Outliers
Current National Institute for Health and Care Excellence (NICE)
guidelines recommend using a restrictive RBC transfusion threshold of
70g/litre (80g/litre if concomitant cardiovascular disease) and a Hb
concentration target of 70-90g/litre after transfusion. Furthermore,
single-unit transfusions for adults who are not actively bleeding have
been shown to be more clinically beneficial and cost-effective when
compared to liberal RBC transfusion targets.20 A
subgroup analysis revealed a total of 57 instances out of 187
transfusion orders that were requested above the threshold advised by
NICE. Of these, 20 were outliers after excluding those that were
actively bleeding or symptomatic with borderline Hb levels. These can be
divided into 14 outliers who were transfused due to flap formation, 5
that were transfused due to senior clinician request and 1 case having
units ordered but not given.
Ensuring HNC patients only receive allogeneic blood transfusions if
necessary is important, as there is growing evidence that their use is
associated with worse patient outcomes. Szakmany et al. found a
statistically significant increase in mortality for patients undergoing
primary surgery for oral and oropharyngeal cancer with free flaps when
they received three units or greater.21 Danan et al.
replicated these results in a retrospective study in patients undergoing
free flap reconstruction for head and neck cancer, showing not only a
reduction in overall survival but also an increase in wound
infection.22 It has also been shown that liberal
transfusion practice does not improve tissue oxygenation for free flap
reconstruction.23 The individualised practices of
surgeons adds colour to the results in this patient group.
HNC surgeons propose several reasons for post-operative transfusion.
These include: improving the Hb concentration to optimise tissue
healing, in preparation for adjuvant oncological treatment and avoid
potential cardiac complications in high-risk patients. This practice is
idiosyncratic and assertions to such outcomes are yet to be
substantiated by robust research and appear
anecdotal.24