Blood transfusion: summary of NICE guidance

Dear Sirs,

We read with interest and welcome the NICE guidance for blood transfusion summarised in the BMJ [1]. The recommendation for the consideration of alternatives to blood transfusion in surgery is timely. Preoperative anaemia is common in patients undergoing surgery, and has been associated with increased postoperative morbidity and mortality [2]. Meanwhile, data suggests that blood transfusion as a means to treat anaemia does not ameliorate this risk, and actually further increases morbidity and mortality [3].

However, we have concerns regarding the recommendations for iron in patients having surgery. The definition of iron deficiency in the surgical setting remains unmet, particularly that for functional iron deficiency, and no consensus exists outside the setting of chronic renal failure. A Cochrane review of iron therapy in anaemic patients noted that oral iron reduced need for blood transfusion but data for intravenous iron was lacking [4]. Finally, there is concern that intravenous iron is associated with increased risk of infection[5].

The quality of the evidence for the recommendations for the use of iron is recognised by the guideline authors as being ‘very low to low’, which suggests that any estimate of effect is very uncertain, or at best, further research is very likely to change the estimate. A National Institute for Health Research (NIHR) Health Technology Assessment (HTA) funded randomised controlled trial of intravenous iron in the surgical population is recruiting at present [6].

We strongly support the recommendations that patients undergoing surgery should be screened for anaemia, and appropriately investigated for its cause when detected. Further consideration of the cancellation of elective surgery should be made to allow treatment and correction of anaemia. In those patients undergoing surgery, further patient blood management strategies should be initiated.

We advise caution on the use of intravenous iron preoperatively, where evidence of efficacy and effect is lacking. We encourage clinicians to support ongoing research into the treatment of preoperative anaemia, to ensure that benefits outweigh the harms of intervention, and to provide clear indications for use within the NHS.

Professor Toby Richards
Dr Ben Clevenger
On behalf of the PREVENTT Trial Steering Committee

1. Padhi S, Kemmis-Betty S, Rajesh S, et al. Blood transfusion: summary of NICE guidance. BMJ 2015;351:h5832.
2. Clevenger B, Richards T. Pre-operative anaemia. Anaesthesia 2015;70 Suppl 1:20-8, e6-8.
3. Whitlock EL, Kim H, Auerbach AD. Harms associated with single unit perioperative transfusion: retrospective population based analysis. BMJ 2015;350:h3037.
4. Gurusamy KS, Nagendran M, Broadhurst JF, et al. Iron therapy in anaemic adults without chronic kidney disease. The Cochrane database of systematic reviews 2014;12:CD010640.
5. Litton E, Xiao J, Ho KM. Safety and efficacy of intravenous iron therapy in reducing requirement for allogeneic blood transfusion: systematic review and meta-analysis of randomised clinical trials. BMJ 2013;347:f4822.
6. Richards T, Clevenger B, Keidan J, et al. PREVENTT: preoperative intravenous iron to treat anaemia in major surgery: study protocol for a randomised controlled trial. Trials 2015;16:254.