Pulmonary embolism in pregnancy

Revision as of 17:56, 27 January 2017 by Ostermayer (talk | contribs) (Text replacement - " PE " to " PE ")

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 of DVTequal in 1st and 2nd trimesters, higher risk in 3rd trimester and 3 weeks postpartum. [2]
    • PE most commonly occurs in postpartum. [2]
    • Common risk factors include: Advanced maternal age, C-Section, Obesity, multiple gestations, thrombophilia, prior VTE
  • Risk returns to baseline by 12 wks postpartumm[3]
  • Consider MI in differential as risk can increase 3-6 times during the postpartum period

Clinical Spectrum of Venous thromboembolism (VTE)

Only 40% of ambulatory ED patients with PE have concomitant DVT[4][5]


Clinical Features

Symptoms

Signs

  • Tachycardia (HR>100), Tachypnea (RR>20), Hypoxemia (SpO2<95%) are seen ~50% of the time
  • Hypotension (SBP<90) only seen 10% of the time, but largest predictor of mortality
  • Unilateral calf tenderness or edema, suggestive of a DVT
  • Other signs may include accentuated pulmonic component of second heart sound, JVD, or decreased breath sounds

Differential Diagnosis

Chest pain

Critical

Emergent

Nonemergent

Evaluation

Clinical Decision Rules

  • Limited utility as no studies (PERC, Wells) have proven effective in pregnancy
    • 8% (9/114) of PERC Negative patients with CT or V/Q proven PE were pregnant or post-partum [6][7]

If clinical features suggestive of PE and lower extremity swelling then:

  • Bilateral LE Ultrasound
    • if Positive-->treat empirically for PE
    • if Negative-->CTA
      • CTA and V/Q scans yield approximately 0.025 rad and 0.040 rad respectively to the fetus[8]
      • >5 rads is considered teratogenic[9]
  • Up to 17% of pregnant patients have isolated pelvic DVT(not found with ultrasound)[10]
CT (with shield) vs. V/Q is roughly equilivalent radiation exposure

{{Guidelines PE Pregnancy}}

D-Dimer

  • D-Dimer MAY BE used with following limits with very poor evidence[11][12][13]
    • 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

  • Heparin and Enoxaparin are safe (coumadin is not)
    • Heparin 80 units/kg IV bolus followed by continuous infusion 18 units/kg/hr [14]
    • Enoxaparin 1 milligram/kg (100 IU/kg) SC every 12 or 24 h [14]
  • Perimortem cesarean delivery with cardiac arrest with no ROSC in 5 min
  • Consider thrombolysis in severely unstable post-partum pulmonary embolism[15](see Adult pulseless arrest for tPA dosing in pulmonary embolism)

Disposition

  • Admit

See Also

References

  1. ↑ James AH, et al. Venous thromboembolism during pregnancy and the postpartum period: Incidence, risk factors, and mortality. 2006; 194(5):1311–1315.
  2. ↑ 2.0 2.1 Chan et al. Venous Thromboembolism and Antithrombotic Therapy in Pregnancy. SOGC Guidelines. 2014.
  3. ↑ Kamel H, et al. Risk of a thrombotic event after the 6-week postpartum period. N Engl J Med. 2014; 370:1307-1315.
  4. ↑ 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.
  5. ↑ 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.
  6. ↑ Kline JA, et al. Clinical Features of Patients With Pulmonary Embolism and a Negative PERC Rule Result. Ann Emerg Med. 2013 January 60(1): 122-124
  7. ↑ West, J. “When the PERC Rule Fails”. ALiEM. Feb 2014[1]
  8. ↑ Astani SA, et al. Detection of pulmonary embolism during pregnancy: comparing radiation doses of CTPA and pulmonary scintigraphy. Nucl Med Commun. 2014; 35(7):704-711.
  9. ↑ Bentur Y, Horlatsch N, and Koren G. Exposure to ionizing radiation during pregnancy: perception of teratogenic risk and outcome. Teratology. 1991; 43(2):109-112.
  10. ↑ Chan WS, Spencer FA, Ginsberg JS. Anatomic distribution of deep vein thrombosis in pregnancy. CMAJ. 2010; 182(7):657- 660.
  11. ↑ 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
  12. ↑ http://blog.ercast.org/2013/04/pulmonary-embolism-in-pregnancy/
  13. ↑ 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
  14. ↑ 14.0 14.1 Tintinalli's 7th edition
  15. ↑ Stone SE and Morris TA. Pulmonary embolism during and after pregnancy. (Crit Care Med 2005; 33[Suppl.]:S294 –S300.
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