Blood Transfusion: Pre-clinical Pathology and Haematology

Vocabulary practice flashcards covering fundamental pre-clinical haematology and transfusion medicine concepts, including blood components, donor safety, compatibility testing, modifications, autologous methods, and transfusion reactions.

Whole blood

A transfusion product containing red cells, plasma, and platelets with variable post-storage function; reserved for selected major haemorrhage protocols rather than routine replacement of a single deficit.

Red blood cells (RBCs)

Concentrated erythrocytes transfused to increase oxygen-carrying capacity in clinically significant anaemia or blood loss; one unit typically raises adult haemoglobin by approximately $1\,\text{g/dL}$ in a non-bleeding patient.

Platelet concentrates

A cellular blood component stored under controlled conditions with continuous agitation to treat or prevent bleeding due to low platelet count or platelet dysfunction; carries a particular risk of bacterial contamination.

Fresh frozen plasma (FFP)

A component containing multiple soluble coagulation factors indicated for bleeding in the presence of multiple factor deficiencies when specific replacement therapies are unavailable, rather than for simple volume expansion.

Cryoprecipitate

A plasma-derived component enriched in fibrinogen, factor VIII, von Willebrand factor (vWF), and factor XIII, used primarily for patients with low fibrinogen levels and active bleeding.

Plasma-derived medicinal products

Manufactured pharmaceutical preparations derived from pooled plasma—including albumin, immunoglobulins, specific factor concentrates, and prothrombin complex concentrate (PCC)—that are not interchangeable with labile blood components.

Leukoreduction

A processing modification that removes white blood cells from donor blood components, thereby reducing the incidence of febrile non-haemolytic reactions and HLA alloimmunization.

Irradiated cellular components

Blood components exposed to radiation to damage donor lymphocyte DNA and prevent viable donor T cells from proliferating, thereby preventing transfusion-associated graft-versus-host disease (TA-GvHD) in susceptible recipients.

Washed cellular components

Cellular products processed to remove the vast majority of residual plasma, indicated primarily for recipients with recurrent severe allergic transfusion reactions.

Pathogen reduction

A technology applied to platelets and plasma to inactivate a broad spectrum of infectious pathogens, adding an additional safety layer without eliminating all potential infectious risks.

Voluntary non-remunerated donors

Unpaid blood donors whose repeat donations provide the safest and most stable foundation for the blood supply.

Window period

The early phase of an infection during which an infectious agent is present in the donor's blood but screening markers (such as antigens or antibodies) have not yet reached detectable levels.

Nucleic acid testing (NAT)

A highly sensitive molecular testing method used in donor screening for HIV, HBV, and HCV to narrow the infectious window period.

Preoperative autologous donation (PAD)

An autologous transfusion strategy where a patient donates their own blood weeks before an elective surgery; limitations include the risk of preoperative anaemia and blood wastage.

Acute normovolaemic haemodilution (ANH)

An autologous transfusion method where whole blood is collected from the patient immediately following induction of anaesthesia while intravascular volume is maintained with replacement fluids, followed by re-infusion of the blood postoperatively or after haemostasis.

Intraoperative cell salvage

The collection, filtration, washing, and re-infusion of blood shed by a patient during surgery; contraindicated in contaminated or malignant operative fields.

Antibody screen

A pre-transfusion laboratory test performed on recipient plasma to detect clinically significant, unexpected red-cell antibodies directed against non-ABO antigens.

Serological crossmatch

A physical compatibility test incubating donor red blood cells with recipient serum or plasma to verify the absence of unexpected haemolytic reactivity prior to issue.

Electronic crossmatch

A validated computer-assisted verification of donor-recipient ABO and RhD compatibility without physical mixing of samples, permitted only when the antibody screen is negative and there is no past record of atypical red-cell antibodies.

Forward grouping

The portion of ABO blood typing in which a patient's red blood cells are tested with known reagent antisera (anti-A and anti-B) to identify cell-surface antigens.

Reverse grouping

The portion of ABO blood typing where patient plasma or serum is tested against known reagent A and B red blood cells to verify expected naturally occurring antibodies.

Acute haemolytic transfusion reaction (AHTR)

A rapid, severe, life-threatening immunological reaction typically caused by ABO incompatibility, marked by acute intravascular haemolysis, fever, chills, loin pain, hypotension, and haemoglobinuria.

Febrile non-haemolytic transfusion reaction (FNHTR)

An acute reaction presenting with temperature elevation and chills in the absence of haemolysis, bacterial sepsis, or other identifiable cause.

Transfusion-associated circulatory overload (TACO)

A hydrostatic pulmonary complication occurring during or shortly after transfusion characterised by acute dyspnoea, hypertension, fluid overload, and pulmonary oedema; managed by stopping or slowing the transfusion, sitting upright, and administering diuretics.

Transfusion-related acute lung injury (TRALI)

A form of non-cardiogenic pulmonary oedema presenting with acute hypoxaemia and bilateral lung infiltrates typically within $6\,\text{h}$ of transfusion, driven by immune-mediated capillary leakage.

Transfusion-associated graft-versus-host disease (TA-GvHD)

A nearly always fatal delayed complication occurring days to weeks after transfusion, in which viable donor T lymphocytes attack recipient tissues, resulting in fever, rash, diarrhoea, hepatitis, and bone marrow failure.

Delayed haemolytic transfusion reaction (DHTR)

A secondary anamnestic immune response occurring days to weeks post-transfusion in an alloimmunized recipient, typically manifesting as an unexpected drop in haemoglobin, jaundice, and hyperbilirubinaemia.

Post-transfusion purpura (PTP)

A rare delayed complication typically occurring days after transfusion, marked by rapid, severe immune-mediated destruction of both donor and autologous platelets with clinical bleeding.

Haemovigilance

A structured system of surveillance, reporting, and quality control covering the entire transfusion chain from donor recruitment to bedside administration, designed to identify, trace, and prevent adverse events.