What are the current indications for blood transfusion in adult patients according to UK guidelines?

The current indications for blood transfusion in adult patients according to UK guidelines are:

• Red blood cell transfusions: Use restrictive thresholds, considering transfusion when haemoglobin levels are around 70 g/litre for most patients, with a target of 70–90 g/litre after transfusion. For patients with acute coronary syndrome, consider a threshold of 80 g/litre and a target of 80–100 g/litre. For patients needing regular transfusions for chronic anaemia, individual thresholds and targets should be set. Transfusions should be considered for adults without active bleeding, often as single-unit transfusions, with reassessment after each unit.
• Platelet transfusions: Offer to patients with thrombocytopenia who are bleeding and have a platelet count below 30×10^9/L, or higher thresholds (up to 100×10^9/L) for severe bleeding or bleeding in critical sites. Prophylactic transfusions are indicated for platelet counts below 10×10^9/L in non-bleeding patients without specific conditions, and for invasive procedures or surgery, thresholds may be raised to 50×10^9/L or higher depending on risk.
• Fresh frozen plasma: Consider for patients with clinically significant bleeding and abnormal coagulation tests, especially if they are having invasive procedures or surgery with bleeding risk. It is not routinely used to correct abnormal coagulation in non-bleeding patients or for reversal of vitamin K antagonists.
• Cryoprecipitate: Consider for patients with significant bleeding and fibrinogen levels below 1.5 g/litre, or below 1.0 g/litre before invasive procedures or surgery with bleeding risk.

These guidelines emphasize restrictive and targeted transfusion practices based on clinical need and specific thresholds.