Hemostasis, Surgical Bleeding, and Transfusions Flashcards
Describe Hemostasis after an injury?
5
- Vasoconstriction for about 60 seconds
- Next is platelets adhere to site of vascular injury
- After adhesion, platelets release adenosine diphosphate (ADP) causing platelet aggregation
- Formation of initial white thrombus
- Formation of permanent thrombus with fibrin
Coagulation pathway
1. Use of various coagulation factors to generate what?
- Extrinsic coagulation pathway
- Begins with what?
- Interacts with factors what? - Intrinsic coagulation pathway
- Requires which factors? - Common coagulation pathway
- Which factors? - Bleeding may occur with deficiency of any factors except factor what?
- fibrin
- thromboplastin
- VII to convert factor X to Xa
- Requires factors XII, XI, IX, and VIII to convert factor X to Xa
4.Involves factor X, V, II (prothrombin), and I (fibrinogen) Factor XIII (fibrin-stabilizing factor)
- XII
Evaluation of the patient
History
Most important step
Ask about medications specifically? 4
PE look for signs of what?
- OTC
- ASA
- Clopidogrel (Plavix)
- Warfarin (Coumadin)
Bleeding disorder
Evaluation of patient for high risk of bleeding
Test
5
- Platelet count
- Prothrombin time (PT)
- Partial thromboplastin time (PTT)
- Bleeding time
- Thrombin time
- Platelet count verifies what?
- If abnormal can order what?
- Normal platelet values?
- Verifies that an adequate number of platelets are available in the circulation
- blood smear to look at platelets under a microscope
- Normal values 150,00 – 400,000
- What does prothrombin time measure?
- Evaluates what factors? 5
- Which pathway? - Most common use for this lab?
- PT is reported as?
- Measures ability of the blood to form stable thrombi
- Evaluates factors VII, X, and V, prothrombin, and fibrinogen, and extrinsic pathway
- Most common use is monitoring Warfarin
- PT is reported with international normalized ratio (INR)
A ratio of a patient’s prothrombin time to a normal (control) sample
Partial Thromboplastin Time
- Evaluates what? 8
- Which pathway? - Most commonly used to monitor what?
- Normal in patients with what disorder?
- Evaluates adequacy of fibrinogen, prothrombin, factors V,VIII, IX, X, XI, XII, and intrinsic/common pathways
- Most commonly used to evaluate unfractionated heparin therapy
- Normal in patients with factor VII deficiency
- Describe the bleeding time procedure? 2
- Normal range?
- Prolonged time may indicate what? 3
- Two incisions with lancet on the forearm
- Time from injury to cessation of bleeding from both wounds is measured
- Normal range is 5-10 minutes
- Prolonged time may indicate;
- Thrombocytopenia
- Medication (ASA)
- Von Willebrand disease
UREMIA
- What does thrombin time evaluate?
2. Prolongations means? 4
- Evaluates fibrinogen-to-fibrin conversion with an external source of thrombin
- Prolongation;
- Low fibrinogen levels
- Abnormal fibrinogen
- Fibrin and fibrinogen split products
- Heparin
DIC and Chronic liver disease too
Surgical bleeding
- Patients can loose large volumes of blood from generalized oozing post-op
- Some operations are associated with large blood loss
Preexisting hemostatic defects
that make patients at risk for bleeding? 3
- Congenital bleeding disorders
- Acquired bleeding disorders
- Medication-Associated Bleeding
Congenital Bleeding Disorders: Von Willebrand Disease 1. Pathophysiology? 2. Site of bleeding 3. Inheritance 4. Lab studies? 3
- Reduced factor VIII activity and von Willebrand activity
- Mucocutaneous
- Autosomal dominant
- Prolonged PTT
- Normal PT
- Abnormal platelet function
Von Willebrand
Tx?
2
- Cryoprecipitate infusions
2. Desmopressin (DDAVP)
Congenital bleeding disorders
Hemophilia A
1. Pathophysiology?
2. Site of bleeding?
- Gender?
- Labs? 3
- Treatment?
- Reduced or absent factor VIII activity
- Joints and intramuscular
- Only males
- Prolonged PTT
- Normal PT
- Normal platelet function
- Purified factor VIII products
Acquired bleeding disorders
More common than congenital bleeding disorders
Causes? 5
- Advanced liver disease
- Anticoagulation therapy
- Acquired thrombocytopenia
- Platelet-inhibiting drugs
- uremia
Acquired bleeding disorder
Liver disease- Common cause
1. PP?
2. Which factors are affected? 4
- What may lead to clotting factor deficiencies? 2
- Respond well to what?
- Inability to synthesize proteins leads to decreased levels of
- prothrombin and factors V, VII, and X
- Obstructive jaundice
- Cirrhosis
- vitamin K
Anticoagulation therapy
Warfarin (Coumadin)
1. Depression of what factors? 4
- Reversed how? 2
Heparin
3. Increased speed of antithrombin III binds to and neutralizes factors what? 5
- Reversed with?
- Depression of clotting factors II, VII, IX, X
- Can be reversed with fresh frozen plasma (FFP) or vitamin K in an emergency
- IXa, Xa, Xia, XIIa, and thrombin
Prolongs PTT and thrombin time - Reversed with protamine sulfate
Acquired thrombocytopenia
3 mechanisms
- Decreased platelet production in bone marrow
- Increased destruction of platelets in peripheral blood
- Splenic pooling in enlarged spleen
Platelet Inhibiting drugs? 3
-When should these be stopped before surgery?
Platelet-inhibiting drugs 1. ASA Should stop 1 week before surgery 2. Clopidogrel (Plavix) Should be stopped 7-10 days before surgery 3. NSAIDs
Uremia
- Causes what?
- Patients who are bleeding and need surgery require what to correct platelet dysfunction?
- Platelet dysfunction
2. dialysis
Medication-Associated bleeding: Causes?3
- Anticoagulants
- Platelet inhibiting drugs
- OTC Meds/Herbal
Which drugs make up the following categories
- Anticoagulants? 2
- Platelet inhibiting drugs? 2
- OTC Meds/Herbal? 6
- Anticoagulants
- Warfarin (Coumadin)
- Heparin - Platelet-Inhibiting drugs
- Clopidogrel (Plavix)
- ASA - OTC medications
- Herbal
- Dong quai (Angelica)
- Garlic
- Ginger
- Gingko biloba
- Ginseng
- St. John’s wort
Intraoperative Bleeding
1. Shock -Can aggravate what?
- Massive transfusion of what?
- Bleeding from where? 3
- Controled with? 4
- consumptive coagulopathy
- packed RBCs
- needle holes,
- vascular suture line, or
- extensive dissection
- Gelfoam
- Surgicel
- Floseal
- Tisseel
Post-Op Bleeding
- 50% is caused by?
- Other causes? 3
- 50% is caused by poor hemostasis during surgery
- Other causes;
- Residual heparin
- Shock
- Altered liver function
Three main categories of post op bleeding?
- Primary bleeding
- Reactive bleeding
- Secondary bleeding
DIC
1. Characterized by what?
- Results in what?
- intravascular coagulation and thrombosis that is diffuse instead of localized at the site of injury
- systemic deposition of platelet-fibrin microthrombi that causes diffuse tissue injury
DIC
Etiology
4
- Release of tissue debris into bloodstream after trauma or an obstetric catastrophe
- Extensive endothelial damage to vascular wall
- Hypotension
- Operations will large blood loss
Operations with large blood loss possibly promoting DIC?
3
- Prostate,
- lung, &
- malignant tumors
DIC
- Diagnosed by?
- Labs? 4
- Diagnosed by diminished levels of coagulation factors and platelets
- Labs
- Prolonged PTT & PT
- Hypofibrinogenemia
- Thrombocytopenia
- Presence of fibrin and fibrinogen products
DIC Treatment
1. Most important management?
- Severe DIC
- What is best method to replace fibrinogen loss? - What may be necessary ?
- ________ helps replace other deficits
- remove the precipitating factors
- Cryoprecipitate
- Platelet transfusion
- FFP
What are the most common cause of fatal transfusion reactions?
ABO incompatibilities
Typing and Cross-Matching
1. Only two groups have immunological relevance. What are they?
- Antigens involved in ABO? 4
- ABO Group
- Rhesus Group
- A only has the A antigen
- B only has the B antigen
- AB has both
- O has neither antigen
Rhesus (Rh antigen)
- Only _____ antigen is tested
- What on RBC makes Rh+?
- What on RBC makes Rh-?
- D
- D antigen
- No D antigen
Transfusion of RBC
5 types?
- Whole blood
- Packed red blood cells
- Washed red blood cells
- Leukoreduced red blood cells
- Divided or pediatric unit RBCs
Used for massive transfusions and life-saving transfusions
Transfusion of RBC
Decision to transfuse is multifactorial and individualized. Factors that go into this? 5
- Reason for the anemia
- Degree and acuity/chronicity of anemia
- Underlying medical condition
- Anticipated future transfusions
- Hemodynamic instability
One unit of packed red cells into an average 70kg person raises the hematocrit by ___% and hemoglobin by ____ g/dL
- 3
2. 1
- FFP is the what?
- Does not contain what? 3
- Indication for use? 2
- platelet-poor plasma removed from whole blood\
- RBC,
- leukocytes, or
- platelets
- Lab evidence of coagulation factor deficiency with clinical bleeding
- Need for invasive procedure
- Platelets are indicated for what?
- Labs? 2
- Transfusion of six platelets raise count by what?
- Indicated for patients with thrombocytopenia due to platelet dysfunction
- Labs
- Bleeding time
- Whole blood platelet function testing - Transfusion of six platelets raise count by 50,000 to 100,000
Blood Transfusions: Side effects include?
5
- Metabolic derangements
- Immunologic reactions
- Infection complications
- Volume overload
- Pulmonary complications
Considerations on mass transfusions
Complications with blood transfusion:
- Metabolic derangements
1. Seen when? 2
- Most common are? 3
- with large volume or
- older blood products
- Hypocalcemia
- Hyper and Hypokalemia
- hypothermia
Complications with blood transfusion:
Metabolic derangements cont.
Hypocalcemia
1. Seen with what?
- Presents with? 3
- Hyper/Hypokalemia
- High levels of potassium are found in units of blood frozen longer than what? - After transfusion infused K+ is taken up by what? Causing what?
- Hypothermia
Multiple transfusions needs to be through a what?
- rapid transfusion
- Muscle tremors
- ST segment prolongation
- Delayed T waves
- 35 days
- After transfusion infused potassium is taken up by the red cell causing hypokalemia
- fluid warmer
Blood Transfusion Complications:
Immunologic reactions?
7
- Febrile reactions
- Acute and delayed hemolytic reactions
- Thrombocytopenia
- Anaphylactic shock
- Urticaria
- Graft versus host disease
- Immune suppression
Immunologic reactions
- Febrile reaction
- Most common as result of what? - Present with? 2
- Pretreat with what? 3
- antileukocyte antibodies
- Fever/Chills
- Tachycardia
- Pretreat with
- ASA,
- antipyretics, and
- antihistamines
Immunologic reactions
Hemolytic reactions
1. Most caused by what?
- Present with what? 5
- Tx?
- ABO-mismatched blood
- Hot or cold flushing
- Chest pain
- Low back pain
- Fever
- hypotension
- Stop transfusion and recheck blood
Immunologic Reactions:
Graft versus host disease
1. Happens when?
- Onset of symptoms are what?
- Symptoms? 4
- Prevent with what? 2
- immunosuppressed patients receive donor leukocytes
- delayed
- Fever
- Rash
- Liver dysfunction
- Diarrhea
- leukocyte-reduced red cells or
- irradiated red cells
Infectious agents
Bacteria
1. Most likely from what?
2. Present with what? 3
- Viruses: Which ones? 3
Parasites
- platelets
- fever/chills,
- tachycardia,
- hypotension
- Hep B: 1 in 200,000
- Hep C: 1 in 2 million
- HIV: 1 in 2 million
Transfusion-related lung injury
1 in 5,000 transfusions
1. Most common with what?
- Characterized by what?
- Treatment? 2
- units that contain plasma
- pulmonary edema after transfusion
- is supportive
- May require intubation
- Massive transfusions are defined as?
2. Complications? 6
- > 10 packed red cells in 24 hours or pt.’s total blood volume in 24 hours, or half pt.’s blood volume in 1 hour
- Dilutional coagulopathy
- Oxygen transport abnormalities
- Electrolyte/Acid-base derangements
- Hypothermia
- Disease transmission
- ARDS
- What are Autologous Blood?
- Collection done how? 2
- Reasons? 4
- Collection and re-infusion of a patients own blood
- Pre-surgical donation
- Intraoperative cell saver
- Fully compatible
- No risk of transmission
- Less dependent on blood bank
- Patients with rare blood types