Based on data from more than 30 clinical trials, the AABB clinical practice guidelines recommend restrictive transfusion thresholds for hemodynamically stable adult patients. The majority of these trials involve patients who are either post-operative or in an intensive care unit. There are limited data on optimal transfusion thresholds for patients during surgical procedures. A recently published feasibility trial in the journal Blood evaluated a restrictive transfusion threshold (<8 g/dL) compared to a liberal transfusion threshold (<9.7 g/dL) among 58 patients undergoing vascular surgery. As expected, the restrictive transfusion threshold group used significantly less red blood cell units. The restrictive transfusion threshold group, however, had significantly higher levels of cerebral oxygen desaturation and major vascular complications. Given that the trial was a feasibility study, it was not designed to fully assess adverse outcomes. In an accompanying editorial, Dr. Beth Shaz, stated that the “study creates pause” as the transfusion medicine field moves towards restrictive transfusion thresholds as there may be certain patient populations that benefit from liberal transfusion strategies. Additional clinical trial data are needed to further address transfusion thresholds for specific patient populations.
References:
Shaz BH. Red blood cells: beyond the transfusion. Blood 2019; 133(25):2627-8.
