Topic 7 - Blood conversion Flashcards
Average units of blood used during heart surgery?
6 units of blood
6 units of platelets
Average units of blood used during organ transplant?
40 units of blood
30 units of platelets
20bags of Cryo
25 units FFP
% of open heart patients require transfusions
30-70%
Leads to 2-4 donor exposures
% of RBC units transfused in US occur during
CABG procedures
10%
Blood transfusions can lead to complications?
Lead to complications–post op infections, ventilator-acquired pneumonia, central line sepsis, Increased LOS, mortality rates
Blood transfusions Infectious risks (3)
Bacterial
Hepatitis
HIV
Blood transfusions non-Infectious risks (8)
- febrile reactions
- uticarial (allergic) reactions
- anaphylactic reactions
- acute hemolytic reactions
- volume overload
- hypothermia
- citrate toxicity
- potassium effects
Febrile reactions
-non infectious
-Pt antibodies are reacting with white cell antigens or white cell fragments in the transfused blood products.
OR-due to cytokines which accumulate during storage.
-Most common with platelet transfusions
uticarial (allergic) reactions
- non infectious
- 1%
- Urticaria, itching , flushing
- Caused by foreign proteins
Anaphylactic Reactions
- non infectious
- -Hypotension, tachycardia, cardiac arrhythmia, shock, cardiac arrest
- -caused by patients who have IgA deficiency who have anti-IgA antibodies.
- -Require special washed/ tested blood products
Acute Hemolytic Reactions
Symptoms?
-Non infectious
-Caused by transfusion of ABO incompatible blood
-Chills, fever, pain, hypotension, dark urine,
uncontrolled bleeding due to DIC
Hypothermia
-non infectious risks
Caused by transfusion of too many cold blood products
Citrate Toxicity
- non infectious risks
- Metabolized by liver
- Rapid transfusion of large quantity of blood products
- Binds calcium and magnesium–depleting stores
- Myocardial depression
- Coagulopathy
Potassium effects from bagged RBCs
-non infectious risks
-Stored RBC leak K+
-Irradiation increased the rate of leak ( irradiation is
the process or fact of irradiating or being irradiated)
-Cardiac effects
TRALI (transfusion related acute lung injury)
– symptoms
- Similar to ARDS
- Hypotension, Fever, Dyspnea, Tachycardia
TRALI occurs within what time frame and how often?
-Occurs within 6 hours of tx
Most cases present w/in 1-2 hours
-Occurs 1/2000 transfusions
TRALI (transfusion related acute lung injury)
Non-Cardiogenic pulmonary edema with diffuse bilateral pulmonary infiltrates on CXR
TRALI attributed to?
Pathophysiology: Unclear.
Attributed to HLA Antibodies, Granulocyte
antibodies and biologically active mediators in the blood
TRALI treatment?
Treatment: Ventilator support for ~96 hours
Mortality: 5-10%
MULTIMODALITY and MULTIDISCIPLINARY
approach to patient care without the use of allogenic blood
Bloodless medicine
Transfusion Free
Blood conservation
Global concept aimed at reducing patient exposure to allogenic blood products. Does not exclude use
Surgeon Gerald Klebanoff (Vietnam Vet) introduced
the first cell saver in a military hospital
Recombinant Factor VIIa
For Hemopheliacs
Israeli army discovered potential to stop life
threatening hemorrhage
tolerance of anemia is ___ dependent
Age dependent
Elderly don’t tolerate
As age increases, risk of transfusion increases
Gender and transfusion
women are more likely than men to get
transfused
Lower hct and prone to blood loss with menses
Weight and Height affect on tranfusion?
Small patients and obese patients are at risk for transfusion
Pre-Op lab work
Hgb
PT/INR / PTT
Platelet Count and Platelet Function Tests
Treat Polycythemia pre-op
Risk of hemorrhage during surgery (hyperviscosity)
Plebotomy
Pre-op pharmacological coagulopathies to avoid ? (7 ish)
Drugs (not anticoagulants) than have increased
bleeding risk
NSAIDs, PCN, NTG, High dose Vitamin C, St. John’s Wort, Ginger, Garlic, etc.
Fluid administration
Restrict until surgical hemostasis is achieved
Intravascular pressure is not too high
Autologous Donation
Donation where the donor and recipient are
identical
-Patient donates blood to be used on themselves during surgery.
-Avoids use/ risks of donor blood
-May not be practical or cost effective for most cardiac surgeries
pre-op autologous donation avoided
unless at least …
2 weeks/unit of blood removed to regenerate lost RBC
Autodonation requires a hematocrit of what?
Requires a hematocrit of 33%
Autodonation contraindications (7)
Recent MI CHF Aortic Stenosis Transient Ischemic Attacks Hypertension Unstable Angina Bacteremia
Plateletpheresis and Plasmapheresis in Autodonation
Allows the donation of platelets and plasma
Prebypass autologous normovolemic hemodilution
- hct%
requires a hct of 35%
Prebypass autologous normovolemic hemodilution
– removes how many mls? depending on what?
about 500-1000mL (1-3 units)
Depends on starting hct
Depends on age of patient
Depends on BSA
Depends on coexisting conditions
Prebypass autologous normovolemic hemodilution
- Used to remove blood from the patient pre-bypass for transfusion later in the case
- Removed volume is replaced with crystalloid
Prebypass autologous normovolemic hemodilution
– Contraindications (7)
COPD CHF CAD Unstable Angina Renal Insufficiency Severe Aortic Stenosis Coagulopathy
Prebypass autologous normovolemic hemodilution
– reinfused when?
Reinfused after protamine is administered
retrograde autologous priming
Performed prior to bypass
Arterial and venous cannula are in place
Use the patient’s blood pressure to displace
prime.
retrograde autologous priming
– Remove prime via: (3)
- Stopcock on ALF
- Arterial sampling manifold
- Y’s in circuit
Dry venous line technique
- - how? - - how much volume?
Venous line is emptied prior to connection to
the venous cannula
Volume is removed to a bag and discarded or
sequestered
Eliminates about 400-1000mL
Dry venous line technique
— Only works if
Only works if patient has adequate volume pre-op
Mini Circuits do? (3)
Decreases foreign surface area
Decreases prime volume
Decreases blood-air contact
Mini Circuit attempt to ? (3)
Decrease hemodilution
Decrees inflammatory response
Decrease volume shifts
Mini Circuits is a ?
Closed A-V Loop with centrifugal pump, membrane oxygenator, coated tubing
- No venous reservoir
- No cardiotomy
- Often no heat exchanger or arterial line filter
Centrifugal pump provides kinetic assisted venous drainage and blood flow
Mini Circuits prime volume ?
Prime volume is about 500mL
◦Can be decreased with RAPing
Mini Circuits used mostly for what procedures?
CABG
Mini Circuits
– 2 Types
Totally Integrated Devices
Combination of components
Mini Circuit: Totally Integrated Devices
Include air handling and elimination systems,
centrifugal pump and membrane oxygenator.
CorX (Cardiovention)
Cobe Synergy
Mini circuit: Combination of components
MECC System (Jostra)
MCPB
DeltaStream ERP (Medos)
Resting Heart System (Medtronic)
Mini circuit
Benefits: (5)
Less inflammatory reaction
Less activation of coagulation and fibrinolysis
Less hemodilution
Less use of autologous blood
Marginally improved renal and neurological function
Mini Circuit
variables impacting outcomes: (5)
steroids Aprotinin degree of heparinization type of tubing coating patient population
