Limitations of Hb/Hct Triggers 

Over-reliance on the Hb/Hct triggers for transfusion decision making has been called into question. Use of Hb/Hct alone may overstate anemia, potentially leading to unnecessary transfusion since the volemic status of the patient is unknown. Specifically, intra-operative Hb/Hct measurements are subject to the following limitations: 

Demonstration of the Hemodilution Effect. Source: Marino PL, Sutin KM. The ICU Book. Lippincott Williams & Wilkins; 2012. 

Demonstration of the Hemodilution Effect. Source: Marino PL, Sutin KM. The ICU Book. Lippincott Williams & Wilkins; 2012. 

 

  • Hb/Hct is confounded by intravascular hemodilution due to crystalloid/colloid infusion, blood transfusion, insensible losses, third spacing, or acute hemorrhage.

  • In the early hours after a bleeding event, the Hb/Hct is only a reflection of the resuscitation effort and not the true reduction in red cells  [7-9]

  • Hb/Hct measurments are often delayed or highly unreliable in the dynamic surgical setting. [10]