Multiple choice questions

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1. Correct Answers: B, C

2. Correct Answers: A, D, E

3. Correct Answers: A, B, E

4. Correct Answer: D

This patient has absolute iron deficiency anaemia. Her Hb is less than 130 g/l and ferritin less than 30 μg/L.

Anaemia affects a significant number of pre-operative patients and has independently been associated with increased morbidity and mortality. There remains a lack of conclusive evidence that optimizing the haemoglobin (Hb) pre-operatively impacts on the increased risks, but there is increasing evidence normalizing iron stores has a positive impact.

Where possible, red cell transfusions are avoided pre-operatively given associations with worse surgical outcomes, there may be circumstances however where both transfusions and erythropoiesis stimulating agents are considered.

Iron replacement can be delivered both orally and intravenously (IV). IV iron is known to be highly effective treatment for iron store replenishment and Hb correction in both absolute and functional iron deficiency. It is also associated with quicker Hb responses, a factor which may be of importance depending on time to surgery. IV iron may also be considered pre-operatively when the time to surgery is insufficient to allow for oral iron replacement (<6 weeks).

Erythropoiesis stimulating agents (ESA) have demonstrated improvements in Hb and reductions in the need for red cell transfusions. ESAs have however been associated with an increased thrombotic risk and mortality. The routine use of ESAs is therefore not recommended. ESA therapy may however be considered in patients who have underlying medical conditions for which their use is recommended for example anaemia associated with renal impairment or myelodysplasia.

5. Correct Answer: A

‘Acute Obstetric Coagulopathy’ (AOC) syndrome is characterized by low fibrinogen, dysfibrinogenaemia and marked fibrinolysis, and is associated with specific obstetric conditions e.g. placental abruption, and amniotic fluid embolism.

Detection and correction of coagulopathy therefore is an important aspect of management of severe haemorrhage. British Society for Haematology (BSH) guidelines recommend the use of serial standard laboratory tests (SLTs) taken every 30–60 minutes to monitor major haemorrhage. European trauma guidelines recommend viscoelastic haemostatic assay (VHA) testing i.e. TEG and ROTEM.

Although prolonged PT and aPTT results are clearly associated with poorer clinical outcomes in major bleeding these tests are poor predictors of transfusion requirement across all specialty groups.

VHA-guided transfusion therapy for major bleeding is often used but, outside cardiac and liver transplant surgery settings, there is currently insufficient evidence for NICE to support their use. However, RCT data are emerging which provide support for the use of VHA-guided transfusion thresholds. In an RCT of women with moderate to severe PPH, a FIBTEM A5 >12 mm indicated a fibrinogen level that was adequate for haemostasis and no supplementation was needed. In trauma, a recent large multi-centre RCT (iTACTIC) comparing clinical outcomes in patients treated using VHA- and SLT-guided transfusion algorithms, concluded that VHA testing is able to identify coagulation issues rapidly and direct therapy sooner than SLT alone but this does not translate to a reduction in mortality or reduced requirement for blood component in this study.

Fibrinogen is a better predictor of bleeding in PPH than PT/aPTT in the early stages of bleed onset. A large observational study showed that a fibrinogen level of 2 g/L gave a 100% positive predictive value for severe (vs non-severe) PPH, and for each 1 g/L decrease in fibrinogen the risk for severe PPH increased by 2.63-fold.

It is important to recognize that transfusion strategies such as empiric high ratio FFP: RBC which have been shown to benefit trauma patients may not be the optimal therapy for other patient groups.