PMED(M1.2)- HEMATOLOGIC DISORDERS

ACQUIRED BLEEDING DISORDERS

conditions that alter the ability of blood vessels, platelets, and

coagulation factors to maintain hemostasis

ACQUIRED BLEEDING DISORDERS

occurs as a result of vascular wall integrity, platelet

production or function, or coagulation factors are impaired

ACQUIRED BLEEDING DISORDERS

pathologic alteration of blood vessel walls

ACQUIRED BLEEDING DISORDERS

significant reduction in the number of platelets,

defective platelets or platelet function

ACQUIRED BLEEDING DISORDERS

deficiency of one or more coagulation factors

ACQUIRED BLEEDING DISORDERS

most common cause of prolonged and severe

bleeding

ACQUIRED BLEEDING DISORDERS

may appear in the skin or mucous membranes or

after trauma or invasive procedures

coumarin, antiplatelet meds, and increased age

__ can increase bleeding complication:

Congenital coagulation disorders

only one factor is affected

Acquired hemophilia

caused by autoantibody inhibitors

directed against “self”-clotting

factor VIII

“self” clotting factor

heparin and coumarin

may disrupt the

coagulation process.

Antiplatelet medications, aspirin, other nonsteroidal

antiinflammatory drugs (NSAIDs), penicillin

may interfere with

platelet function

herbal supplements

impair hemostatic

function for the control of bleeding

Fish oil or concentrated omega-3 fatty acid

supplements

may impair platelet activatio

omega-3 fatty acids

may result in a prolonged bleeding time and abnormal platelet

aggregation

vascular phase, platelet phase, coagulation phase, fibrinolytic phase

Phases of hemostasis for controlling bleeding

vascular phase

phase that begins immediately after injury

platelet phase

phase where platelet and vascular wall becomes sticky

platelet phase

phase that begins seconds after an injury

coagulation phase

phase that takes place more slowly than other phase

fibrinolytic phase

wherein the fibrin clot is dissolved

coagulation phase

end product: fibrin clot

Liver disease

s/s Jaundice spider angiomas, and ecchymoses and hyperplenism

hyperplenism

petichiae on the skin and mucosa

PARTIAL THROMBOPLASTIN TIME

used to check the intrinsic system (factors VIII, IX,

XI, and XII) and the common pathways (factors V and

X, prothrombin, and fibrinogen)

PARTIAL THROMBOPLASTIN TIME

best single screening test for coagulation disorders

ACTIVATED PARTIAL THROMBOPLASTIN TIME

prolonged in cases of mild to severe deficiency of

factor VIII or IX

ACTIVATED PARTIAL THROMBOPLASTIN TIME

the test result is abnormal when a given factor is 15%

to 30% below its normal value

25-35 seconds

normal aptt

PROTHROMBIN TIME

used to check the extrinsic pathway (factor VII) and

the common pathway (factors V and X, prothrombin,

and fibrinogen)

11-15 seconds

normal prothrombin time

INTERNATIONAL NORMALIZED RATIO

test is used to evaluate the level of anticoagulation with coumarin-like drugs

PLATELET COUNT

used to screen for possible bleeding problems

caused by thrombocytopenia

150,000 to 450,000/μL

normal platelet count

between

50,000 and 100,000/μL

Patients with a platelet count of

___ manifest excessive

bleeding only with severe trauma

below 50,000/μL

Patients with platelet counts ___

demonstrate skin and mucosal purpura and

bleed excessively with minor trauma.

below 20,000/μL

Patients with platelet counts ___

may experience spontaneous bleeding.

THROMBIN TIME

this test bypasses the intrinsic, extrinsic, and most of

the common pathway

9-13 seconds

normal thrombin time

VASCULAR DEFECTS

caused by structural malformation of vessels, hereditary

disorders of connective tissue, and acquired connective tissue

disorders

SCURVY

deficiency of vitamin C

SCURVY

resulting in weakened collagen fibers

SMALL VESSEL VASCULITIS

inflammation of small vessels, including arterioles, venules,

and capillaries

SERUM SICKNESS

can lead to purpura ad caused by drugs such as penicillin, hydralazine, sulfonamides,

and thiazide diuretics and hepatitis

PLATELET DISORDERS

caused by defective production of thromboxane and other

times by a deficiency in the production of dense-granule ADP

DISSEMINATED INTRAVASCULAR COAGULATION

the syndrome is associated with a number of disorders such as

infection, obstetric complications, cancer, and snakebites

DISSEMINATED INTRAVASCULAR COAGULATION

results when the clotting system is activated in

all or a major part of the vascular system.

DISSEMINATED INTRAVASCULAR COAGULATION

major clinical problem is bleeding, not thrombosis

DISSEMINATED INTRAVASCULAR COAGULATION

caused when large quantities of thromboplastic substances are

introduced into the vascular system and “trip” the clotting

cascade

Acute DIC

may be caused by obstetric complications, sepsis and septic shock,

and acidosis

Acute DIC

include severe bleeding from small

wounds

Acute DIC

spontaneous bleeding from the nose,

gums, gastro- intestinal tract, or

urinary tract

Traumatic hemolytic anemia

may occur when RBCs are “sliced”

by fibrin strands

Chronic DIC

may occur in association with certain

types of cancer

Chronic DIC

caused by antigen-antibody

complexes associated with systemic

lupus erythematosus

Chronic DIC

thrombosis is more common than

bleeding

Cryoprecipitate and fresh frozen plasma

(FFP)

tx if bleeding is the major

problem

Heparin

tx if thrombosis is the major

problem

FIBRINOGENOLYSIS

may develop if active plasmin is generated in the circulation

FIBRINOGENOLYSIS

can occur in patients with liver disease, lung cancer, prostate

cancer, or heatstroke

FIBRINOGENOLYSIS

severe bleeding results from the depletion of fibrinogen (split by

plasmin) and the formation of fibrin split products

FIBRINOGENOLYSIS

can be treated with ε-aminocaproic acid or tranexamic acid

ε-aminocaproic acid or tranexamic acid

inhibits both plasmin and plasmin

activators

Standard heparin

treatment usually consists of an IV infusion in

a hospital setting

Standard heparin

has a half-life of 1 to 2 hours

LMWHs

exhibit less binding to plasma proteins,

endothelial cells, and macrophages

LMWHs

have better bioavailability when

administered subcutaneously, longer half-lives,

and more predictable anticoagulant effects

LMWHs

administered subcutaneously in the

abdomen

LMWHs

half-life of about 2 to 4 hours

Fondaparinux

a synthetic heparin

Fondaparinux

a useful alternative

to heparin or LMWH

Direct thrombin inhibitors

do not require a plasma cofactor

Desirudin

given subcutaneously to patients

who are about to undergo hip

replacement

Lepirudin

given intravenously to patients with

history of heparin-induced

thrombocytopenia (HIT) for treatment

of DVT or for hip replacement

Bivalirudin

administered to patients about to

undergo percutaneous coronary

intervention

Dabigatran

first orally administered direct

thrombin inhibitor

Dabigatran

use to prevent stroke

Dabigatran

has replaced warfarin as a standard

anticoagulant

Warfarin

most widely used coumarin in the

United States

Warfarin

inhibits the

biosynthesis of vitamin K–dependent

-

coagulation proteins

Warfarin

bound to albumin, metabolized

through hydroxylation by the liver,

and excreted in the urine.

ASPIRIN

a prototypical antiplatelet drug

ASPIRIN

exerts its antithrombotic action by irreversibly inhibiting platelet

COX,

IBUPROFEN AND INDOBUFEN

act as reversible inhibitors of COX

TICLOPIDINE AND CLOPIDOGREL

inhibits ADP

ABCIXIMAB

a monoclonal antibody

EPTIFIBATIDE

small molecule inhibitors used as antiplatelet agents

a. a thorough history

b. physical examination

c. screening clinical laboratory tests

d. observation of excessive bleeding after a surgical

procedure

four risk assessment methods

HEREDITARY HEMORRHAGIC TELANGIECTASIA

also referred to as Osler-Weber-Rendu syndrome

HEREDITARY HEMORRHAGIC TELANGIECTASIA

characterized by

multiple telangiectatic lesions involving the skin, mucous

membranes, and viscera

HEREDITARY HEMORRHAGIC TELANGIECTASIA

characterized by a high frequency of

symptomatic pulmonary arteriovenous malformations and

cerebral abscesses

HEREDITARY HEMORRHAGIC TELANGIECTASIA

bleeding tendencies are thought to be because of mechanical

fragility of the abnormal vessels

HEREDITARY HEMORRHAGIC TELANGIECTASIA

recurrent epistaxis is common

HEREDITARY HEMORRHAGIC TELANGIECTASIA

severity of the disorder often can be gauged

by the age at which the nosebleeds begin

HEREDITARY HEMORRHAGIC TELANGIECTASIA

In the GI tract, the stomach and

duodenum are more frequent sites of

bleeding than is the colon

venous lakes and papular, punctate, matlike,

and linear telangiectasias appear on all areas

laser treatment

For cutaneous lesions (hereditary hemorrhagic telangiectasia

split thickness skin grafting

For epistaxis (hereditary hemorrhagic telangiectasia

pulmonary resection or embolization

For GI lesions (hereditary hemorrhagic telangiectasia