Question 1

A 43-year-old woman is transferred to your Intensive Care Unit from a regional hospital following a motor vehicle crash. She is in haemorrhagic shock secondary to abdominal and pelvic trauma and received 3L crystalloid and 8 units O Rh(D) negative blood prior to arrival in your hospital.

  • What are the risks of giving O negative uncrossmatched blood to this patient?
  • Indicate whether crossmatch is needed or not for each of the following blood products:
    • Packed red blood cells
    • Platelets 
    • Fresh frozen plasma
    • Cryoprecipitate 
    • Prothrombin concentrate
    • Granulocyte concentration 
    • Intravenous immunoglobulin

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College Answer

Risks common to all blood transfusions

(infection, allergy, haemolysis, TRALI, fluid overload, dilutional coagulopathy, etc)

Risks specific to O-ve uncrossmatched 
Mixed field group and screen (unclear blood group)

Prolong group and cross match if specimen not taken before.

Non-ABO, non Rh (D) antigens/antibodies leading to allo-immunisation (sensitization) and delayed haemolytic reactions


Blood Product

Need for Crossmatch

Packed red blood cells




Fresh Frozen Plasma




Prothrombin concentrate


Granulocyte concentrate


Intravenous immunoglobulin



Type O uncrossmatched blood generally seems safe enough to use when needed.

In general, the adverse events associated with of blood transfusion are diminishing in incidence, but one should know what they are:

  • ABO-incompatible blood transfusion (due to administrative error)
  • Bacterial contamination of platelet components (1:2,000)
  • Sepsis from bacterial contamination of red cell components(1:500,000)
  • HIV infection ( 1:2,135,000)
  • Hep C infection (1:1,935,000)
  • Hep B infection (1:205,000)
  • Human T-lymphocytic viruses (1:2,993,000)
  • Transfusion-related acute lung injury (TRALI)
  • Fluid overload and heart failure
  • Dilutional coagulopathy

Mixed-field RBC agglutination is a case of "false chimerism" where there are two very different blood cell populations, confusing the automated testing apparatus. It may take longer for the technicians to identify some safely transfuseable crossmatched blood after receiving a specimen like that.

On top of this, sensitization can occur, leading to hemolytic reactions. The chances of this happening are around 0.4%.

And, lastly, only the red cells and granulocytes need crossmatching - the other blood products can be given willy-nilly.


SCHWAB, C. WILLIAM, JOHN P. SHAYNE, and JOHN TURNER. "Immediate trauma resuscitation with type O uncrossmatched blood: a two-year prospective experience." Journal of Trauma and Acute Care Surgery 26.10 (1986): 897-902.

Busch, Michael P., Steven H. Kleinman, and George J. Nemo. "Current and emerging infectious risks of blood transfusions." Jama 289.8 (2003): 959-962.

Sandler, S. G., H. Yu, and N. Rassai. "Risks of blood transfusion and their prevention." Clinical advances in hematology & oncology: H&O 1.5 (2003): 307-313.

Bluth, Martin H., Marion E. Reid, and Noga Manny. "Chimerism in the immunohematology laboratory in the molecular biology era." Transfusion medicine reviews 21.2 (2007): 134-146.

Goodell, Pamela P., et al. "Risk of hemolytic transfusion reactions following emergency-release RBC transfusion." American journal of clinical pathology134.2 (2010): 202-206.