Taking Less Blood for Lab Testing Reduces Transfusions in Intensive Care, Shows World-First Clinical Trial

By LabMedica International staff writers
Posted on 13 Oct 2023

Image: Using small-volume tubes for blood collection can reduce transfusions (Photo courtesy of 123RF)

Most hospitals utilize standard tubes to automatically collect four to six milliliters of blood frpm their patients for laboratory testing. However, the typical lab test usually needs less than half a milliliter of blood, resulting in over 90% of the drawn blood being wasted. There are commercially available tubes that draw less blood due to a weaker vacuum inside, which can be particularly beneficial in intensive care units (ICUs). In ICUs, patients often need numerous blood samples collected multiple times a day, which can lead to a significant loss of blood. This loss can result in anemia, as ICU patients are often unable to regenerate red blood cells quickly enough. As a result, these patients frequently require blood transfusions. Now, a world-first clinical trial has come up with an easy way to save blood.

The trial by researchers at the University of Ottawa (Ontario, Canada) involved over 27,000 patients across 25 adult ICUs. The study showed that the use of "small-volume" tubes for blood collection reduced the need for a blood transfusion in nearly one out of every 10 patients. The trial was innovative in its design, as it involved randomizing different ICUs to use either small-volume blood collection tubes or regular tubes for different periods of time, before switching to the other tubes. The researchers tracked blood transfusion data for each patient through electronic medical records, excluding those who were in the ICU for less than 48 hours.

While previous observational studies have suggested the benefits of using small-volume tubes, this is the first clinical trial to rigorously evaluate their efficacy in a hospital environment. The trial not only found that the use of these tubes reduced the incidence of anemia and the need for blood transfusions, but also confirmed that the lesser amount of blood drawn did not affect the quality of lab tests. After excluding data collected during the peak of the pandemic, the findings remained consistent, albeit not statistically significant. The research is significant because anemia can cause patients to feel weak and tired, potentially leading to other complications and extended hospital stays. Although blood transfusions are generally effective in treating anemia, they can occasionally lead to rare but serious side effects like respiratory difficulties, allergic reactions, and infections.

“This trial showed that we can save one blood transfusion for every 10 ICU patients by simply switching to small-volume tubes for blood collection,” said senior author Dr. Deborah Siegal, a scientist and hematologist at The Ottawa Hospital who led the trial. “At a time when everyone is trying to find ways to make health care more sustainable, and preserve our supply of blood products, this study provides a simple solution that can be implemented without additional cost or negative effects.

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University of Ottawa