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DVT and PE Pathophysiology, prophylaxis, treatment Anton Sharapov

DVT and PE

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DVT and PE. Pathophysiology, prophylaxis, treatment Anton Sharapov. Cases to consider. 38 yom for elective IHR 65 yom for elective IHR 65 yom, obesity/CHF/prev DVT for IHR 25 yof post severe head injury 25 yom post trauma/abdo/chest 75 yof post hip # 65 yom post THA, obese. - PowerPoint PPT Presentation

Text of DVT and PE

  • DVT and PEPathophysiology, prophylaxis, treatment Anton Sharapov

  • Cases to consider38 yom for elective IHR65 yom for elective IHR65 yom, obesity/CHF/prev DVT for IHR25 yof post severe head injury25 yom post trauma/abdo/chest75 yof post hip #65 yom post THA, obese

  • Scope of the problemCommon postop complicationAsymptomatic > symptomaticDifficult to studyMost studies evaluate asymptomatic pts

  • EpidemiologyVTE 48:100,000PE 69:100,000Incidence 20-70% surgery pts begin in OR

  • EpidemiologyDVT and PE different stages of same disease process10% proximal DVTs progress to symptomatic PE25% distal DVTs become proximal

  • OutcomesMost asymptomatic VTE recover sans treatment and complicationsLess then 1 in 8 confirmed clots progress to symptomatic thromboembolic diseaseImportant to observe clots over a period of time

  • Outcomes of PEOutcomes of PE are difficult to assessRegistry estimates are always higher then in clinical studies (7% vs 2%)Mortality is a function of RV function, clot burden, and comorbiditiesRisk of fatal PE greatest 3-7 postopAsymptomatic PE are common40% of asymptomatic prox DVTs

  • AssessmentAssess risk of DVT and risk of bleedingAssess duration of prophylaxisAssess Virchov triadVenous stasisEndothelial injuryhypercoagulability

  • Risk factors: venous stasisImmobility & tourniquet applicationInstitutionalizationCVAParalysisCHFTravel >4 hoursObesityRespiratory failureVaricose veinsDuration/extent of postop immobilization

  • Risk factors: endothelial injuryTraumaAtherosclerosisPerioperativeMalignancyPost-phlebitic syndromePrior DVTCV catheterInflamatory conditionHyperhomocysteinemia

  • Risk factors: hypercoagulability, Acquired

    Post opMalignancyHormone replacementEstrogen therapy

  • Risk factors: hypercoagulability, Acquired:Antiphospholipid antibodyLupus anticoagulant 5-10 fold riskMyeloproliferative d/oParoxysmal nocturnal hemoglobinuriaNephrotic syndromePn loosing enteropathy

  • Risk factors: hypercoagulability, Inherited:

    Factor V leiden APC resistanceAbsolute risk post op VTE is small - 1/100Relative risk increased (3-5 fold)Screening not recommendedAntithrombin, pn C/S deficiencyFibrinogen/TPA defectsProthrombin gene mutation

  • Risk factors: MiscelaneousUse/nonuse of thrombopophylactic measuresAge - rises linearly after 40

    Ethnicity:Asian/South Pacific - threefold lowerAfrican American - slightly higherLatin - slightly lower

    Site/extent traumatic injuryKnee/spine=major trauma>hip>uro/gyny> neuro>general/thoracic

  • Risk of DVT, miscellaneousSurgical procedure - most important

    Neurosurgery & ortho - 6% & 3%

    Major vascular

    Bowel, bladder, gastric bypass and kidney transplant

    Radical neck, IHR, lap chole (0.3%),TURP, thyroid/parathyroid - lowest risk

  • Need for global integrative assessmentAmerican College of Chest PhysiciansRisk stratification toolProblems:What defines major vs minor surgeries?No weighting of Risk FactorsWhy age 40 and 60 important?

  • Patient RFSurgical procedureDVTPElowAge40ImmobilizationObesityMalignancyGeneralNeuroUro/gyn20%30%40%2-3%highHx of DVTThrombophiliaHipKneeSpineTrauma50%60%60%60%5%

  • Risk of bleedingBleeding d/oUse of antiplatelet medsPrevious GI bleedCancerHepatic/renal insufficiency?age

  • VTE prophylaxis: whats available?Intermittent compression deviseStockingsASA 80-325 mgUF heparin 5000 bid, tidLMW bidWarfarinAnti Xa pentasaccharide (fondaparinix)

  • Efficacy of mechanical VTE prophylaxis

    Mode VTEbleedingStockingsIPC bootsIVC filter50-60%50-60%PE,DVTNoneNoneProcedure related

  • Early ambulationRoutine for all ptsAcceptable as sole mode for low riskUseful adjunct esp post knee/hip surgery

  • Elastic stockingsFirst shown to work in 1952Decrease venous poolingEvidence of benefit for mod/high risk, but used only as adjunctHarmful if not work correctly

  • ICDWork very wellNot useful form BMI >25Only effective if used correctly and continuously when pt not ambulatingHave potential to reduce ambulationRecommended in mod-high risk gyn surgery as soloNot recommended as sole mode inHighest risk except neurosurgeryHigh risk urologicalHip and knee surgery

  • IVCFor absolute contraindication of anticoagulationFor life-threatening hem on ACFor failure of ACUsed to prevent fatal PETemporary filters preferredIf left in place, cause DVTs

  • Efficacy of pharmacological VTE prophylaxis

  • AspirinNot recommended as sole prophylaxisBeneficial post hip-fracture160 mg OD, 5/52, 13,000 ptsCombined with routine prophylaxisPE 0.7 vs 1.2Fatal PE 18 vs 43

  • UF heparinGood for moderate risk gen surgeryModest increase in bleeding Compared to LMWH (2.65% vs 1.8%)Additive effect of stockings and ICD]Risk of HIT

  • warfarinFor very high risk with lower extremity orthopedic and neuro surgeryFor gen surgery other methods work just as wellGood for extended prophylaxisDelayed onset of action, may start preop!Recommended forHip #, THA, TKA

  • LMW heparin and PentasaccharidedsPreferential inhibition of factor XaFDA approved for DVT prophylaxisNot FDA approved as of yet for DVT prophylaxis in pregnancy, spinal cord injury, trauma, neurosurgery but are being used

  • LMW heparin and Pentasaccharideds contdEffective for mod risk general surgeryGyn/obssecond line to mechanicalTraumaMethod of choice only if risk of bleeding is not significant. If it is stocking+/-ICDRecommended for ortho lower extremity surgeryFondoparinix reduces asymptomatic DVTs only

  • LMW heparin and Pentasaccharideds contdRisk of epidural hematomaStrategiesAvoid regional anesth in those prone to bleedNeedle in 12 h after onset of LMWHSingle dose anesthetic better then infusionD/c cath in 12 hNo dosing of LMWH within 2 h of cath d/c

  • Direct thrombin inhibitorsEffective in initial studiesComparable to LMWHFor HIT pts

  • Duration of prophylaxisStart immediately after or prior to surgery7-10 days postWarfarin may be started 10/7 prior but INR should be less then 1.5Argument for prolonged (30 day) prophylaxis for high risk. DVT incidencesympt 3% vs 1% on treatmentAsympt 19% vs 9% on treatment

  • Prolonged prophylaxisOrthopedicsPost THA for 4-6 weeks with LMWH or warfarin, especially with Risk FactorsObesity, sedentary, prior DVTGeneral surgeryProlonged treatement with LMWH prevents out-pt DVTs but at a marginal cost that was deemed inappropriate

  • Screening for DVT?Not in the asymptomatic pts.

  • Diagnostic strategy of DVTSuspectDupplexFor proximal or ANY symptomatic treatFor distal AND asymptomatic follow with serial duplex US

  • Accuracy of Tests for Diagnosis of PEClinical suspicion is paramount

    testsensitivityspecificityHigh Prob VQ41%97%Spiral CT91%93%D-Dimer90-100%25-60%

  • Diagnostic strategy for PESuspectVQ If normal AND D-Dimer low ruled outIf high probability start treatmentIf indeterminate/nondiagnostic angio, angio CT

  • TreatmentIV heparin, aPTT 1.5- 2.3 normal 5/7May use LMWCoumadin INR 2-3Overlap heparin and warfarin 4/7On warfarin 3-6/12Consider ECHO/trop to evaluate RVF for PE to id High Risk pts.

  • TreatmentHemodynamically unstable PE may require pressure support, fluid status monitoring, and/or thromolysis / surgery

  • Cases to consider38 yom for elective IHR None, low risk65 yom for elective IHRModerate risk, Consider UN heparin pre-op, ambulation, stockings post op50 yom, obesity/CHF/prev DVT for IHRHigh risk, consider LMWH preop/post op. Conisder warfarin

  • Cases concluded25 yof post severe head injuryHigh risk, mechanical, 25 yom post trauma/abdo/chestHigh risk, mechanical initially, consider LMWH when risk of bleeding is low75 yof post hip # High, consider LMWH periop, warfarin or aspirin post op

    65 yom post THA, obeseHigh, consider LMWH periop, warfarin or aspirin post op