Ideal hemoglobin transfusion target for resuscitation of massive-transfusion patients

Overtransfusion of packed red blood cells is known to increase the risk of death in stable patients. With the delineation of minimum transfusion ratios in hemorrhaging patients complete, attention must be turned to the other end of the massive transfusion spectrum-that of defining the maximum transfusion of packed red blood cells. We aimed to define the ideal hemoglobin range 24 hours after anatomic hemostasis associated with the lowest mortality.

Massive-transfusion patients (≥10 units packed red blood cells within 24 hours) were reviewed from 2010-2013. The hemoglobin 24 ± 6 hours after anatomic hemostasis was used to stratify patients into undertransfusion (<8.0 g/dL), hemoglobin transfusion target (8.0-11.9 g/dL), and overtransfusion (>12.0 g/dL) groups; patients not surviving to 24 hours were excluded.

We identified 418 patients (351 [84%] in the hemoglobin transfusion target group, 38 [9%] in the undertransfusion group, and 29 [7%] in the overtransfusion group) with an overall mortality of 18%. Undertransfusion patients had the greatest risk of death (odds ratio 3.3; 95% confidence interval 1.6-6.7) followed by overtransfusion patients (odds ratio 2.5; 95% confidence interval 1.1-5.6). Though pretransfusion hemoglobin was similar (9.5 ± 2.2 g/dL vs 9.5 ± 2.3 g/dL), overtransfusion patients had greater hemoglobin values during massive transfusion (8.3 ± 3.0 g/dL vs 6.9 ± 1.4 g/dL), persisting until hospital dismissal/death (11.4 ± 2.3 g/dL vs 9.6 ± 1.1 g/dL). In total, 657.4 excess packed red blood cell units were transfused (1.9 ± 1.5 per patient).

Overtransfusion patients had increased mortality, comparable to undertransfusion patients, despite younger age and fewer comorbidities. Shorter massive transfusion durations foster a scenario in which patients are at greater risk of overtransfusion.