Patient Blood Management

Patient blood management is a patient centred approach that improves outcomes by reducing unnecessary transfusion. It rests on three pillars: optimising the patient's own haemoglobin and red cell mass, minimising blood loss and bleeding, and harnessing and optimising tolerance of anaemia. It begins before admission and continues after discharge.

Why it matters. Anaemia before surgery is common and independently associated with more complications and more transfusion. Treating the cause is cheaper and safer than transfusing.

Risk context. Risks of omission include avoidable transfusion, overload, and preventable dependence on a limited blood supply. Risks of the alternatives include thrombosis with erythropoiesis stimulating agents, allergic reactions to intravenous iron, and thrombosis with antifibrinolytics in patients with active clotting.

Special groups. In East Africa, common causes of anaemia are iron deficiency, malaria, hookworm, HIV, sickle cell disease, chronic inflammation and nutritional deficiency, so the work up must include them.

Pillar 1: optimise haemoglobin.

• Screen elective surgical patients for anaemia at least 4 weeks before surgery where possible.

• Measure haemoglobin, ferritin, transferrin saturation, vitamin B12, folate, renal function and inflammatory markers. Iron deficiency is likely with ferritin under 30 micrograms/L, or under 100 micrograms/L with inflammation and transferrin saturation under 20%.

• Treat malaria, helminths and other causes.

Iron therapy.

• Oral iron: elemental iron 60 to 200 mg daily or on alternate days, taken on an empty stomach where tolerated; reassess haemoglobin in 2 to 4 weeks (expected rise about 1 to 2 g/dL over 2 to 4 weeks).

• Intravenous iron: when oral iron is not tolerated, absorbed or effective, when haemoglobin must rise quickly (surgery within about 6 weeks), in chronic kidney disease, and in late pregnancy. Total deficit can be estimated from weight x (target haemoglobin minus current haemoglobin in g/dL) x 2.4, plus 500 mg stores. Ferric carboxymaltose can be given up to 1000 mg in a single infusion, not over 20 mg/kg; the dose and interval for other preparations differ by product.

Erythropoiesis stimulating agents. Used in chronic kidney disease, selected chemotherapy induced anaemia, and in patients refusing blood. Iron must be replete first. Dose depends on the agent. Avoid pushing haemoglobin over 12 g/dL because of thrombotic risk, and avoid use when cure is the aim in cancer.

Pillar 2: minimise blood loss.

• Meticulous surgical haemostasis, minimally invasive techniques and warming.

• Tranexamic acid: in major trauma, 1 g intravenously over 10 minutes within 3 hours of injury, then 1 g over 8 hours; in postpartum haemorrhage, 1 g intravenously within 3 hours of birth, repeated once after 30 minutes if bleeding continues; in surgery, about 10 to 15 mg/kg or 1 g before incision. Reduce the dose in renal impairment. Avoid with active thromboembolism, and watch for seizures at high doses.

• Stop or reverse anticoagulants and antiplatelet drugs when the risk of bleeding exceeds the risk of thrombosis.

• Cell salvage in major surgery, with leucocyte filtration in obstetric use; use caution in infected or malignant fields.

• Reduce diagnostic blood loss: smaller paediatric tubes, closed sampling and only necessary tests.

Pillar 3: harness tolerance of anaemia. Maximise oxygen delivery with oxygen and cardiac output, reduce oxygen consumption (treat fever, pain and shivering), and use evidence based restrictive thresholds.

Red flags. Anaemia unresponsive to iron (consider haemolysis, bleeding, B12 deficiency or marrow disease), and thrombosis during treatment.

Preoperative plan.

1. Screen and diagnose anaemia early.

2. Treat the cause and replete iron.

3. Plan blood sparing techniques.

4. Set a threshold and a dose strategy before surgery.

5. Review postoperative haemoglobin and iron.

In the acute setting. Give antifibrinolytic therapy early in major haemorrhage, correct coagulopathy with targeted components, and avoid hypothermia, acidosis and hypocalcaemia.

For patients who refuse blood. Combine every available measure, and plan for the most severe scenario in advance.

Use of blood in shortage. Prioritise by indication, use single units, accept lower thresholds where safe, and reserve scarce products for patients with the greatest need.

Monitoring. Haemoglobin and ferritin response to iron, blood pressure and signs of hypersensitivity or anaphylaxis for 30 minutes after intravenous iron, thrombotic events with erythropoiesis stimulating agents and antifibrinolytics, and renal function.

Complications. Hypersensitivity to intravenous iron, hypophosphataemia after some intravenous iron products, thrombosis, hypertension with erythropoiesis stimulating agents, and seizures with high dose tranexamic acid.

Referral and escalation. Haematology for refractory anaemia, nephrology for chronic kidney disease, anaesthesia for perioperative planning and obstetrics for antenatal anaemia.

Disposition. Record the cause of anaemia, treatment started, and follow up of haemoglobin after discharge.