Venous disease lecture Flashcards
(29 cards)
Describe perforating veins
Communicate between the superficial & deep venous systems.
Venous blood flow is usually superficial to deep in the leg except in the foot - deep to superficial
Describe the Muscular venous pump
muscle contraction pumps [deep] venous blood toward the heart (proximally)
Venous pump:
1) What prevent retrograde flow and protect superficial veins from increased pressure?
2) Ambulatory venous pressure in the superficial system is normally between what?
1) Competent valves
2) 20 and 30 mmHg
True or false: Most PEs come from DVTs
True
VTEs: What are the 2 main kinds? How common are they?
1) 2/3 DVT: Proximal DVT, 40% also have PE
2) 1/3 PE: 70% of patients with PE have DVT
What is the mortality rate for DVT
What abt for PE?
1) 6% with DVT
2) 12% with PE
List the risk factors for VTE
1) Virchow’s triad: Stasis, Hypercoagulability, Endothelial injury
2) Male, family Hx, prior episode of VTE, prior stroke, malignancy, Covid, pregnancy/postpartum, OCP, smoking
3) Obesity
Pre-Test Probability for DVT is evaluated with what tool?
Wells criteria
Describe what’s used to diagnose DVT
1) D-dimer (ELISA)
2) Pre-test probability affects interpretation of test results
3) Negative/normal D-dimer in low probability DVT unlikely - monitor
4) Moderate or high probability Wells Score - D-dimer not helpful, obtain US
-Venous compressive US has 94% PPV
Venous compressive US has 94% PPV for DVT:
1) What if it’s negative but high clinical suspicion?
2) Who does it have best sensitivity and specificity for?
3) What are the limitations?
1) Re-image in 5-7 days
2) Symptomatic patient with proximal DVT LE
3) New vs. old clot, isolated pelvic clot can be missed, tumor or abscess may lead to false positive test result
Work up in patient with a positive US for DVT should include what 5 things?
1) Screening for malignancy – cancer risk 1.3 x baseline
2) H&P with rectal and pelvic exams
3) Labs: CBC, LFTs, stool guiac
4) CXR
5) Age-appropriate screening
+Screening for thrombophilia if risk criteria
Describe screening for malignancy in a pt with a US + for DVT
1) Aggressive work up not recommended – cancer typically makes presence known prior to VTE
-Myeloproliferative, lung, ovary, brain, malignant melenoma
Describe when you should screen for thrombophilia when a pt has a + US for DVT
Don’t routinely screen; consider screening if:
1) Initial VTE prior to age 50
2) Family hx of VTE
3) Non-extremity site of DVT
4) Warfarin induced skin necrosis
A pt has a + US for DVT:
1) Thrombophilia Testing ideally done prior to what?
2) Explain what this includes
1) Anticoag
2) Protein C & S, fibrinogen, AT III, factor 5 Leiden, lupus anticoagulant, anticardiolipin antibody, prothrombin 20210 (protein C & S, ATIII can be inaccurate with active clot)
How do you Tx VTE when GI cancer is not present?
1) DOAC preferred when GI cancer not present: increased time in therapeutic window, lower bleeding risk, patient conveinence
a) Rivaroxaban (Xarelto) or Apixaban (Eliquis) – no bridge
b) Dabigatran (Pradaxa) or Edoxaban (Savaysa) – requires Lovenox bridge
2) Dose adjust DOAC for renal disease
3) LMWH with concurrent warfarin is still acceptable
VTEs: Describe reversal of DOACs
Antidotes now available for some
Charcoal
Hemodialysis
How do you Tx cancer associated VTE?
1) DOACs recommended over LMWH except for GI luminal cancers: use LMWH
2) Warfarin 3rd line: more bleeds and recurrences of VTE
Acute isolated distal DVT: What part of Tx can you skip? Explain
1) Can skip AC
2) No severe symptoms and low risk for extension – serial US q2 weeks vs. OAC
What are some risks for extension of Acute isolated distal DVT?
-Strong + d-dimer
-> 5 cm clot
-Thrombus close to proximal veins
-No reversible provoking factors
-Active cancer
-Previous VTE
-Inpatient status
Outpatient Rx with DOAC is safe and cost effective for managing VTE if what 4 things are true?
1) Ambulatory and stable – no oxygen requirement or need for IV antibiotics or pain control
2) Low risk of bleeding
3) No renal insufficiency
4) Reliable patient, system to monitor for complications
What are the 3 main inpatient Tx criteria for VTEs?
1) Massive DVT or symptomatic PE
2) High risk for bleeding
3) Co-morbid conditions
Describe the duration of VTE Tx
1st 3 months is highest risk of extension or embolization; treatment duration:
1) 3 months for transient (provoked) DVT/PE
-Surgical or non-surgical, Covid
2) 3+ months if permanent (chronic or non-provoked) DVT/PE
3) Long term if low or moderate risk of bleeding
-If stopping at 3 months, start ASA if no contraindications
4) Indefinite if recurrent DVT/PE
VTE management: Describe the pros and cons of catheter directed thrombolysis of DVT
(don’t really need to know)
1) Adjunct to AOC to reduce the clot burden faster and prevent post thrombotic syndrome
-Less chronic venous insufficiency
Iliac and proximal femoral vein most benefit
2) Risk: bleeding
VTE management:
1) When should you consider systemic thrombolysis? What should you start prior?
2) When should you consider IVC filter?
(don’t really need to know)
1) If SBP < 90; start AOC prior to confirm
2) If AC contraindicated; remove after treatment window to decrease risk of recurrence of DVT
