Morning Report: Diagnosing PE in Pregnancy

Dr. Grock presents today’s Morning Report!

Case:

32 F 18 wks by LMP presents with chest pain: sharp, non-exertional, 7/10, mildly decreased ET, bilat LE edema.

VS HR 102, BP 130/74, RR 20, Temp 99.8 oral, O2sat 98% on RA.

What are you worried about?

PE?

MI?

Let’s start with PE. Work-up? PE?

Some use, some don’t.

PERC/Wells/Geneva – not validated for pregnancy
Do you use D-Dimer?

ATS 2011 – don’t use d-dimer (weak recommendation, very low quality evidence).

– All low quality or very low quality evidence

Kline et al. D-Dimer Concentrations in Normal Pregnancy: New Diagnostic Thresholds Are Needed. 50 pt’s got dimers, excluded other causes that would elevate dimer – pre-preg (estimated 60% would get pregnant?!), 1^st trimester, 2^nd trimester, 3^rd trimester, 4 wks post-partum. Results: Mean increase in Dimer per trimester: 0.16, 0.41, 0.69, 0.2.

Cogley et al. PE Evaluation in the Pregnant Patient: A Review of Current Imaging Approaches – neg dimer rules out PE.

US – YES
CXR – YES: evaluate the patient for other causes of her symptoms.
CTA vs V/Q – V/Q has technetium which is excreted in the urine. The baby is then exposed to the radiation as this goes from kidney to bladder. CTA has LESS radiation to the BABY, but MORE radiation to the MOM.
1. Per ATS: No preferences. Equally effective. For V/Q can only do Q scan (if nml, no V scan).
2. Per ACR: CTA better (less non-diagnostic studies).

So now you know everything about diagnosing PE in pregnancy. But what if I told you the prevalence of PE in pregnancy is NOT what you thought!?

Kline et al. Systematic Review and Meta-analysis of Pregnant Patients Investigated for Suspected PE in the ED – 17 studies with 25,339 patients worked up for PE, VTE+ rate 4.1% (21/506) vs 12.4% among non-pregnant patients. Ref: in Minnesota, rate of VTE 32/100,000 – same as all women under 40 in the same region. In the UK, rate of VTE 20/100,000 vs 55/100,000 for pregnant + 1 VTE risk factor. 70% of VTE occur during delivery and postpartum and PE 3/100,000 pregnancies.

References:

Leung et al. An Official American Thoracic Society/Society of Thoracic Radiology Clinical Practice Guidline: Evaluation of Suspected Pulmonary Embolism In Pregnancy. AM J Respir Crit Care Med Vol 184. Pp1200-1208. 2011
Kline et al. D-Dimer Concentrations in Normal Pregnancy: New Diagnostic Thresholds Are Needed. Clin Chem 51:5, 825-829. 2005
Cogley et al. PE Evaluation in the Pregnant Patient: A Review of Current Imaging Approaches. Semin US CT MRI 33:11-17. 2012
Bettmann et al. Acute Chest Pain – Suspected Pulmonary Embolism. American College of Radiology ACR Appropriateness Criteria. 2011
Kline et al. Systematic Review and Meta-analysis of Pregnant Patients Investigated for Suspected PE in the ED. Acad Emerg Med. 2014 Sep;21(9):949-59