Run the List Podcast
Episode: Pulmonary Embolism
Date: April 7, 2025
Host(s): Walker Redd, Emily Gutowski, Navin Kumar, Joyce Zhou, Blake Smith
Guest: Dr. Allison Greco, Assistant Professor at NYU, Director of Critical Care Consult Service and Pulmonary Embolism Response Team (PERT) member
Episode Overview
This episode centers on the recognition, risk stratification, diagnosis, and management of pulmonary embolism (PE). Using a clinical case, Dr. Allison Greco offers a high-yield, practical discussion on how to approach PE from the emergency room through discharge, highlighting recent research, risk factors, diagnostic pathways, and evolving treatment algorithms.
Key Discussion Points & Insights
1. Case Presentation & Pathophysiology
Timestamp: 01:25–03:42
- Case Summary: 66-year-old woman with obesity, hypertension, hip replacement presenting with acute dyspnea and chest pain, tachycardia, hypoxia, tachypnea.
- Basic Explanation of PE:
“A pulmonary embolism is a blood clot. It conventionally starts in the venous system… travels through the circulation from the legs up until the right side of the heart and back into the pulmonary arteries and gets lodged there. I usually explain it to patients, it’s like when you put your finger over a garden hose... the same thing happens in your pulmonary artery and your heart.”
— Dr. Greco, 02:23 - Disease Spectrum: Severity depends on clot location and its effect on pulmonary pressures and right heart function.
2. Risk Factors & Patient History
Timestamp: 03:42–06:33
- Virchow’s Triad:
- Stasis (immobility, prolonged travel/surgery, sedentary work)
- Endothelial Injury (trauma, devices, infection, inflammation)
- Hypercoagulability (hereditary states, cancer, pregnancy, age, smoking, obesity)
- Key historical questions:
- Family history of clots
- Personal history (DVT, miscarriages)
- Recent trauma/surgeries, cancer, medications (OCPs, HRT, steroids)
- Occupational immobility
“Don’t forget to ask about those [desk jobs, drivers]... that is another way to think about immobility that folks are probably likely to have more often than taking transatlantic flights.”
— Dr. Greco, 05:30
3. Clinical Presentation & Physical Exam
Timestamp: 06:33–07:48
- Common Findings:
- Dyspnea, tachypnea, tachycardia
- Many have a NORMAL exam
- DVT signs: Unilateral leg swelling, skin changes (if present, supportive but not always seen)
“Most folks have a very bland or even a normal exam.”
— Dr. Greco, 07:31
4. Risk Stratification: Wells Score & D-Dimer
Timestamp: 07:48–09:42
- Wells Score: Clinical pre-test probability tool—guides further investigation/treatment
- D-Dimer:
- Used in low-risk patients (Wells 0 or low)
- Low D-dimer effectively rules out VTE
- High clinical suspicion:
- Initiate treatment before diagnostic confirmation if necessary
“If your pretest probability based on your well score is high enough... initiate treatment while you pursue additional diagnostic testing.”
— Dr. Greco, 08:41
- Initiate treatment before diagnostic confirmation if necessary
5. Diagnosis: Labs, Imaging, and EKG
Timestamp: 09:42–13:39
- Common Labs:
- CBC (platelets, hemoglobin), chemistry panel (renal/hepatic function)
- Lactate (prognostic)
- Troponin, BNP (RV strain markers)
- D-Dimer
- EKG Findings:
- Most commonly sinus tachycardia
- S1Q3T3 is classic but uncommon
- Other: T-wave changes, right axis deviation, RBBB
- Imaging:
- CTPE (CT pulmonary embolism protocol): Definitive diagnostic test (“contrast has to be timed to opacify the pulmonary arterial system”)
- RV:LV ratio on CT (prognostic)
- Transthoracic Echocardiogram (TTE): Assesses RV strain more directly
- Lower Extremity Dopplers:
“Useful for thinking about treatment decisions in sick patients, but... does not formally risk stratify in terms of RV strain.”
— Dr. Greco, 13:32
6. Treatment: Spectrum & Practical Considerations
Timestamp: 13:39–18:42
- Anticoagulation: Mainstay for all PE patients
- Low Risk: Direct oral anticoagulants (DOACs) preferred
- High Risk: Hemodynamic instability/hypotension → systemic thrombolysis, if safe
- Intermediate Risk:
- Multi-disciplinary risk stratification (PESI score, biomarkers, echo)
- Consider catheter-based therapies (mechanical or low-dose thrombolysis) depending on risk
- Systemic thrombolysis NOT recommended due to bleeding risk
- Special Cases:
- Recent Major Surgery: Need careful multidisciplinary deliberation re: systemic thrombolysis
- IVC Filter: Only for patients unable to be anticoagulated, NOT as add-on if able to anticoagulate
- Anticoagulant Agent Choice:
- Heparin often used, but requires therapeutic levels (bolus may be needed)
- Low Molecular Weight Heparin (LMWH/Lovenox): Faster to therapeutic, but has limitations (e.g., procedural, renal clearance)
“I describe [catheter-based options], as I say, we’re going to go in and roto-rooter and we’re going to remove a clot.”
— Dr. Greco, 16:19
7. Discharge Planning, Anticoagulation Duration, and Follow-up
Timestamp: 18:42–20:41
- Switch from LMWH to DOAC typically appropriate
- Bleeding education: Counsel on DOAC risks, but better tolerated than warfarin
- Duration:
- Provoked PE (transient risk factor): Minimum 3 months
- Large, hemodynamically significant, or ongoing risk factors: May require prolonged/lifelong therapy
- Scoring systems now used to determine long-term need
- Follow-up Echo:
- Required for intermediate/high risk PEs at ~3 months to document RV recovery
"All patients with intermediate and high risk PEs also additionally need a follow up echo at about three months as well to make sure that that RV dysfunction has normalized."
— Dr. Greco, 19:46
- Required for intermediate/high risk PEs at ~3 months to document RV recovery
8. Clinical Pearls & Memorable Moments
Timestamp: 20:41–22:18
- Classic Paper Recommendation:
“One of the things that’s kind of like a must read is... called The Golden Hour... It goes through the hemodynamic effects of PEs in such great detail.”
— Dr. Greco, 21:05 - Intermediate Risk PE Caution:
“Their highest risk for decompensation [is] in the first 12 to 24 hours... while you're becoming therapeutic... patients are highest risk for clot propagation or further embolization of the clot.”
— Dr. Greco, 21:45- ICU-level monitoring for first 24h for intermediate/high risk PE
- Discharge conversations only after 24h of stability
Notable Quotes
- “It’s like when you put your finger over a garden hose... the same thing happens in your pulmonary artery and your heart.” — Dr. Greco, 02:33
- “Most folks have a very bland or even a normal exam.” — Dr. Greco, 07:31
- “The discriminatory decisions are really only made in those low risk populations... In higher risk patients... you should probably just go ahead and initiate treatment.” — Dr. Greco, 08:36
- “CTPE is the diagnostic test of choice in these cases... Not all CTs with contrast are able to effectively evaluate the pulmonary arterial circulation.” — Dr. Greco, 11:41
- “If someone cannot be anticoagulated and they have a DVT, all the guidelines recommend an IVC filter. There’s no evidence to support the use of IVC filter in folks that can otherwise tolerate anticoagulation.” — Dr. Greco, 17:59
- “I describe [catheter-based thrombectomy]... as I say, we’re going to go in and roto-rooter and we’re going to remove a clot.” — Dr. Greco, 16:19
- “In the first 12 to 24 hours, while you're becoming therapeutic... patients are highest risk for clot propagation or further embolization...” — Dr. Greco, 21:45
Important Timestamps
| Segment | Timestamp | |-----------------------------------|---------------| | PE Definition & Pathophys | 02:23–03:42 | | Risk Factors Overview | 04:01–06:33 | | Physical Exam Features | 07:05–07:48 | | Wells Score & D-Dimer | 08:01–09:42 | | Diagnostic Workup | 09:52–13:39 | | Treatment Algorithms | 13:59–18:42 | | Anticoagulation Duration & FU | 18:59–20:41 | | Clinical Pearls | 20:57–22:18 |
Summary
This episode delivers a pragmatic, evidence-based framework for PE recognition and management. Dr. Greco’s explanations illuminate key clinical reasoning steps and update listeners on the latest best practices—emphasizing multidisciplinary care for complex cases, judicious risk stratification, and patient-centered discharge planning. Her clinical pearls and memorable teaching metaphors make this episode invaluable for internal medicine trainees and practitioners alike.