This chapter deals with the indications, contraindications and complications of blood transfusion in the ICU. The contents and properties of packed red blood cells, the physiology of acute haemorrhage and the physiological responses to blood transfusion are detailed in other chapters.
The National Blood Authority of Australia has issued a series of practice guidelines which can be helpful in guiding the shaking bloodied hand of the ICU practitoner. The guidelines have been endorsed by our college, which means that at least some of the Australian intensivists must agree with them.
The following entries are a summary of these clinical practice guidelines, to help answer past paper SAQs such as Question 21 from the second paper of 2007 and Question 13 from the first paper of 2003.
The critical care module of the NBA guidelines makes the following recommendations for critically ill patients who are not hosing blood out of every orifice:
The NBA makes the following statements about the use of separated blood products:
Much of the above has been guided by the 1999 TRICC study, which observed the effects of transfusing 838 ICU patients to different Hb levels (70-90 vs 100-120). Though they did not find any 30-day mortality difference between the two groups, there was a significant in-hospital mortality difference (22% vs 28%) which favoured the restrictive transfusion strategy.
Since 1999, many more RCTs have contributed data to the growing impression that keeping Hb over 70 in most patients is a superior approach in terms of mortality and morbidity. A 2013 JAMA article provides a helpful synopsis of these results, and summarizes a total of over 6000 patient cases in support of restrictive transfusion practice. The lower haemoglobin threshold was associated with no harm, and may be associated with some sort of survival benefit.
A "routine transfusion" in this setting is the transfusion which has a "numeric trigger" as opposed to a clinical indication (i.e. the patient is asymptomatic).
Spahn et al (2013) have done an excellent review of this for Lancet. In summary: