pe and dvt
DESCRIPTION
PE and DVT. Pathogenesis of VT. Virchow’s triad: Damage to vessel wall Venous stasis Hypercoagulability. Source. Most PE’s originate from thrombi in the deep venous system of the legs, although they may also originate in the pelvic, renal or upper extremity veins. - PowerPoint PPT PresentationTRANSCRIPT
PE and DVTPE and DVT
Pathogenesis of VTPathogenesis of VT
Virchow’s triad:Virchow’s triad:– Damage to vessel wallDamage to vessel wall– Venous stasisVenous stasis– Hypercoagulability Hypercoagulability
SourceSource
Most PE’s originate from thrombi in the deep Most PE’s originate from thrombi in the deep venous system of the legs, although they may venous system of the legs, although they may also originate in the pelvic, renal or upper also originate in the pelvic, renal or upper extremity veins. extremity veins. HOWEVER, less than 30% of pts will have HOWEVER, less than 30% of pts will have symptoms in their legs at the time of diagnosis of symptoms in their legs at the time of diagnosis of PEPE20% of calf vein thrombi propagate above the 20% of calf vein thrombi propagate above the popliteal fossa. popliteal fossa. 20% of lower extremity venous emboli begin in 20% of lower extremity venous emboli begin in the proximal veins without prior calf involvement. the proximal veins without prior calf involvement.
Acquired Risk FactorsAcquired Risk Factors
AgeAgePrevious thrombosisPrevious thrombosisImmobilizationImmobilizationMajor surgery – especially OrthoMajor surgery – especially OrthoEstrogen – OCP, HRT, SERMsEstrogen – OCP, HRT, SERMsAntiphospholipid Ab syndromeAntiphospholipid Ab syndromeMalignancyMalignancyNephrotic syndromeNephrotic syndromeInflammatory bowel diseaseInflammatory bowel diseaseMyeloproliferative d/o – esp p. vera and ETMyeloproliferative d/o – esp p. vera and ETPNHPNHLong distance air travelLong distance air travelHITHIT
Inherited Risk FactorsInherited Risk Factors
Factor V Leiden mutationFactor V Leiden mutation
G20210A prothrombin gene mutationG20210A prothrombin gene mutation
Antithrombin deficiencyAntithrombin deficiency
Protein C or S deficiencyProtein C or S deficiency
DysfibrinogenemiaDysfibrinogenemia
HyperhomocysteinemiaHyperhomocysteinemia
PresentationPresentation
DyspneaDyspneaPleuritic chest painPleuritic chest painCough +/- hemoptysisCough +/- hemoptysisOn exam may have On exam may have
TachypneaTachypneaTachycardiaTachycardiaS4S4Loud P2Loud P2May have fever – rarely >102May have fever – rarely >102In massive PE can have hypotension and shockIn massive PE can have hypotension and shock
Look at legs for swelling and Homan’s sign – but Look at legs for swelling and Homan’s sign – but only helpful if positive. only helpful if positive.
Homan’s SignHoman’s Sign
Passive dorsiflexion of the foot with the Passive dorsiflexion of the foot with the knee straight may give pain in the calf and knee straight may give pain in the calf and back of the knee when there is a deep back of the knee when there is a deep venous thrombosis. venous thrombosis.
Some concern that vigorous dorsiflexion of Some concern that vigorous dorsiflexion of the foot can expel clot from the veins and the foot can expel clot from the veins and so this test may have its dangers. so this test may have its dangers.
The sign is not specific for DVTThe sign is not specific for DVT
DDX swollen calfDDX swollen calf
DVTDVTBakers CystBakers CystCellulitisCellulitisGout – if really bad it can sometimes look Gout – if really bad it can sometimes look like a cellulitislike a cellulitisIf bilateral think about CHF, Nephrotic If bilateral think about CHF, Nephrotic syndrome, liver failure, venous syndrome, liver failure, venous insufficiency, pregnancy or pelvic mass, insufficiency, pregnancy or pelvic mass, vasodilators esp nifedipinevasodilators esp nifedipine
ABGABG
Usually shows hypoxia, hypocapnia, respiratory alkalosisUsually shows hypoxia, hypocapnia, respiratory alkalosisA-a gradient:A-a gradient:
Normal 7-14 depending on ageNormal 7-14 depending on ageIncreases with age, FiO2 and supine postureIncreases with age, FiO2 and supine postureEstimate of normal for age: Estimate of normal for age:
– Age/4 +4Age/4 +4
A-a gradient = (FiO2 x713 – pCO2/0.8) – PaO2A-a gradient = (FiO2 x713 – pCO2/0.8) – PaO2
If A-a gradient normal, PaO2 <80, Pa CO2 >45 then If A-a gradient normal, PaO2 <80, Pa CO2 >45 then hypoventilation accounts for hypoxiahypoventilation accounts for hypoxiaIncreased A-a gradient occurs in V/Q mismatch, Increased A-a gradient occurs in V/Q mismatch, shunting and any kind of barrier to diffusion (e.g. shunting and any kind of barrier to diffusion (e.g. pulmonary edema)pulmonary edema)BUT can be normal and still have PE!BUT can be normal and still have PE!
LabsLabs
Troponin, LDH, AST and BNP may all be Troponin, LDH, AST and BNP may all be elevatedelevated
Check baseline CBC, PT/PTT/INR, CrCheck baseline CBC, PT/PTT/INR, Cr
D-dimer D-dimer Normal D-dimer excludes PE, but positive D-Dimer Normal D-dimer excludes PE, but positive D-Dimer is not helpful (as it can be positive in many is not helpful (as it can be positive in many conditions including sepsis, immobility, post Sx and conditions including sepsis, immobility, post Sx and CAP)CAP)
EKGEKG
May have non specific ST and T wave changesMay have non specific ST and T wave changes
““Typical” SI, QIII, TIII - rare. Typical” SI, QIII, TIII - rare.
Sinus tachycardiaSinus tachycardia
T wave inversions in right to mid chest leadsT wave inversions in right to mid chest leads
Poor R wave progression (acute RV dilation)Poor R wave progression (acute RV dilation)
P pulmonaleP pulmonale
RV conduction delaysRV conduction delays
Right axis shiftRight axis shift
CXRCXR
May have area of atelectasisMay have area of atelectasis
May have wedge shaped infarct May have wedge shaped infarct peripherallyperipherally
Pleural effusion occurs in about 40%Pleural effusion occurs in about 40%
DVT – D-DimerDVT – D-Dimer
Fibrin degradation product elevated in active Fibrin degradation product elevated in active thrombosisthrombosis
Negative test can help exclude VTENegative test can help exclude VTE
Preferred testPreferred test– Quantitative Rapid ELISA – sensitivity 96/95% for Quantitative Rapid ELISA – sensitivity 96/95% for
DVT/PEDVT/PE– Other methods include latex agglutination and RBC Other methods include latex agglutination and RBC
agglutination (SimpliRED)agglutination (SimpliRED)
Stein PD, Hull RD, Patel KC, et al. D-dimer for the exclusion of acute venous thrombosis and pulmonary embolism: a systematic review. Ann Int Med. 2004;140(8):589-602
DVT – D-DimerDVT – D-Dimer
In 283 patients with In 283 patients with suspected DVT, low-suspected DVT, low-moderate Wells DVT moderate Wells DVT score and negative d-score and negative d-dimer only 1 (NPV dimer only 1 (NPV 99.6%) had DVT over 99.6%) had DVT over next 3 monthsnext 3 months
Bates SM, Kearon C, Crowther M, et al. Ann Intern Med. 2003;138:787-94
• Sensitive d-dimer testing can rule out DVT in low-moderate risk patients
Doppler US of lower extremitiesDoppler US of lower extremities
If high clinical suspicion should be If high clinical suspicion should be repeated 7-10 days after initial scan as repeated 7-10 days after initial scan as below knee DVT can propagatebelow knee DVT can propagate
Also remember that some pt develop Also remember that some pt develop DVT’s elsewhere – so you may not find a DVT’s elsewhere – so you may not find a DVT in their legs if the source was their DVT in their legs if the source was their arm!arm!
PE – Assigning Pretest ProbabilityPE – Assigning Pretest Probability
Single most important step in the diagnosis of Single most important step in the diagnosis of pulmonary embolismpulmonary embolismMay be done based on clinical judgment or May be done based on clinical judgment or aided by a clinical scoring systemaided by a clinical scoring systemModified Wells Criteria is the most widely used Modified Wells Criteria is the most widely used and studiedand studiedReliably stratifies patients by likelihood of PE to Reliably stratifies patients by likelihood of PE to allow selection of safe (<2% VTE risk if no allow selection of safe (<2% VTE risk if no anticoagulation) management strategyanticoagulation) management strategy
DVT – Wells ScoreDVT – Wells Score
CancerCancerParalysis or plaster Paralysis or plaster immobilizationimmobilizationBedrest > 3d or surgery Bedrest > 3d or surgery in past 4 wksin past 4 wksLocalized tendernessLocalized tenderness
Entire leg swollenEntire leg swollenCalf > 3cm larger than Calf > 3cm larger than unaffected legunaffected legPitting edema greater Pitting edema greater than unaffected legthan unaffected legCollateral superficial Collateral superficial veinsveins
The following were assigned a point value of 1 if present:
• Alternative diagnosis more likely than DVT = - 2 points• Probability High (≥ 3), Moderate (1-2) or Low (0 or less)• DVT risk: High – 75%, Moderate – 17%, Low – 3%
Wells PS, Andersen DR, Bormanis J et al. Lancet. 1997;350:1795-8
PE – Imaging StudiesPE – Imaging Studies
PIOPED study quantified the value of V/Q scans PIOPED study quantified the value of V/Q scans in diagnosing PEin diagnosing PE– Normal/near-normal scans exclude PE in low-Normal/near-normal scans exclude PE in low-
moderate risk patientsmoderate risk patients– High probability scans confirm PE in moderate-high High probability scans confirm PE in moderate-high
risk patientsrisk patients– Drawbacks: more difficult test and 73% patients had Drawbacks: more difficult test and 73% patients had
indeterminate scansindeterminate scans
LE compression US showing DVT helps LE compression US showing DVT helps diagnostically, but a negative study insufficient diagnostically, but a negative study insufficient to exclude VTEto exclude VTE
PIOPED Study. JAMA. 1990;263(20):2753-59
Clinical Models to Assess PE RiskClinical Models to Assess PE RiskPIOPED Criteria – Correlates well with incidence of PEPIOPED Criteria – Correlates well with incidence of PE
Based entirely of clinician impression, not clinical risk factorsBased entirely of clinician impression, not clinical risk factors
Pretest Clinical Gestalt Pretest Clinical Gestalt of PE Probability of PE Probability
Actual PE Rate on PA Actual PE Rate on PA AngiogramAngiogram
Low (“<20%” should Low (“<20%” should have PE) have PE)
9% 9%
Intermediate (“20-79%” Intermediate (“20-79%” should have PE) should have PE)
30% 30%
High (“80-100%” should High (“80-100%” should have PE) have PE)
68% 68%
PIOPED Investigators. JAMA 1990; 263: 2753-2759.
PE – Helical CT (CTA)PE – Helical CT (CTA)
Eng performed a systematic review (SR) of all studies & Eng performed a systematic review (SR) of all studies & SRs on CTA prior to 2003SRs on CTA prior to 2003– Only 1/6 SRs and 3/8 primary studies found CTA >90% sensitive Only 1/6 SRs and 3/8 primary studies found CTA >90% sensitive
for PEfor PE
In a similar SR in 2005 Roy concludedIn a similar SR in 2005 Roy concluded– Negative CTA could safely exclude PE in low risk patientsNegative CTA could safely exclude PE in low risk patients– Negative LE US plus negative CTA could exclude PE in Negative LE US plus negative CTA could exclude PE in
moderate risk patientsmoderate risk patients
At the time of those SRs no studies of faster At the time of those SRs no studies of faster multidetector CTA (MDCT) were availablemultidetector CTA (MDCT) were available
Eng J, Krishnan JA, Segal JB, et al. AJR 2004;183(6):1819-27. Roy PM, Colombet I, Durieux P, et al. BMJ 2005;331(7511):259.
PE – PIOPED IIPE – PIOPED IIPublished June 2006 in NEJMPublished June 2006 in NEJM– 1090 consecutive patients with suspected PE1090 consecutive patients with suspected PE– All given Modified Wells ScoreAll given Modified Wells Score– MDCT - mostly 4 sliceMDCT - mostly 4 slice– Gold standard – composite - V/Q, angiogram & Gold standard – composite - V/Q, angiogram &
LE USLE US
FindingsFindings– MDCT: sens 83% & spec 96% for PEMDCT: sens 83% & spec 96% for PE– Positive predictive value >90% in Positive predictive value >90% in
moderate/high riskmoderate/high risk– Negative predictive value 96% in low risk Negative predictive value 96% in low risk
patients but only 89% in moderate risk patientspatients but only 89% in moderate risk patients
Findings generally consistent with Roy’s Findings generally consistent with Roy’s SRSR
V/Q scanningV/Q scanning
Look for evidence of ventilation perfusion Look for evidence of ventilation perfusion mismatchmismatch
Can only really be done if pt has normal CXRCan only really be done if pt has normal CXR
Normal scan virtually excludes PE even if Normal scan virtually excludes PE even if pretest clinical probability was felt to be high. pretest clinical probability was felt to be high.
If a patient with intermediate clinical probability If a patient with intermediate clinical probability of PE has an intermediate scan then need of PE has an intermediate scan then need further testingfurther testing
A 60-year-old man with asthma is evaluated in the emergency A 60-year-old man with asthma is evaluated in the emergency department because of the acute onset of chest pain while lifting a department because of the acute onset of chest pain while lifting a heavy object. The pain is sharp and accentuated by deep breathing heavy object. The pain is sharp and accentuated by deep breathing and by movement of the upper extremities. It is located over the left and by movement of the upper extremities. It is located over the left precordium. precordium.
The physical examination and chest x-ray are normal. A ventilation-The physical examination and chest x-ray are normal. A ventilation-perfusion lung scan shows matched areas of perfusion and perfusion lung scan shows matched areas of perfusion and ventilation. ventilation.
Which one of the following is the correct interpretation of the Which one of the following is the correct interpretation of the ventilation-perfusion lung scan?ventilation-perfusion lung scan?( A ) Normal( A ) Normal( B ) Low probability( B ) Low probability( C ) Indeterminate( C ) Indeterminate( D ) High probability( D ) High probability
Correct Answer = Correct Answer = AA
The lung scan is normal, with matched perfusion and The lung scan is normal, with matched perfusion and ventilation. This lung scan rules out a pulmonary ventilation. This lung scan rules out a pulmonary embolism, and another source for the chest pain should embolism, and another source for the chest pain should be sought. Often asthma does complicate the be sought. Often asthma does complicate the interpretation of the lung scan, but the problem relates to interpretation of the lung scan, but the problem relates to matched defects in which the airway obstruction matched defects in which the airway obstruction decreases the ventilation to an area of the lung. The decreases the ventilation to an area of the lung. The consequent hypoxia in that area leads to reduction in consequent hypoxia in that area leads to reduction in blood flow in the same area. These areas are rarely blood flow in the same area. These areas are rarely segmental. segmental.
Spiral CT/CT angiogramSpiral CT/CT angiogram
Used if CXR not normalUsed if CXR not normal
Picks up large central emboli but is less Picks up large central emboli but is less sensitive for the smaller peripheral emboli. sensitive for the smaller peripheral emboli.
True pulmonary angiography rarely used True pulmonary angiography rarely used now, though can do direct thrombolysis in now, though can do direct thrombolysis in massive PE.massive PE.
EchoEcho
More than 80% of pts with PE will have More than 80% of pts with PE will have abnormalities of RV size or function, or TR.abnormalities of RV size or function, or TR.
McConnells sign – regional wall motion McConnells sign – regional wall motion abnormalities that spare the R ventricular apex abnormalities that spare the R ventricular apex are very suggestive of PEare very suggestive of PE
BUT echo is only really used for Dx of massive BUT echo is only really used for Dx of massive lifethreatening PE’s when rapid diagnosis is lifethreatening PE’s when rapid diagnosis is needed to determine whether thrombolysis needed to determine whether thrombolysis should be given.should be given.
TreatmentTreatment
Identify any contraindications to Identify any contraindications to anticoagulations – if yes then IVC filteranticoagulations – if yes then IVC filterInquire about h/o HITInquire about h/o HIT
If yes, then use direct thrombin inhibitorIf yes, then use direct thrombin inhibitor
Assess need for hospitalizationAssess need for hospitalizationExtensive iliofemoral DVT with circ compromiseExtensive iliofemoral DVT with circ compromiseIncreased risk of bleedingIncreased risk of bleedingLimited cardioresp reserveLimited cardioresp reservePoor compliancePoor complianceCI to LMW heparinCI to LMW heparin
TreatmentTreatment
Administer LMW heparin or unfractionated Administer LMW heparin or unfractionated heparinheparin
Goal 1.5-2.5 x PTT in first 24 hoursGoal 1.5-2.5 x PTT in first 24 hours
Check platelet count on day 3-5Check platelet count on day 3-5
Treat at least five days and until patient’s Treat at least five days and until patient’s INR is >2 on coumadin for two INR is >2 on coumadin for two consecutive daysconsecutive days
Start coumadin on day 1Start coumadin on day 1
Treatment DurationTreatment Duration
3-6 months in most patients3-6 months in most patientsIndefinite treatment:Indefinite treatment:– >1 spontaneous event>1 spontaneous event– One spontaneous life threatening eventOne spontaneous life threatening event– Antiphospholipid syndromeAntiphospholipid syndrome– Antithrombin deficiencyAntithrombin deficiency– >1 genetic allelic abnormality>1 genetic allelic abnormality
– Homozygote for Factor V Leiden or prothrombin gene mutationHomozygote for Factor V Leiden or prothrombin gene mutation– Heterozygote for bothHeterozygote for both
– Protein C/S deficiencyProtein C/S deficiency– Continuing RF especially active advanced CAContinuing RF especially active advanced CA
Contraindications to Contraindications to AnticoagulationAnticoagulation
AbsoluteAbsolute– Active bleedingActive bleeding– Severe bleeding diathesisSevere bleeding diathesis– Platelet count <20Platelet count <20– Neurosurgery, ocular surgery or intracranial Neurosurgery, ocular surgery or intracranial
bleeding within the past 10 daysbleeding within the past 10 days
Contraindications to Contraindications to AnticoagulationAnticoagulation
RelativeRelative– Mild/moderate bleeding diathesis or Mild/moderate bleeding diathesis or
thrombocytopeniathrombocytopenia– Brain metsBrain mets– Major abdominal surgery within 2 daysMajor abdominal surgery within 2 days– GI or GU bleeding within 14 daysGI or GU bleeding within 14 days– EndocarditisEndocarditis– Severe HTN (SBP >200, DBP > 120)Severe HTN (SBP >200, DBP > 120)
Inferior Vena Cava FilterInferior Vena Cava Filter
Reduce risk of PE but carry increased risk Reduce risk of PE but carry increased risk of DVTof DVT
Use in pts with DVT who cannot take Use in pts with DVT who cannot take anticoagulation e.g. due to bleeding riskanticoagulation e.g. due to bleeding risk
Also used with or without anticoagulation Also used with or without anticoagulation in patients with high risk of death should in patients with high risk of death should further PE occur. further PE occur.
Hypercoagulation WorkupHypercoagulation Workup
Test all patients for unprovoked VT for Test all patients for unprovoked VT for antiphospholipid ab syndrome and antiphospholipid ab syndrome and hyperhomocysteinemiahyperhomocysteinemia
Hypercoagulation WorkupHypercoagulation Workup
Test for Factor V Leiden, prothrombin gene Test for Factor V Leiden, prothrombin gene mutation and deficiencies of antithrombin, mutation and deficiencies of antithrombin, protein C/S in the following patients:protein C/S in the following patients:
Family h/o VTFamily h/o VT
VT before the age of 50VT before the age of 50
Recurrent VTRecurrent VT
Thrombosis in an unusual site (mesenteric, renal, cerebral, Thrombosis in an unusual site (mesenteric, renal, cerebral, hepatic)hepatic)
Heparin resistance (antithrombin deficiency)Heparin resistance (antithrombin deficiency)
Warfarin induced skin necrosis (protein C/S def)Warfarin induced skin necrosis (protein C/S def)
Neonatal purpura fulminansNeonatal purpura fulminans
Hypercoagulation WorkupHypercoagulation Workup
Wait to check for deficiency in Wait to check for deficiency in antithrombin, protein C or S until 2 weeks antithrombin, protein C or S until 2 weeks after anticoagulation rx is completedafter anticoagulation rx is completed
VTE – Prevention UnderutilizedVTE – Prevention Underutilized
DVT-FREE DVT-FREE prospective prospective registry of 5,451 registry of 5,451 patients at 183 patients at 183 US hospitalsUS hospitals
Only 32% of Only 32% of medical patients medical patients with DVT with DVT received DVT received DVT prophylaxisprophylaxis
0
5
10
15
20
25
30
35
40
45
US 1991 US 2001 Canada2002
UK 2005
VTE – Prophylaxis in Medical VTE – Prophylaxis in Medical PatientsPatients
IndicationsIndications– CHF or severe respiratory diseaseCHF or severe respiratory disease
– Bedrest with additional risk factorBedrest with additional risk factorCancerCancer
Prior VTEPrior VTE
– Most ICU patientsMost ICU patients
OptionsOptions– Low dose unfractionated heparin or LMWHLow dose unfractionated heparin or LMWH
– Sequential compression devicesSequential compression devices
– Graduated compression stockingsGraduated compression stockings
•Acute neurologic disease•Inflammatory bowel disease