MLS 2551 Unit 5: Transfusion Practice Cases & Calculations

What is the first step in pretransfusion testing?

Establishing the reliability of the patient-specimen link.

What are the terms to distinguish in pretransfusion testing?

Type and screen, antibody screen, antibody identification, major crossmatch, immediate-spin crossmatch, AHG crossmatch, electronic crossmatch, DAT, IAT, ABO-identical, ABO-compatible, and wrong blood in tube.

What is the significance of specimen timing in transfusion practice?

Recent transfusion or pregnancy can change specimen requirements even when ABO type is unchanged.

What does a current antibody screen establish?

It identifies clinically significant antibodies that may require further investigation.

What are the three compatibility pathways in transfusion practice?

Immediate-spin, AHG, and electronic compatibility pathways.

What is the purpose of the AHG crossmatch?

To detect antibodies that may cause hemolytic reactions during transfusion.

What is the role of informed consent in donor assessment?

To ensure donors understand the risks and have the ability to withdraw from the donation process.

What factors are considered in donor eligibility criteria?

Hemoglobin/hematocrit levels, pulse, blood pressure, temperature, weight, and donation interval.

What is the difference between allogeneic and autologous donation?

Allogeneic donation is from a volunteer donor, while autologous donation is from the patient themselves.

What is the significance of the window period in infectious testing?

It refers to the time after infection during which tests may not yet detect the infection.

What are common donor reactions during blood collection?

Vasovagal symptoms and citrate-related effects.

What does the term 'storage lesion' refer to?

Changes in red blood cells during storage that can affect their function.

What is the role of 2,3-DPG in oxygen affinity?

It decreases hemoglobin's affinity for oxygen, facilitating oxygen release to tissues.

What are the key components of quality control in blood products?

Concentration, total yield, residual cells, pH, and recipient response.

What is the importance of traceability in blood donation?

To ensure the safety and accountability of blood products from donor to recipient.

What does 'quarantine' mean in the context of blood products?

A status indicating that a blood component is held for further testing before release.

What is the difference between whole-blood donation and apheresis?

Whole-blood donation collects all components, while apheresis selectively collects specific components.

What is the purpose of anticoagulation during blood collection?

To prevent clotting and ensure the integrity of the collected blood components.

What is the significance of the 'wrong blood in tube' error?

It can lead to serious transfusion reactions if not identified and corrected.

What are the storage conditions for platelets?

They must be stored at room temperature with continuous agitation.

What does 'deglycerolization' refer to?

The process of removing glycerol from frozen red blood cells before transfusion.

What is the importance of specimen integrity in transfusion practice?

To ensure accurate test results and safe transfusion outcomes.

What is the role of the major crossmatch?

To test compatibility between donor red blood cells and recipient serum.

What are the implications of a reactive screening test?

It indicates the presence of antibodies that may require further investigation.

What is the purpose of rejuvenation in blood products?

To restore the function of red blood cells that have been stored for extended periods.

What is the significance of the expiration clock in blood products?

It determines the shelf life and usability of blood components.

What should be chosen to support a patient's functional deficit?

Support should consider compatibility, required attributes, clinical context, and measured response.

What are the terms to distinguish in patient blood management?

Patient blood management, leukoreduction, irradiation, washing, CMV-seronegative selection, platelet additive solution, pathogen reduction, platelet increment, and corrected count increment.

What is the principal clinical role of RBCs?

RBCs are primarily responsible for oxygen transport.

What is the correct direction of ABO compatibility for RBCs versus plasma?

RBCs must be compatible with the recipient's plasma; do not transfer RBC shortcuts to plasma.

What does patient blood management involve?

It involves assessment before, during, and after a transfusion decision, including expected increments.

What is leukoreduction?

A process that removes white blood cells from blood components to reduce the risk of febrile non-hemolytic transfusion reactions.

What does irradiation do in blood component processing?

It prevents graft-versus-host disease by inactivating lymphocytes.

What is the significance of a corrected count increment?

It relates the platelet count increment to body surface area and the dose expressed in units of 10¹¹ platelets.

What are the immediate responses to transfusion reactions?

Recognize suspected reactions and review the immediate response sequence.

What is the difference between acute immune hemolysis and delayed hemolysis?

Acute immune hemolysis occurs immediately after transfusion, while delayed hemolysis occurs days to weeks later.

What does a positive Direct Antiglobulin Test (DAT) indicate?

It indicates the presence of antibodies attached to RBCs, but must be interpreted with other evidence.

What are the metabolic complications of large-volume transfusion?

They include electrolyte imbalances and acid-base disturbances, which differ from immune mechanisms.

What should be included in a laboratory report regarding transfusion reactions?

Keep observation, supported interpretation, and remaining uncertainty separate.

What is the importance of donor eligibility in transfusion?

It ensures the safety and compatibility of the blood component for the recipient.

How should evidence be weighed in transfusion decisions?

Use the most likely explanation supported by combined findings, separating strong support from absolute proof.

What is the expected RBC response in transfusions?

It should be applied under stated assumptions, recognizing reasons for differing measured responses.

What is the significance of expiration dates in blood component storage?

They must be compared with processing deadlines to ensure safety and efficacy.

What is the role of patient and component cultures in infection investigation?

They help identify potential sources of infection and guide appropriate treatment.

What does the term 'alloimmunization' refer to?

It refers to the immune response against transfused blood group antigens that are foreign to the recipient.

What are the clinical patterns to recognize in transfusion reactions?

They include hemoglobinemia, hemoglobinuria, hematuria, and various types of hemolysis.

What is the purpose of component-specific pathogen reduction?

To reduce the risk of transfusion-transmitted infections.

What is the importance of separating strong support from absolute proof in transfusion decisions?

It helps in making informed decisions based on the most likely explanations rather than assumptions.

What does the term 'TACO' stand for in transfusion reactions?

Transfusion Associated Circulatory Overload.

What does 'TRALI' refer to in the context of transfusion reactions?

Transfusion Related Acute Lung Injury.

What is the significance of reviewing qualifiers, units, and timing during tests?

It ensures accurate interpretation of results and appropriate clinical decisions.

What is the primary reason Maya Torres is being evaluated?

She is being evaluated for uterine fibroids due to heavy menstrual bleeding.

What is Maya's hemoglobin level and its significance?

Her hemoglobin level is 6.8 g/dL, which is below the normal reference interval of 12.0-16.0 g/dL, indicating anemia.

What does a flag of 'L' indicate in the context of laboratory results?

'L' indicates that the result is below the listed reference interval.

What was the last date Maya received a transfusion?

Maya's last transfusion was on 10/03/2026.

What is the significance of the confirmed anti-K from 2024 in Maya's blood bank record?

It indicates that Maya has a historical antibody that could affect compatibility for transfusions.

Can the 11/02 specimen be used for the planned transfusion on 11/06?

No, the last valid calendar date for the specimen is 11/05, making it expired for use on 11/06.

What is the expected hemoglobin increase after one RBC unit transfusion?

The expected hemoglobin increase is approximately 1 g/dL.

What is the primary blood count abnormality in Maya's case?

The primary abnormality is low hemoglobin (6.8 g/dL), indicating anemia.

What type of blood component is ordered for Devin Cole?

An adult apheresis platelet component that is leukoreduced and irradiated.

What is Devin Cole's platelet count and its significance?

His platelet count is 8 × 10⁹/L, which is significantly below the normal range of 150-400 × 10⁹/L, indicating thrombocytopenia.

What symptoms is Devin experiencing that relate to his blood count?

Devin is experiencing new petechiae and brief gum bleeding.

What does the term 'leukoreduced' mean in the context of blood components?

'Leukoreduced' means that the white blood cells have been reduced to minimize the risk of transfusion reactions.

What is the expiration date of the platelet unit P-5102-D?

The expiration date of platelet unit P-5102-D is 11/06 at 10:00.

What is the significance of the apheresis platelet unit being quarantined?

The unit is quarantined due to a reactive infectious-disease screening result under investigation.

What is the reference interval for hemoglobin in adults?

The reference interval for hemoglobin in adults is 13.5-17.5 g/dL.

What does the term 'irradiated' refer to in blood component processing?

'Irradiated' refers to the process of exposing blood components to radiation to prevent graft-versus-host disease.

What is the relationship between Maya's fatigue and her hemoglobin level?

Maya's fatigue is likely due to her low hemoglobin level, which indicates anemia and reduced oxygen-carrying capacity.

What does a 4+ result in the forward grouping reactions indicate?

A 4+ result indicates strong agglutination, confirming the presence of that blood type antigen.

What is the significance of the absolute neutrophil count being low in Devin's case?

A low absolute neutrophil count (0.30 × 10⁹/L) indicates a high risk of infection due to compromised immune function.

What is the purpose of compatibility testing before transfusion?

Compatibility testing ensures that the donor blood is safe for the recipient to prevent transfusion reactions.

What is the expected outcome of transfusion for Maya's condition?

The expected outcome is an improvement in symptoms related to anemia, such as fatigue and breathlessness.

Why is it important to monitor the patient's condition after a transfusion?

Monitoring is crucial to detect any adverse reactions or complications that may arise from the transfusion.

What is the role of the hematology team in Devin's treatment?

The hematology team is responsible for managing Devin's blood counts and determining the need for transfusions.

What does the term 'abnormal qualitative finding' mean in lab results?

An abnormal qualitative finding indicates a result that deviates from the expected normal response, often requiring further investigation.

What blood-count abnormality explains the planned platelet support for Devin?

A low platelet count, specifically 8 ×10⁹/L, which is below the reference interval of 150-400 ×10⁹/L.

What hemostatic function do the ordered platelets support?

The platelets are intended to support hemostasis, which is the process of stopping bleeding.

What is the minimum corrected count increment (CCI) for an adequate early response?

An approximate CCI of at least 7,500 is considered an adequate early response.

How do you calculate the corrected count increment (CCI)?

CCI is calculated using the formula: CCI = (Posttransfusion count - Pretransfusion count) × (Body surface area / Platelet dose).

What does an adequate early response indicate about Devin's platelet count?

An adequate early response does not necessarily mean his platelet count is normal; it indicates a significant increase but may still be below the normal range.

Why can't component yield alone predict a patient's response?

Component yield cannot predict response because individual patient factors, such as immune response and underlying health conditions, can affect platelet increment.

What are two patient-related factors that could lower the response to platelet transfusion?

1. Immune response to transfused platelets. 2. Underlying conditions like splenomegaly or active bleeding.

What immediate action should be taken when Eleanor shows signs of distress during transfusion?

The first immediate action is to stop the transfusion.

What are two important changes in Eleanor's clinical observations indicating acute deterioration?

1. Increased heart rate from 84/min to 112/min. 2. Decreased SpO₂ from 97% to 86%.

What does the chest imaging reveal about Eleanor's condition?

Chest imaging shows new bilateral pulmonary edema compared with the admission film.

What findings suggest the most likely transfusion reaction for Eleanor?

The timing of symptoms during transfusion and the presence of new dyspnea and bilateral crackles suggest a transfusion-related acute lung injury (TRALI).

What is a distinguishing feature that favors a diagnosis over TRALI?

The absence of fever or hypotension during the reaction favors a diagnosis of transfusion-associated circulatory overload (TACO) over TRALI.

What do compatibility, DAT, and hemolysis findings suggest about acute immune hemolysis?

These findings suggest that acute immune hemolysis is unlikely, as there are no discrepancies in compatibility and DAT results.

Why are the hemolysis results not enough to consider the respiratory reaction harmless?

Even without hemolysis, the respiratory reaction can indicate serious complications like fluid overload or lung injury.

What is one patient-specific risk-reduction change for Eleanor's future transfusions?

One change could be to administer diuretics before transfusion to help manage fluid balance and reduce the risk of overload.

What is the reference interval for platelet counts?

The reference interval for platelet counts is 150-400 ×10⁹/L.

What was Eleanor's hemoglobin level before transfusion?

Eleanor's hemoglobin level was 7.1 g/dL, below the normal range of 12.0-16.0 g/dL.

What does a posttransfusion platelet count of 32 ×10⁹/L indicate?

It indicates a significant increase from the pretransfusion count but is still below the normal range.

What is the significance of a negative DAT result?

A negative DAT result suggests that there is no evidence of hemolytic transfusion reaction due to antibody-mediated destruction of red blood cells.

What does the term 'jugular venous distention' indicate in Eleanor's case?

Jugular venous distention indicates fluid overload or heart failure exacerbation.

What is the importance of monitoring vital signs during a transfusion?

Monitoring vital signs helps detect early signs of transfusion reactions and ensures patient safety.

What is the role of oxygen therapy in Eleanor's treatment?

Oxygen therapy helps alleviate hypoxia and improve oxygen saturation in patients experiencing respiratory distress.

What does a net positive fluid balance indicate?

A net positive fluid balance indicates that the patient has received more fluids than they have excreted, which can lead to fluid overload.

What is the significance of the postreaction specimens collected?

Postreaction specimens are important for investigating potential transfusion reactions and ensuring patient safety.