Hematology - Anesthesia Review Flashcards
The extrinsic pathway is initiated by the release of a group of proteins known as _________when tissues are damaged?
Tissue Factor when tissues are damaged.
Tissue Factor forms a complex with and
Factor VII, and in an enzymatic reaction requiring calcium, catalyzes the activation of Factor X.
Proaccelerin is the other name for factor
Factor V
Exposure of the blood to collagen can initiate the
intrinsic pathway.
Fibrinogen is another name for
factor I.
Sickle cell and hematocrit
Sickle cell and hematocrit results in the destruction of red blood cells which lowers the hematocrit
Labs that are elevated in acute DIC
PT PTT Thromboplastin time D-dimer Fibrin degradation products
The circulating levels of what components will be increased by DDAVP administration in a patient with von Willebrand disease? 2 answers
Von Willebrand disease
Factor VIII
Medications that are considered safe for use in patients with porphyria.
Nitrous oxide, neostigmine, morphine, fentanyl, succinylcholine, pancuronium, and propofo
Medications that are NOT considered safe and should all be avoided for patients with Porphyria?
Ketorolac
thiopental
thiamylal
etomidate, pentazocine, methohexital, and nifedipine s
Factor X deficiency is _______deficiency
Stuart-Prower
Aspirin and other NSAIDs on platelet
acetylate and inactivate platelet cyclooxygenase.
Aspirin inactivates cyclooxygenase for
the life of the platelet
Unlike ASA, NSAIDs inactivate them how and how long does it last?
Reversibly, and the effect lasts only about 24 hours.
In the extrinsic coagulation pathway, disruption of the endothelium leads to exposure of tissue factor which binds to
factor VII
Tissue Factor forms a complex with Factor VII, and in an enzymatic reaction requiring
calcium, catalyzes the activation of Factor X.
Porphyria is a disorder of
Heme
Why are Heme pigments essential?
are essential elements in the construction of hemoglobin, myoglobin, and the cytochrome
Many pharmacologic agents (especially those that induce the cytochrome p450 system) can precipitate a porphyric crisis such as
BarbSulfaPhenyEtha Barbiturates Sulfonylureas Sulfonamides Estrogens, phenytoin, tolbutamide, and ethanol.
The underlying cause of organ failure due to disseminated intravascular coagulation is
organ ischemia due to thrombosis
What is the second most common cause of hospitalization in sickle cell patients and accounts for 25% of all sickle cell related deaths.
Acute chest syndrome
How is acute chest syndrome diagnosed?
It is diagnosed by the development of new infiltrates on chest film and may be caused by atelectasis, pulmonary microembolic episodes, or pulmonary infection.
Acute chest syndrome is a potential complication of sickle cell disease. When it develops, it is typically ___days following surgery and
2-3
Treatment of acute chest syndrome
Aggressive hydration
oxygenation, transfusions to treat anemia
antibiotics to treat pulmonary infection, and occasionally nitric oxide may be used to treat pulmonary hypertension.
Which form of hemoglobin is most commonly found in the normal, adult bloodstream?
hemoglobin A
Hemoglobin C is implicated in a type of
hemolytic anemia,
2 agents would be appropriate to administer in the treatment of a patient with von Willebrand disease?
Cryoprecipitate AND Desmopressin
What is the dose of desmopressin?
0.3mcg/kg
Desmopressin given for mild to moderate hemophilia will increase what factors
increase plasma levels of factor VIII and vWF
Cryoprecipitate vs FFP which one is preferred for hemophilia A?
Cryoprecipitate preferred because it is hard to increase the factors level with FFP alone.
3 treatments for hemophiliac patients : Other than desmopressin
Cryoprecipitate
Tranexamic acid
Epsilon aminocaproic acid.
Synthetic Arginine analog of Vasopressin
Desmopressin
Cryoprecipitate is made how?
Collected off the top of FFPs at it being thawed
In the intrinsic pathway, what is the component required to convert factor XII to factor XI?
Prekallikrein
Romponents like High Molecular Weight Kininogen required to activate
Factor XI.
Commonly given medication to avoid porphyria crisis
Ketorolac
Both hemophilia A and hemophilia B exhibit a
prolonged PTT and a normal PT.
The primary function of von Willebrand factor is
To promote platelet aggregation and adhesion to collagen
Potential side effect of DDAVP administration in the treatment of von Willebrand disease?
HoTN
What treatment regimens are effective in ameliorating the symptoms of von Willebrand disease? (select two)
Desmopressin and concentrated von Willebrand Factor are both effective in treating the symptoms of von Willebrand disease.
Factor IX-PCC is used in the treatment of
Hemophilia B
Major surgery –> how to replace vWF
achieve 100% vWF preoperatively and maintain trough levels of 50% until adequate wound healin
In treating type 1 vWD which agent is preferred?
Desmopressin because it produces a complete partial response in more than 90% of patients
In treating type 2 and type 3 vWD which agent is preferred?
Type 2 and type 3 require vWF concentrate administration.
Heparin-Induced Thrombocytopenia (HIT) Type I and Type II
type I non immune mediated, onset 1-4 days
type II immune mediated (immunoglobulin G) 5-14 days
Blood component therapy for HIT
1. Indications: active bleeding or high risk for bleeding
- Fresh frozen plasma
- Platelets
- In some cases, consider cryoprecipitate, antithrombin III
Most events of acute stent thrombosis occur within the
first 30 days after stent placement
Absolute contraindication to neuraxia
Thrombolytics
When is there no contraindication for heparin SC dosing for neuraxial.
No contraindication with twice-daily dosing and total daily dose < 10,000 units
Upper endoscopy and colonoscopy with or without biopsy –> Warfarin stop?
NO NEED for interruption in therapy
• Endoscopic retrograde cholangiopancreatography (ERCP) without sphincterotomy Warfarin stop ?
NO NEED for interruption in therapy
Do not need to stop warfarin for these procedures?
Prosthetics
Cataracts
Elective noncardiac surgery should be delayed______after bare metal stent and _______after DES
30 days after bare metal stent (BMS) implantation and optimally 6 months after drug eluting stent (DES) implantation
Discontinue ticlopidine _____days prior to neuraxial
14 days
Discontinue clopidogrel ____Days prior to neuraxial
7 days
Discontinue GP IIB/IIIa inhibitors _______prior to neuraxial.
8–48 hours in advance
A powerful vasodilator, also interferes with platelet formation and aggregation is ______
prostacyclin
Anatomy of a platelet
Platelets contain alpha (α) granules that store proteins (e.g., vWF, fibrinogen, fibronectin, platelet factor 4, and platelet growth factor) and dense granules that store nonproteins (e.g., serotonin, ADP, adenosine triphosphate [ATP], histamine, and epinephrine).
Converts to plasmin
Plasminogen
3 Vasoconstrictors of vessesl
Thromboxane A2
ADP
Serotonin
3 Vasodilators of vessels
Nitric oxide
Prostacyclin
Vessel Injury contracts after injury leading to
a tamponade, decreasing blood flow. This contraction is a result of autonomic nervous system reflexes and the expression of thromboxane- A2 and ADP. The area adjacent to the injury vasodilates and distributes blood to the surrounding organs and tissues
After injury to the vessel , contraction leads to what
Contraction is followed by three separate stages in the formation of a primary plug: adhesion, activation, and aggregation.
Factor not produced by the liver
III
Substance synthesized vascular wall and extravascular cell membranes; released from traumatized cells
vonWillebrand
Bleeding time Normal
3-7 minutes
Normal ACT
80-150
Normal PT
12-14 sec
Normal PTT`
25-33
Extrinsic (Warfarin vs Heparin)
Heparin
Intrinsic (Warfarin vs Heparin)
Warfarin
A normal platelet count is
150,000 to 300,000/mm3.2
Adhesion is associated with
Vonwillebrand
Activiation and aggregation associated with
ADP and thromboxane A2
When are PRBCs transfused? are
transfused to improve tissue oxygenation
The major reasons for transfusion therapy in the operating room are to
replace volume and coagulation factors and improve oxygen-carrying capacity.
The recommended dose for platelet replacement is
one plateletpheresis pack per each 10 kg of patient weight
Protamine sulfate dosing
1 mg neutralizes 100 units of heparin
1 unit of platelet is ______ml
250 mL
1 unit of plate increases the platelet count by
30,000–60,000/mm3
FFP unit = _____ml
200-250 ml
Hypofibrinogenemia, massive hemorrhage –> what is used
Cryoprecipitate.
Hemophilia, massive hemorrhage
Factor VII
1 unit single- donor apheresis platelets comes from how many platelet concentrates?
Four to five platelet concentrates,
Laboratory analysis will reveal the need for FFP by a
PT and aPTT prolonged more than 1.5 times normal.
Cryoprecipitate is then refrozen and thawed on use. It is rich in.
fibrinogen
Factors VIII
Factor XIII
Fibronectin
The recommended dose of factor VII for hemophilia is
90 to 120 mcg/kg
Cryoprecipitate Infusion Guidelines
1) When a test of fibrinogen activity indicates a fibrinolysis
(2) When the fibrinogen concentration is less than 80 to 100 mg/dL IN THE PRESENCE OF EXTENSIVE BLEEDING
(3) As an adjunct in massively transfused patients when fibrinogen concentrations cannot be measure in a timely fashion;
(4) For patients with congenital fibrinogen deficiencies.
Transfusion of cryoprecipitate is rarely indi- cated if fibrinogen concentration is
greater than 150 mg/dL in non- pregnant patients.
A sickle cell crisis may be triggered by
hypoxemia, hypothermia, infection, dehydration, venous stasis, and acidosis.
P2Y12 ADP Receptor Inhibitors: name 3
ticlopidine, clopidogrel, prasugrel
Platelet Glycoprotein IIb/IIIa Receptor Blockers: Name 3
abciximab, tirofiban, eptifibatide
Heparin half life
1.5 hours
Warfarin half life
2-4 days
Abciximab half life
30 minutes
ASA half life
20 minutes
NSAIDs half life
2-10 hours
COX-1 receptor inhibition by is responsible for the gastric irritation,
NSAIDs
COX-1 receptor inhibition by NSAIDS is responsible for the
Gastric irritation
Decrease in renal blood flow, and platelet inhibition associated with nonselective NSAIDs.
The removal of multiple units of blood from the patient right before surgery and replacement of the removed blood volume with crystalloid is referred to as
Acute normovolemic hemodilution
Preoperative autologous donation is most effective when it is
combined with erythropoietin therapy
Which of the following are disadvantages to storing blood? (select two)
Adenosine triphosphate levels decrease in stored blood
. 2, 3 DPG levels decrease in stored blood
Which of the following are disadvantages to storing blood? (select two)
Adenosine triphosphate levels decrease in stored blood
2, 3 DPG and ATP levels decrease in stored blood
The potassium present in the plasma in
packed red blood cells stored for 21 days can reach levels as high as 35 mEq/L.
COX-1 receptors in the body
distributed throughout the body
Which COX inhibition results in inhibition of thromboxane A2?
COX-1 receptor. By doing so, it disrupts thromboxane A2’s ability to promote platelet aggregation.
COX-2 receptors are present in the
kidneys and central nervous system and can be synthesized in response to inflammatory processes.
What are the effects of COX-2 receptor inhibition?
reduce prostacyclin release from the vascular epithelium and can result in increased platelet aggregation.
The ability of coagulation factors to function correctly decreases
10 percent with every 1 degree Celsius drop in body temperature. Rapid transfusions of cold blood products can increase the likelihood of further bleeding.
Which infectious disease has the highest risk of transmission via blood transfusion?
CMV
Acute hemolytic transfusion reaction is an _____ mediated reaction.
IgM
Phosphodiesterase inhibitors increase the level of cyclic AMP which is an
inhibitor of platelet aggregation.
What sign is consistent with an acute hemolytic transfusion reaction?
Hematuria
Transfusion-Associated Cardiovascular Overload (TACO) refers to the development of
pulmonary edema due to blood product administration. It is not immune-related or due to an alteration in the permeability of pulmonary capillary membranes and is responsive to diuretics and reduction of afterload.
During preoperative assessment, a patient reveals a prolonged PT due to vitamin K deficiency. How long does it take for intravenous vitamin K to improve the PT?
6-8 hours
Vitamin K oral administration exhibits the highest bioavailability, it can take up to ___hours to see effects.
24 hours to exhibit significant clinical effects.
