Synopsis
Reduce avoidable transfusion and manage perioperative anaemia and bleeding in adults through early diagnosis, blood conservation, appropriate tranexamic acid, component-specific decisions and reassessment after each intervention.
- Find anaemia early before major elective surgery, investigate the cause and treat iron deficiency; transfusing an otherwise stable haematinic deficiency exposes the patient to harm without correcting the cause.
- For adults having operating-theatre surgery that breaches skin or mucosa and carries any bleeding risk, NICE 2026 says offer tranexamic acid just before surgery, typically 1 g by slow IV injection.
- Outside major haemorrhage, acute coronary syndrome and regular chronic-transfusion settings, consider a restrictive red-cell threshold of 70 g/L and target 70–90 g/L; in non-bleeding adults give one unit then reassess and recheck Hb.
Key red flags
Haemodynamic instability, brisk drain or wound loss, diffuse surgical-field bleeding, falling temperature or rising lactate should trigger haemorrhage escalation without waiting for a low haemoglobin result.
A historical antibody, previous transfusion reaction, complex blood group, sickle-cell disease or anticipated massive loss requires early transfusion-laboratory communication because compatible components may take time.
New fever, rigors, dyspnoea, hypoxaemia, hypotension, pain, urticaria or dark urine during transfusion may be an acute reaction: stop the component, keep IV access, assess ABC and contact the laboratory immediately.
Tranexamic acid given by the intrathecal or epidural route can be fatal; storage, labelling and route checks must prevent neuraxial administration.
Active thromboembolic disease, ongoing intravascular clotting or renal impairment changes the benefit-risk and repeat-dose plan for tranexamic acid.
The restrictive 70 g/L red-cell threshold does not apply unchanged to major haemorrhage, acute coronary syndrome or people needing regular transfusion for chronic anaemia.
Tachycardia, hypotension, altered perfusion, unexpected operative loss, increasing drain output, acidosis, hypothermia and diffuse bleeding require source control and major-haemorrhage coordination.
Fever, rigors, dyspnoea, chest or loin pain, urticaria, hypoxaemia, hypotension or dark urine during a component may represent an acute reaction and requires immediate cessation and assessment.
Reasoning priorities
Detect preoperative anaemia and classify the initial red-cell pattern early enough for cause-directed treatment.
Microcytosis can support iron deficiency but ferritin and transferrin saturation refine diagnosis; normal cell size does not exclude iron deficiency, renal disease or inflammation.
Worked reasoning
An adult several weeks before planned major surgery has low haemoglobin, small red cells and biochemical iron deficiency without instability.
- Inform the patient, surgeon and perioperative team, investigate the bleeding and deficiency cause, and assess how surgical urgency constrains the time available for correction.
- Offer oral iron when it can be tolerated and there is enough time; consider intravenous iron when absorption, tolerance, adherence, functional deficiency or a short interval makes oral therapy ineffective.
- Do not use red-cell transfusion simply to treat a stable haematinic deficiency without a separate clinical indication; transfusion adds risk and leaves the cause untreated.
- Recheck haemoglobin response at a clinically useful interval and review ongoing loss, nutrition, renal disease and inflammation if the response is inadequate.
- Document the expected blood-loss plan, consent and preferences, compatibility needs and postoperative transfusion strategy. For this adult operating-theatre surgery that breaches skin or mucosa and carries any bleeding risk, offer tranexamic acid just before surgery, typically 1 g by slow IV injection; consider cell salvage separately when very high blood loss is expected.
An adult is haemodynamically stable after surgery, has no active bleeding or acute coronary syndrome and does not require regular transfusions.