Clinical Outcomes of ABO-Incompatible RBC Transfusions

Kim A. Janatpour, MD; Norman D. Kalmin, MD; Hanne M. Jensen, MD; Paul V. Holland, MD


Am J Clin Pathol. 2008;129(2):276-281. 

In This Article

Abstract and Introduction


Factors that predict outcome after ABO-incompatible RBC transfusions are not well defined. We studied whether the volume of incompatible blood transfused would determine the signs and symptoms and survival outcome for ABO-incompatible RBC transfusions. We reviewed ABO-incompatible RBC transfusions from our institutions and our consultations for 35 years and from a survey of America's Blood Centers' members regarding causes, volume, signs, symptoms, and outcomes of ABO-incompatible RBC transfusions in their service areas from 1995 through 2005.

All ABO-incompatible transfusions were due to error; 26 (62%) of 42 occurred at the patient's bedside. Of 36 patients who received more than 50 mL of incompatible blood, 23 (64%) manifested signs or symptoms related to the incompatible transfusion, and 6 (17)% died. Only 3 (25%) of 12 patients who received 50 mL or less of incompatible blood had associated signs or symptoms, and none died. Hypotension, hemoglobinuria, and/or hemoglobinemia were the most frequent findings in survivors and patients who died.

ABO-incompatible RBC transfusion does not inevitably mean death or even occurrence of symptoms. Prompt recognition and discontinuation of the transfusion are critical because transfusing less ABO-incompatible blood may minimize signs and symptoms and may prevent death.


During the past 3 decades, there has been tremendous improvement in blood transfusion safety, largely owing to a decline in infectious hazards.[1] However, blood transfusion still has potential risks of morbidity and mortality. One of the greatest risks to transfusion recipients is from errors leading to transfusion of an incorrect blood component.[1,2] ABO-incompatible RBC transfusions can be devastating and have accounted for as many as 51% of transfusion-related fatalities reported to the US Food and Drug Administration (FDA).[3] Within the last 9 years, this figure has declined to an average of approximately 10% of all transfusion-related deaths (Leslie Holness, MD, FDA, written communication, October 21, 2005). Other data indicate that ABO-incompatible RBC transfusions occur in an estimated 1:38,000 to 1:100,000 transfusions and that the risk of receiving such an incompatible blood component and consequently dying is 1:1.5 million to 1:2 million.[4,5]

The decline in the relative percentage of deaths associated with ABO-incompatible RBC transfusions has followed implementation of numerous safety measures such as bar-code devices for patient and blood sample identification and procedures to verify the ABO type of the patient. However, despite these efforts, ABO-incompatible transfusions still occur. Efforts must continue to be made to identify the errors leading to ABO-incompatible transfusions in order to improve transfusion processes and safety. In the United Kingdom, the Serious Hazards of Transfusion scheme was established in 1996 as a confidential system for reporting adverse patient events associated with transfusion (it is not limited to deaths). This system has built an evidence base of transfusion risks that has been used to improve patient safety by informing policy decisions, improving standards of hospital transfusion practice, supporting production of clinical guidelines, and educating clinical users of blood.[6]

In the United States, transfusion-related deaths must be reported to the FDA. However, the transfusion has to be recognized as "related" to the fatality (may be claimed not to be for various reasons, eg, possible lawsuit). Reporting of serious but nonfatal events and so-called near misses is not required but is encouraged through the FDA's Adverse Event Reporting System.[7] Determination of what constitutes a transfusion-related death is not always straightforward, particularly in seriously ill or anesthetized patients who receive an ABO-incompatible transfusion. The signs and symptoms of a hemolytic transfusion reaction may overlap with those of a patient's underlying condition or may not be apparent owing to anesthesia. Determination of the clinical consequences of ABO-incompatible transfusions is further complicated by the fact that patients who have received ABO-incompatible blood do not always manifest overt signs and symptoms, nor is the hemolytic reaction uniformly fatal.

We sought to highlight the types of errors that lead to ABO-incompatible transfusions and the clinical sequelae of these by using case reports and a survey of America's Blood Centers (ABC). We sought to verify whether the volume of incompatible blood would determine, or predict, the signs, symptoms, and survival outcome for ABO-incompatible RBC transfusions. A study by Binder et al[8] found that there were no deaths in patients who received less than 50 mL of incompatible blood. In another report by Glasser,[9] patients who received less than 80 mL of incompatible RBCs survived and manifested minimal signs and symptoms compared with patients who received a larger volume of incompatible blood, most of whom had symptoms and 50% died.


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