Bleeding and Clotting

Question 1

describe primary and secondary hemostasis

Answer 1

primary: platelet adhesion dependent on glycoproteins, mediated by vWF –> activates platelets secrete factors to recruit other platelets –> platelet plus
secondary: serum coagulation factors catalyze development of fibrin latticework to support the platelet plus

Question 2

describe DIC

Answer 2

intrinsic and extrinsic coagulation systems are activated –> local and general escape of thrombin into the circulatory system –> initial thrombosis stage

as platelet and clotting factors are depleted –> bleeding ensues (major feature of dz)

Question 3

symptoms of TTP

Answer 3

thrombocytopenic purpura, microangiopathic hemolytic anemia, neuro sx, renal dysfunction, fever

Question 4

treatment of vWF dz

Answer 4

cryoprecipitate (replaces vWF)

desmopressin (DDAVP) (causes release of vWF from endothelium)

Question 5

describe hereditary hemorrhagic telangiectasia

Answer 5

thinning of vessels walls w/ telangiectatic formations, arteriovenous malformations, and aneurysmal dilations throughout the body

Question 6

cause of hereditary hemorrhagic telangiectasia

Answer 6

AD mutation in endoglin (CD105)

Question 7

clinical features of hereditary hemorrhagic telangiectasia

Answer 7

telangiectasias (skin, mucous membranes, visceral tissues)

bleeding (w/ mild or inapparent trauma, epistaxis)

Question 8

clinical features of antithrombin III deficiency

Answer 8

recurrent lower extremity thrombophlebitis and DVTs, venous insufficiency, chronic leg ulcers

50% have DVT or PE by age 30

Question 9

clinical features of protein C or S deficiency

Answer 9

(similar to antithrombin III def.)

recurrent lower extremity thrombophlebitis and DVTs, venous insufficiency, chronic leg ulcers

Question 10

clinical features of antiphospholipid antibody syndrome

Answer 10

• connective tissue dz (>50% cases)
• prolonged PTT
• valvular heart dz
• coronary artery dz

Question 11

what is homan’s sign

Answer 11

pain in calf or popliteal area on dorsiflexion of the foot

• clinical clue to DVT

Question 12

what is moses sign

Answer 12

pain with compression of calf against the tibia but NOT when squeezing the calf

• clinical clue to DVT (neither sensitive or specific)

Question 13

what is lisker’s sign

Answer 13

pain with percussion of anteromedial tibia

• clinical clue to DVT (not sensitive or specific)

Question 14

what is lowenberg’s sign

Answer 14

BP cuff applied to mid-calf and pain is elicited with inflation to 80 mmHg

• clinical clue to DVT (not sensitive or specific)

Question 15

most common malignancies associated with DVT/PE

Answer 15

• lung (17%)
• pancreas (10%)
• colon and rectum (8%)
• kidney (8%)
• prostate (7%)

Question 16

list the drugs that are associated with drug-induced hypercoagulability

Answer 16

tamoxifen, bevacizumab, thalidomide, lenalidomide