Red Blood Cell Transfusion in the Intensive Care Unit

Abstract

ImportanceRed blood cell (RBC) transfusion is common among patients admitted to the intensive care unit (ICU). Despite multiple randomized clinical trials of hemoglobin (Hb) thresholds for transfusion, little is known about how these thresholds are incorporated into current practice.ObjectiveTo evaluate and describe ICU RBC transfusion practices worldwide.Design, Setting, and ParticipantsInternational, prospective, cohort study that involved 3643 adult patients from 233 ICUs in 30 countries on 6 continents from March 2019 to October 2022 with data collection in prespecified weeks.ExposureICU stay.Main Outcomes and MeasuresThe primary outcome was the occurrence of RBC transfusion during ICU stay. Additional outcomes included the indication(s) for RBC transfusion (consisting of clinical reasons and physiological triggers), the stated Hb threshold and actual measured Hb values before and after an RBC transfusion, and the number of units transfused.ResultsAmong 3908 potentially eligible patients, 3643 were included across 233 ICUs (median of 11 patients per ICU [IQR, 5-20]) in 30 countries on 6 continents. Among the participants, the mean (SD) age was 61 (16) years, 62% were male (2267/3643), and the median Sequential Organ Failure Assessment score was 3.2 (IQR, 1.5-6.0). A total of 894 patients (25%) received 1 or more RBC transfusions during their ICU stay, with a median total of 2 units per patient (IQR, 1-4). The proportion of patients who received a transfusion ranged from 0% to 100% across centers, from 0% to 80% across countries, and from 19% to 45% across continents. Among the patients who received a transfusion, a total of 1727 RBC transfusions were administered, wherein the most common clinical indications were low Hb value (n = 1412 [81.8%]; mean [SD] lowest Hb before transfusion, 7.4 [1.2] g/dL), active bleeding (n = 479; 27.7%), and hemodynamic instability (n = 406 [23.5%]). Among the events with a stated physiological trigger, the most frequently stated triggers were hypotension (n = 728 [42.2%]), tachycardia (n = 474 [27.4%]), and increased lactate levels (n = 308 [17.8%]). The median lowest Hb level on days with an RBC transfusion ranged from 5.2 g/dL to 13.1 g/dL across centers, from 5.3 g/dL to 9.1 g/dL across countries, and from 7.2 g/dL to 8.7 g/dL across continents. Approximately 84% of ICUs administered transfusions to patients at a median Hb level greater than 7 g/dL.Conclusions and RelevanceRBC transfusion was common in patients admitted to ICUs worldwide between 2019 and 2022, with high variability across centers in transfusion practices.

A novel measure to summarize blood transfusion practice during critical illness

“…To recapitulate measures of central tendency reported in prior large-scale practice pattern studies of RBC transfusion during critical illness, 1,3 we limited to patient-days in which an RBC transfusion was administered and calculated the distribution, mean and median pretransfusion hemoglobin concentrations (defined as the first hemoglobin concentration on the day that an RBC transfusion occurred).…”

“…1 Critical care guidelines 2 recommend red blood cell (RBC) transfusion to treat severe anemia when hemoglobin concentrations drop below a threshold of 7.0 g/dL. Prior large-scale studies 1,3 of RBC transfusion practice have used traditional measures of central tendency (i.e., mean hemoglobin concentrations at the time of RBC transfusion) to summarize triggers that drive clinical practice. For example, Raasveld et al 3 report the overall pre-transfusion mean hemoglobin concentration (7.4 g/dL).…”

“…Prior large-scale studies 1,3 of RBC transfusion practice have used traditional measures of central tendency (i.e., mean hemoglobin concentrations at the time of RBC transfusion) to summarize triggers that drive clinical practice. For example, Raasveld et al 3 report the overall pre-transfusion mean hemoglobin concentration (7.4 g/dL). However, these traditional measures of central tendency fail to identify the specific guideline-recommended hemoglobin concentration thresholds that drive practice.…”

Blood Transfusion Procedure: Assessment of Serbian Intensive Care Nurses’ Knowledge

“…According to the literature, approximately 15-53% of ICU patients receive transfusions [6]. In the United States, in 2021, more than 1.7 million red blood cell units were transfused in ICUs [7]. However, data on the number of administered blood units and the incidence of transfusion in ICU patients in Serbia have not been published.…”

Blood, Bleeding, and Transfusion—A Theme Issue

“…In the first original report, Raasveld and colleagues place these guidelines in context of current practice using an international, prospective cohort study of 3643 adult patients from 233 intensive care units (ICUs) . They found wide variability in stated transfusion thresholds, transfusion event triggers, and measured hemoglobin values at the time of transfusion.…”