Presentation on theme: "Deep Vein Thrombosis Brian M. Johnson, MD CCRMC PBL 11/7/12."— Presentation transcript:
Deep Vein Thrombosis Brian M. Johnson, MD CCRMC PBL 11/7/12
Case 1 Mrs. Z, a 44-year-old woman without significant PMH, presents for an urgent visit with left leg swelling of two days duration. She takes no medications and reports moderate leg pain but no chest pain, shortness of breath, or palpitations.
What is the differential diagnosis of unilateral leg swelling? 1.DVT 2. Cellulitis 3. Baker’s cyst 4. Lymphedema 5. Fracture 6.Post-thrombotic syndrome 7.Venous insufficiency 8.Scorpions? Or bee stings? 9.Toxins 10.Mass 11.Trauma / Compartment syndrome
What are risk factors for DVT? 1.Hospitalization 2.Long-term immobility 3.OCP 4.Smoking 5.Age 6.Surgery 7.Cancer 8.CHF 9.Renal disease 10.Cirrhosis 11.Pregnancy 12.Anti-psychotics 13.Thrombophilias 14.Obesity 15.Restrictive clothing 16.Gender 17.Lupus (and other autoimmune diseases) 18.Sickle Cell
Case Continued… She reports that she has no family history of blood clots to her knowledge and that she is not pregnant. She denies any “warning signs” of cancer and is up to date on her cancer screening (mammogram, Pap smear; no colorectal cancer screening, but she denies family history of colorectal cancer so she is not yet due). She denies recent immobilization or trauma. Her exam is significant for a minimally swollen right calf. To ensure a reliable assessment of circumference, you mark off 10cm below each tibial tuberosity and measure the circumference at that level. You find that the right calf measures 1cm larger in circumference than the left. There is no edema or skin changes; no masses/cords are palpable. The thighs are symmetric, and no superficial veins are noted.
How could you determine the probability of the DVT in this patient?
What is the probability that this patient has a DVT? Modified Wells Clinical featureScore * * Active cancer within 6 mo1 Paralysis, paresis, or cast of lower extremity 1 Recently bedridden >3 d or major surgery within 4 wk 1 Localized tenderness along distribution of deep vein system 1 Calf diameter >3 cm larger than opposite leg † † 1 Pitting edema1 Collateral superficial veins (nonvaricose)1 Alternative diagnosis as likely or greater than that of DVT Clinical model for predicting pretest probability for DVT * Interpretation: 0 = low probability = 3% frequency of DVT; 1-2 = medium probability= 17% frequency of DVT; ≥3 = high probability = 75% frequency of DVT. † Measured 10 cm below tibial tuberosity. -2
How would a d-dimer help? Statistically -Sensitive not Specific (useful if it’s negative) -High false positive rate Biomedically - measures level of coagulation process in the body
Case 2 Ms. W, comes with the exact same presenting complaint and past medical history. The only difference in the presentation of Ms. W. is that she does report that she had the “flu” about one week ago and was in bed for four to five days. Additionally, her exam is significant for a swollen and tender right calf, measuring 4 cm wider in circumference than the left. There is pitting edema on the right lower extremity, extending to the inferior calf. There is no change in the skin, and no masses/cords are palpable. The thighs are symmetric, and no superficial veins are noted.
What’s the probability this patient has a DVT? 75%!! High, with wells score greater than 3
What’s the value of doing a d-dimer? If high probability 21% still positive for DVT even with negative D-dimer
What other test could you preform? Venous Doppler (venography)
Operating characteristics of diagnostic tests for proximal DVT * Black et al. Diagnostic testSensitivity, %Specificity, %Positive LRNegative LR Venography~100 Infinity0 Duplex ultrasonography Impedence plethysmography Iodine 125 fibrinogen scan D-Dimer level LR = likelihood ratio. *
U/S negative. End of story? With high probability clinical exam but NEGATIVE U/S: – Consider other imaging, repeat study or obtain D- dimer. – Consider treatment
U/S positive. Can she be treated as an outpatient? Yes – Need immediate anticoagulation (i.e. Lovenox) then can bridge to warfarin No – Obesity – Cachetic – Renal failure (GFR <40) – High bleeding risk – Complicated medical history – Poor resources
For how long? Unprovoked 6 months? Provoked 6 months?
What’s a provoked DVT and why does it matter? Risk factors – Major: Cancer, Major Surgery, Major trauma – Minor: Preg., long flight, OCP, smoking, minor trauma, minor surgery
Risk of VTE recurrence after stopping anticoagulation Risk factor1 st yearNext 5 years Distal DVT3%<10% Major transient3%10% Minor transient5-6%15% UnprovokedAt least 10%30% Recurrent>10%>30% Kearon, American Society Hematology Dec. 2004
Is longer anticoagulation better in idiopathic DVT? TRIALDurationRecurrenceDurationRecurrence THRIVE3mo7.6/ 100pt yrs2.1 yrs2.6/100pt yrs PREVENT6mo12.6%18 mo2.8% Schulman et al. N Engl J Med 2003 Ridker et al. N Engl J Med. 2003
Do the experts agree with the ACCP recommendations? 8 th ACCP guideline British Thoracic Society Recent recommendations First VTE, Provoked 3 months4-6 weeks 3 months if distal or upper extremity; 6 if proximal DVT or PE First VTE, Idiopathic At least 3 months, evaluate for indefinite tx 3 monthsIndefinite
Should I do the thrombophilia work up?
23 Incidence of recurrent VTE Christensen et al. JAMA Patient group (total 474 pt)Recurrence of VTE/year With 1 thrombophilia2.5% Initial VTE provoked1.8% Initial VTE idiopathic3.3% Idiopathic with thrombophilia 3.4% Idiopathic without thrombophilia 3.2% Total group2.6%
24 How can I determine who’s at risk for recurrent clot? Thrombophilia Male gender Active cancer (i.e. ongoing risk factors) Recurrent dvt Proximal over distal Morbidity from DVT Repeat studies (US and ddimer)
Algorithm for Determining Duration of Treatment After 3m CHECK U/S assess bleeding risk (& discuss indefinite tx if pt with PE, Male or thrombophilia) Female: No residual clot. Clinical risk rule <1, stop AC Male: No residual clot, stop AC, measure d-dimer after 30d and stop if normal. Evidence of residual clot, continue AC and repeat U/S
REFERENCES Bates SM, Kearon C, Crowther M, et al. A diagnostic strategy involving a quantitative latex D-dimer assay reliably excludes deep venous thrombosis. Annals of Internal Medicine. 2003;138(10): Black ER, Bordley DR, Tape TG, Panzer RJ. Diagnostic Strategies for Common Medical Problems. Philadelphia: American College of Physicians; Bruinstoop, E., Klok, F. A.,Van de Ree, M. A., Oosterwijk, F. L. and Huisman, M. V., Elevated d-dimer levels predict recurrence in patients with idiopathic venous thromboembolism: a meta-analysis. Journal of Thrombosis and Haemostasis, 2009;7: 611–618 Ofri D Diagnosis and treatment of deep vein thrombosis West J Med September; 173(3): 194–197. Ridker PM, Goldhaber SZ, Danielson E, Rosenberg Y, Eby CS, Deitcher SR, Cushman M, Moll S, Kessler CM, Elliott CG, Paulson R, Wong T, Bauer KA, Schwartz BA, Miletich JP, Bounameaux H, Glynn RJ, PREVENT Investigators N Engl J Med. 2003;348(15):1425 Rodger et al. Identifying unprovoked thromboembolism patients at low risk for recurrence who can discontinue anticoagulant therapy. CMAJ August 26, 2008 vol. 179 no. 5 Schulman S, Wåhlander K, Lundström T, Clason SB, Eriksson H. Secondary prevention of venous thromboembolism with the oral direct thrombin inhibitor ximelagatran.. N Engl J Med 2003 Oct 30;349: