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SU3.1-3 | Blood and Blood Components — Glossary

Glossary — SU3.1-3 | Blood and Blood Components

Key terms in this module. Tap a term to see its definition.

ABO incompatibility

Transfusion of red cells carrying an A or B antigen against which the recipient has pre-formed IgM antibody, causing acute intravascular haemolysis.

Acute haemolytic transfusion reaction

Immediate immunological reaction (usually ABO incompatibility) with IgM-mediated complement activation and intravascular haemolysis; fever, loin pain, haemoglobinuria, shock and DIC.

Baseline observations

Temperature, pulse, blood pressure, respiratory rate and oxygen saturation recorded immediately before transfusion, against which any reaction is judged.

Bedside check

The final pre-transfusion verification at the patient's side that this unit, on its compatibility label, matches this identified patient; the last barrier against wrong-patient transfusion.

Cell salvage

Collection and re-infusion of a patient's own blood lost during surgery; an alternative that can reduce the need for allogeneic transfusion.

Citrate toxicity

Hypocalcaemia caused by the citrate anticoagulant in stored blood chelating ionised calcium, prominent in rapid massive transfusion.

Compatibility label

The label attached to a crossmatched blood unit recording the intended recipient's identifiers, blood group and the unit's donation number, checked against the patient at the bedside.

Component therapy

The practice of separating donated blood into its components and transfusing only the fraction the patient lacks, rather than whole blood.

Crossmatch

Pre-transfusion compatibility test between donor cells and recipient serum confirming ABO/Rh compatibility and detecting clinically significant antibodies.

Cryoprecipitate

Cold-insoluble precipitate from thawed FFP, rich in fibrinogen, factor VIII, von Willebrand factor and factor XIII; used for hypofibrinogenaemia and factor replacement.

Delayed haemolytic transfusion reaction

Extravascular haemolysis appearing days after transfusion from an anamnestic IgG response to a minor red-cell antigen; unexplained Hb fall, jaundice, positive DAT.

Donor deferral

Temporary or permanent exclusion of a prospective donor for reasons that risk donor or recipient safety (e.g. anaemia, recent illness, recent tattoo, high-risk behaviour).

Febrile non-haemolytic transfusion reaction (FNHTR)

Fever and rigors during or soon after transfusion from recipient anti-leucocyte antibodies or accumulated cytokines, without haemolysis.

Fresh frozen plasma (FFP)

Plasma frozen at ≤ −30 °C (keeps ~1 year) containing all coagulation factors; used for multiple-factor deficiency and massive-transfusion or liver-disease coagulopathy.

Informed consent

A competent patient's voluntary agreement after disclosure of the indication, benefits, material risks and alternatives of a proposed treatment such as transfusion.

Inter-donation interval

The minimum gap between whole-blood donations (three months in India) allowing the donor to recover iron stores and blood volume.

Massive transfusion

Replacement of ~1 blood volume (≈10 units) in 24 h (or ≥4 units in 1 h / 50% blood volume in 3 h), risking hypocalcaemia, hyperkalaemia, hypothermia and coagulopathy.

Packed red blood cells (PRBC)

Red-cell concentrate with most plasma removed, stored at 2–6 °C for ~35–42 days; used for symptomatic anaemia and red-cell replacement (~1 g/dL Hb rise per unit).

Plasma derivatives

Products fractionated from pooled plasma — albumin, specific clotting-factor concentrates and immunoglobulins.

Platelet concentrate

Platelet component stored at 20–24 °C with continuous agitation for ~5 days; used for thrombocytopenic bleeding or platelet dysfunction.

Positive patient identification

Confirming identity by having the patient state their own full name and date of birth and matching these to the wristband and the unit's compatibility label.

Stop-transfusion sequence

The immediate response to a suspected reaction: stop the transfusion, keep the line open with saline, recheck identity, support airway/breathing/circulation, call for help, return the unit and a sample.

TACO (transfusion-associated circulatory overload)

Hydrostatic pulmonary oedema from volume overload during transfusion, with raised JVP and hypertension; treated by slowing/stopping transfusion and a diuretic.

TRALI (transfusion-related acute lung injury)

Non-cardiogenic pulmonary oedema within 6 hours of transfusion caused by donor anti-leucocyte antibodies activating recipient lung neutrophils.

Transfusion-transmissible infections (TTI)

Infections screened for in every donation; in India mandatorily HIV, hepatitis B, hepatitis C, syphilis and malaria.

Voluntary non-remunerated donation

Blood donation given freely without payment; the safest source of blood because donors have no incentive to conceal risk factors.

Whole blood

Unseparated donated blood containing red cells, plasma, platelets and clotting factors; largely replaced by component therapy except in major haemorrhage.

Window period

The early phase of infection during which a donor is infectious but screening tests are still negative; minimised by voluntary repeat donors and nucleic-acid testing.

28 terms in this module