ED Critical Care Conference: August 2013

PULMONARY EMBOLISM

Summary by Dr. Eugene Kang

Diagnosis and EKG:

-Most common EKG finding: non-specific ST-T changes (at least for our boards)

-Other findings: sinus tachycardia, complete or incomplete RBBB, RAD, right atrial enlargement, dominant R in V1, atrial tachyarrhythmias

-Some likelihood ratios (see Kline paper in references):

-S1Q3T3, LR=4.9 (2.4-10.3)

-TWI in V1-4, LR=3.1 (1.4-6.9)

-Although certain EKG abnormalities (S1Q3T3, anterior+inferior TWI) can help in the diagnosis of pulmonary embolism, absence of these findings should not decrease suspicion

Consequences:

-Massive PE can obviously cause hemodynamic instability leading to death

-Smaller but clinically significant PE can lead to pulmonary hypertension, RV dysfunction and subsequently poor quality of life (decreased exercise tolerance and even dyspnea at rest)

Treatment: Who do we lyse?

AHA

-Massive: hemodynamic instability defined as SBP<90 (or 40 point drop from baseline) for >15 minutes

-YOU MUST LYSE (if no contraindications to thrombolytic therapy)

-Similar recommendations by European Society of Cardiology, American College of Chest Physicians

-Submassive: hemodynamically stable but with signs of RV strain (elevated troponin/BNP, echo findings of RV dysfunction)

-AHA says thrombolysis may be considered (level IIb/C)

-ESC/ACCP similarly says choose case-by-case (i.e. lyse younger patients who are less likely to bleed and also need their RV function intact)

ACEP

-Hemodynamically unstable patients: lyse (if benefits outweigh risks of bleeding)

-Level B recommendation

-Hemodynamically stable patients: insufficient evidence to lyse

-”Thrombolytics have demonstrated faster improvements in RV function and pulmonary perfusion, but these benefits have not translated to improvements in mortality.”

MOPETT (Moderate Pulmonary Embolism Treated with Thrombolysis):

-Symptomatic moderate defined as ≥2 signs/symptoms (7 total in inclusion criteria) in addition to:

-CTPA involvement of >70% involvement of thrombus in ≥2 lobar, or left or right main pulmonary arteries

-Ventilation/perfusion scan showing mismatch in ≥2 lobes

-SBP<95 excluded

-enoxaparin/heparin only vs enoxaparin/heparin + half dose tPA (10mg bolus then 40mg over 2 hours)

-primary end point: pulmonary HTN at 28 months

-rates in treatment group=16%, control group=57%

-combined end point: pulmonary HTN at 28 months + recurrent PE

-treatment group=16%, control group=63%

-no patients in either group bled

-Conclusion: results suggest that half-dose thrombolysis is safe/effective in the treatment of moderate PE, with a significant immediate reduction in pulmonary artery pressure that was maintained at 28 months.

-Still, the measured outcome is of questionable significance as opposed to actual measurements of quality-of-life.

-Perhaps consider in younger in whom potential improvement in exercise tolerance in remaining lifetime may be more relevant than in older, immobile patients.

*At the American College of Cardiology Scientific Assembly this year, Jeff Kline presented the TOPCO study that assessed patient-oriented outcomes. Please see the reference below.

References:

Kline J et al. 12-Lead ECG Findings of Pulmonary Hypertension Occur More Frequently in ED Patients With Pulmonary Embolism Than in Patients Without Pulmonary Embolism. Annals of Emergency Medicine. 2010; 55(4): 331-335
Sharifi M et al. Moderate Pulmonary Embolism Treated with Thrombolysis. The American Journal of Cardiology. 2013; 11(2): 273-277.
Jaff MR. Management of massive and submassive pulmonary embolism, iliofemoral deep vein thrombosis, and chronic thromboembolic pulmonary hypertension: a scientific statement from the American Heart Association. Circulation. 2011; 123(16):1788-830
Clinical Policy: Critical Issues in the Evaluation and Management of Adult Patients Presenting to the Emergency Department with Suspected Pulmonary Embolism. Annals of Emergency Medicine. 2011; 57: 628-652.
Kline J et al. Randomized Trial of Tenecteplase Placebo with Low Molecular Weight Heparin For Acute Submassive Pulmonary Embolism: Assessment of Patient-Oriented Cardiopulmonary Outcomes at Three Months. Journal of the American College of Cardiology. 2013: 61(10)

The views expressed on this blog are the author's own and do not reflect the views of their employer. Please read our full disclaimer here. Any references to clinical cases refer to patients treated at a virtual hospital, Janus General Hospital.

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Jay Khadpe MD

Editor in Chief of "The Original Kings of County" Assistant Professor of Emergency Medicine Assistant Residency Director SUNY Downstate / Kings County Hospital