Welcome to the inaugural post for an exciting new ultrasound-based case series called “Ultrasound For The Win!” (#US4TW). In this peer-reviewed case series, we will focus on real clinical cases where bedside ultrasound changed the management or aided in the diagnosis. In our first case, we present a 28-year-old female with shortness of breath.
Case Presentation
A 28-year-old female with active cancer on chemotherapy presents to the ED with 1-week of progressively worsening shortness of breath. On examination, the patient appears distressed, tachypneic, and requires 15L O2 via non-rebreather to maintain a normal oxygen saturation.
Vitals
BP 102/69 mmHg
P 142 bpm
RR 22 respirations/min
O2 100% saturation on non-rebreather mask
T 36.9
Differential Diagnosis
Congestive heart failure
Pericardial effusion
Pleural effusion
Pneumonia
Pneumothorax
Pulmonary embolism (PE)
Point-of-Care Ultrasound
Bedside echocardiogram showing intra-ventricular thrombus (arrow) and dilated right ventricle
RV = right ventricle; LV = left ventricle
Immediately evident on bedside echocardiogram are distinct ultrasonographic findings that are highly suggestive of pulmonary embolism:
An intra-ventricular thrombus within a dilated right ventricle (blue arrow), with an RV to LV size ratio greater than 1:1 indicative of right heart strain. Visualization of a clot is a rare (estimated to be present in only 4-18% of acute PE [1]) but specific echocardiographic finding.
Right ventricular hypokinesis with apical sparing (McConnell Sign).
In this clinical context, the bedside echo findings are highly suggestive of an acute PE.
Ultrasound Image Quality Assurance
An important aspect of ultrasonography is appropriate and optimal image acquisition. The ultrasound clip shows an apical view of the heart with appropriate depth and gain. While the providers were not able to obtain an apical 4-chamber view, the right and left ventricles are clearly demonstrated, and the clip is of sufficient quality to provide valuable diagnostic information. Patients with acute respiratory distress can be challenging to image due to tachypnea and the inability to turn to a left lateral decubitus position.
Of note, the probe indicator-to-screen orientation is oriented to the patient’s right, which is the reverse of the cardiology convention [2]. Whether you use the ED or cardiology convention, it is important to know how you are oriented so that you are properly identifying the right and left sides of the heart especially when trying to identify pathology such as right heart strain. In this case, the right side of the heart is on the left side of the screen. If the probe is reversed, one can misinterpret a normal LV as being a RV.
The clip could be improved by attempting to better visualize both atria so that all four chambers are in view. In addition, the interventricular septum should be ideally oriented vertically down the screen rather than on an angle as in the clip. Sliding the transducer laterally so that the septum is centered on the screen, and angling the beam back towards the inferior tip of the right scapula will result in a more vertical orientation to the interventricular septum.
Disposition and Case Conclusion
A CT angiogram of the chest was obtained which revealed a massive PE extending from the right ventricle causing near-total occlusion of bilateral pulmonary arteries extending to all segmental pulmonary arteries.
Heparin was started in the ED, and the patient was admitted to the medical ICU. The patient continued to decompensate during her admission, and tPA was administered with subsequent clinical improvement.
The patient was discharged home after a full recovery with normal oxygen saturations on enoxaparin.
Take Home Points
Bedside echocardiogram, in correlation with the appropriate clinical picture, can be a beneficial diagnostic tool in the unstable patient with suspicion for acute PE.
Echocardiographic features of PE can be classified into direct (high specificity, low sensitivity) and indirect (low specificity, moderate sensitivity) findings [3]:
PA = pulmonary artery; DVT = deep vein thrombosis; US = ultrasound
McConnell sign, which is RV hypokinesis with apical sparing, in its original description was found to be 77% sensitive and 94% specific for diagnosing PE [4]. However, more recent literature has shown that McConnell sign is non-specific, found in 2/3 of patients with RV infarction [5], and should not be used in isolation for the diagnosis of PE, nor for the decision to adminster thrombolytics.
Be aware of the differences between the ED and cardiology echo conventions to avoid confusion and potential misinterpretation of findings.
Special thanks to Dr. Chris Moore for permission to use the included ultrasound clips and images!
References
Sokmen G, et al. Witnessed migration of a giant, free-floating thrombus into the right atrium during echocardiography, leading to fatal pulmonary embolism. Turk Kardiyol Dem Ars. 2009 Jan;37(1):41-3. PMID: 19225252
Moore C. Current issues with emergency cardiac ultrasound probe and image conventions. Acad Emerg Med. 2008 Mar;15(3):278-84. PMID: 18304059
Borloz M, et al. Emergency department focused bedside echocardiography in massive pulmonary embolism. J Emerg Med. 2011 Dec;41(6):658-60. PMID: 21820258
McConnell MV, et al. Regional right ventricular dysfunction detected by echocardiography in acute pulmonary embolism. Am J Cardiology. 1996 Aug 15;78(4): 469-473. PMID: 8752195
Casazza F, et al. Regional right ventricular dysfunction in acute pulmonary embolism and right ventricular infarction. Eur J Echocardiogr. 2005 Jan;6(1):11-4. PMID: 15664548.
*Note: All identifying information and certain aspects of the case have been changed to maintain patient confidentiality and protected health information (PHI).
ALiEM Copyedit
September 8, 2014
Nice idea for a series. Such practical examples of how ultrasonography can impact patient care using a case-based format is a great framework. Some comments:
Please add temp to vitals.
Beware of abbreviations. For example MICU may be more of a North American convention. So spelled out to medical ICU. Used “PE” after first mention of. Intermittently was spelled out versus not spelled out.
For lists such as DDx, if there’s no reasoning for the order (e.g. pretest probability), then would alphabetize per copyedit convention.
Use generic names of medications (enoxaparin).
Rephrased conclusion a bit to point less to a specific person’s case (changed from active to passive voice).
Overall great case. Nice video. Thanks for creating your own UF4TW Youtube account. When this gets published, please add the final URL link into the descriptor for the YouTube video. Thanks!
[AUTHOR RESPONSE: Thank you for your comments and constructive feedback! I have made the appropriate changes as suggested.]
Michelle Lin, MD, ALiEM Editor in Chief; Associate Professor of Emergency Medicine, UC San Francisco
Pre-Publication Critique
September 8, 2014
Hi guys. I love what you are doing here. This will be an amazing way to help people anchor what they’re learning about ultrasound to real-life, even real-time clinical scenarios. Here are my notes:
In the introductory paragraph – “In this… series we will focus on real …cases”, not “a case”, since this will be an ongoing series.
I agree with Dr Lin about the paragraph beneath the video. Perhaps you can reword it? Maybe something like,
“This clip demonstrates two distinct ultrasonographic findings which are highly suggestive of pulmonary embolism. a)There is a visible intraventricular thrombus within the RV (blue arrow). Visualized intramural thrombus is a rare (only seen in 4-18% of cases) yet highly specific finding (how specific?). b) We can also appreciate RV hypokinesis with apical sparing (McConnell’s sign) which is also a highly specific finding (77% sensitivity and a 94% specificity).”
I might also shy away from using the phrase “For diagnosing a PE” with ultrasound, as it is not yet considered a “gold standard” diagnostic imaging modality and instead consider phrases like “ultrasonographic evidence of PE”, or “highly suggestive of PE”.
Agree with Dr Lin on abbreviations including CTA – CT Angiogram
Grammar Police Report: There are numerous errant commas running amok.
Very impressive presentation. It’s an honor to provide review.
[AUTHOR RESPONSE: Thanks Drake! I have reworded the description of the ultrasound findings which hopefully makes it more clear.
McConnell sign is not as specific for pulmonary embolism as originally thought, and can be seen in other pathologic conditions such as right ventricular infarction, which is noted in the 'Take Home Points'.
I completely agree that ultrasound is not the gold standard imaging modality for diagnosing pulmonary embolism, and I've changed the wording to make this more clear.
Overall, great feedback that I think helps clarify what we see on the ultrasound clip, and what that suggests clinically.
I hope this case (and subsequent cases to come!) makes point-of-care ultrasound more accessible to all emergency physicians. The goal of this series is to provide bite-sized, evidence-based, high-yield pearls that any emergency physician can use clinically to aid in the management of their patients and improve patient care.]
Drake Coffey, MD, Assistant Professor, Ultrasound Faculty; Department of Emergency Medicine, UT Health Science Center at San Antonio
Expert Peer Review
September 8, 2014
Appreciate the opportunity to provide peer review. My thoughts as follows:
CASE PRESENTATION
Reads well. No substantive edits.
DIFFERENTIAL DIAGNOSIS
Would add pericardial effusion to the differential diagnosis of any cancer patient with dyspnea. Likewise I’m not sure I’d include panic attack in the differential of a hypoxic patient with a heart rate of 142/minute…
POINT-OF-CARE ULTRASOUND
Small point but the text states “In this clinical context, the bedside echo findings are concerning for acute PE.” When intracardiac thrombus is visualized (direct evidence), I would say the echo findings are “highly suggestive of PE”
ULTRASOUND IMAGE QUALITY ASSURANCE
This is an extremely foreshortened view using an apical window (neither atria nor AV valves are visualized). Would not state “The video clip is quite good and shows an apical four-chamber view of the heart with appropriate depth and gain,” as this isn’t a four-chamber view. Might consider something like “This is an apical view of the heart, with appropriate depth and gain. While the providers were not able to obtain an apical 4-chamber view, the right and left ventricles are clearly demonstrated, and the clip is of sufficient quality to provide valuable diagnostic information. Patients with acute respiratory distress can be challenging to image due to tachypnea and the inability to turn into a left lateral decubitus position.”
Would edit this section as follows (original followed by suggested edits):
“In addition, the interventricular septum should be ideally oriented vertically down the screen rather than on an angle as in the clip; this can usually be achieved by sliding your probe laterally and inferior on the patient’s chest wall.”
“In addition, the interventricular septum should be ideally oriented vertically down the screen rather than on an angle as in the clip. Sliding the transducer laterally so that the septum is centered on the screen, and angling the beam back towards the inferior tip of the right scapula will result in a more vertical orientation to the interventricular septum.”
DISPOSITION AND CASE CONCLUSION
No substantive edits.
TAKE HOME POINTS
Would reword take home point 3 as follows:
“McConnell sign, which is RV hypokinesis with apical sparing, in its original description was found to be 77% sensitive and 94% specific for diagnosing PE [4]. However, more recent literature has shown that McConnell sign is non-specific, found in 2/3 of patients with RV infarction [5], and should be not be used in isolation for the diagnosis of PE, nor for the decision to administer thrombolytics.”
Additional comments:
In patients who are hemodynamically stable, CT angiogram is widely considered the diagnostic imaging test of choice to confirm or exclude pulmonary embolism. In contrast, patients with hemodynamic instability (one could argue this patient is unstable due to the profound tachycardia and borderline hypotension) can be treated for pulmonary embolism when direct evidence of pulmonary embolism (such as right atrial or right ventricular thrombus) is present.
In addition, point-of-care evaluation for deep venous thrombosis can be an incredibly valuable, time- and cost-saving technique in the correct clinical context:
From Konstantinides, S., & Konstantinides, S. (2008). Clinical practice. Acute pulmonary embolism. The New England Journal of Medicine, 359(26), 2804–2813. doi:10.1056/NEJMcp0804570 “A compression ultrasonographic examination detects proximal deep-vein thrombosis in about 20% of patients with pulmonary embolism, and the rate of detection is twice as high when the distal veins are also examined. A positive result essentially establishes the diagnosis of venous thromboembolism and can obviate the need for additional imaging studies.”
[AUTHOR RESPONSE: Thank you Mike for being the Expert Peer Reviewer for this case. I appreciate the feedback and edits.
I agree that a pericardial effusion should be added to the differential diagnosis, and have made this change.
Great tip on how to best position the probe to obtain an ideal apical 4-chamber view!
Thanks for the added comments and reference for the utility of point-of-care ultrasound for deep venous thrombosis. I think this can be a great additional paragraph as part of your expert peer review commentary when it is published to the final blog post.]
Mike Stone, MD, Division Chief, Emergency Ultrasound; Emergency Ultrasound Fellowship Director; Department of Emergency Medicine, Brigham and Women's Hospital; Assistant Professor of Emergency Medicine, Harvard Medical School
Author information
Jeffrey Shih, MD
Emergency Ultrasound Fellow
Instructor in Emergency Medicine
Yale University School of Medicine
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