topic 8 Flashcards
1
Q
Avg #of units required:
Car Accident
A
50 units of blood
2
Q
Avg #of units required:
Heart Surgery
A
6 units of blood
6 units of platelets
3
Q
Avg #of units required:
Organ Transplant
A
40 units of blood
30 units of platelets
20 bags of Cryo
25 units FFP
4
Q
Avg #of units required:
Bone Marrow Transplant
A
120 units of platelets
20 units of blood
5
Q
Avg #of units required:
Burn
A
20 units of platelets
6
Q
% of open heart patients that require transfusions
A
30-70%
Leads to 2-4 donor exposures
7
Q
Percentage of all RBC units transfused in US occur during CABG procedures.
A
10%
8
Q
Blood usage in US is significantly ________ than other Western countries
A
higher
9
Q
Blood is a
A
liquid transplant
10
Q
Blood transfusions cause
A
changes in the immune system
11
Q
new transfusion=
A
new donor
12
Q
Blood transfusions lead to complications such as
A
Post op infections
Ventilator-acquired pneumonia
Central line sepsis
Increased LOS, mortality rates.
13
Q
Transfusion risks- infections
A
Bacterial
Hepatitis
HIV
14
Q
Transfusion risks non-infectious:
Febrile Fever=
A
- Fever, chills
- 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
15
Q
Transfusion risks non-infectious:
Uticarial (Allergic) Reactions=
A
1%
Urticaria, itching , flushing
Caused by foreign proteins
16
Q
Transfusion risks non-infectious:
Anaphylactic Reactions
A
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
17
Q
Transfusion risks non-infectious:
Acute Hemolytic Reactions
A
- Caused by transfusion of ABO incompatible blood
- Chills, fever, pain, hypotension, dark urine, uncontrolled bleeding due to DIC
18
Q
Transfusion risks non-infectious:
Hyopthermia
A
Caused by transfusion of too many cold blood products
19
Q
Transfusion risks non-infectious:
Volume…
A
overload
20
Q
Transfusion risks non-infectious:
Citrate Toxicity
A
- Metabolized by liver
- Rapid transfusion of large quantity of blood products
- Binds calcium and magnesium – depleting stores
- Myocardial depression
- Coagulopathy
21
Q
Transfusion risks non-infectious:
Potassium Effects
A
- Stored RBC leak K+
- Irradiation increased the rate of leak
- Cardiac effects
22
Q
Transfusion Related Acute Lung Injury
◦Symptoms
A
Similar to ARDS
-Hypotension, Fever, Dyspnea, Tachycardia
23
Q
Transfusion Related Acute Lung Injury (TRALI) =
A
Non-Cardiogenic pulmonary edema with diffuse bilateral pulmonary infiltrates on CXR
◦Occurs within 6 hours of tx- Most cases present w/in 1-2 hours
◦All blood products are culprits
◦Occurs 1/2000 transfusions
24
Q
TRALI is attributed to
A
HLA Antibodies
Granulocyte antibodies
Biologically active mediators in the blood.
25
TRALI treatment
Ventilator support for ~96 hours
26
TRALI mortality
5-10%
27
Clinically, transfusions are associated with
Longer hospital stays
Longer time to extubation
Morbidity
Mortality
28
9 techniques to minimize blood usage
1. Autologous transfusion
2. Pre-bypass autologous donation
3. Intraoperative Cell Saver use
4. Shed mediastinal blood recovery
5. Accept lower hematocrit
6. Retrograde Autologous Priming
7. Hemoconcentration
8. Plasma/Platelet Pheresis
9. Mini-circuits
29
Bloodless medicine=
MULTIMODALITY and MULTIDISCIPLINARY approach to patient care without the use of allogenic blood.
-AKA: Transfusion-Free Medicine
30
Blood conservation=
Global concept aimed at reducing patient exposure to allogenic blood products. Does not exclude use
31
Denton Cooley (Early 1960’s)=
Published article in the American Journal of Cardiology (1964) titled Open heart surgery in the Jehovah’s Witness”
- Described his techniques for treating these patients
- 1977 – reported experience with 500 JW patients
32
World War 1=
Blood Anticoagulation
- Allowed for transport of blood to the wounded
- PROBLEM: Storage
33
World War 2=
Storage problem overcome with the advent of blood banks
34
1953=
Use of blood alternatives
- Switched from plasma to Dextran (volume expander)
- Sugar substrate
- Due to incidence of hepatitis transmittal
35
1985=
Started looking into “blood substitutes”
| Searched for oxygen carrier
36
Introduction of cell savers
Surgeon Gerald Klebanoff (Vietnam Vet) introduced the first cell saver in a military hospital
37
Recombinant Factor VIIa
- Hemopheliacs
| - Israeli army discovered potential to stop life threatening hemorrhage
38
Currently, there are more than ___ organized bloodless programs in the US
100
There is a huge demand
-Patients are asking for it
39
Pre-op history: Age
tolerance of anemia is age dependent
Elderly don’t tolerate
As age increases, risk of transfusion increases
40
Pre-op history: Gender
- women are more likely than men to get transfused
| - Lower hct and prone to blood loss with menses
41
Pre-op history: Height/weight
- required to do calculations
| - Small patients and obese patients are at risk for transfusion
42
Pre-op history: race/ethnicity
Anemia and Coagulation disorders are associated with certain races
43
Ask about patient-related obstacles to transfusion-free therapy:
```
◦Anemia
◦Hemostatic disturbances
◦Medical conditions increasing perioperative blood loss
◦Obstacles to surgical hemostasis
◦Factors decreasing anemia tolerance
```
44
Pre-op lab work
Hgb
PT/INR / PTT
Platelet Count and Platelet Function Tests
45
Pre-op treat any:
- coagulopathies
| - anemia: Optimize Hgb prior to surgery
46
Pre-op treat polycythemia
- Risk of hemorrhage during surgery (hyperviscosity)
| - Plebotomy
47
Pre-op avoid pharmacological coagulopathies
Drugs (not anticoagulants) than have increased bleeding risk
| -NSAIDs, PCN, NTG, High dose Vitamin C, St. John’s Wort, Ginger, Garlic, etc.
48
Anesthesiologist is a good resource to help detect any
obstacles in blood management
49
Anesthesia helps to
- correct any coagulopathies/anemia preop.
- Help position the patient to decrease blood loss
- Provide controlled hypotension
50
Keeping the patient
Optimizes clotting
51
Anesthesia Timing of fluid administration
- Restrict until surgical hemostasis is achieved
| - Intravascular pressure is not too high
52
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
53
Auto donation Requires a hematocrit of
33%
54
Auto donation contraindications:
```
Recent MI
CHF
Aortic Stenosis
Transient Ischemic Attacks
Hypertension
Unstable Angina
Bacteremia
```
55
Auto Donation:
| Donation of whole blood can be split
- Allows not only donation of RBC, but also FFP
| - Requires special order from physician
56
Auto Donation:
| Plateletpheresis and Plasmapheresis
Allows the donation of platelets and plasma
57
Prebypass autologous normovolemic hemodiultion=
- Used to remove blood from the patient pre-bypass for transfusion later in the case.
- Removed volume is replaced with crystalloid
58
Prebypass autologous normovolemic hemodiultion Spares platelets from bypass and requires a hct of
35%
59
Prebypass autologous normovolemic hemodiultion: remove about
```
500-1000mL (1-3 units)
◦Depends on starting hct
◦Depends on age of patient
◦Depends on BSA
◦Depends on coexisting conditions
```
60
Prebypass autologous normovolemic hemodiultion: Blood is placed in a bag with
anticoagulant
| ◦Usually CPD
61
Prebypass autologous normovolemic hemodiultion: Reinfused after
protamine is administered
62
Prebypass autologous normovolemic hemodiultion: contraindications
```
◦COPD
◦CHF
◦CAD
◦Unstable Angina
◦Renal Insufficiency
◦Severe Aortic Stenosis
◦Coagulopathy
```
63
Dry Venous Line=
- Requires the use of VAVD
- 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
64
Dry Venous Line cautions=
- Only works if patient has adequate volume pre-op
| - If patient is dry, will need the volume anyways
65
Mini Circuit=
AKA: Miniaturized Extracorporeal Circuits
Decreases foreign surface area
Decreases prime volume
Decreases blood-air contact
66
Mini Circuits attempt to:
- Decrease hemodilution
- Decrees inflammatory response
- Decrease volume shifts
67
Mini Circuit setup
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
68
Mini Circuit prime volume
500mL
| ◦Can be decreased with RAPing
69
Mini Circuits are mainly used for
CABGs
| ◦Some valves have been done
70
Mini Circuits- 2 types=
Totally Integrated Devices
| Combination of components
71
Mini Circuit: Totally Integrated Devices
Include air handling and elimination systems, centrifugal pump and membrane oxygenator.
- CorX (Cardiovention)
- Cobe Synergy
72
Mini Circuit: Combination of components
MECC System (Jostra)
MCPB
DeltaStream ERP (Medos)
Resting Heart System (Medtronic)
73
Mini Circuit benefits
- Less inflammatory reaction
- Less activation of coagulation and fibrinolysis
- Less hemodilution
- Less use of autologous blood
- Marginally improved renal and neurological function
74
Mini Circuit: variables impacting outcomes
```
steroids
Aprotinin
degree of heparinization
type of tubing coating
patient population
```
75
Mini Circuit Concerns
- Air handling
- Requires surgeon to take care to avoid air entrapment around the cannula
- More microemboli with MECCs compared to normal circuits
- No reservoir = no way to handle excess volume
- No immediate volume infusion
- No heat exchanger (on most)
- Use of separate cell saver (Delay in processing, loss of factors/platelets)
- Increased cost
- Adaptability when surgical complications/ need requires normal ECC
76
Things you can do instead of using mini circuits
- Cut lines short
- Get as close to the table as possible
- Elevate the reservoir: Use VAVD
- Put modular pump heads near outlet/inlet of oxygenator
- Dry venous line: Requires VAVD
- Go on with low prime volume
77
Ultrafiltration/hemoconcentors=
Filtration of water across a semipermeable membrane via hydrostatic pressure gradient
- Water crosses the membrane which creates a solute concentration gradient
- Solutes have a higher concentration in blood so they move to the water side which has a lower solute concentration
78
Ultrafiltration/hemoconcentors removes
water and electrolytes
79
Ultrafiltration/hemoconcentors: Z-BUFing
you need to make sure to add sodium bicarb to the normal saline you’re Z-BUFing with to avoid acidosis
80
Modified Ultrafiltration (MUF)=
- Withdrawing blood from the patient via the arterial line (post bypass)
- Running the blood through a hemoconcentrator
- Pumping the blood back into the patient via the venous line
81
Modified Ultrafiltration (MUF) is primarily used in
pediatrics
82
Modified Ultrafiltration (MUF): Can use the cardioplegia circuit
Make sure to flush out the cardioplegia solution with blood
◦Already have a roller pump, bubble trap, heat/exchanger, line pressure monitor, already connected to the arterial line.
◦Risk of air entrapment around the arterial cannula: Don’t transfuse up the arterial cannula once started MUF
◦Pump flow rate less than MUF flow rate.
83
Cell saving=
- Use heparinized saline or CPD as an anticoagulant
- Cells are separated from the fluid by a centrifuge
- RBC fall to the bottom, Plasma on top
- RBC washed with 3x bowl volume (min)
- Put in a reinfusion bag for administration
84
Cell saving removes
```
Fat
air
tissue debris
potassium
hormones
bioactivators
```
85
Cell saving limitations
```
◦Delay in processing
◦Loss of plasma proteins
◦Loss of coagulation factors and platelets
◦Expense
◦Operator attention and time
```
86
Reinfusion of shed blood
- Blood collected from the mediastinum and pleural cavities post op can be reinfused
- Doesn’t clot due to defibrination
- Increased level of free Hgb
- Contains activated products
87
Cardiopat=
- Shed blood can be collected and processed
- Uses a dynamic disk to process.
- Processes a variable volume of blood
- Consistently delivers washed RBCs w/ hct of 70-80%
- Processes up to 2 liters per hour or as little as 5 mL of RBCs
