Red blood cell (RBC) transfusion is a common practice in the ICU. We investigated the epidemiology of RBC transfusion and its relation to outcome.
We included all 3147 adult patients admitted to 198 European ICUs between May 1 and May 15, 2002. Patients were followed up until death, hospital discharge, or for 60 days. Patients were classified into those who received RBC transfusion at least once during the ICU stay and those who were not transfused. Propensity score case-matching according to the transfusion status was performed and matched pairs were examined for baseline characteristics and outcome.
Of 3147 patients, 1040 (33.0%) received a RBC transfusion (59.2% of patients staying more than 7 days in the ICU) and 2107 (67.0%) did not. The transfused patients were older, had a higher incidence of liver cirrhosis and hematologic dysfunction, were more commonly surgical admissions, had greater SAPS II and SOFA scores, and had higher rates of sepsis syndromes. Both ICU and hospital mortality rates were higher in transfused patients (23.0 vs. 16.3 and 29.9 vs. 22.5%, p<0.001) than in nontransfused patients. Patients receiving ≥ 4 units (n=490) had higher ICU and hospital mortality rates than those who received < 4 units (28.6 vs. 18.0, and 34.7 vs. 25.6% p<0.01). In 821 matched-pairs according to a propensity score, ICU and hospital mortality rates were identical in transfused and non transfused patients (22.7 vs. 22.1 and 29.1 vs. 29.0%, p=NS). Survival at 30 days was similar between the two matched groups (log rank = 2.9; p = 0.09), with a tendency towards lower survival in non transfused patients.CONCLUSIONS: In this observational study, RBC transfusion was not associated with increased mortality. However, higher transfusion rates were associated with worse outcome.
These data contrast with those of other recent studies, possibly due to the implementation of routine blood deleukocytation in Europe. Evaluation of current transfusion strategies may help explain the differences.
J. Vincent, None.