How should I obtain informed consent for a blood transfusion in an adult patient, including discussion of risks, benefits, alternatives, and handling emergencies or lack of decision‑making capacity?

Blood Transfusion Consent in Adult Patients

When blood transfusion is anticipated, you must discuss it with the patient before surgery and document valid consent in the medical record. 1, 2

Timing and Setting of Consent Discussion

• Obtain consent during pre-assessment whenever possible, well before the anticipated transfusion, allowing time for the patient to process information and ask questions 2, 3
• The discussion should occur in the absence of factors that could unduly influence the patient's decision 2
• Consent must be voluntary, informed, and given free of undue influence 4

Essential Elements to Discuss

Benefits and Indications

• Explain specifically why the transfusion is needed for their condition and the expected benefits (e.g., correcting anemia, improving oxygen delivery, preventing complications) 5, 2
• Describe the expected outcome without transfusion to help the patient understand the necessity 3

Risks to Communicate

• Transfusion-related acute lung injury (TRALI) 5
• Transfusion-associated circulatory overload (TACO) 5
• Infection transmission risk (though rare with modern screening) 5
• Allergic reactions and anaphylaxis 5
• ABO incompatibility (the most serious transfusion error, usually due to identification failures) 1
• Transfusion reactions (febrile, hemolytic) 2

Alternatives to Allogeneic Transfusion

• Cell salvage (intra-operative blood recovery and reinfusion) should be discussed for procedures where blood loss >500 ml is anticipated 1, 2
• Autologous blood donation (pre-operative donation of patient's own blood) where applicable 5, 2
• Tranexamic acid administration to reduce bleeding 1
• Pre-operative anemia correction (iron therapy, erythropoietin) when surgery can be delayed 1

Documentation Requirements

The consent discussion must be clearly documented in the patient's medical record, including: 2

• The risks and benefits discussed 5, 2
• Alternatives considered 5, 2
• The patient's questions and responses given 2
• The patient's decision and agreement to proceed 2
• Confirmation of the patient's capacity to provide informed consent 2
• Verification that the patient understood the information provided 2

Documentation can be completed on a standard consent form, on the anaesthetic record, or separately in the patient's notes 2

Special Populations and Circumstances

Patients with Religious or Personal Objections

• Document the precise nature of any restrictions imposed by the patient (e.g., Jehovah's Witnesses refusing specific blood products) 2
• Draw attention to the clause on consent forms that allows patients to list procedures for which consent is not agreed 2
• Document the explanation of risks that took place when patients refuse transfusion 2
• Competent adults have the right to refuse treatment regardless of their reasons, even if refusal will result in death—you must respect their decision 4

Emergency Situations Without Capacity

When a patient lacks decision-making capacity and transfusion is urgent: 1, 2

• Healthcare professionals can make decisions on behalf of patients and must do so in the patient's best interests 4
• All hospitals should have a clear local policy for transfusion of patients whose identity is unknown 1, 2
• In emergency situations, the patient should still have identification attached (even if "unknown male/female" with a unique identification number) 1
• Group O RhD negative blood should be used for women of childbearing potential (<50 years) and children; Group O RhD positive for other adults 1
• Group-specific blood should be available within 15-20 minutes of the laboratory receiving correctly-labeled samples 1

Patients with Advance Directives

• Check whether patients have made relevant advance decisions to refuse treatment 2
• A properly documented Do-Not-Resuscitate (DNR) order does not automatically prohibit blood transfusion—DNR limits only CPR and intubation, not other interventions 6

Post-Transfusion Requirements

• Inform patients before discharge that they have received blood components, as they will otherwise be unaware 1, 2
• Explain that receiving blood removes them from the donor pool 1
• Inform the patient's general practitioner that they received blood components 1, 2
• Monitor for adverse reactions including signs of TRALI or TACO 5

Common Pitfalls to Avoid

• Do not obtain consent as part of a general surgical consent—blood transfusion requires separate, specific discussion 7
• Do not delegate consent discussions to untrained staff—all staff obtaining consent must be properly trained and competency-assessed 2
• Do not assume patients remember or understand the discussion—research shows 88% of patients do not recall discussion of specific risks or alternatives despite signing consent 8
• Do not use medical jargon—explain issues in terms the patient can understand, providing support and communication aids as needed 4
• Do not rush the process—there must be adequate time for information provision and discussion 3