Board Review: OBGYN/SURGERY
A 32 year old female G3P2002 at 25 weeks gestation presents to the ED with progressively worsening dyspnea associated with pleuritic chest pain. You are concerned that this patient has a pulmonary embolism. All of the following may be appropriate diagnostic studies for this patient with the exception of:
C. V/Q scan
Answer: A. Obtaining a d-dimer in a pregnant patient will not be helpful in diagnosing a PE because d-dimer levels are elevated in normal pregnancy. In 2011, the American Thoracic Society published the algorithm below to guide diagnostic imaging for PE in pregnancy. However, it was based on low level evidence and is therefore inconsistently followed according to local practices and availability. Additionally, an abnormal CXR often results in a nondiagnostic V/Q scan. Thus, many ED providers often order a CT of the chest as their definitive PE study of choice.
Dado CD, Levinson AT, Bourjeily G. Pregnancy and Pulmonary Embolism. Clin Chest Med. 2018 Sep;39(3):525-537. doi: 10.1016/j.ccm.2018.04.007. PMID: 30122177.