Chp. 5 Blood and Blood Products Flashcards
What is blood component therapy?
-Involves administration of specific blood product according to need of the clinical condition of the patient
What are available blood products that can be used in SA before, during, and after GA?
- pRBCs
- Fresh frozen plasma
- Cryoprecipitate
- Cryoprecipitate-poor plasma
- PRP
How can practitioners acquire these products if they do not have the capability to process whole blood?
-blood banks
What are common indications for blood component therapy during perioperative period?
-Severe hemorrhage during surgery
-Acute/chronic anemia DT variety of causes -> trauma, neoplasia, chronic inflammation
-Hypoproteineima
-von Willebrand’s Disease
-Coagulopathies (DIC, liver dz)
-Thrombocytopenia
Components of: whole blood
RBCs
Clotting factors
Proteins
vWF
Platelets
Components of: pRBCs
red blood cells only
Components of: fresh frozen plasma
all clotting factors including albumin, vitamin-K dependent proteins
Components of: stored frozen plasma
similar to FFP with reduced concentration of cofactors V and VIII (check this*)
Components of: cryoprecipitate
high concentration of factor VIII, fibrinogen, vWF, fibronectin
Components of: cryoprecipitate-poor plasma
Similar to FFP or SFP with decreased VIII, fibrinogen, vWF, and fibronectin (check this*)
Indications for whole blood
-Massive blood loss (>20% blood volume) before/during GA
-Coagulopathy resulting in massive blood loss
-Some patients with DIC
Indications for pRBCs
-Less severe blood loss during surgery, normovolemic anemia
Indications for FFP
-von Willebrand’s disease
-Hemophila A, B
-Liver disease
-Coagulopathy
-DIC
-Rodenticide intoxication
-Hypoproteinemia
Indications for SFP
-Similar indications as for FFP except in patients with hemophilia A or wVF deficiency
Indications for cryoprecipitate
-DIC
-vWF deficiency
-Hemophilia A
-Generalized sepsis - fibronectin enhances mononuclear
Indications for cryoprecipitate
-DIC
-vWF deficiency
-Hemophilia A
-Generalized sepsis - fibronectin enhances mononuclear phagocytic activity
Indications for cryoprecipitate-free plasma
Similar to FFP or SFP except in conditions that require factor VIII, vWF, and fibronectin
What is the best approach to correcting hypoalbuminemia if you don’t have canine albumin?
-FFP ideally not used as only source of album
-To increase [alb] by 1g/dL, plasma should be given at 45mL/kg -> expensive
-Without concurrent administration of other colloids, albumin from transfused plasma equilibrates rapidly with extravascular space -> consider adding synthetic colloids
Do blood and blood products require special administration sets?
Should be administered through 170um filter bc have micro agglutinates
What are the advantages of blood component therapy in the field of anesthesia?
- Main advantage = minimal volume needed for administration, preventing circulatory overload
In anemic patients with normal blood volume…
- Administration of pRBCs preferable to whole blood
- Colloid component of whole blood can result in vol overload when attempting to increase oxygen-carrying capacity of the patient
What are other advantages to using specific blood components?
- Fewer complications assoc with transfusion bc unnecessary components not administered
- Longer storage time for some components includ. plasma, plasma derivatives
- Better use of blood resources
- Better therapeutic approach to patient’s problem
Which crystalloid solution can be mixed with blood during administration?
- Normal saline (0.9%) can be mixed with blood
- Crystalloid solution that contain calcium will active coagulation system
- Some preparations either hypotonic or hypertonic –> hemolysis
Is there any specific temperature requirement for blood products before administration to patient?
- Blood and blood products, except PRP, should be warmed before transfusion
- Temp should not be warmed to more than 37*C
What is the problem with blood products heated and administered at temps higher than 37*C?
- Higher temperatures will result in hemolysis and precipitation of numerous proteins
At what temperature can PRP be administered?
22*C
Equation for calculating dose of blood and blood products
mL of blood required = Blood volume x (desired PCV - recipient PCV)/Donor PCV
How should blood products be administered?
- Volume administered slowly for first 5-15’ at rate of 5.0mL/kg/hr
- Animal closely observed for adverse reactions
- Rate increased to 10mL/kg/hr if no complications observed
- If patient hypovolemic, rate of infusion increased to 66mL/kg/hr
Dose: FFP
- 10mL/kg
- Repeated until bleeding controlled
Dose: Frozen Plasma
- 10mL/kg
- Repeated until bleeding controlled
Dose: cryoprecipitate-poor plasma
- 10mL/kg
- Repeated until bleeding controlled
Dose: Cryoprecipitate
to effect at 1U/10kg
repeated after 12hrs, if bleeding continues
Dose: PRP
1U/10kg
Recommended rate of infusion of plasma products in normovolemic patient
22mL/kg for 24hr
Recommended rate of infusion of plasma products in hypovolemic patient
- rate of infusion should not be more than 22mL/kg/hr
- Rate further reduced to 4.0mL/kg/hr in patients with compromised cardiac function
How would you detect acute transfusion reaction during anesthesia?
- Hypotension = most common sign associated with transfusion reaction in an anesthetized patient
- Both acute hemolytic reactions and acute hypersensitivity reactions will be manifested as hypotension
- Tachycardia can be manifested if acute hemolysis results in shock
What are the early signs of a hemolytic transfusion reaction?
- pyrexia
- Tremors
- Vomiting
- Dyspnea
- Salivation
What is important to remember about anesthesia and the early signs of a hemolytic transfusion reaction?
- Anesthesia will mask the early signs of a transfusion reaction
T/F: presence of hypotension and tachycardia due to ongoing blood loss will complicate detection of an acute hemolytic reaction
True
Important to remember that acute hemolytic reaction can occur within minutes of the start
If hypotension persists despite blood transfusion and other therapeutic modalities (positive inotrope and lowered ax concentration), it is prudent to stop transfusion and check blood for hemolysis
Signs of an acute hypersensitivity reaction to transfusion
- Vasoactive substances (histamine, serotonin, kallikreins, proteases) are released
- No hemolysis
- Onset of a reaction usually 1-45min from start of infusion
- In dogs, urticaria also seen with acute hypersensitivity reaction –> can also result in severe shock
What steps should be taken to minimize reaction to blood and blood products?
- Cross-matching in dogs
- Cross-matching or blood-typing in cats prior to transfusion
Minor Cross-Match
- Will detect AB in donor plasma against cells of the recipient
- Considered if will be receiving plasma product repeatedly
Incompatibilities
- Occur as a result of earlier sensitization of the recipient or presence of naturally occurring isoantibodies in either the donor or recipient
- Impt to remember compatible cross-match does not stop patient from being sensitized against donor cells
When do you expect to see incompatibility reactions?
- Incompatibility reactions can occur as early as 4d following transfusion
- Previously transfused patients should always be cross-matched, even if blood from same donor is used
T/F: dog that has never received donor blood can safely be given a transfusion without cross-match
True check which type of blood
Blood transfusions and cats
- Blood typing or cross-matching should be done before transfusion
- Have naturally-occurring alloantibodies
- Untyped or uncross-matched blood given to a cat that has never received a transfusion can be fatal
When are blood/blood products needed when hemorrhage occurs during ax? Which blood products an be administered in this situation?
- Whole blood generally required when massive blood loss occurs during ax
- Whole blood also indicated if blood loss and patient is hypoproteinemic
-If blood loss <20% blood volume and PCV of patient approaching 20%, can administer pRBCs
-Vol of blood products administered should equal blood loss, must be administered at a rate that should replace loss as rapidly as possible
What is considered “massive” blood loss?
- If more than 20% of blood volume is lost
What can you do if you need whole blood but it’s not available?
Combine FFP and pRBCs
A dog is under GA and severe bleeding occurs unexpectedly. No cross-match was made before GA, and hub-based oxygen carrying solution is not available. How do you approach this situation?
- No prior transfusion: whole blood or pRBCs from any donor can be used
- Prior transfusion: synthetic colloid may have to be used until cross-match performed
A cat is under GA and severe bleeding occurs unexpectedly. No cross-match was made before GA, and hub-based oxygen carrying solution is not available. How do you approach this situation?
- Breed may play role in decision making –> if cat belongs to breed with type B frequency of 0%, blood from type A donor can be used without cross-match
- If breed has known type B blood, has to be typed before administration
The patient has low oxygen carrying capacity, and no blood or blood products are available. What is an alternative therapy?
-Hbg-based oxygen-carrying solutions
What is Oxyglobin?
- ultra purified, polymerized hemoglobin solution (13.0mg/dL) of bovine origin in modified Ringer’s lactated solution
What are main physical features of Oxyglobin?
pH 7.8
Osmolality of 300 most/kg
Less viscous than blood
What are Oxyglobin’s main indications during the perioperative period?
- Mainly indicated in relieving signs associated with anemia
- Used to improve/maintain perfusion
- Can be used in patients that develop severe hemorrhage during ax or any shock that in which volume loading is necessary
Are there any reported complications associated with Oxyglobin?
- Reported to increase pulmonary resistance
- Patients with PTE or pulmonary contusion developed pulmonary edema and died
- Best to avoid in patients with pulmonary disease
- check current guidelines/recommendations
- Other complications: volume overload, interference with some blood tests
How is Oxyglobin administered to dogs and cats?
- Standard IV set
- Very small patients: infusion pump will aid in accurate dosing
Oxyglobin dose in cats
10mL/kg at an infusion rate not to exceed 5.0mL/kg/hr
Oxyglobin dose in dogs
15.0-30.0 mL/kg with rate of administration limited to 10.0mL/kg/hr
–In cases of hemorrhagic shock and hypovolemic shock, bolus administration can be used
What should you see with administration of whole blood and pRBCs?
- Will see increased HCT and plasma HGB
What should you see with administration of Oxyglobin?
- Plasma hgb should be checked bc HCT will stay low
What should you see with administration of plasma to increase colloid oncotic pressure?
Increased plasma protein levels
Improvements DT synthetic colloid cannot be measured by refractometer –> will need oncometer to determine colloid oncotic pressure
What should you see with administration of cryoprecipitate?
Normalize buccal mucosa bleeding time (2-4min, <5min)
Practical approach to treating von Willebrand’s disease
What is the most important endpoint of therapy when treating coagulopathies?
When active bleeding ceases
Coagulation tests using PT, aPTT can assist in determining success of surgery
In the case of hemorrhage, hypovolemia, and shock during anesthesia, effective transfusion therapy should result in…
- Normal HR
- Improved systemic BP
- Normal CVP
- increased urine output
- Pink mucous membranes
RR may not change bc of the blunting effects of anesthetics
If capnography is being used for monitoring, increased ETCO2 without any change in ventilatory status indicates an improving perfusion rate
How do you time the administration of blood products?
- Determined by severity of the problem and need to perform surgery immediately in life-threatening conditions
- If there is bleeding associated with coagulopathies, admin of plasma components before ax should be timed such that patient received initial dose before surgery
How to time blood products for von Willebrand’s Disease?
- Cryoprecipitate started 1-2hr prior to surgery, usually continues through surgery until required dose is given
- More units of cryoprecipitate will be needed if there is bleeding through surgery
How to time blood products for anemic patients?
- If PCV <20%, whole blood or pRBCs can be administered until the desired PCV is reached (~25%)
In invasive procedures during which blood loss is expected…
Infusion of pRBCs continues through surgery at a rate of 5.0mL/kg/hr
In hypoproteinemic patients…
- plasma administered before anesthesia until plasma protein concentration greater than or equal to 4.0 g/dL is reached
What are signs of volume overload during anesthesia?
- Serous nasal discharge
- Chemosis
- Pulmonary crackles, edema
- With severe PE, frothy fluid may be found in the ETT and breathing circuit
- Sudden elevation in CVP
- In conscious patients, tachypnea, dyspnea, tachycardia –> anesthetics tend to blunt these responses
