Pulmonary embolism in pregnancy

Background

  • Incidence of VTE in pregnancy and postpartum is 1.72 per 1000[1]
  • The risk is significantly elevated in the 6 wks postpartum
  • Risk returns to baseline by 12 wks postpartumm[2]

Clinical Spectrum of Venous Thromboembolism

Clinical Spectrum of Venous thromboembolism (VTE)

Only 40% of ambulatory ED patients with PE have concomitant DVT[3][4]

Types

Clinical Features

Symptoms

According to the PIOPED II study, these are the most common presenting signs[5]

Signs

  • Tachypnea (54%)
  • Calf or thigh swelling, erythema, edema, tenderness, palpable cord (47%)
  • Tachycardia (24%)
  • Rales (18%)
  • Decreased breath sounds (17%)
  • Accentuated pulmonic component of the second heart sound (15%)
  • JVD (14%)
  • Fever (3%)

Differential Diagnosis

Chest pain

Critical

Emergent

Nonemergent

Workup

If clinical features suggestive of PE and lower extremity swelling then
  1. Bilateral LE Ultrasound
  1. if Positive-->treat empirically for PE
  2. if Negative-->CTA


CT (with shield) vs. V/Q is roughly equilivalent radiation exposure

American Thoracic Society In Pregnancy[6]

  • D-dimer is not recommended for excluding PE (weak recommendation, very-low-quality evidence).
  • If signs and symptoms of deep venous thrombosis (DVT), first perform bilateral venous compression ultrasound (CUS) of lower extremities, followed by anticoagulation treatment if positive and by further testing if negative (weak recommendation, very-low-quality evidence).
  • If no signs and symptoms of DVT, pulmonary vascular imaging should be used over bilateral lower extremity ultrasounds(weak recommendation, very-low-quality evidence).

D-Dimer

  • D-Dimer MAY BE used with following limits with very poor evidence[7][8][9]
    • 1st trimester: <750 ng/mL (+50% increase from normal lab threshold)
    • 2nd trimester: <1000 ng/mL (+100% from normal)
    • 3rd trimester: <1250 ng/mL (+150% from normal)

Management

Disposition

Admit

See Also

Sources

  1. James AH, et al. Venous thromboembolism during pregnancy and the postpartum period: Incidence, risk factors, and mortality. 2006; 194(5):1311–1315.
  2. Kamel H, et al. Risk of a thrombotic event after the 6-week postpartum period. N Engl J Med. 2014; 370:1307-1315.
  3. Righini M, Le GG, Aujesky D, et al. Diagnosis of pulmonary embolism by multidetector CT alone or combined with venous ultrasonography of the leg: a randomised non-inferiority trial. Lancet. 2008; 371(9621):1343-1352.
  4. Daniel KR, Jackson RE, Kline JA. Utility of the lower extremity venous ultrasound in the diagnosis and exclusion of pulmonary embolism in outpatients. Ann Emerg Med. 2000; 35(6):547-554.
  5. Stein PD et al. Clinical characteristics of patients with acute pulmonary embolism: data from PIOPED II. Am J Med. 2007;120(10):871.
  6. Leung, A et al. An Official American Thoracic Society/Society of Thoracic Radiology Clinical Practice Guideline: Evaluation of Suspected Pulmonary Embolism PDF
  7. Kovac M. The use of D-dimer with new cutoff can be useful in diagnosis of venous thromboembolism in pregnancy. Eur J Obstet Gynecol Reprod Biol. 2010 Jan;148(1):27-30
  8. http://blog.ercast.org/2013/04/pulmonary-embolism-in-pregnancy/
  9. D-Dimer Concentrations in Normal Pregnancy: New Diagnostic Thresholds Are Needed. Kline et all. Clinical Chemistry May 2005 vol. 51 no. 5 825-829 http://www.clinchem.org/content/51/5/825.long