Blood Products Flashcards
What are the five main components of blood?
Red Blood Cells, White Blood Cells, Platelets, Coagulation factors, Plasma
Blood Type A
Red Cell Type: A
Antigens: A-Antigens
Antibodies: Anti-B
Blood Type B
Red Cell Type: B
Antigens: B-Antigens
Antibodies: Anti-A
Blood Type AB
Red Cell Type: AB
Antigens: AB-Antigens
Antibodies: N/A
Blood Type O
Red Cell Type: O
Antigens: N/A
Antibodies: Anti-AB
Coagulation type and pathways
Coagulation is a cell based process that occurs via a cascade. Its pathways are intrinsic (12,11,9,8), extrinsic (7,3), and common (10)
Platelet Count Levels
Normal: 150,000-400,000/mm3
Thrombocytopenia: 400,000/mm3
Activated Clotting Time (ACT)
Measures the amount of time required for whole blood to clot in a test tube
Used to monitor heparin therapy in the OR
Normal – 70-180 seconds
Sufficient for CPB –> 400 seconds
Prothrombin Time (PT)
Normal 10-14s or 30-40s (depending on reagent used)
PT test varies in sensitivity among laboratories
Partial Thromboplastin Time (PTT)
Normal 25-38s
Can be used to monitor anticoagulation therapy
International Normalized Ratio (INR)
developed to standardize PT values to better monitor oral anticoagulation therapy
Type and Screen
Recipient’s blood has been typed for A, B, and Rh antigens and screened for common antibodies
Type and Cross-Match
Recipient’s blood is incubated with the donor blood product
Clumping occurs if the cross-match is incompatible
Factors that determine when to transfuse
Extensive blood loss
Inadequate perfusion
Low hemoglobin concentration
Poor coagulation
When do you know if you need to give blood products?
For the average 70 kg patient who has lost ~1L – 1.5L of blood, send off coagulation studies and start documenting lab values and coagulation status
Packed Red Blood Cell Therapy
Indicated for treatment of anemia (often associated with blood loss)
1 unit contains 250-300 mL volume with a hematocrit of 70-80%
When to give PRBC’s
Evidence of Rapid Acute Hemorrhage w/o immediate control
Estimated blood loss >30-40%, presence of symptoms of severe blood loss
When to use crystalloid/colloid resuscitation
Estimated blood loss 20-30%
How much does 1 unit of PRBC increase hemoglobin and hematocrit
Hemoglobin: 1 g/dL
Hematocrit: 3%
Washed PRBC’s
Centrifuged in saline to remove plasma and cytokines
Once washed, PRBCs can be stored for no longer than 24 hrs
Leukocyte-reduced PRBCs
Centrifuged, washed, or filtered
- To avoid nonhemolytic febrile reactions
- To prevent sensitization of patients with aplastic anemia
- To minimize transmission of HIV or CMV
Irradiated PRBCs
Cells are exposed to a standard dose of ionizing radiation
Irradiated blood is for people who are not capable of mounting a counterattack and neutralizing transfused lymphocytes
Cell Saver
Blood salvaged from the surgical field
Hematocrit ~ 65-70%
When to give a platelet transfusion
Usually not indicated during surgery unless the platelet count is less than 50,000/mm^3
How are platelets prepared
- Centrifuging individual units from multiple whole blood donors (5 x 10^10 platelets in 50-70cc of plasma per unit) – 5 to 10 units of platelets may be pooled together in a single bag
- Single donor apheresis (3-5 x 10^11 platelets in 200-400cc plasma)
Platelet Transfusion level increase
Rough rule of thumb is that a pool of 6-8 units of whole-blood platelets (a “six pack”) or 1 unit of apheresis will raise the patients platelet count by 30-50 x 109 /L
Initial dose = 10 cc/kg
Things to Know about Platelet Transfusion
- DO NOT warm or cool platelets
- Use a 150 micron filter when giving platelets. Microaggregate filters (20-40 micron) should not be used because they will remove most of the platelets.
Fresh Frozen Plasma (FFP)
the FLUID portion obtained from a single unit of whole blood that is frozen within 6 hours of collection (whole blood → platelet rich plasma → platelets + plasma)
When should FFP be transfused
Indicated when PT, PTT, or both are at least 1.5 times greater than normal.
In emergent situations, FFP may be used to reverse the effects of warfarin prior to surgery
How much FFP to give
10 to 15 mL/kg will raise most coagulation proteins by 25-30% (5-8 ml/kg may be sufficient to reverse warfarin anticoagulation)
Cryoprecipitate (Cryo)
- The fraction of plasma that precipitates when FFP is thawed
- Each bag of Cryo contains ~ 200 mg of fibrinogen and 100 units of Factor VIII (80 to 110 IU)
Complications of Blood Transfusion
- Transfusion reactions
- Transmission of disease
- Transfusion-Related Acute Lung Injury
- Suppression of cell-mediated immunity
- Metabolic derangements
Febrile Reactions (FNHTR)
Occur in 0.5-1% of transfusions
Due to immune reaction between cytokines (released by leukocytes) or platelets with recipient antibodies (from previous transfusions or pregnancy)
Mild Allergic Reactions
- Can occur in blood which has been properly typed and cross-matched
- Clinical manifestations
- –Increased body temperature
- –Pruritis
- Treatment
- –IV antihistamines
- –Discontinuation of transfusion if severe
Hemolytic Reactions
- Medical emergency that results from the administration of the ABO incompatible blood
- Caused by the rapid destruction of donor erythrocytes by recipient antibodies
- Most often the result of clerical or procedural error
Hemolytic Reactions
Hypotension -Dyspnea
Fever -Skin flushing
Chills
Lumbar/Substernal Pain
Anaphylactic Reactions
Rapid onset Shock Hypotension Angioedema Respiratory distress
Treatment of Anaphylactic Reactions
Stop the transfusion Epinephrine – bolus and possible infusion Airway maintenance, oxygenation Volume maintenance with saline Vasopressors if necessary
Transfusion Related Acute Lung Injury (TRALI)
Characterized by acute respiratory distress, hypoxemia, hypotension, fever, and pulmonary edema, initially without signs of left ventricular failure.
Symptoms usually begin within two to four hours of beginning the transfusion
How to treat Transfusion Related Acute Lung Injury
Steroid therapy for 96 hours
