Pulmonary Embolism / Venous Thromboembolism

last updated: March 25, 2016

General

 

  • Risk Factors

  • Epidemiology

  • Prevention (in hospital)

    • SCDs

    • DVT prophylaxis 

      • heparin 5000 SC qday bid/tid

      • lovenox 40mg SC qday; 30mg SC qday (GFR <30)

Pathophysiology

  • Virchow's triad

Diagnosis

  • ABG

 

  • CXR

    • Hampton's hump

    • Westermark's sign

 

  • EKG

 

  • D-dimer

 

  • brain natriuretic peptide

 

  • troponin T or I

 

  • Lower extremity ultrasound

 

  • venography

 

  • ECHO

    • right ventricular dilation

    • high tricuspid jet tells you how severe the clot burden is

    • not used to diagnose PE

 

  • V/Q scan

    • nuclear medicine scan (Xenon gas, Tc99m)

    • low probability < 20% PE

    • intermediate probability 20-80% PE

    • high probability > 80% PE

    • pneumonia or any CXR abnormalities impair this test

    • good for impaired kidney function

 

  • CT angio chest (test of choice)

    • looking for vascular filling deficits

 

  • Pulmonary angiogram (gold standard)

    • the most accurate test

 

    • almost never dones, dangerous

Treatment

  • anticoagulation

    • prevent further cloth formation

    • 6-9 months of treatment

    • heparin (unfractionated)

      • 80U/kg bolus, 18U/kg (PTT goal 60-90 sec)

      • can be turned off quickly

    • LMWH (SC) Enoxaparin (Lovenox)

      • 1mg/kg SQ q12hours (q24 with impaired renal function <30 GFR)

      • low-molecular-weight heparin in cancer patients provides better VTE prophylaxis compared with vitamin K antagonists

    • warfarin (coumadin)

      • INR goal 2-3

      • many drug interactions

 

  • thrombolytic

    • dissolves the clot immediatly

 

  • IVC filter

    • used for GI bleed patients

    • allergic to heparin

    • failed anticoagulation (recurrent PE despite being anticoagulated)

    • proximal DVT with a massive PE

    • retrievable vs permanent IVC filters 

      • retrievable for 3 months

    • complications

      • thrombosis

      • migration

      • tilting

      • penetration of vena cava wall

      • access site hematoma

      • infection

 

  • pulmonary embolectomy 

 

  • ECMO

... but I would more especially commend the clinician who, in acute diseases, by which the bulk of mankind are cutoff, conducts the treatment better than others.
 
Hippocrates, 400 BC