Bleeding and Clotting Disorders Flashcards

Exactly 80 vocabulary flashcards covering the phases of hemostasis, coagulation pathways, laboratory tests, inherited and acquired bleeding/clotting disorders, and dental management protocols based on the lecture notes.

Hemostasis

A balanced process in which injury to a blood vessel wall stimulates mechanisms that lead to the stoppage of blood loss.

Vascular phase

The first phase of hemostasis where immediate reflex vasoconstriction occurs upon blood vessel injury.

Platelet phase

The second phase of hemostasis where platelets become activated, aggregate, and form a Platelet Plug.

Coagulation cascade phase

The third phase of hemostasis where step-by-step activation of clotting factors results in the production of Thrombin and cross-linked Fibrin.

Fibrinolytic phase

The fourth phase of hemostasis where Plasmin degrades Fibrin to clear remnants from the blood vessel lumen.

Platelet Plug

A structure formed by activated platelets and Von Willebrand Factor (vWF) adhering to an exposed basement membrane.

Thrombin

The end product of the coagulation cascade that causes Fibrin to cross-link and strengthen the blood clot.

Plasmin

A proteolytic enzyme responsible for degrading Fibrin during the fibrinolytic phase.

Disseminated Intravascular Coagulation (DIC)

A condition caused by the defective clearance of precipitated fibrin, leading to widespread microthrombi and subsequent bleeding.

Intrinsic pathway

A coagulation pathway initiated by injury in the vascular endothelium which is slower and involves factor XII.

Extrinsic pathway

A coagulation pathway initiated by external injury and triggered by Factor III (tissue thromboplastin).

Common pathway

The final stage of coagulation where factors Xnd V work together to convert prothrombin to thrombin.

Hess test

A laboratory test used to assess abnormalities in the blood vessel wall.

Bleeding time

A lab test that is prolonged in both quantitative and qualitative platelet defects.

Platelet function analyzer (PFA)

An instrument used to test the functional capacity of platelets.

aPTT

Activated partial thromboplastin time, a test for the intrinsic and common coagulation pathways.

PT and INR

Tests used to evaluate the extrinsic and common coagulation pathways.

Thromboplastin time (TT)

A laboratory test used to assess the common coagulation pathway.

Thrombocytopenia

A bleeding disorder caused by a reduced platelet count.

Thrombocytosis

A condition characterized by an increased platelet count.

Bernard-Soulier syndrome

A congenital qualitative platelet disorder caused by a defect in platelet adhesion.

Glanzmann's thromboasthenia

A congenital qualitative platelet disorder caused by a defect in platelet aggregation.

Scurvy

A blood vessel wall defect caused by a deficiency of Vitamin C, leading to weak collagen synthesis.

Rendu-Osler-Weber syndrome

Also known as Hereditary Hemorrhagic Telangiectasia, it is a genetically transmitted disease involving abnormal capillary formation.

Hemophilia A

The most common type of hemophilia (85-90%), caused by a deficiency of Factor VIII:C.

Hemophilia B

Also known as Christmas disease, it is caused by a deficiency of Factor IX.

Hemophilia C

A clotting disorder caused by the deficiency of Factor XI.

Parahemophilia

A rare clotting disorder caused by a deficiency of Factor V.

Factor VIII:C

The small molecule of Factor VIII produced in liver cells that provides coagulant activity.

Von-Willibrand (VIII:vWF)

The large molecule of Factor VIII produced in endothelial cells that facilitates platelet adhesion.

Hemarthrosis

Spontaneous bleeding into muscle and joint spaces, which is characteristic of coagulation disorders.

Desmopressin (DDAVP)

A drug used in mild cases of Hemophilia A and vWD, administered at $0.3\,\mu g/kg$, to elevate Factor VIII levels.

Cryoprecipitate

A blood product used to supply Factor VIII in moderate to severe cases of Hemophilia A.

Tranexamic acid

An antifibrinolytic agent used to prevent clot lysis, often given at $25\,mg/kg$ t.i.d.

Von Willebrand disease (vWD)

An inherited disorder involving quantitative or qualitative defects in vWF, affecting both platelet adhesion and the coagulation cascade.

Vitamin K

A fat-soluble vitamin stored in the liver that is essential for the synthesis of factors II, VII, IX, and X.

Warfarin (Coumarin)

A plant-derived oral anticoagulant that acts as a Vitamin K antagonist to inhibit the synthesis of factors II, VII, IX, and X.

Heparin

An animal-derived, rapid-acting anticoagulant that activates antithrombin to block factors II and X.

Protamine sulphate

The agent used as an antidote to neutralize the effects of Heparin or its overdose.

Apixaban

A direct-acting oral anticoagulant (DOAC) that directly blocks the active site of factor X.

Fibrin degradation products

A laboratory test finding associated with Disseminated Intravascular Coagulation (DIC).

Normal platelet count

A value ranging between $150-400 \times 10^9/L$.

Spontaneous bleeding threshold

The point when the platelet count falls below $20,000/mm^3$.

Platelet count for outpatient oral surgery

A minimum threshold of $75,000/mm^3$ is required for these procedures.

Platelet count for major dental surgery

A minimum threshold of $100,000/mm^3$ is required for procedures under general anesthesia.

Idiopathic thrombocytopenic purpura (ITP)

An autoimmune condition where IgG antibodies destroy platelets, common in children and young adults.

Platelet Rich Plasma (PRP)

A transfusion product used to treat patients with low platelet counts.

Aspirin

A drug that irreversibly blocks the COX-1 enzyme, affecting platelet function for $7-10$ days.

NSAIDS

Drugs that cause a reversible defect in platelet function, typically lasting $24$ hours.

GP Ib/IX-V

The glycoprotein complex on platelet membranes that functions as a receptor for vWF, absent in Bernard-Soulier syndrome.

GP IIb/IIIa

The fibrinogen receptor on the platelet surface that is defective or deficient in Glanzmann's disease.

Petechiae

Small, pinpoint hemorrhagic flat lesions that occur in clusters and do not blanch under pressure.

Ecchymosis

Large submucosal or subcutaneous bruises occurring due to blood extravasation.

Diascopy

A blanching test used to differentiate vascular lesions from petechial hemorrhages.

Gelfoam

An absorbable gelatin sponge that serves as a scaffold for clot formation in extraction sockets.

Ehlers-Danlos syndrome

An inherited disorder of connective tissue that can cause blood vessel wall defects.

Cushing's syndrome

A clinical condition that can lead to acquired blood vessel wall alterations and bleeding.

Uremia

An acquired condition that causes a qualitative defect in platelet function.

Christmas disease

The alternative name for Hemophilia B, caused by Factor IX deficiency.

X-linked trait

The mode of inheritance for Hemophilia A and B, which explains why males are more commonly affected.

Vitamin K injections

A treatment for liver-related bleeding, given for $3$ days intravenously or subcutaneously.

HHT (Hereditary Hemorrhagic Telangiectasia)

A synonym for Rendu-Osler-Weber syndrome, characterized by purple papules on the lips and oral mucosa.

Aminocaproic acid

A systemic antifibrinolytic agent that prevents fibrinolysis and clot lysis following surgery.

Heparin bridging

A protocol using low MW heparin for patients at high risk of thromboembolism when warfarin is stopped before surgery.

Unfractionated heparin (UFH)

A type of heparin that blocks factor X and factor II (anti-thrombin) and is monitored via aPTT.

LMWH (Low Molecular Weight Heparin)

A fractionated heparin that primarily inhibits factor X and is administered only subcutaneously.

INR range 2.5-3

The typical therapeutic therapeutic range for patients on warfarin requiring dose regulation.

Factor X inhibitor

The mechanism of action for the direct-acting oral anticoagulant Apixaban.

Microthrombi

Tiny blood clots that form in the capillaries or microcirculation during DIC.

Platelet Aggregometry

The most accurate test for evaluating platelet functional integrity in response to agonists like ADP or Collagen.

Submucosal petechiae

An oral manifestation of thrombocytopenia, often found on the soft palate.

Hemorrhagic bullae

Blood-filled blisters that can appear on the oral mucosa in cases of severe platelet disorders.

Gingival retractor

A tool used with adrenalin in conservative dentistry to avoid gingival bleeding during preparations.

Nerve block injection risk

A procedure that requires a minimum factor concentration of $25\%-30\%$ in hemophiliacs to avoid airway-endangering hematomas.

Buccal approach for lower third molar

The preferred surgical approach in hemophiliacs to prevent bleeding tracking into planes that endanger the airway.

Antibiotic coverage post-surgery

A measure provided for $10$ days to avoid the risk of infection following oral surgery in hemophiliacs.

Factor level for extraction

A safe concentration of $50-100\%$ is required for this surgical procedure.

Matrix band

A dental tool that must be used with caution in hemophiliacs to avoid traumatic bleeding.

Intra-pulpal injection

A safe and effective anesthesia technique preferred over extraction for endodontic treatment in hemophiliacs.

HHT purple papules

Vascular lesions found on vermilion, tongue, and buccal mucosa that blanch on pressure.