DVT / PE – ED

Deep Venous Thrombosis (DVT)/Pulmonary Embolus (PE)

1. In a patient whom you suspect may have a DVT/PE, include the specific elements in the history that will permit an accurate assessment of the patient’s baseline risk of the illness.

History:

  • dyspnea at rest or with exertion
  • Pleuritic pain
  • calf/thigh pain or swelling
  • Cough / hemoptesis
  • orthopnea
  • wheezing
  • Hemoptysis
  • syncope (10%)

Strong predictor: unexplained dyspnea in ambulatory patient & hemoptysis

At risk population:

  1. inherited thrombotic disorders
  2. active cancer / malingnancy
  3. hx of stroke / spina cord injury – immobility
  4. Hospitalized surgical/medical/ICU – especially gyne surgery, total joint replacement
  5. Trauma pt
  6. Pregnancy
  7. Estrogen use

Virchow’s triad

  1. Venous stasis
    1. immobilization / travel (knee 90o >6hr): hospitalizedk institutionalized
    2. General anesthesia
    3. Venous insufficiency
    4. CHF/COPD
    5. Obesity
  2. Endothelial injury
    1. Trauma (4wk): especially spinal cord injuries
    2. Post op (4wk): abd, knee/hip, post-op ICU
  3. Hypercoagulable states
    1. Malignancy – active advanced, metastatic abd/pelvis cancer
    2. pregnancy – up to 6wk postpartum; especially late pregnancy, peri-partum, C/s
    3. Estrogen – esp initiation of hormone therapy
    4. inherited or autoimmune disease – SLE/RA, Factor V leiden (activated protein C resistance, Protein C/S deficiency, antithrombin 3 deficiency, antiphospholipid, plasminogen deficiency, Factor XII deficiency, hyperhomocysteinemia, dysplasminogenemia, dysfibrinogenemia, prothrombin 2021A mutation
    5. Obesity / heavy cigarette smoking

DVT – Well’s criteria

  1. Active Cancer
  2. Paralysis, paresis, recent plaster immobilization of the lower extremities
  3. Recently bedridden for 3 days or Major surgery within 12 wk
  4. Local tenderness along the deep vein system
  5. Entire leg swollen
  6. Calf swelling >=3cm larger than asyptomatic side
  7. Pitting edema confined to symptomatic leg
  8. collateral superfical veins
  9. Hx of documented DVT
  10. Alternative dx at least as likely as DVT = -2

Plegmasia cerulea dolens – thrombolyties

2. In a patient whom you suspect may have a DVT/PE, examine specifically for the presence or absence of signs consistent with DVT/PE and for those suggestive of other competing diagnoses.

Common signs

  • tachypnea
  • calf or thigh swelling, erythema, edema, tenderness, palpable cords
  • tachycardia
  • Rales
  • Decreased breath sound
  • accentuated pulmonic component of the 2nd heart sound
  • JVD
  • Fever mimicking PNA

3. In a patient whom you have questioned and examined for a possible DVT/PE, use available clinical decision rules to determine the patient’s pre-test probability of having a DVT/PE.

PERC (only in low risk pt)

  • Age <50, PUlse <100, SaO2 >94%
  • No hemoptysis
  • no recent trauma/surgery (4wk)
  • no prior PE/DVT
  • No estrogen use
  • No unilateral leg swelling

Wells Criteria: <2 low, 2-6 mod, >6 high or >4 PE likely

  • 3 = Suspected DVT, No alt dx more likely
  • 1.5 = HR>100, Immobilization >=3d or surgery <4wk, previous DVT/PE
  • 1 = hemoptysis, active cancer

4. In a patient with a determined specific pre-test probability of having a DVT/PE, investigate using ancillary tests appropriate to this pre-test probability (e.g., do not order a D-dimer test in high-risk patients).

ECG – abn in 85% PE

  • tachycardia and nonspecific ST changes
  • TWI R precordial & inferior leads
  • Poor prognosis: atrial fibrillation, <50 or >100bpm, new RBBB, inferior Q wave, anterior ST changes and TWI, S1Q3T3

Dimer – only used in low clinical suspicion PE

  • false negative: small clots, delayed presentation, use of anticoagulants
  • false positive: cancer, infection, >70, recent trauma/surgery, ACS, CVA, vasculitis, pregnancy (100% in 3rd trimester), DIC, arterial thrombosis, vaso-occlusive sickle cell crisis, atrial fibrillation, phlebitis

CXR – look for alternate cause

  • normal CXR in a dyspneic hypoxemic pt makes PE more likely
  • abnormal findings: pleural effusion, cardiomegaly, elevated hemidiaphram, enlarged pulmonary artery, atelectasis, pulmonary infiltrate
  • Hampton’s hump – pleural based infiltrate with rounded border facing hilum
  • Westermark sign – dilated pumonary vsculator proximal to embolus with oligemia distally

Trop – risk stratify

BNP – PE pt tend to have higher BNP

POCUS for unstable pt to justify use of anticoagulation / thrombolysis

5. In a patient whom you are investigating for a DVT/PE, adapt the testing to take into account their underlying medical history or comorbid conditions (e.g., ultrasound legs first for pregnant women, CT instead of VQ in patients with underlying respiratory disease).

VQ scan – more likely to be diagnostic in young pt w/o underlying cardiopulmonary dz

CT-PE

  • detect other unsuspected diagnosis: mediastinal tumor, bronchogenic cancer, post-irradiation fibrosis, aortic dissection, pneumonia, PTX
  • false positive: tortuous arteries, atelectasis, movement artifact, overdiagnose subsegmental PEs
  • False negative – smaller sub-segmental clots, improper dye injection

Strategy in the pregnant pt

  • suspected PE with negative CXR – V/Q scan
  • CTPE if abnormal CXR or VQ indeterminate
  • reduce radiation with V/Q by using 1/2 microurie dose, prehydration, foley catheter

Women of reproductive age with suspected PE

  • clinical prediction rule & dimer
  • US doppler of pelvic/lower extremities veins
  • CT if US negative

Unstable patient – bedside echocardiography and venous compression US

  • Echocardiography – mortality 10% if RV dysfunction & near zero in the absence of RV dysfunction

6. In a patient with a confirmed DVT/PE, initiate appropriate treatment adapted to their underlying medical history or comorbid conditions (e.g., no warfarin in pregnancy, no low-molecular-weight heparin in renal failure).

LMWH is the main treatment over IVUFH

IVUFH

  • severe renal failure
  • Thrombolytic therapy considered
  • medical / surgical procedures to be performed
  • concern RE sc absorption of LMWH

Hemodynamic unstable

  • sBP<90 or sBP drop >40 for >15min,
  • hypotension requiring vasopressors (not due to other causes)
  • evidence of shock
  • POCUS – dilated RV 
  • Tx: IVF, Oxygen, vasopressor support prn, IVUFH

Thrombolysis  indications – Hemodynamic instability, respiratory distress, severe RV dysfunction, major MI

  • Massive PE
    • acute PE with sBP<90 >15min or req inotropes
    • pulselessness
    • Persistent profound bradycardia (HR<40) with s/sx of shock
  • Submassive PE – aucte PE w/o HoTN (sBP>90)
    • RV dysfunction: RV dilation or systolic dysfunction on echo or CT; BNP >500; ECG changes – RBBB, STE/STD/TWI in anterior leads
    • MI – inc troponin
  • Contra-indications:
    • Absolute: hx of ICH, intracranial dz: AVM/aneurysm/neoplasm, CVA in 3mo, suspected aortic dissection, active bleeding / bleeding diathesis; recent surgery on the spinal canal/brain, recent closed head /facial trauma
    • Relative: >75yo, pregnant, use of anticoagulation, noncompressible vascular punture, Traumatic/prolonged CPR, recent internal bleeding – 2wk, HTN >180/110, Dementia, remote CVA >3mo, major surgery within 3wk
  • surgical embolectomy: thrombolysis contraindicated, for pt unlikely to survive with delay of medical Tx

IVC filters (no survical benefits) – dec PE but inc DVT

  • consider for pt with c/i to anticoagulation, recurrent PE despite anticoagulation, high likelihood of falls, with massive PE

7. In a patient with a confirmed DVT/PE, use objective findings (e.g., respiratory rate, oxygen saturation, biomarkers) to determine the safety of a potential treatment as an outpatient.

Troponins – elevated in 50% of moderate to large PE

  • marginal purpose for dx
  • stratify for risk of morbidity and mortality

BNP – not sensitive/specific – tend to have higher BNP in PE

  • BNP >100 or proBNP >600 have higher in hospital mortality
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