving the tourniquet on for too long, shaking the sample too vigorously, and even a difficult draw are all potential causes of hemolysis.
Beyond the many possible causes during phlebotomy, which account for anywhere from 50-75% of cases of sample hemolysis, transportation, temperature, and prolonged storage can also result in the rupture of red blood cells in the sample.
When hemolysis occurs in vivo, it’s due to the premature death of red blood cells during circulation. Here are a few of the potential causes of in vivo hemolysis:
Since the vast majority of instances of hemolysis in samples occurs at the time blood is drawn, the most effective way to stop it is to make sure that the phlebotomist understands the causes of hemolysis and avoids them. Having highly-trained and carefully vetted staff to draw blood for samples is critically important.
Another important factor in stopping hemolysis is making sure the samples are carefully transported, using methods that keep the sample tubes cushioned and within the proper temperature range. Samples that are going to be separated should never be frozen, for example.
Samples aren’t either hemolyzed or not. Instead, there’s a scale from no hemolysis at all to gross hemolysis. Sanguine guidelines dictate that samples are discarded when hemolysis meets or exceeds 200 milligrams per deciliter.
Samples are determined to be hemolyzed, or not, based on their color. Once a sample has been spun, it is likely anywhere from a pale yellow color to a dark red color. The redder the shade of the sample, the more hemolyzed it is.
Given the fact that hemolysis can impact the results of studies, it’s important to feel confident about the samples you use.
“Although the root cause of hemolysis is difficult to determine on a case by case basis, Sanguine does its best to mitigate the risks that can lead to hemolysis to ensure scientists receive specimens that are useful for their research,” says Sagar Amin, CCRA, Biorepository Project Manager at Sanguine.