Smaller volume blood draw tubes can prevent excess blood loss in sickest patients

Editor's Note

Using a tube that collects about half the blood of a standard tube will still provide enough blood for a lab test while reducing transfusions for critically ill patients, a new investigative study published by JAMA Network reports. The study, titled "Small-Volume Blood Collection Tubes to Reduce Transfusions in Intensive Care," was published on October 12.

Following are select findings:

• Researchers compared the use of regular and lower-volume tubes for tests involving 27,000 patients at 25 intensive care units (ICUs) across Canada between 2019 and 2021, not including 5 months during the pandemic.
• 90% of blood collected by a standard test tube—which can draw up to six milliliters—is wasted.
• Only 0.5 ml is needed for a standard lab test.
• Switching to the lower-volume test tubes saved one blood transfusion for every 10 patients in ICUs.
• The lower-volume tubes allow for a smaller draw because they contain less anticoagulants. 

About 40% of very sick patients need repeat lab tests, which results in significant loss of blood. This in turn can contribute to anemia and more blood transfusions. Currently, the smaller volume tubes are only used with children.