From the Guidelines
The immediate management for a pregnant patient with suspected pulmonary embolism (PE) and positive D-dimer involves prompt imaging with a chest CT pulmonary angiogram (CTPA) while maintaining left lateral positioning to prevent aortocaval compression, and initiation of therapeutic anticoagulation with low molecular weight heparin (LMWH) as recommended by the 2020 ESC guidelines 1.
The patient should be positioned in left lateral decubitus to prevent aortocaval compression. If CTPA is unavailable or contraindicated, ventilation-perfusion (V/Q) scanning is an alternative. While awaiting confirmatory imaging, therapeutic anticoagulation should be initiated with LMWH, such as enoxaparin 1 mg/kg subcutaneously twice daily, unless there are contraindications to anticoagulation. LMWH is preferred over unfractionated heparin in pregnancy as it doesn't cross the placenta and has a lower risk of heparin-induced thrombocytopenia and osteoporosis, as stated in the 2014 ESC guidelines 1.
Some key points to consider in the management of PE in pregnancy include:
- The use of formal diagnostic pathways and algorithms, including CTPA or V/Q lung scan, which can be used safely during pregnancy 1.
- The preference for anticoagulation with LMWH over other types of anticoagulants, due to its safety profile in pregnancy 1.
- The importance of close collaboration between the obstetrician, the anaesthesiologist, and the attending physician in the management of labour and delivery in patients with PE 1.
- The need for regular follow-up examinations after acute PE, to check for possible signs of VTE recurrence, cancer, or bleeding complications of anticoagulation, and to detect/treat comorbidity or ‘simple’ deconditioning 1.
It's also important to note that D-dimer levels naturally increase during pregnancy, but a positive result combined with clinical suspicion still necessitates further investigation as PE remains a leading cause of maternal mortality. Vital signs should be continuously monitored, supplemental oxygen provided to maintain saturation above 94%, and IV access established. If the patient is hemodynamically unstable with hypotension, immediate critical care consultation is warranted to consider thrombolysis.
From the Research
Immediate Management for Pregnant Patient with Suspected Pulmonary Embolism (PE) and Positive D-dimer
- The immediate management for a pregnant patient with a suspected pulmonary embolism (PE) and a positive D-dimer involves prompt anticoagulant therapy until an objective diagnostic test is performed, unless there is a clear contraindication to anticoagulation 2.
- Low-molecular-weight heparins (LMWHs) are safer and more convenient than unfractionated heparin (UFH) for the treatment and prevention of venous thromboembolism (VTE) in pregnancy 2, 3.
- For women with acute venous thromboembolism (VTE), adjusted-dose LMWH throughout pregnancy or IV UFH for at least 5 days, followed by adjusted-dose UFH or LMWH for the remainder of the pregnancy and at least 6 weeks postpartum is recommended 4.
- Compression ultrasound should be used to evaluate pregnant women for deep venous thrombosis, followed by magnetic resonance imaging of the pelvis for a negative test and strong remaining clinical suspicion 5.
- For pulmonary embolism, a chest x-ray should be used to triage the patient to either a ventilation/perfusion study after a normal X-ray or a CT pulmonary angiogram after an abnormal one 5.
Treatment and Prophylaxis
- Treatment generally consists of low molecular weight heparin through a minimum of six weeks post-partum 5.
- Thrombolysis might have merit in life-threatening, massive pulmonary embolism 5.
- VTE prophylaxis in at-risk populations remains a major area of uncertainty, with mechanical prophylaxis for all women undergoing cesarean having a paucity of supportive evidence 5.