A 36 year old female is post-op day 3 for a colectomy for ulcerative colitis. She is on oral iron replacement and feels well with a minimal need for analgesia. Her chart indicates that her heart rate was 110 bpm and there is an order for 2 units of packed red blood cells if the Hgb is <100g/L. You question the evidence behind such an order and call the surgical service covering her care.
Points of Discussion: What are the indications for transfusion? Is there any evidence that exists to help with when and how much blood should be transfused?
Indications for Transfusion
- Symptomatic anemia in a NORMOVOLEMIC patient
- Hb <70g/L
- Hb <80g/L in chronic transfusion patients
- Inappropriate if Hb >100g/L
- Atherosclerosis, unstable angina, other cardiac, pulmonary,↑ oxygen consumption, unpredictable bleeding
- DO NOT transfuse based solely on Hb
- Always use Hb in combination with clinical status and history
Discussion Point: The TRICC Trial was a RCT of transfusion requirements in critical care to determine whether a restrictive strategy of red-cell transfusion (i.e. transfuse once Hgb < 70g/L to maintain a Hgb between 70–90g/L) and a liberal strategy (transfuse to keep Hgb >100g/L) produced equivalent results in critically ill patients. Results compared the rates of death from all causes at 30 days and the severity of organ dysfunction.
|Category||Hb >100||Hb >70|
|30 day mortality||23%||19% (p=0.11)|
|Overall mortality*||28%||22% (p=0.05)|
|Age <55*||Worse||Better (less cardiopulmonary events: TACO, TRALI)
|Apache II <20*||16% mortality||8.7% mortality (p=0.03)|
*Illustrates statistically significant results
Carson JL et al. Red blood cell transfusion: a clinical practice guideline from the AABB*. Ann Intern Med. 2012 Jul 3;157(1):49-58
Hebert et al. A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care. Transfusion Requirements in Critical Care Investigators, Canadian Critical Care Trials Group. NEJM 1999;340:409-17