Blood Conservation- Exam 1 Flashcards
Blood Transfusion Complications (General)
Post-op infections Ventilator- acquired pneumonia Central line sepsis Increased LOS Increased mortality rates
2 Types of Transfusion Risks
Infectious
Non-infectious
Types of Infectious Transfusion Risks
Bacterial
HIV
Hepatitis
Types of Non-Infectious Transfusion Risks
Febrile Rxns Urticarial (Allergic) Rxns Anaphylactic Rxns Acute Hemolytic Rxns Volume Overload Hypothermia Citrate Toxicity Potassium Effects
Febrile Reactions
Fever, chills
Antibodies reacting w. white cell antigens or white cell fragments in transfused blood products or due to cytokines which accumulate during storage
Most common with platelet transfusions
What non-infectious reaction is most common with platelet transfusions?
Febrile Reactions
Urticarial (Allergic) Reactions
1%
urticaria, itching, flushing
caused by foreign proteins
Anaphylactic Reactions
Hypotension, tachycardia, cardiac arrythmia, shock, cardiac arrest
caused by patients who have IgA deficiency who have anti-IgA antibodies (require specially washed/tested blood products)
Acute Hemolytic Reactions
Caused by transfusions of ABO incompatible blood
Chills, fever, pain, hypotension, dark urine (plasma free hgb) uncontrolled bleeding due to DIC
Volume Overload
Not on bypass; big concern in ICU; no where for volume to go
On bypass- can tx a lot of rxns and can prevent volume overload
Citrate Toxicity
Metabolized by liver
Rapid transfusion of large quantiity of blood products
Binds calcium and magnesium- depleting stores
Myocardial depression
Coagulopathy
Potassium Effects
Stored RBC leak K+
Irradiation increased the rate of leak
Cardiac effects (must give slowly or they could go into cardiac arrest)
TRALI
transfusion related acute lung injury
TRALI Symptoms
Similar to ARDS
Hypotension, fever, dyspnea, tachycardia
What is TRALI?
Non-cardiogenic pulmonary edema with diffuse bilateral pulmonary infiltrates on CXR
How fast can TRALI occur?
Occurs within 6 hours of tx
Most cases present within 1-2 hours
What are the culprits for causing TRALI?
All blood products
How common is TRALI?
1/2000 transfusions
TRALI Pathophysiology
Unclear.
Attributed to HLA Antibodies, Granulocyte antibodies and biologically active mediators in the blood
What is the Tx for TRALI?
Ventilator support for ~96 hours
What ii TRALI mortality?
5-10%
Clinically, transfusions are associated with….
Longer hospital stays
Longer time to extubation
Mobidity
Mortality
What are some techniques to minimize our impact on blood usage?
Autologous transfusion Pre-bypass autologous donation Intraoperative cell saver use Shed mediastinal blood recovery Accept lower HCT RAP Hemoconcentration Plasma/Platelet Pheresis Mini-circuits
Bloodless Medicine
Transfusion-free medicine
Multimodality and Multidisciplinary approach to patient care without the use of allogenic blood.
Blood Conservation
Global concept aimed at reducing patient exposure to allogenic blood products. Does not exclude use.
Jehovah’s Witness booklet related to bloodless medicine
Blood, Medicine, and the law of God (1961)
- Transfusion rxns
- Transfusion related syphilis, malaria, hepatitis
Which doctor took JW tranfusion requests to heart?
Denton Cooley (1960’s)
What is Cooley’s 1964 publication
Open Heart Surgery in the JW; described techniques for treating these patients
1977- reported experience with 500 JW patients
How did the military contribute to blood management?
Did surgery on wounded soldiers before transfusions were even available
confronted with blood loss but not way to replace the blood; stopped bleeding promptly and effectively
WWI and Blood Management
Blood Anticoagulation
Allowed for transport of blood to the wounded
Problem: Storage!
WWII and Blood Management
Storage problem overcome with the advent of blood banks
What blood management development occurred in 1953?
Use of blood alternatives
Switched from plasma to Dextran (volume expander) deue to incidence of hepatitis transmittal
Dextran
Sugar substrate, used outside US instead of plasma in 1953
What blood management develoment occured in 1985?
Started looking into blood subsitutes; military role
Searched for oxygen carrier
Who introduced the first cell saver in a military hospital?
Surgeon Gerald Klebanoff (Vietnam Vet)
What is significant about Recombinant Factor VIIa?
Hemopheliacs
Israeli army discovered potential to stop life threatening hemorrhage (used aprotinin before)
How many organized bloodless programs are in the US?
More than 100
What is the major variable related to percent transfusions?
Institution physicians (not patients!)
What should be obtained in a focused patient Hx pre-op?
Age
Gender
Weight/Height
Race/ethnicity/background/religion
Why is age important in a focused hx?
Tolerance of anemia is age dependent
As age increased, risk of transfusion increases
Why is gender important in focused hx?
Women more likely than men to get transfused
lower hct; prone to blood loss with menses
What size patients are at risk for transfusion?
Small patients
Obese patients
What patient-related obstacles should be asked about in pre-op?
Anemia Hemostatic disturbances Medical conditions increasing perioperative blood loss Obstacles to surgical hemostasis Factors decreasing anemia tolerance
What lab work should be done pre-op?
Hgb
PT/INR/PTT
Platelet count and platelet function tests
Drugs that have increased bleeding risk
NSAIDs, PCN, NTG, HIgh doses of Vitamin C, St. John’s Wort, Ginger, Garlic, etc.
What temperatures optimize clotting?
Warm
How long before surgery would autologous donation have to be done?
At least 2 weeks prior
Auto-Donation requires what HCT?
33%
Contraindications for Autologous Donation
Recent MI CHF Aortic Stenosis Transient Ischemic Attacks HTN Unstable Angina Bacteremia
What allows the donation of platelets and plasma?
Plateletpheresis and Plasmapheresis
Prebypass Autologous Normovolemic Hemodilution
Used to remove blood from the patient pre-bypass for transfusion later in the case (spares platelets)
Removed volume replaced with crystalloid
Prebypass Autologous Normovolemic Hemodilution HCT requirement
AT least 35%
How much fluid is removed in prebypass autologous normovolemic hemodilution?
500-1000mL (1-3 units)
-Depends on starting HCT, age, BSA, existing conditions
When is blood reinfused during PANH?
After protamine is administered
Contraindications for PANH?
COPD CHF CAD Unstable Angina Renal insufficiency Severe aortic stenosis Coagulopathy
How much prime do you remove in RAP?
200-600mL of prime
Dry Venous Line Technique
Venous line emptied prior to connection to venous cannula
Requires VAVD
Volume removed to a big and discarded or sequestered
How much fluid does the dry venous line technique remove?
400-1000 mL
Mini-Circuit Advantages
Decreased foreign surface area (less inflammatory)
Decreases prime volume (less hemodilution)
Decreases blood-air contact
What does a mini circuit lack?
Venous reservoir
Cardiotomy
Often no heat exchange or art line filter
What is mini circuit prime volume?
500 mL; can be decreased with RAP- ing
What procedures use mini circuits usually?
Mostly CABGs
Some valves have been done
2 types of Mini-circuits
Totally Integrated Devices
Combination of Components
Totally Integrated Devices (Mini circuit)
Include air handling and eliminiation systems, centrifugal pump and membrane oxygantor
ex. CorX (Cardiovention) and Cobe Synergy
Combination of Components
MECC System (jostra)
MCPB
Deltra Stream ERP(medos)
Resting Heart System (Medtronic)
What variables affect the outcomes in mini circuits?
Steroids Aprotinin Degree of heparinization Type of tubing coating Patient population
ERC
Electric Remove Clamp
APC
Air Purge Control
Ultrafiltration/Hemoconcentration
Filtration of water across a semipermeable membrane via hydrostatic pressure gradient
Water crosses membrane which creates a solute concentration gradient
Solute from blood (high concentration) to water (low concentration)
What must you add if you’re Z-BUFing?
Add sodium bicarb to the normal saline you’re Z BUFing with to avoid acidosis
MUF
Modified Ultrafiltration
Withdrawing blood from the patient via the arterial line (post bypass); run blood through hemoconcentrator, pump blood back to patient via venous line
What does a cell saver remove?
Fat, air, tissue debris, potassium, hormones, bioactivators, etc.
Cell Saver Limitations
Delay in processing Loss of plasma proteins Loss of coag factors and plts Expense Operator attention and time
Cardiopat
Shed blood collected and processed
Uses dynamic disk to process- processes variable volume of blood
Consistently delivers washed RBCs w/ hct of 70-80%
Processes up to 2 L/hr or as little as 5mL of RBCs
What HCT can you tolerate if you are healthy and have good LV function?
20-25%
