The STRATUS randomized clinical trial
Key points Does transitioning from standard-volume blood collection tubes to small- volume tubes for laboratory testing in intensive care units (ICUs) reduce red blood cell (RBC) transfusion? Findings After transitioning to small-volume tubes in this stepwise cluster randomized trial, RBC transfusion was not significantly different in the primary analysis of 21,201 patients, excluding 6,210 admitted during the COVID-19 pandemic (relative risk, 0 .91), but it was significantly lower in the secondary analysis of the 27,411 patients (RR, 0.88; absolute decrease, 9.84 erythrocyte units/100 patients). The frequency of insufficient samples was not different (≤0.03%). Meaning Small volume blood collection tubes in the ICU can decrease red blood cell transfusions without affecting laboratory tests. |
Importance
Blood collection for laboratory testing in intensive care unit (ICU) patients modifiable contributors to anemia and red blood cell (RBC) transfusion. Most of the blood drawn is not needed for the analysis and is discarded.
Aim
To determine whether transitioning from standard volume vacuum tubes to small volume vacuum tubes for blood collection in ICUs reduces red blood cell transfusion without compromising laboratory testing procedures.
Design, environment and participants
Stepwise cluster-randomized trial in 25 adult medical-surgical ICUs in Canada (February 5, 2019 to January 21, 2021).
Intervention ICUs were randomly assigned to transition from standard volume tubes (n = 10,940) to small volume tubes (n = 10,261) for laboratory testing.
Main results and measures
The primary outcome was red blood cell transfusion (units per patient per ICU stay). Secondary outcomes were patients who received at least one RBC transfusion, hemoglobin decline during ICU stay (adjusted for RBC transfusion), samples with insufficient volume for testing, length of ICU stay and hospital, and mortality in the ICU and hospital.
The primary analysis included patients admitted for 48 hours or more, excluding those admitted during a 5.5-month pause in the COVID-19-related trial.
Results
In the primary analysis of 21,201 patients (mean age, 63.5 years; 39.9% women), which excluded 6,210 patients admitted during the early COVID-19 pandemic, there were no significant differences in RBC units. per patient per ICU stay (relative risk [RR], 0.91 [95% CI, 0.79 to 1.05]; P = 0.19; absolute reduction of 7.24 RBC units/100 patients per ICU stay [95% CI, −3.28 to 19.44]).
In a prespecified secondary analysis (n = 27,411 patients), RBC units per patient per ICU stay decreased after transition from standard-volume tubes to small-volume tubes (RR, 0.88 [95% CI , 0.77 to 1.00]; P = 0.04; absolute reduction of 9.84 RBC units/100 patients per ICU stay [95% CI, 0.24 to 20.76]).
The median decrease in transfusion-adjusted hemoglobin was not statistically different in the primary population (mean difference, 0.10 g/dL [95% CI, −0.04 to 0.23]) and smaller in the secondary population (mean difference, 0.17 g/dL [95% CI, 0.05 to 0.29]).
Samples with insufficient quantity for analysis were rare (≤0.03%) before and after the transition.
Conclusions and relevance
The use of small-volume blood collection tubes in the ICU may decrease red blood cell transfusions without affecting laboratory tests.
Trial Registration ClinicalTrials.gov Identifier: NCT03578419
