Evaluation of a thrombophilic patient Flashcards
A 52-y female 4 days after undergoing a right mastectomy for breast cancer develops left leg swelling 3 cm more than her right leg. She has pitting edema on left leg only but no JVD or SOB; and no redness of skin but has calf pain. What is her diagnosis?
- Congestive heart failure
- Left leg DVT
- Post surgical cellulitis
- Allergic reaction to anesthesia
- Left leg DVT
cellulitis- would cause redness
allergic- usually global
*cancer is a high stakes situation for developing DVT
What are the symptoms of DVT?
- calf pain and swelling
- homans sign (pinch the calf)
(or none or sudden death)
What are the symptoms of pulmonary embolism?
- SOB
- pleuritic chest pain
- hemopytsis (coughing up blood)
- shock
(or none or sudden death)
What are some classic risk factors for atherothrombosis?
- smoking
- hypertension
- hyperlipidemia
- metabolic syndrome
- mental stress, depression, CV risk (= high cortisol levels)
What are some novel risk factors for atherothrombosis?
- high-sensitivity CRP + TC:HDLC
- inflammation
- homocysteine
- Fibrinogen and D-Dimer
- Excess VMF or VIII
What are some lab findings that indicate atherothrombosis risk (higher to lower)?
- high-sensitivity CRP + TC:HDLC
- hsCRP
- Apolipoprotein B
- serum amyloid A
- LDL cholesterol
Is obesity a risk factor for VTE?
Patient population at risk?
Yes, BMI over 30 associated with 2-2.5 fold increased risk
incident goes up with age (pre-menopausal females are slightly protected)
Obesity also potentiates the risk of VTE with other factors such as ____ and _____.
Oral contraceptives (10 fold instead of 2-3 fold)
HRT (6 fold instead of 2-3 fold)
What is Wells criteria?
scoring system for likelihood of getting DVT
What are some of the Wells criteria?
- active cancer treatment (within last 6 months)=1
- paralysis=1
- recent bedridden for 3+ days=1
- entire leg swollen=1
- localized tenderness along the distribution of the deep venous system=1
- 3 cm calf swelling=1
- pitting edema on leg=1
- previous DVT=1
- alternative cause = -2
5+ is very high
What are white clots?
clots in high flow arterial circulation consisting of platelets and fibrin mostly
What are red clots?
clots in low flow (stasis) venous circulation consisting of red cells and fibrin
Why would hemolytic anemias lead to thrombus formation?
- reversal of phosphotidylserine residues activates prothrombinase complex
- free hemoglobin quenches NO (increases vasospasm)
- more phospholipid surfaces are made (PF3)
T or F. Leukocytosis promotes thrombus formation
T. Obviously, too many red cells or platelets can cause thrombus formation too
T or F. The classical risk factors for atherothrombosis are less for VTE but are similar
T.
Factor V Leiden and G20210A Prothrombin are common in what populations?
Caucasian
Risk of DVT is factor V homozygous-80x (higher than prothrombin and oral contraceptive risks)
Elevated FVIII is common in what population?
African American (so is sickle cell trait)
T or F. Anticoagulant deficiencies are more severe than things like Factor V leiden or Prothrombin 20210A.
T. Antithrombin deficiency is more severe than protein C, followed by S deficiency
then Factor V then Prothrombin 20210A
What are you at risk of, bleeding or clotting, with a factor XII deficiency?
could be EITHER! XII is also a feedback inhibitor of the process
How would the PT of a prothrombin 20210A patient look?
shorter due to increased production of prothrombin
pregnancy is affected here too
How can renal failure lead to hyper-homocytseinemia?
renal failure leads to decreased folic acid levels
high homocysteine= high clot risk
What is the biggest acquired cause of thrombophilia?
cancer
What are some other acquired causes of thrombophilia?
- surgery
- diabetes
- nephrotic syndrome
- congestive heart failure
- antiphospholipid syndrome
- PNH, TTP, DIC
- oral contraceptives
Why would surgery cause a hyper-coagulable state?
whenever you cut someone open the body will naturally start to clot
Why would nephrotic syndrome cause a hyper-coagulable state?
you are spilling out proteins like antithrombin
Why would CHF cause a hyper-coagulable state?
because you are affecting the liver and slowing venous circulation
Why would oral contraceptives cause a hyper-coagulable state?
increases FVIII and messes with fibrinolytic mechanisms
Why would prothetic valves cause a hyper-coagulable state?
surface for coagulation
When would antithrombin be reduced?
pregnancy liver disease DIC nephrotic syndrome surgery acute thrombosis heparin estrogen
When would protein C be reduced?
liver disease
DIC
acute thrombosis
warfarin
When would protein S be reduced?
pregnancy liver disease DIC acute thrombosis warfarin estrogen
What is the clinical triad for PNH?
- hemolytic anemia
- venous thrombosis (much higher risk than anti-coag deficiencies)
- bone marrow failure
What will you see on a dipstick for PNH?
dipstick positive for blood but no red cells, only hemoglobin
What are some of the side effects of lupus anticoagulant (APS)?
- not bleeding
- venous thrombosis
- pregnancy loss in 2nd tri.
- livedo reticularis
- thrombocytopenia
What cancer have the highest risk of VTE?
GI cancer, then pancreatic then breast on chemo
What is the most common anti-coagulant therapy in cancer patients?
low molecular weight heparin
When does thrombosis require workup for thrombophilia?
- venous thrombosis under 45 y/o
- unprovoked or recurrent thrombosis
- family history
What is the best predictor of recurrence for VTE?
D-Dimer
What defenses does the endothelium have against clot?
- ADPase
- NO
- PGI2
- thrombomodulin
- t-PA
ACCP Guidlines for duration of anticoag therapy
first event reversible- 3-6 months at INR 2-3
unprovoked VTE, first or second event- 6-12 months at INR 2-3 and then review risk of recurrence
infinite- cancer, APS, any anticoag deficiencies
