1 / 124

PULMONARY EMBOLISM AND DEEP VENOUS THROMBOSIS

PULMONARY EMBOLISM AND DEEP VENOUS THROMBOSIS. James Huffman 11.13.2008 Thanks to Dr. Gil Curry, Dr. Nadim Lalani. Outline. Epidemiology / Pathophysiology DVT Anatomy Clinical Presentation Diagnostic Approach Pre-test probability Labs Imaging Real-Life Algorithm Treatment. Outline.

acton
Download Presentation

PULMONARY EMBOLISM AND DEEP VENOUS THROMBOSIS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. PULMONARY EMBOLISM AND DEEP VENOUS THROMBOSIS James Huffman 11.13.2008 Thanks to Dr. Gil Curry, Dr. Nadim Lalani

  2. Outline • Epidemiology / Pathophysiology • DVT • Anatomy • Clinical Presentation • Diagnostic Approach • Pre-test probability • Labs • Imaging • Real-Life Algorithm • Treatment

  3. Outline • PE • Clinical Presentation • Diagnostic Approach • Pre-test probability • Labs • EKG • Imaging • X-ray, CT, MR • Real-Life Algorithm

  4. Focus: the bottom line

  5. Epidemiology • VTE is a ‘spectrum’ : Simple superficial thrombophlebitis to fatal PE • Est incidence : 100 /100 000 • 1/3 of cases are PE • Increases dramatically with age (sharp increase after the age of 45) • DVT: • Only 1/3 of pts investigated for DVT have it • “silent” PE present in 40-60% of pts with DVT • In asymptomatic pts w/ proven DVT, up to 1/3 will have undiagnosed PE • With treatment 50% have residual clot up to 1y • Without treatment 50% recurrence w/ in 3 mo

  6. Epidemiology • PE: • 10% fatal w/ in 1st Hour • 75% pt w/ PE have DVT (2/3 proximal vein) • Classic presentations are less common than atypicals and asymptomatic VTE is common • 20% have “pleuritic CP” in ED • 5-10% PE have shock as initial presentation • Despite treatment, kills 1-8% • Complications: • postphlebitic syndrome [40%] • pulmonary HTN [4%]

  7. Pathophysiology of Thrombosis • Fibrinogen is converted to fibrin in response to vasc. Injury and inflammation • Fibrin is 1° structural framework of embolized clots and excessive fibrin deposition provides the nidus of VTE • VTE is the end-product of imbalanced clot formation and breakdown What promotes this imbalance of fibrin deposition and removal?

  8. Virchow’s TriadWhite, RH: The epidemiology of venous thromboembolism. Circulation 107(23 Suppl 1):I4, 2003. • Injury to the vascular endothelium • Alterations in blood flow • Hypercoagulability Anything else associated with imbalanced clot formation? Age – likely through a combination of the above mechanisms

  9. Coagulation Cascade

  10. Coagulation Cascade PTT Heparin PT/INR Warfarin

  11. Anatomy • Depth • Deep • Superficial* • Proximal • Popliteal v. or higher • Distal *Superficial femoral vein is a member of the deep group

  12. Case 1 • 55♀: Referred to ED for pain, redness and swelling of right calf • WIC today: Sent to ED with note:

  13. History • Started 3/7 ago • Denies previous DVT • Has been on IV combo chemotherapy for ovarian Ca diagnosed six months ago (extensive pelvic lymph node involvement – which has improved as per recent U/S) • Fell day before this started and “twisted her knee” • All this is good – what are your main goals with history? • Determine pre-test probability of DVT • Look for other causes

  14. DVT: History is Risk Assessment Hypercoagulability: • Autoimmune Disease and Immune Deficiency • Not just SLE! Remember IBD • Cancer • Chemotherapy: especially breast CA • Coagulopathy:  Factor V Leiden. Present in 7% pop = 50%  Protein C, protein S & antithrombin III deficiency = 15% DVT.  Resistance to aPC  Lupus anticoagulant  Prothrombin G20210A  antiphospholipid antibodies  others

  15. DVT: History is Risk Assessment Stasis: • Immobility: Not just surgery – remember other conditions (oldies!) • Heart Disease (AMI & CHF): independent of bedrest • Travel ?Duration / proximity? • Hyperlipiedmia • Polycythemia Endothelial Injury: • Stroke • Vascular surgery • PVD Others: • Age, race, prior DVT, blood types, tissue antigens, homocysteine

  16. Case 1 Continued • When you examine her what do you expect to find? • P/E: • Generalised tenderness to her calf • Exquisite pain in popliteal fossa along vein • Edema, erythema and warmth • Swollen 3.5 cm • Homan’s Sign + • What do you think of this?

  17. Physical is Risk AssessmentAnand, SS, Wells, PS, et al. 1998. Does this Patient have deep vein thrombosis? JAMA:279(14) • Classically: • Leg tenderness , Homan’s Sign • Swelling • Pitting edema • Dilated superficial veins • Erythema • Calor • Neither sensitive nor specific • OR’s between 2- 4

  18. Physical is Risk AssessmentAnand, SS, Wells, PS, et al. 1998. Does this Patient have deep vein thrombosis? JAMA:279(14)

  19. DVT: H&P Bottom Line • Neither is sensitive or specific • i.e. you can’t rule-in or rule-out a DVT • Use them to decide pre-test probability

  20. Clinical Prediction Rule: EvolutionLandefeld et. Al 1990 • 354 pts suspected of DVT that underwent venography • 5 clinical predictors identified: • 1 or more  95% Sens [92-100] 20% spec [15-25] • Swelling above the knee • Swelling below the knee • Recent immobility • Fever • Cancer • Absence of all  only 5% DVT

  21. Pretest ProbabilityWells, P., et al. 1995. Accuracy of Clinical Assessment of Deep Vein Thrombosis. Lancet:345; 1326-30 • First Wells Criteria • Based on literature review and clinical experience of investigators • Study showed value in stratifying pretest probability with respect to eliminating need for repeat u/s

  22. Pretest ProbabilityWells, P, et al. 1997. Lancet:350;1795. • Revised Wells score through logistic regression analysis • Prospectively validated using same treatment algorithm (next slide) • 593 patients from two Canadian tertiary care centres • Score ≥ 3 (high risk), 1 or 2 (moderate risk), <1 (low risk)

  23. Pretest ProbabilityWells, P, et al. 1997. Lancet:350;1795. • 593 pts w/ suspect DVT • Stratified low, mod, high risk  compression U/S /veno • 3% of Low risk, 17% of moderate risk, 75% of high risk pts had DVT • Concluded that Clinical probability + U/S safe [0.6% missed]

  24. Pretest Probability • This algorithm re-presented in JAMA rational clinical examination series Anand SS, Wells PS, Hunt D, Brill-Edwards P, Cook D, Ginsberg JS. Does this patient have deep vein thrombosis? JAMA. 1998 Dec 2;280(21):1828-9. • What’s missing? The N’Dimer!

  25. Assay Sensitivity Specificity Whole blood 80 - 85% 70 - 90% agglutination (SimpliRED) Latex 90 - 95% 40 - 90% agglutination R apid ELISA 95 - 100% 30 - 60% D-Dimer Testing • U/S not a perfect test • Degradation product of fibrin • Non-specific • PPV bad • +ve: surgery, trauma, hemorrhage, CA, pregnancy, sepsis, >80 yrs old • Sensitivity variable • Need Pre-test probability to r/o DVT CHR uses

  26. D-Dimer TestingWells, P., et al. 2003. NEJM: 349(13); pp1227-35 • RCT (N=1096) • D-Dimer vs no D-Dimer • DVT Likely = Wells ≥ 2 • # of U/S per pt decreased in D-dimer group (0.78 vs 1.34)

  27. D-Dimer TestingWells, P., et al. 2003. NEJM: 349(13); pp1227-35 • “Modified” Wells Criteria • Used SimpliRED and IL-Test assays (less sens) • Conclusion: • Clinical prediction rule + D-Dimer can safely r/o DVT

  28. Case 1 continued • Pretest probability? • Active cancer (1) • Localized tenderness (1) • Calf swelling (1) • Edema (1) • Other Diagnosis? Compression by pelvic nodes? (Doesn’t matter – score would still be “not low risk”) • What about the D-Dimer – Would you order it? • Doesn’t matter – it was sent already • Level positive at 1.77C • Both CMAJ and Well’s protocols would have you order it anyway (we’ll discuss) So she gets either 4 or 2 points = DVT likely

  29. What next Einstein?

  30. UltrasoundAmerican Journal of Respiratory Critical Care Medicine. 1999: 160; 1043-66 • Well studied • Widely available • Proven accurate for Dx symptomatic prox DVT • Like CT/PE provides other Dx: hematomas, baker’s cysts, lymphad, aneurism, thrombophlebitis and abscess • Has been advanced by the combination of compression and doppler Bottom line: U/S is the test of choice for DVT

  31. Duplex UltrasoundStork, A. 2005. Calgarian J of PPT Slides. 1(1) pp1 • Two parts i) Compression - Tech applies pressure - clot  not compressible ii) Doppler (B mode) • Shows blood flow

  32. Ultrasound Fields, JM, & Goyal, M. Venothromboembolism. Emerg Med Clin of N Am. 2008; 26: 649-83

  33. EDE • Jolly BT, et al. Acad Emerg Med 1997;4(2):129–32. • Retrospective analysis 1994 • EPs trained to perform colour doppler US (20-30 studies each) • 100% sensitive, 75% specific for acute DVT • 2 false-positives were in chronic DVT • Frazee BW, et al. J Emerg Med 2001;20(2):107–12. • Prospectively demonstrated 95.7% NPV for EP performed LCUS

  34. Naughty by Nature - “Feel me flow”

  35. EDE – ED Flow • Blaivas M, et al. Acad Emerg Med. 2000;7(2):120–6. • Median exam time of 3m 28s • 98% correlation with vascular lab-performed studies on same pts • Theodoro D, et al. Am J Emerg Med. 2004;22(3):197–200. • 125m reduction in time to pt disposition with EP-performed US • Kappa = 0.9, 99% agreement (154/156 cases) • Jang T, et al. Acad Emerg Med. 2004;11(3):319–22. • 8 emerg residents (4 PGY-1, 2 PGY-2, 2 PGY-3) • 1h focused training (didactic and practice on 2 healthy volunteers) • SN = 100%, SP = 91.8%, avg scan time = 11.7min (self-reported) • 4 false-positives (chronic DVT), 0 false-negatives

  36. Ultrasound: Limitations • Obese, ++edema, immobilsation devices (x-fix) • Doesn’t see isolated thrombi in iliac or superficial femoral veins within abductor canal MRI better • Pelvic masses may cause noncompressibility in absence of thrombus  false +’ve • Most importantly: U/S doesn’t return to normal after acute DVT • Therefore use impedance plethysmography for recurrent DVT • U/S - 60-70% of studies return to normal at one year • IP – 90% return to normal within a year

  37. CT-VenographyGoodman LR, Stein PD, Matta F, et al. AJR Am J Roentgenol 2007;189(5): 1071–6 • PIOPED II Data • 711 pts with CT-V and sonography • Results: • 95.5% concordance for dx or exclusion of proximal DVT • Kappa = 0.809 • Simlar results across all subgroups (asymptomatic, symptomatic, previous DVT)

  38. Bottom Line Thus Far? • Hx/PE help us decide pretest probability (Wells) • We add in a sensitive Test (D-Dimer) • And a sensitive confirmatory test (U/S) ‘Cause Stone Cold says so!

  39. Real-Life ApproachScarvelis, D., and P. Wells. 2006. Diagnosis and Treatment of DVT. CMAJ: 175(9); 1087.

  40. Or…the 1620h approachFields, JM, & Goyal, M. Venothromboembolism. Emerg Med Clin of N Am. 2008; 26: 649-83

  41. CHR Approach • The next 4 slides describe the current Calgary Health Region approach • Not many people use this as it is a bit outdated but I’ve kept the slides here for your interest

  42. Wells Criteria for Probability of DVT LOW PROB < 0 points MOD PROB 1 or 2 points HIGH PROB >3 points

  43. LOW PROBABILITY DVT D-Dimer Neg Positive STOP CUS legs DVT Normal STOP TREAT

  44. MODERATE PROBABILITY DVT D-Dimer Neg Positive STOP CUS legs Normal DVT CUS leg in 1 week TREAT Normal Positive STOP TREAT

  45. HIGH PROBABILITY DVT CUS legs Normal DVT Venography TREAT Normal Positive STOP TREAT

  46. Case 1 Continued • Okay back to it… • U/S shows popliteal vein DVT • Management Doctor?

More Related