Blood Disorders (Exam III)- Corndog Flashcards
What are the S/S of vWF disorder?
- Easy bruising
- epistaxis
- menorrhagia
- Patients usually unaware until surgery
What is the most common hereditary bleeding disorder?
vWF disorder
What type of vWF is the mildest and most common type?
What medication does it respond best to?
- Type I inherited vWF disease.
- Responds best to DDAVP out of all 6 types.
What type of vWF is the most severe and rarest type?
What medication does it respond best to?
- Type 3 inherited vWF disease.
- Responds best to factor concentrates such as Factor VIII. Does not respond well to DDAVP.
What would lab values be for someone with vWF deficiency?
- Normal PT & aPTT
- Bleeding time is prolonged
What are the treatments for vWF deficiency?
- Desmopressin
- Cryoprecipitate
- Factor VIII
How does DDAVP work in regards to treatment of vWF?
- A synthetic analogue of vasopressin
- Stimulates vWF release from endothelial cells
What is the dose for DDAVP?
0.3 mcg/kg-0.8mcg/kg in 50 mL over 15-20 mins (Do not bolus)
What is the onset & duration of DDAVP?
- Onset: 30mins
- Duration: 6-8hrs
What are side effects of DDAVP?
- HA
- Stupor
- hypotension
- tachycardia
- hyponatremia
- water intoxication (excessive water retention)
What is the most major side effect of DDAVP?
Hyponatremia through water retention
And subsequent seizures from severe hyponatremia
Someone that gets DDAVP needs to be on what?
Fluid restriction (oral and IV) 4-6hrs before & after DDAVP
What are the CNS and EKG changes seen with a serum sodium of 120mEq/L?
- CNS - Confusion and restlessness
- EKG - slight widening of QRS.
What are the CNS and EKG changes seen with a serum sodium of 115mEq/L?
- CNS - Somnolence and Nausea
- EKG - Elevated ST segment and widening of QRS.
What are the CNS and EKG changes seen with a serum sodium of 110mEq/L?
- CNS - Seizures and Coma
- EKG - Vtach or Vfib.
What blood product can be utilized for vWF disease if the patient is unresponsive to DDAVP?
Cryoprecipitate
1 unit of Cryo raises the ____ level by ___?
Fibrinogen by 50 mg/dL
What is a potential risk factor with cryoprecipitate?
Increased risk of infection (not submitted to viral attenuation)
How many units are typically in a bag of cryoprecipitate?
2-10 units, from multiple donors which can increase risk of infection and reaction.
What is Factor VIII concentrate made of?
- Prepared from pool of plasma from a large number of donors
- Contains Factor VIII and vWF
- Undergoes viral attenuation, which gives you less risk for infection
When is Factor VIII given?
Preop or intraop
When should DDAVP be given prior to surgery?
60mins before Sx
What blood product poses an increase risk for infection? Why?
- Cryoprecipitate
- Not sent for viral attenuation
What are the anesthesia considerations for patient’s with blood disorders?
- Needs a hematologist evaluation prior to surgery.
- Normalization of bleeding time and improved levels of Factor VIII should be confirmed before surgery.
- If indicated, DDAVP should be given 60 minutes prior to surgery.
- General anesthesia may be more appropriate due to increased risk of hemorrhage and developing hematomas with blocks and spinals.
Pts with coagulopathies undergoing neuraxial anesthesia are at increased risk for what?
- Spinal and epidural hematoma
- Nerve compression
What four things to avoid?
What are the anesthesia considerations (in terms of bleeding) for someone with vWF deficiency?
- Avoid trauma (particularly airway)
- avoid IM sticks
- avoid arterial lines (if feasible)
- avoid spinals
What is acquired bleeding?
Bleeding that comes from medication such as heparin, warfarin, fibrinolytics, and antiplatelets.
What is the most common medication that causes acquired bleeding?
Heparin; Traditional heparin as well as LMWH (Lovenox)
How does heparin work?
- Thrombin inhibition
- Antithrombin III activation
What kind of patients does heparin not work for?
- Patients with antithrombin III deficiency.
- When you give them heparin, nothing happens.
What is the treatment for a patient with antithrombin III deficiency?
- Give them 2 units of FFP to provide the patient with antithrombin III to get the heparin to work. This is what is done most often.
- You can also switch to a different medication besides heparin.
What labs are monitored with heparin?
PTT &/or ACT
What is an ACT?
- Stands for activated clotting time.
- Is a rapid blood test that measures how long it takes for blood to clot, how many seconds.
- 70-150 seconds is a normal value.
- Below 70 seconds means your blood is clotting too quickly.
- Above 120 seconds means your blood is taking longer to clot and you are at increased risk for bleeding.
What is the ACT range if you are trying to anticoagulate someone for a systemic procedure like cardiac bypass?
350-400 seconds
What is a PTT?
- Stands for partial thromboplastin time.
- A blood test that measures how long it takes your blood to clot.
- A normal value is between 25-35 seconds.
- Below 25 seconds means your blood is clotting faster than normal.
- Above 35 seconds means your blood is taking longer to clot and you are at increased risk for bleeding.
What is an INR?
- Stands for international normalized ratio.
- A blood test that measures how long it takes your blood to clot.
- A normal value is between 0.8 and 1.1.
- Below 0.8 means your blood is clotting faster than normal.
- Above 1.1 means your blood is taking longer to clot and you are at increased risk for bleeding.
What are heparins anticoagulant effects rapidly reversed by?
Protamine
When do you do continuous lab draws/monitoring for patients on heparin?
- You do it of they are on a continuous heparin drip infusion. Frequency = q6-q8 hours.
- You do not need continuous lab draws for patients getting subq heparin or loveno TID.
What is the mechanism of action of Coumadin?
Inhibition of vitamin K-dependent factors.
Which factors are vitamin-K dependent?
II, VII, IX & X
What is the antidote for Coumadin?
What is the downside of this?
- Vitamin K
- It takes a really long time to work. 6-8 hours. Your patient will be dead by then.
What is the onset for Vitamin K administration?
Takes 6-8hrs to reverse Coumadin. Quicker methods are preferred.
3
What drugs/products can be given to reverse coumadin faster than Vit K?
- Prothrombin complex concentrates
- Factor VIIa
- FFP
What is the main problem with using prothrombin complex concentrates?
- They are very expensive
- Smaller facilities may not have it available.
- These are mixed/given using weight based doses that have to be prepared by the pharmacy which could prolong your time in giving it.
What are 3 examples of fibrinolytic agents?
- Tissue plasminogen activator (tPA)
- streptokinase (SK)
- urokinase (UK)
What are fibrinolytic agents used for?
- To break up intracerebral and/or intracardiac clotting.
What is the mechanism of action for fibrinolytics (UK, streptokinase & tPA)?
Convert plasminogen to plasmin, which cleaves fibrin —> causing clot lysis
* Fibrinolytics work on existing clots.
What are 3 examples of antifibrinolytics?
- TXA - tranexamic acid
- Amicar - ε–aminocaproic acid
- aprotinin
What are antifibrinolytics used for?
- Menorrhagia, Women who have extreme period bleeding. This was the first indication.
- Epistaxis and oral bleeding/surgery came next.
- To control bleeding on trauma patients.
What was TXA (antifibrinolytic) originally designed for?
Menorrhagia, Women who have extreme period bleeding.
What is the indication for oral TXA as a home med?
- Menorrhagia
- Peridontal disease
- Recurrent epistaxis
How do tranexamic acid (TXA) and aminocaproic acid work?
- Inhibit conversion of plasminogen to plasmin
- Antifibrinolytics don’t cause clot formation, they just keep the existing clots together and from being broken down.
What is the dosage for antifibrinolytics?
- Adult dose is 1-2 grams as a slow IV push.
- The pediatric dose is 15mg/kg.
How do you figure out if someone has TXA toxicity?
They will become color-blind after the dose.
What are anesthesia considerations for antiplatelet therapy?
- Be mindful of when the patient had their last dose.
- Consider getting a platelet function panel pre-op to assess where they are at.
- If need be you can always give the patient platelets prior to surgery.
What is DIC?
What is its mechanism of action?
- Disseminated Intravascular Coagulopathy.
- MOA: The systemic activation of the coagulation system that simultaneously leads to thrombus formation and exhaustion of platelets and coagulation factors.
- Initially the patient burns through all their clotting factors and have widespread thrombus
After they brun through all their clotting factors, then they start hemorrhaging from everywhere.
What are the initial S/S of DIC?
- Petechiae is the biggest sign.
- loss of peripheral perfusion.
What underlying disorders can cause DIC?
- Sepsis
- Amniotic fluid embolus.
- Trauma
- Malignancy/tumors
- incompatible blood transfusions
What will labs show for someone in DIC?
- ↓Platelet count
- Prolonged PT, PTT & TT.
- ↑ fibrin degradation products (FDP)
What lab work will show fibrin degraproducts (FDP)?
- DIC panels
What is the best way to treat DIC?
Treat the underlying cause precipitating hemostatic activation.
What is another treatment for DIC after treating the underlying condition?
- Normalize clotting status by giving blood component transfusions to replete coagulation factors and platelets consumed in the process.
- Plasmapheresis can also be done to normalize clotting status.
When is antifibrinolytic therapy given to someone in DIC?
Trick question, it shouldn’t. Antifibrinolytics are contraindicated in DIC be ause they can lead to catastrophic thrombotic complications
What is an APACHE score?
A test used to evaluate and grade patients with sepsis and DIC.
What are the 2 most common prothrombotic disorders?
- Factor V Leidon disease
- HIT - Heparin induced thrombocytopenia
What is factor V?
- Protein for normal clotting.
- When enough fibrin has been made, activated protein C inactivates factor V thus stopping clot growth*.
What is Factor V Leiden disease?
- Genetic mutation in factor V
- Abnormal version of factor V that is resistant to activated protein C —> excessive fibrin and clotting
In what type of patients is factor V Leiden disease most often seen?
- Pregnant patients who have had a lot of previous miscarriages.
- They usually only find out because after so many miscarriages your doctor will do hematologic and genetic testing.
What anesthesia considerations are there for patients with Factor V Leiden disease?
- Factor V Leiden is associated with an increased risk of developing an episode of DVT (with or without a PE)
- Because of high risks of DVT and PE, patients are on anticoagulants
Factor V Leiden is usually silent until?
- Pregnancy
- First presention of DVT, repeated late-stage abortions/fetal losses occurs
- Prophylactic anticoagulation may be indicated in some cases to prevent venous or placental thrombosis, because improved placental blood flow is likely to lead to better pregnancy outcomes
What anticoagulant medications could someone with Factor V Leiden be put on?
- The most common is LMWH (lovenox) as a home med
- Warfarin
- Unfractionated heparin
What kind of anesthesia will we use for a patient with Factor V Leiden who is delivering a baby?
- General anesthesia over an epidural because the patient is on at home lovenox and we are concerned with doing neuraxial anesthesia on these patients.
- There is a greater risk of bleeding and spinal hematoma with daily lovenox and neuraxial anesthesia.
What is the hallmark sign of HIT?
Plt count <100,000
thrombocytopenia
What is HIT?
- An autoimmune-mediated drug reaction that occurs in as many as 5% of patients after exposure to unfractioned heparin.
- HIT activates platelets –> causes clotting –> depletes platelet count
When does thrombocytopenia occur in HIT patients?
5-14 days after initial therapy.
Non-heparin anticoagulants used after HIT?
Direct-thrombin inhibitors
* Argratroban
* Bivalirudin
Factor Xa Inhibitor
* Fondaparinaux in place of lovenox
Diagnosis of HIT should be entertained when?
- For any patient experiencing thrombosis or thrombocytopenia during/after heparin administration
- D/C heparin immediately.
What should be done if HIT is suspected?
- Check a second PTT or ACT to make sure
- D/C heparin immediately.
- Administer non-heparin anticoagulation such as bivalirudin, lepirudin, or argatroban. (Direct thrombin inhibitors)
