7. Clinical Considerations (Hematology) Pt. I Flashcards
(38 cards)
Congenital Bleeding Disorders
Introduction
- Hereditary bleeding disorders are a diverse group of diseases that include abnormalities of primary and secondary hemostasis.
- Primary hemostasis involves formation of the ____ which involves ____, the blood vessel wall and ____; abnormalities can include problems in platelet ____, adhesion or aggregation.
- Secondary hemostasis involves the formation of ____ through the coagulation cascade; abnormalities include deficiencies of ____ factors, deficiencies or abnormalities of ____ or connective tissue diseases
platelet plug
platelets
von willebrand factor
number
fibrin
coagulation
fibrinogen
Congenital Bleeding Disorders Introduction • The most common congenital bleeding disorders include: -\_\_\_\_ disease -Hemophilia A (factor \_\_\_\_ deficiency) -Hemophilia B (factor \_\_\_\_ deficiency)
von willebrand
VIII
IX
Congenital Bleeding Disorders
Laboratory Evaluation
• When tissue is injured it initiates the ____ cascade leading to the formation of a blood clot.
- This cascade is comprised of three pathways: extrinsic, intrinsic, and common.
- Two laboratory tests are used commonly to evaluate coagulation disorders: Prothrombin Time (PT) which measures the integrity of the ____ system as well as factors common to both systems and Partial Thromboplastin Time (PTT), which measures the integrity of the ____ system and the common components.
coagulation
extrinsic
intrinsic
Congenital Bleeding Disorders
Laboratory Evaluation - PT
• The PT test is used to monitor patients taking certain medications as well as to help diagnose clotting disorders.
• The PT test is performed by adding the patient’s plasma to some source of ____ and calcium chloride. The test is timed from the addition of the calcium chloride until the plasma ____. This time is called the Prothrombin Time.
• The prothrombin test specifically evaluates the presence of factors I (____), II (____), ____, ____, and ____.
tissue factor
clots
fibrinogen prothrombin V VII X
Congenital Bleeding Disorders
Laboratory Evaluation - PT
• A ____ PT indicates a deficiency in any of factors: I (fibrinogen), II (prothrombin), V, VII, and X.
- Vitamin K deficiency: Vitamin K is needed for synthesis of factors II (____), ____, ____ and ____.
- Liver disease: The liver hepatocytes synthesize all clotting factors except ____ which is synthesized by the liver ____ endothelial cells
- Medications: Coumadin (____) inhibits the vitamin K dependent clotting factors, mimicking vitamin K deficiency.
prologned
prothrombin
VII
IX
X
VIII
sinusoidal
warfarin
Congenital Bleeding Disorders
Laboratory Evaluation - PT
• The PT was introduced in 1935,it was originally used to detect a coagulation disorder in chickens but was later adapted for control of oral anticoagulants.
• Universal adoption of the PT test unfortunately did not produce uniform or safe oral anticoagulant dosage because of the failure to ____ the thromboplastin in the PT and also because of different methods of reporting results.
• The ____ was introduced in an attempt to standardize the PT.
standardize
INR
Congenital Bleeding Disorders
Laboratory Evaluation - PTT
- The activated partial thromboplastin time (aPTT) test is used to monitor patients taking certain medications as well as to help ____ clotting disorders.
- The aPTT test is performed by adding ____ and ‘activating substances’ to the patients plasma. This starts the ____ pathway of the coagulation cascade. The partial thromboplastin time is the time it takes for a ____ to form.
diagnose
calcium
intrinsic
clot
Congenital Bleeding Disorders
Laboratory Evaluation - PTT
• A prolonged PTT indicates a deficiency in any of factors: ____, ____, ____, ____ and ____ clotting pathways.
• Liver disease: The liver hepatocytes synthesize all clotting factors except ____ which is synthesized by the liver sinusoidal endothelial cells
• Medications: ____ inhibits the blood coagulation by binding to antithrombin III which functions as a inactivator of active clotting factors as factors ____.
VIII
IX
XI
XII
VIII
V, IX, X, XI and XII
Congenital Bleeding Disorders
Laboratory Evaluation – Summary
• PT (INR): Evaluates the ____ and common pathway. Used to monitor Coumadin (____).
• PTT: Evaluates the ____ and common pathway. Used to monitor ____.
extrinsic
warfarin
intrinsic
heparin
Congenital Bleeding Disorders
Risk assessment
• The four methods by which you can identify a patient who may have a bleeding disorder are a good ____, careful physical ____, screening ____ tests, and occurrence of excessive ____ after a dental procedure.
• A history of spontaneous ____ and muscle hemorrhages is suggestive of severe hemophilia.
• A history of frequent ____, gingival bleeding, and ____ are found in patients with thrombocytopenia, platelet disorders, or von Willebrand disease.
history
examination
laboratory
bleeding
hemarthroses
epistaxis
menorrhagia
Congenital Bleeding Disorders
Risk assessment
• Inspect the exposed skin and mucosa of the oral cavity and pharynx for signs that might indicate a possible bleeding disorder.
• Signs include ____, ecchymoses, spider ____, telangiectasias, ____, pallor, and cyanosis.
• When any of these signs are found that cannot be explained by the history or other clinical findings, the patient should be referred for ____ evaluation prior to invasive treatment.
petechiae
angioma
jaundice
medical
Congenital Bleeding Disorders
Von Willebrand Disease
• Von Willebrand disease is an inherited disease marked by ____ deficiency.
• It is the most common ____ bleeding disorder, affecting 1% of the population and affects both ____ equally.
• vWF acts as a carrier for factor ____ and increases its half- life and is important for platelet ____ at wound sites.
von willebrand factor (vWF) congenital sexes VIII adhesion
Congenital Bleeding Disorders
Von Willebrand Disease • There are 3 types:
• Type 1: ____ defect. Generally have vWF levels ____% of normal. Most common, ____ severe.
• Type 2: ____ defect. ____ vWF levels, but they are ____.
• Type 3: Almost complete ____ of vWF. Most ____ form of disease.
quantitative
20-50
least
qualitative
normal
defective
absence
severe
Congenital Bleeding Disorders
Von Willebrand Disease
• Screening tests show a ____ platelet count and, possibly, a slightly ____ PTT.
• Diagnosis is based on low levels of ____ antigen and abnormal ____ activity.
normal
prolonged
vWF
ristocetin cofactor
Congenital Bleeding Disorders
Von Willebrand Disease
• Mild variants are characterized by a history of cutaneous and mucosal ____. In the more severe forms of the disease, ____ and dissecting intramuscular hematomas may occur.
• ____ are rare in these patients. However, GI bleeding, epistaxis, and menorrhagia are very common.
• Serious bleeding can occur in these patients after ____ or surgical procedures.
bleeding
hemarthoses
petechiae
trauma
Congenital Bleeding Disorders
Von Willebrand Disease
• Management of these patients depend on the type of procedure and the type of Von Willebrand disease the patient is diagnosed with.
• Available treatment options include ____, factor VIII concentrates with vWF multimers (Humate-P), and ____ (DDAVP).
cryoprecipitate
desmopressin
Congenital Bleeding Disorders
Von Willebrand Disease
• Desmopressin is an analog of ____ (vasopressin) that stimulates the release of ____ into the plasma causing a 2 to 5-fold increase in plasma von Willebrand factor and factor ____ concentrations.
• Desmopressin may be helpful for type ____ VWD but is usually of no value in other types.
ADH
vWF
VIII
1
Congenital Bleeding Disorders
Von Willebrand Disease
• Patients with type 2 and 3 Von Willebrand disease are treated with factor ____ replacement that contains____ (Humate-P).
VIII
vWF multimers
Congenital Bleeding Disorders
on Willebrand Disease
• ____ agents are used in conjunction with clotting factor replacement therapy.
• These agents include ____ analogs such as ____ and aminocaproic acid (Amicar). Both agents can be taken ____ or intravenously.
• These drugs prevent postoperative bleeding by inhibiting the activation of ____ to plasmin, which works to degrade fibrin clots.
antifibrinolytic lysine tranexamic acid orally plasminogen
Congenital Bleeding Disorders
Hemophilia
• Hemophilia is an ____ disorder caused by a deficiency in blood coagulation factors. It is the second most common coagulation disorder after von Willebrand disease.
• Hemophilia A is characterized by a deficiency of factor ____
• Hemophilia B is caused by a deficiency of factor ____.
• The incidence is estimated to be 1 in ____ males for hemophilia A and 1 in ____ males for hemophilia B.
x-linked recessive VIII IX 5,000 30,000
Congenital Bleeding Disorders
Hemophilia
- The first manifestation of hemophilia may be bleeding from the ____ when deciduous tooth exfoliates or prolonged bleeding following dental hygiene procedures or tooth extractions.
- The incidence of dental caries and periodontal disease is ____ in patients with bleeding disorders, which may be related to lack of effective oral ____ due to fear of bleeding.
- The importance of good oral ____ should be stressed reduce the chances of future problems.
gingiva
higher
hygiene
hygiene
Congenital Bleeding Disorders
Hemophilia
• The management of patients with requires collaboration with the patient’s hematologist
as well as an awareness of local hemostatic measures and techniques that cause the least amount of trauma.
• Routine dental procedures can cause soft tissue ____ as well as local ____.
• Fatal hemorrhage in hemophiliac patients has been reported following local anesthetic injections due to ____.
trauma
bleeding
airway compromise
Congenital Bleeding Disorders
Hemophilia
• To prevent complications, discuss treatment with their hematologist. Explain the procedure, expected bleeding and the types of postoperative local hemostatic measures that will be applied.
• Various types of medical interventions can be selected by the hematologist to increase the level of factor based on the patients deficiency and severity of the dental procedures. Agents that can be administered include ____, factor concentrate, ____ factors, and antifibrinolytic agent (____ or amicar).
desmopressin acetate
recombinant
tranexamic acid
There are different severities for hemophilia.
Mild factor VIII deficiency - will get ____ care, can do most dentistry, except very ____ procedure you will want to consult hematologist.
Moderate to severe - you want to coordinate with ____ prior to much of anything. Some of the discussion will be about how much factor needs to be replaced in order to perform a specific procedure (more ____ therapy needed for extraction than for a prophy).
preventative
invasive
hematologist
replacement
