Blood Compatibility for O Positive Recipients
Individuals with O positive blood type can ONLY receive blood from O positive or O negative donors—they cannot receive blood from A, B, or AB blood types regardless of Rh status. 1
Understanding O Positive Blood Type Limitations
O positive individuals have:
- No A or B antigens on their red blood cells
- Anti-A and anti-B antibodies in their plasma 2
- Rh D positive antigen present
This antibody profile means that transfusing A, B, or AB blood to an O positive recipient will cause a severe hemolytic transfusion reaction due to the recipient's anti-A and/or anti-B antibodies attacking the donor red blood cells. 3
Compatible Blood Types for O Positive Recipients
O positive patients can receive:
The Rh positive status of O positive recipients means they already have the D antigen, so receiving either Rh positive or Rh negative blood poses no risk of Rh alloimmunization. 4
Emergency Transfusion Considerations
In emergency situations when the patient's blood type is unknown:
- Group O RhD positive blood is the standard emergency blood for males and postmenopausal females 1
- Group O RhD negative blood is reserved for women of childbearing potential 1
- Transition to group-specific blood should occur within 10-15 minutes once typing is complete 1
Once an O positive patient is identified, continuing with O positive blood is appropriate and conserves the scarcer O negative inventory. 4, 5
Critical Safety Point
The ABO system is absolute—O positive recipients lack A and B antigens and possess antibodies against them, making transfusion of A, B, or AB blood incompatible and potentially fatal. 2 Most transfusion-related morbidity results from incorrect blood administration, emphasizing the importance of proper patient identification with four core identifiers. 1