Blood transfusion in the older adult — thresholds and hazards

Guiding principle. Transfuse for symptoms and physiology, not for a number. Give a single unit and then reassess ("why give two when one will do"), and always consider treating the cause — iron, B , folate or 12 erythropoietin — instead of transfusing.

Thresholds (AABB 2023 international guidelines). Restrictive threshold of Hb <7 g/dL for haemodynamically stable hospitalised adults, including critical care patients and those with gastrointestinal bleeding. Hb <8 g/dL for patients undergoing orthopaedic or cardiac surgery and those with pre-existing cardiovascular disease.

Special situations. Chronic asymptomatic anaemia should not be transfused — correct the cause. In active bleeding, transfuse by clinical judgement rather than haemoglobin. In heart failure and frailty, transfuse slowly over 3–4 hours per unit with diuretic cover.

Acute hazards. Acute haemolytic reaction from ABO incompatibility (commonest cause is a clerical/identification error), febrile non-haemolytic reaction, allergic and anaphylactic reactions, bacterial contamination and sepsis, TACO — transfusion-associated circulatory overload, the commonest cause of transfusion-related death and the commonest serious hazard in the elderly — and TRALI (non-cardiogenic pulmonary oedema within 6 hours).

Delayed hazards. Delayed haemolytic reaction, red cell alloimmunisation, transfusion-transmitted infection (HIV, hepatitis B and C, malaria, syphilis — relevant to Indian practice), iron overload with repeated transfusion, transfusion-associated graft-versus-host disease (prevent with irradiated components after purine analogues or stem cell transplant), and post-transfusion purpura.

Safe practice. Positive patient identification at the bedside, baseline and 15-minute observations, transfusion during daytime hours wherever possible, documented indication and consent, strict fluid balance monitoring, and a formal TACO risk assessment before every transfusion in an older patient.

AABB 2025 international guideline for acute myocardial infarction (Ann Intern Med 2025;178:1469) — in hospitalised patients with acute myocardial infarction and anaemia, a liberal strategy transfusing at Hb <10 g/dL is now suggested. This follows the MINT trial (NEJM 2023, n=3504, mean age 72) and a patient-level meta-analysis showing lower cardiac death at 30 days and lower all-cause mortality at 6 months with the liberal strategy. It is the first major departure from universal restrictive transfusion.