Devices to Reduce the Volume of Blood Taken for Laboratory Testing in ICU Patients: A Systematic Review

Background: Intensive care unit (ICU) patients are at high risk of anemia, which is associated with adverse clinical outcomes and death. Blood sampling for diagnostic testing is a potentially modifiable contributor to anemia. Methods: We conducted a systematic review by searching MEDLINE and EMBASE from inception to October 5, 2017, for studies reporting the volume of blood taken for laboratory testing using blood sampling conservation devices compared to standard care or another intervention in adult ICU patients. Results: We identified 8 eligible studies (n = 1204 patients) that used 2 types of devices: arterial access devices (n = 5) and reduced-volume blood collection tubes (n = 3). All studies reported a reduction in the volume of blood taken for laboratory testing with devices compared to standard practice (range 19%-80%). The studies were judged to have serious risk of bias, and due to heterogeneity, pooling for meta-analysis was not considered appropriate. Conclusions: Devices used to reduce the volume of blood taken for laboratory testing in ICU patients appear to be effective, although study heterogeneity limited our ability to calculate pooled estimates of efficacy for each device. Further assessment of clinical outcomes may establish clinical benefit with minimal negative consequences for hospitals and laboratories to facilitate the use of small-volume tubes.