Point-of-Care Ultrasound and Right Ventricular Strain: Utility in the Diagnosis of Pulmonary Embolism

Ramzi Ibrahim MD, João Paulo Ferreira MD

Department of Medicine, University of Arizona – Tucson and Banner University Medical Center

Tucson AZ USA

Abstract

Pulmonary emboli are associated with high morbidity and mortality, prompting early diagnostic and therapeutic considerations. Utilization of rapid point-of-care ultrasound (POCUS) to assess for signs of pulmonary emboli can provide valuable information to support immediate treatment. We present a case of suspected pulmonary embolism in the setting of pharmacological prophylaxis for venous thromboembolism with identification of right heart strain on bedside POCUS exam. Early treatment with anticoagulation was initiated considering the clinical presentation and POCUS findings. CT angiogram of the chest revealed bilateral pulmonary emboli, confirming our suspicion. Utilizing POCUS in a case of suspected pulmonary emboli can aid in clinical decision making.

Case Presentation

Our patient is a 50-year-old man with a history of morbid obesity, obstructive sleep apnea, and poorly controlled diabetes mellitus type 2 who was admitted to the hospital for sepsis secondary to left foot cellulitis and found to have left foot osteomyelitis with necrosis of the calcaneus. The patient was started on intravenous antimicrobials, underwent incision and debridement, and completed a partial calcanectomy of the left foot. During the hospital course, he remained on subcutaneous unfractionated heparin at 7,500 units three times a day for prevention of deep vein thrombosis. On post-operative day 12, he developed acute onset of dyspnea requiring 2 liters of supplemental oxygen and was slightly tachycardic in the low 100s. He complained of chest tightness without pain, however, he denied lower extremity discomfort, palpitations, orthopnea, or diaphoresis. Electrocardiogram was remarkable for sinus tachycardia without significant ST changes, T-wave inversions, conduction defects, or QTc prolongation. Rapid point-of-care ultrasound (POCUS) at bedside revealed interventricular septal bowing, hypokinesia of the mid free right ventricular wall, and increased right ventricle to left ventricle size ratio (>1:1 respectively) (Figures 1 and 2).

Figure 1. A: Static apical 4-chamber view showing interventricular bowing into the left ventricle (blue arrow), significantly enlarged right ventricle, and right ventricular free wall hypokinesia (green arrow). B: Video of apical 4-chamber view.

Figure 2. A: Static parasternal short axis view showing interventricular septal bowing in the left ventricle (green arrow). B: Video of parasternal short axis view.

With these findings, the patient was started on therapeutic anticoagulation. CT angiogram of the chest revealed a large burden of bilateral pulmonary emboli (PE). The pulmonary embolism severity index (PESI) score was 130 points which is associated with a 10%-24.5% mortality rate in the following 30 days. Formal echocardiogram showed a severely dilated right ventricle with reduced systolic function, paradoxical septal movement, and a D-shaped left ventricle. Patient remained hemodynamically stable and was discharged home after transition from heparin to rivaroxaban.

Discussion

Pulmonary emboli remain a commonly encountered pathological phenomenon in the hospital setting with a mortality rate ranging from <5% to 50% (1). Venous thromboembolism prophylaxis has been shown to reduce the risk of VTE in hospitalized patients, however, this does not eliminate the risk completely. Prompt diagnosis allows earlier treatment and improved outcomes however this is often challenging given the lack of specificity associated with its characteristic clinical symptoms (2). In the proper context, utilization of POCUS can aid the diagnosis of PE by assessing for signs of right ventricular strain. Characteristic findings seen on a cardiac-focused POCUS that represent right ventricular strain include McConnell’s sign (defined as right ventricular free wall akinesis/hypokinesis with sparing of the apex), septal flattening, right ventricular enlargement, tricuspid regurgitation, and tricuspid annular plane systolic excursion under 1.6 cm (3). Their respective sensitivities and specificities are highly dependent on the pre-test probability. For example, a prospective cohort study completed by Daley et al. (4) in 2019 showed that for patients with a clinical suspicion of PE, sensitivity of right ventricular strain was 100% for a PE in patients with a heart rate (HR) >110 beats per minute, and a sensitivity of 92% if HR >100 BPM. This study provides evidence to support the use of cardiac focused POCUS in ruling out pulmonary emboli in patients with signs of right ventricular strain and abnormal hemodynamic parameters such as tachycardia. Additionally, in settings where hemodynamic instability is present and the patient cannot be taken to the CT scanner for fear of decompensation, rapid POCUS assessment can be helpful. In our patient, given the acute need for supplemental oxygenation and dyspnea, along with his risk factors for a thromboembolic event, the use of POCUS aided in our clinical decision making. The yield of information that can be provided by POCUS is vital for early diagnostic and therapeutic decision making for patients with a clinical suspicion of pulmonary emboli.

References

1. Torbicki A, Perrier A, Konstantinides S, et al. Guidelines on the diagnosis and management of acute pulmonary embolism: the Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology (ESC). Eur Heart J. 2008 Sep;29(18):2276-315. [CrossRef][PubMed]
2. Roy PM, Meyer G, Vielle B, et al. Appropriateness of diagnostic management and outcomes of suspected pulmonary embolism. Ann Intern Med. 2006 Feb 7;144(3):157-64. [CrossRef][PubMed]
3. Alerhand S, Sundaram T, Gottlieb M. What are the echocardiographic findings of acute right ventricular strain that suggest pulmonary embolism? Anaesth Crit Care Pain Med. 2021 Apr;40(2):100852. [CrossRef] [PubMed]
4. Daley JI, Dwyer KH, Grunwald Z, et al. Increased Sensitivity of Focused Cardiac Ultrasound for Pulmonary Embolism in Emergency Department Patients With Abnormal Vital Signs. Acad Emerg Med. 2019 Nov;26(11):1211-1220. [CrossRef][PubMed]

Cite as: Ibrahim R, Ferreira JP. Point-of-Care Ultrasound and Right Ventricular Strain: Utility in the Diagnosis of Pulmonary Embolism. Southwest J Pulm Crit Care Sleep. 2022;25(2):34-36. doi: https://doi.org/10.13175/swjpccs040-22 PDF

Ultrasound for Critical Care Physicians: Sometimes It’s Better to Be Lucky than Smart

Robert A. Raschke MD and Randy Weisman MD

Critical Care Medicine

HonorHealth Scottsdale Osborn Medical Center

Scottsdale, AZ USA

We recently responded to a code arrest alert in the rehabilitation ward of our hospital. The patient was a 47-year-old man who experienced nausea and diaphoresis during physical therapy. Shortly after the therapists helped him sit down in bed, he became unconsciousness and pulseless. The initial code rhythm was a narrow-complex pulseless electrical activity (PEA). He was intubated, received three rounds of epinephrine during approximately 10 minutes of ACLS/CPR before return of spontaneous circulation (ROSC), and was subsequently transferred to the ICU.

Shortly after arriving, a 12-lead EKG was performed (Figure 1), and PEA recurred.

Figure 1. EKG performed just prior to second cardiopulmonary arrest showing S1 Q3 T3 pattern (arrows).

Approximately ten-minutes into this second episode of ACLS, a cardiology consultant informed the code team of an S1,Q3,T3 pattern on the EKG. A point-of-care (POC) echocardiogram performed during rhythm checks was technically-limited, but showed a dilated hypokinetic right ventricle (see video 1).

Video 1. Echocardiogram performed during ACLS rhythm check: Four-chamber view is poor quality, but shows massive RV dilation and systolic dysfunction.

Approximately twenty-minutes into the arrest, 50mg tissue plasminogen activator (tPA) was administered, and return of spontaneous circulation (ROSC) achieved two minutes later. A tPA infusion was started. The patient’s chart was reviewed. He had received care in our ICU previously, but this wasn’t immediately recognized because he had subsequently changed his name of record to the pseudonym “John Doe” (not the real pseduonym), creating two separate and distinct EMR records for the single current hospital stay. Review of the first of these two records, identified by his legal name, revealed he had been admitted to our ICU one month previously for a 5.4 x 3.6 x 2.9 cm left basal ganglia hemorrhage. We stopped the tPA infusion.

On further review of his original EMR is was noted that two weeks after admission for intracranial hemorrhage, (and two weeks prior to cardiopulmonary arrest), he had experienced right leg swelling and an ultrasound demonstrated extensive DVT of the right superficial femoral, saphenous, popliteal and peroneal veins. An IVC filter had been due to anticoagulant contraindication. The patient’s subsequent rehabilitation had been progressing well over the subsequent two weeks and discharge was being discussed on the day cardiopulmonary arrest occurred.

On post-arrest neurological examination, the patient gave a left-sided, thumbs-up to verbal request. Ongoing hypotension was treated with a norepinephrine infusion and inhaled epoprostenol. An emergent head CT was performed and compared to a head CT from four weeks previously (Figure 2), showing normal evolution of the previous intracranial hemorrhage without any new bleeding. 

Figure 2. CT brain four weeks prior to (Panel A), and immediately after cardiopulmonary arrest and administration of tPA (Panel B), showing substantial resolution of the previous intracranial hemorrhage.

A therapeutic-dose heparin infusion was started. An official echo confirmed the findings of our POC echo performed during the code, with the additional finding of McConnell’s sign. McConnell’s sign is a distinct echocardiographic finding described in patients with acute pulmonary embolism with regional pattern of right ventricular dysfunction, with akinesia of the mid free wall but normal motion at the apex (1). A CT angiogram showed bilateral pulmonary emboli, and interventional radiology performed bilateral thrombectomies. Hypotension resolved immediately thereafter. The patient was transferred out of the ICU a few days later and resumed his rehabilitation.

A few points of interest:

• IVC filters do not absolutely prevent life-threatening pulmonary embolism (2,3).
• Sometimes, serendipity smiles, as when the cardiologist happened into the room during the code, and provided an essential bit of information.
• Emergent POC ultrasonography is an essential tool in the management of PEA arrest of uncertain etiology.
• Barriers to access of prior medical records can lead to poorly-informed decisions. But in this case, ignorance likely helped us make the right decision.
• Giving lytic therapy one month after an intracranial hemorrhage is not absolutely contra-indicated when in dire need.
• As the late great intensivist, Jay Blum MD used to say: “Sometimes it’s better to be lucky than smart.”

References

1. Ogbonnah U, Tawil I, Wray TC, Boivin M. Ultrasound for critical care physicians: Caught in the act. Southwest J Pulm Crit Care. 2018;17(1):36-8. [CrossRef]
2. Urban MK, Jules-Elysee K, MacKenzie CR. Pulmonary embolism after IVC filter. HSS J. 2008 Feb;4(1):74-5. [CrossRef] [PubMed]
3. PREPIC Study Group. Eight-year follow-up of patients with permanent vena cava filters in the prevention of pulmonary embolism: the PREPIC (Prevention du Risque d'Embolie Pulmonaire par Interruption Cave) randomized study. Circulation. 2005 Jul 19;112(3):416-22. doi: [CrossRef] [PubMed]

Cite as: Raschke RA, Weisman R. Ultrasound for Critical Care Physicians: Sometimes It’s Better to Be Lucky than Smart. Southwest J Pulm Crit Care. 2021;22(6):116-8. doi: https://doi.org/10.13175/swjpcc016-21 PDF 

Ultrasound for Critical Care Physicians: Caught in the Act

Uzoamaka Ogbonnah MD¹

Isaac Tawil MD²

Trenton C. Wray MD²

Michel Boivin MD¹

¹Department of Internal Medicine

²Department of Emergency Medicine

University of New Mexico School of Medicine

Albuquerque, NM USA

A 16-year-old man was brought to the Emergency Department via ambulance after a fall from significant height. On arrival to the trauma bay, the patient was found to be comatose and hypotensive with a blood pressure of 72/41 mm/Hg. He was immediately intubated, started on norepinephrine drip with intermittent dosing of phenylephrine, and transfused with 3 units of packed red blood cells. He was subsequently found to have extensive fractures involving the skull and vertebrae at cervical and thoracic levels, multi-compartmental intracranial hemorrhages and dissection of the right cervical internal carotid and vertebral arteries. He was transferred to the intensive care unit for further management of hypoxic respiratory failure, neurogenic shock and severe traumatic brain injury. Following admission, the patient continued to deteriorate and was ultimately declared brain dead 3 days later. The patient’s family opted to make him an organ donor

On ICU day 4, one day after declaration of brain death, while awaiting organ procurement, the patient suddenly developed sudden onset of hypoxemia and hypotension while being ventilated. The patient had a previous trans-esophageal echo (TEE) the day prior (Video 1). A repeat bedside TEE was performed revealing the following image (Video 2).

Video 1. Mid-esophageal four chamber view of the right and left ventricle PRIOR to onset of hypoxemia.

Video 2. Mid-esophageal four chamber view of the right and left ventricle AFTER deterioration.

What is the cause of the patient’s sudden respiratory deterioration? (Click on the correct answer to be directed to an explanation)

1. Atrial Myxoma
2. Fat emboli syndrome
3. Thrombus in-transit and pulmonary emboli
4. Tricuspid valve endocarditis

Cite as: Ogbonnah U, Tawil I, Wray TC, Boivin M. Ultrasound for critical care physicians: Caught in the act. Southwest J Pulm Crit Care. 2018;17(1):36-8. doi: https://doi.org/10.13175/swjpcc091-18 PDF 

Ultrasound for Critical Care Physicians: Ghost in the Machine

Ross Davidson, DO

Michel Boivin, MD 

Division of Pulmonary, Critical Care and Sleep Medicine

University of New Mexico School of Medicine

Albuquerque, NM USA

A 53-year-old woman presented to the emergency department after a sudden cardiac arrest at home. The patient had a history of asthma and tracheal stenosis and had progressive shortness of breath over the previous days. The patient’s family noticed a “thump” sound from the patient’s room, and found her apneic. They called 911 and began cardiopulmonary resuscitation. Paramedics arrived on the scene, found an initial rhythm of pulseless electrical activity. The patient eventually achieved return of spontaneous circulation and was transported to the hospital. On arrival the patient was in normal sinus rhythm, with a heart rate of 110 beats per minute. Blood pressure was 80/45 mmHg, on an epinephrine infusion. The patient was afebrile, endotracheally intubated, unresponsive and ventilated at 30 breaths per minute. An initial chest radiograph was compatible with aspiration pneumonitis and a small pneumothorax. Initial electrocardiogram on arrival had 1mm ST-segment depressions in leads V4 to V6. Transthoracic echocardiography was unsuccessful due to patient’s habitus and mechanical ventilation. Because of the patient’s hemodynamic instability and unknown cause of cardiac arrest, an urgent trans-esophageal echocardiogram (TEE) was performed (Videos 1-3).

Video 1. Mid-esophageal 4-chamber view of the heart.

Video 2. Upper esophageal long-axis view of the pulmonary artery and short axis view of the ascending aorta.

Video 3. Upper esophageal short axis view of the pulmonary artery with the ascending aorta in long axis. 

Based on the images presented what do you suspect is the etiology of the patient’s cardiac arrest? (Click on the correct answer for an explanation-no penalty for guessing, you can go back and try again)

1. Massive Pulmonary Embolism
2. Myocardial infarction
3. Pericardial Tamponade
4. Unable to determine

Cite as: Davidson R, Boivin M. Ultrasound for critical care physicians: ghost in the machine. Southwest J Pulm Crit Care. 2018;16(2):76-80. doi: https://doi.org/10.13175/swjpcc027-18 PDF 

August 2016 Critical Care Case of the Month

Jillian L. Deangelis, APRN, CNP

Theodore Loftsgard APRN, ACNP

Department of Anesthesiology

Mayo Clinic Minnesota

Rochester, MN USA

Critical Care Case of the Month CME Information

Members of the Arizona, New Mexico, Colorado and California Thoracic Societies and the Mayo Clinic are able to receive 0.25 AMA PRA Category 1 Credits™ for each case they complete. Completion of an evaluation form is required to receive credit and a link is provided on the last panel of the activity. 

0.25 AMA PRA Category 1 Credit(s)™

Estimated time to complete this activity: 0.25 hours 

Lead Author(s): Jillian L. Deangelis, MS, APRN, CNP.  All Faculty, CME Planning Committee Members, and the CME Office Reviewers have disclosed that they do not have any relevant financial relationships with commercial interests that would constitute a conflict of interest concerning this CME activity.

Learning Objectives:
As a result of this activity I will be better able to:

1. Correctly interpret and identify clinical practices supported by the highest quality available evidence.
2. Will be better able to establsh the optimal evaluation leading to a correct diagnosis for patients with pulmonary, critical care and sleep disorders.
3. Will improve the translation of the most current clinical information into the delivery of high quality care for patients.
4. Will integrate new treatment options in discussing available treatment alternatives for patients with pulmonary, critical care and sleep related disorders.

Learning Format: Case-based, interactive online course, including mandatory assessment questions (number of questions varies by case). Please also read the Technical Requirements.

CME Sponsor: University of Arizona College of Medicine

Current Approval Period: January 1, 2015-December 31, 2016

Financial Support Received: None

History of Present Illness

The patient is a previously healthy, albeit anxious, 15-year-old girl seen by her primary care physician. She has had several months of general malaise and ongoing fatigue and an increased frequency in night terrors over the past few weeks. Her family attributes this to stress of school and her new job. She was noted to have lost 3 kg in the previous nine weeks.

PMH, SH, and FH

Her PMH was unremarkable. She is a student and denies smoking, drinking or drug abuse. Her family history is noncontributory.

Physical Examination

• Vital signs: BP 100/60 mm Hg, P 90 beats/min and regular,  R 16 breaths/min, T 100.8 ºF, BMI 15.  
• Diffuse, non-tender lymphadenopathy through the submandibular and upper anterior cervical chains.
• Lungs: clear
• Heart: regular rhythm without murmur.
• Abdomen: slightly rounded and firm.

Which of the following are diagnostic considerations at this time? (Click on the correct answer to proceed to the second of seven panels)

1. Anorexia nervosa
2. Lymphoma
3. Mononucleosis
4. Teenage adjustment disorder
5. All of the above

Cite as: Deangelis JL, Loftsgard T. August 2016 critical care case of the month. Southwest J Pulm Crit Care. 2016;13(2):46-53. doi: http://dx.doi.org/10.13175/swjpcc056-16 PDF

Ultrasound for Critical Care Physicians: A Tempting Dilemma

Issam Marzouk MD

Lana Melendres MD

Michel Boivin MD

Division of Pulmonary, Critical Care and Sleep

Department of Medicine

University of New Mexico School of Medicine

MSC 10-5550

Albuquerque, NM 87131 USA

A 46 year old woman presented with progressive severe hypoxemia and a chronic appearing pulmonary embolus on chest CT angiogram to the intensive care unit. The patient was hemodynamically stable, but had an oxygen saturation of 86% on a high-flow 100% oxygen mask. The patient had been previously investigated for interstitial lung disease over the past 2 year, this was felt to be due to non-specific interstitial pneumonitis. Her echocardiogram findings are as presented below (Figures 1 and 2).

Figure 1. Parasternal long axis view. Upper panel: static image. Lower panel: video.

 

Figure 2. Apical four chamber view. Upper panel: static image. Lower panel: video

The patient had refractory hypoxemia despite trials of high flow oxygen and non-invasive positive pressure ventilation. She had mild symptoms at rest but experienced severe activity intolerance secondary to exertional dyspnea. Vitals including blood pressure remained stable and normal during admission and the patient had a pulsus paradoxus measurement of < 10 mmHg. She had previously had an echocardiogram 6 months before that revealed significant pulmonary hypertension.

What would be the most appropriate next step regarding management of her echocardiogram findings? (click on the correct answer to move to the next panel)

1. Diagnostic pericardiocentesis
2. Urgent therapeutic pericardiocentesis
3. Avoid pericardiocentesis at this time
4. Urgent thrombolysis with tissue plasminogen activator

Reference as: Marzouk I, Melendres L, Boivin M. Ultrasound for critical care physicians: a tempting dilemma. Southwest J Pulm Crit Care. 2014;9(3):193-6. doi: http://dx.doi.org/10.13175/swjpcc128-14 PDF

August 2013 Critical Care Case of the Month: My, That’s a Big One

Andrew Waas, M.D.

Pulmonary Sciences and Critical Care Medicine

University of Colorado Hospital

Denver, Co

History of Present Illness

A 75 year old male presented to the emergency department with complaints of three days of increasing nausea, generalized weakness, and dyspnea on exertion.  He had undergone a radical prostatectomy 13 days prior to presentation from which he was recovering well until the onset of these symptoms. There was no associated chest pain, cough, fevers, chills or weight loss.

PMH, SH, FH

He had a history of hypertension and prostate cancer for which he underwent a recent prostatectomy.

He was born in Colorado and had not traveled recently.  There was no history of tobacco use, he drank ethanol on rare occasions, and did not use any illicit drugs. 

There was no family history of illnesses of which he was aware.

Medications

• Dutasteride 0.5 mg daily
• Telmisartan 40 mg daily

Physical Exam

Blood pressure 142/85, heart rate 108, temperature 36.7 C, respiratory rate 25, saturating 95% on 2L oxygen. 

Generally, he was in no distress, but was slightly tachypneic.  Lungs were clear to auscultation bilaterally and he was tachycardic but regular.  Otherwise, his exam was normal. 

Laboratory

Laboratory evaluation revealed a mild leukocytosis at 13 x 10⁶ cells/mcL with 72% neutrophils and 20% lymphocytes.  His basic metabolic panel (including creatinine) was normal; his liver function tests were likewise normal. 

Chest Radiography

His initial portable chest x-ray is shown in Figure 1.

Figure 1. Initial portable chest x-ray

Which of the following best describes the chest x-ray?

1. Cardiomegaly
2. Cavitating lung mass
3. Multifocal infiltrates
4. All of the above
5. None of the above

Reference as: Waas A. August 2013 critical care case of the month: my, that's a big one. Southwest J Pulm Crit Care. 2013;7(2):66-74. doi: http://dx.doi.org/10.13175/swjpcc096-13 PDF

November 2012 Critical Care Case of the Month: I Just Can’t Do It Captain! I Can’t Get the Sats Up!

Bridgett Ronan, MD

Department of Pulmonary Medicine

Mayo Clinic Arizona

Scottsdale, AZ

History of Present Illness

A 61 year old man was seen in consultation after undergoing a laparoscopic repeat Nissen fundoplication with mesh reinforcement.  He developed worsening hypoxia postoperatively. He was initially extubated without difficulty to nasal cannula. However, he had progressive hypoxemia requiring a nonrebreathing mask, followed by BiPAP and eventually reintubation. Discussion with the surgeons revealed he had gastric contents present on intraoperative esophagogastroduodenoscopy (EGD). There was a small perforation of the fundus, with possible contamination of the peritoneum.

PMH, FH, SH

He has a long history of a paraesophageal hernia and reflux esophagitis and had previously undergone a Nissen fundoplication. There was also a history of atrial flutter and a 4.8 cm thoracic aortic aneurysm. A pre-operative echocardiogram was othewise normal. There was no remarkable family history. He was a non-drinker and non-smoker.

Physical Examination

Vital signs: Heart rate 79 beats/min, BP 95/67 mm Hg, Temperature 99.4°F, SpO2 78% on 100% FiO2.

His lungs were clear interiorly.

No murmurs or gallops were heard on cardiac auscultation.

His abdomen was post-surgical and distended but soft and nontender.

Which of the following is true regarding hypoxemia?

1. Most hypoxia is secondary to alveolar-capillary block
2. A normal pCO2 excludes hypoventilation as a cause of hypoxemia
3. Low inspired FiO2 is a common cause of hypoxia in the ICU because of attaching air to the oxygen line on the ventilator.
4. A normal chest x-ray excludes ventilation-perfusion mismatch as a cause of hypoxemia
5. The patient’s age of 61 excludes a congenital heart lesion

Reference as: Ronan B. November 2012 critical care case of the month: I just can’t do it captain! I can’t get the sats up! Southwest J Pulm Crit Care 2012;5:235-41. PDF