The Key to Lowering Diagnostic Blood Loss

It’s a surprisingly common story in ICUs across the country: A patient is admitted for an illness, receives blood draw after blood draw for diagnostics tests during the stay, and winds up with hospital-acquired anemia. In fact, up to 85 percent of patients that spend more than a week in the ICU require a blood transfusion. To reduce this massive need for transfusions during hospital stays, many hospitals are making great effort to streamline various aspects of patient blood collection.

Hospitals are intent on reducing blood transfusions because they can harm patients and they’re costly. The patients most likely to become anemic during a hospital stay belong to the populations most vulnerable to the risks associated with transfusions, such as children and the elderly. Those risks include transmission of infectious diseases and adverse reactions to transfusions.2,3 The costs associated with transfusions arise from the direct cost of allogeneic blood units, extended hospital stays for patients receiving transfusions, extra work in blood transfusion labs and nursing units, and potential costs of adverse events related to the transfusion.

 Up to 85 percent of patients that spend more than a week in the ICU develop hospital-acquired anemia and require a blood transfusion.

Patient blood management (PBM) has become a popular term around hospitals. The broad aim of PBM is to improve patient care, and its specific goal is to ensure that individuals tasked with handling patient blood do so in ways that maintain hemoglobin concentrations and minimize anemia and the need for transfusions. PBM efforts commonly implemented by hospitals include: finding biomarkers of anemia-induced tissue hypoxia to detect it earlier; better defining the thresholds for treating anemic patients with transfusion for specific patient populations; better use of banked specimens; reduction of the number of rejected specimens for laboratory testing due to specimen integrity issues; and reduction of diagnostic blood volumes.4 While all of these PBM strategies have merit, arguably the simplest way to reduce anemia and the subsequent need for transfusion is to collect less blood from patients in the first place.

 Patient blood management (PBM) aims to ensure that individuals tasked with handling patient blood do so in ways that maintain hemoglobin concentrations and minimize anemia and the need for transfusions.

Staggering amounts of blood get collected from hospital patients for diagnostic testing. Critically ill patients can lose 40 to 70 ml of blood per day and between 300 and 500 ml over a week-long hospital stay. Far less blood is actually required—as little as 10-20 μl per test is sufficient for diagnostic tests, using modern instruments. Yet it is common practice to fill large-volume tubes, regardless of which tests have been ordered or the amount of sample required for them, so excess blood collection is inevitable. However, there is now growing focus, especially among children’s hospitals, on lowering the blood volumes collected.

The size of tube used for collection largely dictates the volume of blood that patients lose. Standard tubes lead to unnecessarily high levels of diagnostic blood loss; conversely, using the smallest tube size available serves to minimize diagnostic blood loss. Although one study found that smaller blood collection tubes lead to increased error rates,5 the recollection rate is also higher when using larger tubes; thus, smaller tubes result in overall lower blood volumes collected from patients.

 Small-volume tubes serve to minimize diagnostic blood loss. SARSTEDT's S-Monovette® PBM tubes collect over 40 percent less blood volume than traditional tubes, helping hospitals reduce diagnostic blood loss and, ultimately, decrease transfusion rates.

Ranging from 1.1 ml to 1.8 ml, SARSTEDT's S-Monovette® PBM tubes collect over 40 percent less blood volume than traditional tubes. These small blood volumes get drawn directly into a treated syringe-like tube, which enables a more controlled, gentle collection than a pre-evacuated tube and doesn't require subsequent transfer compared to a standard syringe. Filling the 1.1 ml S-Monovette® halfway brings volumes down to what could previously only be achieved with capillary collection, but with the added benefits of obtaining high-quality venous blood without compromising the specimen or introducing additional handling steps. The low-volume tubes, either directly or when placed into carrier tubes, conform to standard dimensions, allowing the S-Monovette® to be easily adapted to analyzers already in the lab.

Hospitals that adopt small-volume tubes reduce diagnostic blood loss, which in turn lowers the incidence of hospital-acquired anemia among patients and serves to decrease transfusion rates.6 Better PBM with the help of small-volume tubes can therefore enable hospitals to achieve two of their most critical aims: to save money and to improve patient safety.

References

1. Corwin, Howard L., Kathy C. Parsonnet, and Andrew Gettinger. "RBC transfusion in the ICU: is there a reason?" Chest 108.3 (1995): 767-771.

2. Perkins, Herbert A., and Michael P. Busch. "Transfusion-associated infections: 50 years of relentless challenges and remarkable progress." Transfusion 50.10 (2010): 2080-2099.

3. Vamvakas, Eleftherios C., and Morris A. Blajchman. "Transfusion-related mortality: the ongoing risks of allogeneic blood transfusion and the available strategies for their prevention." Blood 113.15 (2009): 3406-3417.

4. Hare, Gregory MT, John Freedman, and C. David Mazer. "Risks of anemia and related management strategies: can perioperative blood management improve patient safety?" Canadian Journal of Anesthesia 60.2 (2013): 168-175.

5. Myles, Nicholas, et al. "A cohort study assessing the impact of small volume blood tubes on diagnostic test quality and iatrogenic blood loss in a cohort of adult haematology patients." Internal Medicine Journal 48.7 (2018): 817-821.

6. Sanchez-Giron, Francisco, and Francisco Alvarez- Mora. "Reduction of blood loss from laboratory testing in hospitalized adult patients using smallvolume (pediatric) tubes." Archives of Pathology & Laboratory Medicine 132.12 (2008): 1916-1919.

Learn more at: www.sarstedtsamples.com/CLM/PBM.html