Blood Component Therapy Flashcards
what are the 4 basic blood types and what are they named for?
A, B, AB & O
Named for the antigens present
coagulation is a _________ process
cell-based
list the factor associated with the intrinsic pathway
8, 9, 11, 12
list the factor associated with the extrinsic pathway
3 & 7
what are the 5 tests for evaluating coagulation?
platelet count ACT PTT PT INR
how is the platelet count defined?
actual number of platelets (thrombocytes) per cubic mL of blood
what is the normal range for platelet count in adults?
150,000-400,000/mm3
what are the platelet counts for thrombocytopenia and thrombocytosis?
thrombocytopenia: 400,000/mm3
what is activated clotting time (ACT)?
measures the amount of time required for whole blood to clot in a test tube
what is ACT used for and what are the normal values?
used to monitor heparin therapy
normal: 70-180sec
cardiopulmonary bypass: >400sec
what is PTT used for?
measures factors 8, 9, 11 & 12 (intrinsic) and adequate levels of common pathway factors (1, 2, 5, 10)
can be used to monitor heparin therapy
what is the normal range for PTT?
25-38 seconds or 30-40 seconds (varies with reagent)
what is PT used for?
measures factor 7 (extrinsic) and factors 10, 5, 2 and 1 (common)
what is the normal range for PT? and what will prolong it?
normal: 10-14 seconds
low levels of 7, 10, 5, prothrombin & fibrinogen will prolong PT
what is the only cause of a prolonged PT with a normal PTT?
factor 7 deficiency
why was INR developed?
to standardize PT values to better monitor oral anticoagulation therapy
therapeutic warfarin dosing occurs when INR = ?
2.0-3.0
what does it mean to type and screen blood and when would it be necessary?
type and screening blood means a pt’s blood has been typed for A, B and Rh antigens and screened for common antibodies.
This is done when you are not planning on giving blood, but there is a potential for blood loss (only good for 72hrs)
what does it mean to type and cross match blood and when would it be necessary?
when a recipient’s blood is incubated with donor blood product to test for a rxn.
this is a more specific test required when you are planning on giving blood
what kind of compatibility testing can be done on blood products in the case of an emergency?
have at least type specific blood product with partial cross match.
where are antibodies and antigens located?
antibodies are in the blood plasma and antigens are on the surface of erythrocytes
what type of PRBCs can be transfused to anyone?
type O (universal donor)
what is the universal donor of platelets, FFP and cryoprecipitate?
type AB because they contain neither anti-A nor anti-B antibodies
what factors are considered in the decision to transfuse?
extensive blood loss
inadequate perfusion
low hemoglobin concentration
poor coagulation
what are the different types blood components that can be given to a patient?
PRBCs Cell Saver Platelets FFP Cryoprecipitate
PRBCs are indicated for treatment of what?
anemia
1 unit of PRBCs contains _______ ml volume with a HCT of ______
250-300mL
70-80%
at what Hgb concentration is a PRBC transfusion indicated?
<7 g/dL
at what volume is a rapid volume replacement with RBC indicated?
> 40 percent loss ( >2000 mL)
on average one unit of PRBCs will increase Hemoglobin by ___ g/dL and Hematocrit by ____%
1 g/dL
3 %
how are PRBCs administered?
warmed
with NS (decreases viscosity)
use a filter (at least 150 microns)
what are washed RBCs?
centrifuged in saline to remove plasma and cytokines
when are washed RBCs indicated?
to remove excess Potassium (from lysed cells) from older units
for patients with Hx of transfusion reaction
how long can RBCs be stored once washed?
no longer than 24 hrs
what are leukocyte-reduced PRBCs?
centrifuged, washed or filtered* (*most effective)
when are leukocyte-reduced PRBCs indicated?
to avoid non-hemolytic febrile reactions
to prevent sensitization of pts with aplastic anemia
to minimize transmission of HIV or CMV
what are irradiated PRBCs?
cells are exposed to standard dose of ionizing radiation
when are irradiated PRBCs indicated?
for people who are not capable of mounting a counter-attack and neutralizing transfused lymphocytes
what is a cell saver?
machine that salvages blood from the surgical field to be delivered back to the patient at a HCT of 65-70%
what considerations must be accounted for when administering cell saver blood?
do not warm
use 40 micron filter (more “debris”)
do not pressurize
do not clamp line
when is a platelet transfusion indicated?
platelet count < 50,000 cells/mm3
platelets are routinely given following what procedure to restore normal coagulation?
cardiopulmonary bypass
what two ways can platelets be prepared?
- centrifuging individual units from multiple whole blood donors (5-10 units per bag)
- single donor apheresis
a pool of 6-8 units of whole blood platelets or 1 unit of apheresis will raise the patients platelet count by______?
30-50 x 10^9 /L
how are platelets given?
do NOT warm or cool (would denature)
use a 150 micron filter (not micro aggregate filters)
what is fresh frozen plasma (FFP)?
the fluid portion obtained from a single unit of whole blood that is frozen within 6 hours of collection (contains coagulation factors)
when should FFP be transfused?
indicated when PT, PTT or both are at least 1.5x normal
in emergent situations, FFP may be used to reverse the effects of warfarin prior to surgery
10-15 mL/kg of FFP will raise most coagulation proteins by _____%
25-30%
T or F: FFP should not be used as a primary therapy for specific coagulation defect when specific coagulation factor concentrates are available
TRUE
what is cryoprecipitate?
the fraction of plasma that precipitates when FFP is thawed
when is cryo indicated?
Hypofibrinogenemia due to massive hemorrhage or disseminated intravascular coagulopathy (DIC)
Prophylactically for pts with congenital fibrinogen deficiencies or acquired Factor XIII deficiency.
No longer indicated for Hemophilia A and von Willebrand’s disease (purified Factor VIII concentrates are now used)
what are the 3 main types of transfusion reactions?
- febrile
- allergic
- hemolytic
what causes febrile transfusion reactions?
0.5-1% of transfusions
due to immune reaction between donor antigens on the leukocytes or platelets with recipient antibodies
what are the clinical manifestations of mild allergic reactions and how are they treated?
increased body temp and pruritus
treated with IV antihistamines
discontinuation of transfusion if severe
medical emergency that results from the administration of the ABO incompatible blood is known as a ______
hemolytic reaction
what causes a hemolytic reaction?
rapid destruction of donor erythrocytes by recipient antibodies
what are the clinical manifestations of hemolytic reactions?
hypotension, fever, chills, dyspnea, flushing, lumbar pain
how are hemolytic reactions treated?
discontinuing transfusion and monitoring airway, pressures, HR and urine output
give volume
type and cross from secondary site
what are the clinical manifestations of anaphylactic reactions?
rapid onset shock hypotension angioedema respiratory distress
how are anaphylactic reactions treated?
stop transfusion give eli maintain airway volume vasopressors
which is the most commonly transmitted disease from blood transfusions?
cytomegalovirus (CMV)
What is TRALI?
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.
hydrogen and potassium are increased or decreased in stored blood?
increased
what relationship does 2,3-diphosophoglycerate have with blood?
effects O2 binding to Hgb, decreased in stored blood
the longer blood is in storage the more (acidotic/alkylotic) it becomes
acidotic
