Table 2.
Anemia and red blood cell (RBC) transfusions: intervention and cointerventions∗
| Intervention and cointervention | RBC group |
P value | |
|---|---|---|---|
| Fresh (n = 89) | Standard-issue (n = 89)† | ||
| RBCs transfusions after randomization | |||
| No. of transfusions | 2 (1-3) | 2 (1-2) | .76 |
| No. of patients | |||
| 1 transfusion | 41 (46.1) | 33 (37.1) | .05 |
| 2 transfusions | 20 (22.5) | 35 (39.3) | |
| ≥3 transfusions | 28 (31.1) | 21 (23.5) | |
| Duration of RBC unit storage (d) | 5 (4-6) | 18 (13-22) | <.001 |
| Total volume of RBCs transfused per patient‡ (mL/kg) | 47.2 (28.7-110.2) | 40.0 (28.7-63.5) | .14 |
| Donor exposure to RBCs in transfused patients | |||
| No. of exposures per patient | 2 (1-3) | 2 (1-2) | .98 |
| No. of patients | 89 | 89 | |
| Adherence | |||
| Adherence to study protocol, patients§ | 84/89 (95.5) | 89/89 (100) | .04 |
| Adherence to protocol with respect to length of storage, transfusions‖ | 325/357 (93.7) | 230/230 (100) | |
| CPB priming | |||
| RBCs for priming | 83 (93.3) | 76 (85.4) | .09 |
| Volume of RBCs for priming CBP (mL/kg) | 36.6 (22.0-53.7) | 32.9 (23.0-47.7) | |
| Fresh or fresh frozen plasma for priming | 56 (62.9) | 58 (65.2) | .75 |
| Volume of fresh or fresh frozen plasma for priming (mL/kg) | 18.4 (11.9-31.2) | 18.8 (11.1-29.3) | |
| Blood products during surgery, excluding CPB priming | |||
| RBCs | 44 (49.4) | 41 (46.1) | .65 |
| Volume of RBCs, median (mL/kg) | 31 (15-76) | 22 (12-37) | |
| Fresh or fresh frozen plasma | 42 (47.2) | 47 (52.8) | .45 |
| Volume of fresh or fresh frozen plasma median (mL/kg) | 20 (13-48) | 19 (11-33) | |
| Platelet | 48 (53.9) | 47 (52.8) | .88 |
| Volume of platelet, median (mL/kg) | 16 (8-24) | 15 (10-20) | |
| Cryoprecipitate | 44 (49.4) | 40 (45.0) | .55 |
| Volume of cryoprecipitate (mL/kg) | 3.9 (1.8-7.7) [n = 32] | 3.0 (2.2-5.9) [n = 32] | |
| Median (IQR) (U/kg) | 0.32 (0.22-0.38) [n = 12] | 0.30 (0.20-0.34) [n = 8] | |
| Recombinant factor VIIa | 1 (1.1) | 2 (2.3) | 1.00 |
| Other blood products | 23 (25.8) | 24 (27.0) | .87 |
| Blood products and other cointerventions after randomization¶ | |||
| Frozen or fresh frozen plasma | 71 (79.8) | 70 (78.7) | .85 |
| Apheresis platelets | 52 (58.4) | 50 (56.2) | .76 |
| Random donor platelets | 14 (15.5) | 16 (18.0) | .69 |
| Cryoprecipitate | 51 (57.3) | 51 (57.3) | 1.00 |
| Albumin 5% | 17 (19.1) | 8 (9.0) | .05 |
| Albumin 25% | 78 (87.6) | 74 (83.1) | .40 |
| Systemic corticosteroids in ICU | 19 (21.3) | 14 (15.7) | .33 |
| Use of tranexamic acid in operating room | 86 (97.7) | 87 (97.8) | 1.00 |
| Use of tranexamic acid in ICU | 4 (4.5) | 12 (13.6) | .034 |
| Use of nitric oxide | 44 (49.4) | 35 (39.8) | .20 |
Values are presented as median (interquartile range), n (%), or n/N (%). CBP, Cardiopulmonary bypass; IQR, interquartile range; ICU, intensive care unit.
In all comparisons, the fresh group was used as the reference. Postrandomization characteristics of interventions and cointerventions are presented using frequency distributions with measures of central tendency and dispersion and analyzed using relative risks and 95% CI for dichotomous data and either independent t tests or Wilcoxon rank-sum tests for continuous data depending on their distribution.
One patient who was randomized to the standard-issue group died in the operating room during cardiac surgery and had no data available for the primary outcome, some secondary outcomes, and some cointerventions. This patient was not included in the primary outcome but was included in mortality analyses.
Total volume of RBCs transfused by patient include RBCs transfused in the CPB, during surgery, and in ICU.
For the purpose of this study, patients in the fresh group were considered adherent to protocol if 80% of the RBCs were stored for 7 days or fewer and if no RBCs were stored for more than 14 days during the 28-day follow-up period.
Adherence was defined in the research protocol as (number of transfusions with RBCs stored for ≤7 days)/(total number of transfusions) for fresh group and as (number of standard-issue transfusions)/(total number of transfusions) for the standard-issue group.
Total of blood products other than RBCs transfused after randomization (including CBP priming, during surgery, and during ICU stay).