Can Junior EPs Use E-Point Septal Separation to Accurately Estimate Left Ventricular Function?

Background

Point-of-care echocardiography can provide a rapid and accurate assessment of left ventricular function, which is valuable in differentiating causes of hypotension and dyspnea at bedside. Visual estimation of LV function by experienced practitioners has been shown to correlate well with quantitative estimates. However, the number of examinations required before a practitioner is qualified to visually estimate LV function accurately is unknown. Although there are various comparable parameters for assessing LV function, mitral valve E-point septal separation (EPSS) is an easy-to-obtain measurement inversely correlated with LV function. EPSS is an M-mode measurement of the minimum distance between the anterior mitral valve leaflet and the interventricular septum during diastole. Despite its applicability, the reproducibility and accuracy of EPSS as a bedside tool for evaluating LV function in less experienced emergency physicians has yet to be established.

Can Junior Emergency Physicians Use E-Point Septal Separation to Accurately Estimate Left Ventricular Function in Acutely Dyspneic Patients? 

Clinical Question

This study aims to determine if novice emergency physicians (PGY 3 and PGY 4) are able to obtain EPSS measurements and determine if these measurements correlate to echocardiographic visual estimations of LV function by experienced emergency physicians.

Methods & Study Design

Design:
Prospective observational study of correlation between EPSS to visual estimation and LV function in patients who present to ED with chief complaint of acute dyspnea.

Population:
Convenience sampling of 70 subjects enrolled in the ED from July 2008 and July 2009. Criteria for enrollment included age > 18 years, chief complaint of dyspnea, ED length > 2 hours, no history of trauma, and normal mental status. Patients with known history of mitral valve repair or replacement, aortic insufficiency, or mitral stenosis were excluded.

Intervention:
12 senior residents (PGY 3 and PGY 4) in EM residency program with variable levels of ultrasound experiences (70 to 150 total ED ultrasound examinations; average of fewer than 25 cardiac examinations) performed transthoracic echocardiogram of patients with chief complaint of acute dyspnea. Ultrasound examination included subcostal, parasternal long axis (PLAX), parasternal short axis, and apical four chamber views. Six-second video clips in parasternal short and long axes were obtained. M-mode measurements of EPSS were recorded in PLAX orientation after all video clips were obtained and calculated during diastole. All examinations were performed without the presence of experienced emergency physicians (EPs).

Outcomes:
One of two experienced EPs reviewed stored video and visually estimated LVEF. Two board-certified cardiologists subsequently reviewed one-half of the video clips and estimated LVEF, blinded to both junior EPs’ EPSS measurements and visual estimations by experienced EPs.

Results

58 out of 70 enrolled subjects had complete echocardiographic studies recorded.

Concordance rates between EPSS measurements by EPs and cardiologist for LVEF were acceptable with kappa for visual LVEF estimation of 0.75 (95% CI = 0.48 to 1.00).

Spearman correlation analysis revealed significant correlation (p = -0.844, p< 0.001) between novice physicians’ measurements of EPSS and visual estimation of LVEF by experienced EPs.

Strengths and Limitations

This study compared EPSS measurement by junior EPs with visual assessment by experienced EPs showing a strong correlation. Experienced EPs were not blinded to results, which may have induced bias, but the authors find this less likely given what they interpret as good agreement on visual estimations between experienced EPs and blinded cardiologists. It is debatable whether the agreement between EPs and cardiologists with kappa of 0.75 represents good agreement. This study utilized a convenience sampling design due to logistical constraints, which may impact the generalizability of its results. Many subjects were excluded for incomplete ultrasound views, but authors note that junior EPs were actually able to assess EPSS for all subjects, further supporting the use of this measurement even when other views are difficult to obtain.

Authors Conclusions

PGY 3 and PGY 4 EM residents were able to obtain measurements of EPSS that correlated closely with visual assessments of LVEF by experienced emergency physicians with extensive point-of-care ultrasound and echocardiography experience. EPSS can serve as a quantitative alternative to visual estimation of LVEF in dyspneic ED patients.

Our Conclusions

Rapid assessment of LVEF with bedside echocardiography can provide useful clinical information in the acutely dyspneic patient. The level of expertise required to accurately visually assess a LVEF is unknown. This study supports EPSS as a useful quantitative addition to visual estimation of LVEF in patients with acute dyspnea for novice emergency physicians with less echocardiography experience. The level of correlation between EPSS and visual estimation was not perfect, suggesting use of EPSS as an addition to rather than replacement for standard visual estimation.

The Bottom Line 

EPSS can serve as a quantitative addition to qualitative visual estimation of LVEF with bedside echocardiography, especially for less experienced EM practitioners.

Authors

This post was written by Eugene Han, MS4 at UCSD School of Medicine, with editing by Ben Liotta, MD and Amir Aminlari, MD. 

References

1. Secko MA, Lazar JM, Salciccioli LA, Stone MB. Can junior emergency physicians use E-point septal separation to accurately estimate left ventricular function in acutely dyspneic patients? Acad Emerg Med. 2011 Nov;18(11):1223-6. doi: 10.1111/j.1553-2712.2011.01196.x. Epub 2011 Nov 1. PMID: 22044429.
2. McKaigney CJ, Krantz MJ, La Rocque CL, Hurst ND, Buchanan MS, Kendall JL. E-point septal separation: a bedside tool for emergency physician assessment of left ventricular ejection fraction. Am J Emerg Med. 2014 Jun;32(6):493-7. doi: 10.1016/j.ajem.2014.01.045. Epub 2014 Feb 3. PMID: 24630604.
3. Shahgaldi K, Gudmundsson P, Manouras A, Brodin LA, Winter R. Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography. Cardiovasc Ultrasound. 2009 Aug 25;7:41. doi: 10.1186/1476-7120-7-41. PMID: 19706183; PMCID: PMC2747837.
4. McGowan JH, Cleland JG. Reliability of reporting left ventricular systolic function by echocardiography: a systematic review of 3 methods. Am Heart J. 2003 Sep;146(3):388-97. doi: 10.1016/S0002-8703(03)00248-5. PMID: 12947354.
5. Jacob M, Shokoohi H, Moideen F, Pousson A, Boniface K. An Echocardiography Training Program for Improving the Left Ventricular Function Interpretation in Emergency Department; a Brief Report. Emerg (Tehran). 2017;5(1):e70. Epub 2017 Jun 15. PMID: 29201952; PMCID: PMC5703747.

Can ED physicians use TAPSE to rule out PE?

tapse ultrasound

Background

Pulmonary embolism (PE) often makes it on the differential of emergency department (ED) patients with any sort of cardiac or pulmonary complaint, and it can be a diagnostic challenge to know how far into the work up of PE is necessary for each patient. Any bedside tool that can increase or decrease the likelihood ratio for PE could be beneficial. Bedside echocardiography is one of the key tools in an ED physicians belt to narrow down differentials or potentially rule out certain diseases.

Research shows that 30 to 70% of emergency department patients with a PE will exhibit signs of right ventricular dysfunction (RVD), and a focused transthoracic cardiac ultrasound (FOCUS) is effective at detecting RVD (1). However, common measures of RVD, such as right heart enlargement, can be challenging to assess and often are dependent on the operator (2,3). A different measure, tricuspid annular plane systolic excursion (TAPSE), has been shown to accurately detect RVD while also providing prognostic information and is the least user dependent measure (4-9).

To date, there is little research on the utility of TAPSE in diagnosing PE, this study aimed to assess the diagnostic characteristics of TAPSE for PE and to optimize the measurement cutoff of TAPSE in diagnosing a PE.

 

Emergency physician performed tricuspid annular plane systolic excursion in the evaluation of suspected pulmonary embolism

 

Clinical Question

    • How accurate is TAPSE in diagnosing a PE?
    • What is the optimal measurement cutoff of TAPSE in diagnosing a PE ?
    • How good is the inter-rater reliability of TAPSE
    • How good are physicians at visually estimating TAPSE?

Methods & Study Design

• Design 

Prospective, observational convenience sample of FOCUS in ED patients undergoing evaluation for suspected PE from April 2015 to April 2016.

• Population 

Subjects were eligible if they were 18 years or older and undergoing computed tomographic angiography (CTA) for evaluation of possible PE in the ED. Prisoners, wards of the state, and non–English-speaking patients were excluded.

• Intervention 

Patients underwent a FOCUS in the ED either prior to undergoing CTA or the operator was blinded to the results if the FOCUS was done after the CTA. The operators were ultrasound trained emergency physicians, fellow,  or residents with one medical student participating who was trained in measuring TAPSE.

• Outcomes  

The primary outcome was both describing the diagnostic test characteristics of TAPSE in diagnosing PE and optimizing the measurement cutoff of TAPSE in diagnosing a PE. The secondary outcomes were assessing inter-rater reliability, quantitative visual estimate of TAPSE, and to describe the diagnostic test characteristics of other measures of RVD.

Results

The study found that TAPSE was 72% sensitive and 66% specific when the cutoff was 2.0 cm. When using the pre-established TAPSE cut off of 1.7, TAPSE was 56% sensitive and 79% specific.

They noted that in the sub-group of patients who were either tachycardic or hypotensive, TAPSE became 94% specific and the FOCUS was 100% specific.

Additionally, TAPSE had high inter-rater reliability, physicians were able to qualitatively assess TAPSE as normal or abnormal, and the test characteristics of TAPSE were much more sensitive and specific for a PE than other measures on the FOCUS.

Strength & Limitations

Strengths:

This study was well designed for the question it sought to answer and did a good job limiting bias by blinding the participants. They asked clinically relevant questions.

Limitations:

This study was limited in that it was a convenience sample of patients making it susceptible to selection bias. Additionally, the ultrasound operators in this study had extensive ultrasound training and TAPSE training, thus it may not be generalizable to the standard population of emergency physicians.

Authors Conclusion

"The optimal cutoff for diagnosis of PE using TAPSE was determined to be 2.0 cm. The diagnostic test characteristics of TAPSE for PE are comparable to other measures of RVD, although TAPSE appears to be somewhat more sensitive and less specific. The incorporation of TAPSE into the evaluation of the right heart may increase the accuracy and reliability of beside echocardiography for the detection of PE, although our data suggest that FOCUS is of limited utility in all patients presenting with concern for PE.

However, FOCUS and TAPSE appear to be highly sensitive for PE in patients with tachycardia or hypotension. Additionally, emergency physicians with advanced training in emergency ultrasound are capable of measuring TAPSE with precision comparable to that reported in the cardiology literature. Emergency physicians are able to accurately visually estimate TAPSE as either normal or abnormal, based on an a prior cutoff of 1.7 cm. As a more reliable measure of RVD, TAPSE may also help EPs to determine the severity and prognosis of a patient diagnosed as having a PE."

Our Conclusion

TAPSE is only a moderately sensitive and specific test in diagnosing a PE. However, TAPSE can be a useful tool in patients who are hemodynamically unstable with a suspected PE. In this case, the sensitivity of TAPSE in diagnosing a PE increases dramatically and in the setting of a hemodynamically unstable patient with a normal TAPSE, PE is unlikely the etiology. This can be beneficial if a patient is too unstable to go for a CTA, to help with diagnostic clarification and decision making.

The Bottom Line 

TAPSE is not sensitive or specific enough to rule in or rule out PE, but the sensitivity dramatically improves in hemodynamically unstable patients. TAPSE has high inter-rater reliability.

Authors

This post was written by Allie Frankel, MS4 at UCSD School of Medicine, Charles Murchison, MD and Amir Aminlari, MD. 

References

Daley J, Grotberg J, Pare J, Medoro A, Liu R, Hall MK, Taylor A, Moore CL. Emergency physician performed tricuspid annular plane systolic excursion in the evaluation of suspected pulmonary embolism. Am J Emerg Med. 2017 Jan;35(1):106-111. doi: 10.1016/j.ajem.2016.10.018. Epub 2016 Oct 11. PMID: 27793505.

 

    1. Matthews JC, Mclaughlin V. Acute Right Ventricular Failure in the Setting of Acute Pulmonary Embolism or Chronic Pulmonary Hypertension: A Detailed Review of the Pathophysiology, Diagnosis, and Management. Curr Cardiol Rev 2008;4:49–59.

    2. Pruszczyk P, Goliszek S, Lichodziejewska B, Kostrubiec M, Kurnicka K, Dzikowska- Diduch O, et al. Prognostic value of echocardiography in normotensive patients with acute pulmonary embolism. JACC Cardiovasc Imaging 2014;7(6):553–60.

    3. Zanobetti M, Converti C, Conti A, Viviani G, Guerriniti E, Boni V, et al. Prognostic Value of Emergency Physician Performed Echcardiography in Patients with Acute Pulmonary Embolism. West J Emerg Med 2013;14(5):509–17.

    4. Kline JA, Steuerwald MT, Marchick MR, Hernandez-Nino J, Rose GA. Prospective evaluation of right ventricular function and functional status 6 months after acute submassive pulmonary embolism: frequency of persistent or subsequent elevation in estimated pulmonary artery pressure. Chest 2009;136(5):1202–10.

    5. Jackson RE, Rudoni RR, Hauser AM, Pascual RG, Hussey ME. Prospective evaluation of two-dimensional transthoracic echocardiography in emergency department pa- tients with suspected pulmonary embolism. Acad Emerg Med 2000;7(9):994–8.

    6. Rudoni RR, Jackson RE, Godfrey GW, Bonfiglio AX, Hussey ME, Hauser AM. Use of Two-Dimensional Echocardiography for the Diagnosis of Pulmonary Embolus. J Emerg Med 1998;16(1):5–8.

    7. Bova C, Greco F, Misuraca G, Serafini O, Crocco F, Greco A, et al. Diagnostic utility of echocardiography in patients with suspected pulmonary embolism. Am J Emerg Med 2003;21(3):180–3.

    8. Kopecna D, Briongos S, Castillo H, Moreno C, Recio M, Navas P, et al. Interobserver reliability of echocardiography for prognostication of normotensive patients with pulmonary embolism. Cardiovasc Ultrasound 2014;12:29–38.

    9. Taylor RA, Moore CL. Accuracy of emergency physician-performed limited echocar- diography for right ventricular strain. Am J Emerg Med 2014;32(4):371–4. 

Identifying regional wall motion abnormalities on ultrasound

regional wall motion abnormalities

Background

Traditionally, the focus of emergency point-of-care echocardiography has been threefold: to assess left ventricular systolic function, to identify the presence of right ventricular enlargement and to evaluate for pericardial effusion. Assessing for regional wall motion abnormalities has been left to formal echocardiography and Cardiology (1). However, structural abnormalities can appear within seconds from the onset of myocardial ischemia (2), so identifying wall motion abnormalities in patients with chest pain or suspected acute coronary syndrome (ACS) in the Emergency Department may be clinically beneficial for emergency providers, leading to more prompt and appropriate diagnostic or therapeutic measures.

We evaluate the following article that looks at whether ED physicians can accurately identify regional wall motion abnormalities.

WAMAMI: emergency physicians can accurately identify wall motion abnormalities in acute myocardial infarction

 
 

Clinical Question

Can emergency physicians with basic training in emergency echocardiography accurately identify regional wall motion abnormalities (RWMA) in patients admitted with STEMI?

Methods & Study Design

• Design 

Observational report – one group of residents trained and tested in an ultrasound procedure.

• Population 

75 patients admitted with STEMI. 6 were excluded from the analysis due to withdrawal, leaving AMA or inability to obtain interpretable images.

• Intervention 

Nine residents viewed 2 video instructional modules to provide an introduction to identifying RWMA, and completed an online test evaluating echocardiographic clips for RWMA. They then performed a bedside echocardiogram on patients with known STEMI, though they were blinded to any clinical data about the patient, including the EKG. This was performed within 24 hours of the formal comprehensive echocardiogram.

• Outcomes  

The primary outcome was agreement between resident performed echo and formal comprehensive echo on the presence and localization of RWMA. 

Results

62% of subjects enrolled had a wall motion abnormality identified by the reference standard. Study investigators identified the presence of RWMA with good sensitivity and specificity (Table 2).

 

Inter-rater agreement between the point-of-care echocardiogram and the formal echocardiogram for the presence of RWMA was K = 0.79 (95% CI: 0.64–0.94).

 

Strength & Limitations

Strengths:

Promising results suggest that emergency medicine physicians can be taught to accurately identify RWMA in STEMI with little training. Though the patients in this study were already known to have STEMI on EKG, the application of this procedure may be helpful when patients arrive with NSTEMI or elevated cardiac markers to help in the clinical decision making.

Limitations:

Study was conducted using just 9 residents, and 2 of the residents did the vast majority of the scans. It is possible that these residents are already skilled in ultrasound, so to truly gauge whether this method is broadly teachable, many more residents (with varying levels of baseline ultrasound experience) would need to be evaluated.

Authors Conclusion

The ability to diagnose a RWMA offers emergency clinicians another tool to help manage patients with chest pain and suspected ACS. These data support the introduction of focused training in RWMA identification and expansion of the clinical use of emergency and critical care echocardiography.

Our Conclusion

This is an interesting concept that emergency medicine residents can be trained to successfully identify RWMA using echocardiography. If, and how, this should be implemented in clinical practice is still yet to be explored. Perhaps this could be used in cases of NSTEMI or elevated cardiac markers to help inform clinical decision making, but this study does not answer the question of whether this skill will be clinically useful for ED physicians. 

The Bottom Line 

It is possible to train emergency medicine physicians to identify regional wall motion abnormalities using echocardiography.

Authors

This post was written by Allison Auchter, MS4 at UCSD School of Medicine, Charles Murchison, MD and Amir Aminlari, MD. 

References

P.E. Croft, T.D. Strout, R.M. Kring, et al., WAMAMI: emergency physicians can accurately identify wall motion abnormalities in acute myocardial infarction, American Journal of Emergency Medicine.

 

    1. Cheitlin MD, Armstrong WF, Aurigemma GP, et al. ACC/AHA/ASE 2003 guideline update for the clinical application of echocardiography: summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/ASE Committee to Update the 1997 Guidelines of the Clinical Application of Echocardiography). Circulation 2003;108(9):1146–62.

    2. Wholgelernter D, Cleman M, Highman HA, et al. Regional myocardial dysfunction during coronary angioplasty: evaluation by two-dimensional echocardiography and 12 lead electrocardiography. J Am Coll Cardiol 1986;7(6):1245.

How accurate is EPSS in estimating ejection fraction?

epss echo

Background

Bedside echocardiography has an established role in the time-sensitive assessment for pericardial effusion, relative chamber size, and global cardiac function of emergency department (ED) patients. Most ED physicians use visual estimation to gauge left ventricular ejection fraction (LVEF), a method that may be subject to inter-observer variability and inaccuracy (1). E-point septal separation (EPSS), the minimum separation between the anterior mitral valve leaflet and the interventricular septum, may offer a more objective measure of LVEF.

epss echo

EPSS was first studied in the 1970s as a quantitative, easily measured, and reproducible index of left ventricular function (2). In healthy individuals, the mitral valve leaflet reaches its maximum excursion near or at the septum during early diastole. EPSS increases as left ventricular ejection fraction (LVEF) decreases, and an EPSS of greater than 7mm predicts poor LVEF (3,4).

The gold standard for evaluating LVEF is a quantitative, calculated value obtained from comprehensive transthoracic echocardiography, which is impractical in the emergency department, thus EPSS offers a simple to learn and easy to obtain alternative, requiring only one view in the parasternal long axis. EPSS measurement is a technique feasible for the ED physician to perform at the bedside that can provide a convenient and reliable estimate of LVEF. 

 

E-point septal separation: a bedside tool for emergency physician assessment of left ventricular ejection fraction

Clinical Question

Does EPSS measurements obtained by ED physicians correlate with calculated LVEF from comprehensive transthoracic echocardiography (TTE)?

Can certain EPSS cutoff values be used to predict systolic dysfunction? 

What is the relationship between bedside visual estimates of global cardiac function (GCF) and the calculated LVEF measurements?

Methods & Study Design

• Design 

This was a prospective observational trial.

• Population 

A convenience sample of 80 hospitalized patients undergoing comprehensive TTE for any indication. Subjects were recruited between February and April 2012 from an academic level I trauma center. Exclusion criteria were known pregnancy or age less than 18 years.

• Intervention 

Three emergency ultrasound fellows performed bedside 4-view basic echocardiographic examinations consisting of subxiphoid, parasternal long, and parasternal short and apical views and made estimates of GCF. The fellows then obtained separate parasternal long-axis views and performed M-mode measurements of the EPSS. Comprehensive TTE was separately performed by cardiac sonographers and LVEF was calculated via the Teichholz method.

• Outcomes  

    • Subjective estimates of GCF categorized as normal systolic function (LVEF > 55%), moderate systolic dysfunction (30% > LVEF > 55%), or severe systolic dysfunction (LVEF < 30%)
    • EPSS measurements
    • Calculated LVEFs also categorized as normal/moderate/severe as above

Results

Calculated LVEF ranged from 13%-86%. EPSS ranged from 0.50-29.70 mm.

Men had higher EPSS scores and higher calculated estimates of LVEF. No other demographic or clinical variables were identified as potential covariates. 

The linear regression model revealed that EPSS is a statistically significant predictor (P < .001) of calculated LVEF.

An EPSS measurement of greater than 7 mm was 100% sensitive and 51.6% specific for severely reduced LVEF. An EPSS measurement of greater than 8 mm was 83.3% sensitive and 50.0% specific for any systolic dysfunction.

Estimated GCF and calculated LVEF were in agreement in 49 (69.0%) of subjects with a weighted Cohen κ of 0.58, with strongest agreement for subjects with severe systolic dysfunction.

epss echo

Strength & Limitations

Strengths:

This study is the first to demonstrate that EPSS can provide a quantitative prediction of LVEF. One strength of this study is the generalizability of the findings given that all indications for TTE were included. Another strength is that the ED ultrasound fellows and cardiac sonographers performed their studies independently, unlike a prior study that utilized the same scans performed by residents to obtain both EPSS and LVEF. 

Limitations:

There were possible misestimations of EPSS in certain pathologic states, such as overestimation of EPSS in mitral stenosis. Additionally, this paper describes the Teichholz method, which is subject to inaccuracies, especially in states of dyskinesis. Of note, the Teichholz method has since been supplanted by the modified Simpson’s rule and is no longer used clinically. On average, time from EPSS measurement to comprehensive echocardiogram was 6 hours with the possibility that systolic function changed during that window of time. Finally, the study size was fairly small with 71 subjects included in the final analysis.

Authors Conclusion

ED physicians can assess left ventricular systolic function using the EPSS, and EPSS is strongly correlated with calculated LVEF. An EPSS greater than 7 mm may be used to predict patients with severely reduced LVEF. ED physician visual estimation was less effective and less consistent than EPSS measurement for predicting systolic function.

Our Conclusion

We agree that EPSS is a feasible and useful tool for assessing systolic function at the bedside. This study establishes that a 7 mm EPSS cutoff is highly sensitive for detecting severe systolic dysfunction. The clinical utility of an EPSS cutoff of 8 mm for any systolic dysfunction is less clear. Employing EPSS measurement with the 7 mm cutoff in mind, in conjunction with visual estimation by an experienced ED sonographer, is likely to provide a more complete picture of a patient’s systolic function at the bedside prior to obtaining a formal echocardiogram.

The Bottom Line 

EPSS measured on bedside ultrasound the ED is an easily obtainable, quantitative predictor of systolic dysfunction. A cutoff of 7mm is sensitive in identifying systolic dysfunction.

Authors

This post was written by Jennie Xu, MS4 at UCSD School of Medicine, Charles Murchison, MD and Amir Aminlari, MD. 

References

McKaigney CJ, Krantz MJ, La Rocque CL, Hurst ND, Buchanan MS, Kendall JL. E-point septal separation: a bedside tool for emergency physician assessment of left ventricular ejection fraction. The American Journal of Emergency Medicine. 2014 Jun 1;32(6):493-7.

 

    1. Labovitz AJ, Noble VE, Bierig M, Goldstein SA, Jones R, Kort S, Porter TR, Spencer KT, Tayal VS, Wei K. Focused cardiac ultrasound in the emergent setting: a consensus statement of the American Society of Echocardiography and American College of Emergency Physicians. Journal of the American Society of Echocardiography. 2010 Dec 1;23(12):1225-30.
    2.  Massie BM, Schiller NB, Ratshin RA, Parmley WW. Mitral-septal separation: new echocardiographic index of left ventricular function. The American journal of cardiology. 1977 Jun 1;39(7):1008-16.
    3. Lew W, Henning H, Schelbert H, Karliner JS. Assessment of mitral valve E point-septal separation as an index of left ventricular performance in patients with acute and previous myocardial infarction. The American journal of cardiology. 1978 May 1;41(5):836-45.
    4. Massie BM, Schiller NB, Ratshin RA, Parmley WW. Mitral-septal separation: new echocardiographic index of left ventricular function. The American journal of cardiology. 1977 Jun 1;39(7):1008-16.

Case 23: Diastolic Dysfunction

diastolic dysfunction echo

 

A 79 year old female presented to the emergency room with worsening dyspnea on exertion.  She reported orthopnea, leg swelling, and only being able to walk a few steps without getting short of breath. She denied chest pain, fever, or productive cough, and she had been compliant with her medications. Of note, the patient was seen 3 weeks ago for chest pain, at which point she had a dobutamine stress echo that demonstrated non-reversible ischemic changes. During examination, the providers noted JVD, crackles at bilateral bases, and bilateral lower extremity pitting edema. 

 

Vitals: T 97.3   BP 152/81   HR 83       RR 18      SPO2 97% on RA

 

Your initial impression is a slamdunk heart failure exacerbation. However, a bedside ECHO is performed normal ejection fraction. This doesn’t appear to be the classic HFrEF exacerbation you’ve seen countless times before. What do we see in the echo below? What does it tell us about this patient's diastolic function?

 

diastolic dysfunction echo
e e' echo

Answer and Learning Points

Answer:

The two images above are an apical four chamber view with the doppler gait measuring mitral inflow velocity and tissue doppler, respectively. They show Grade 1 diastolic dysfunction.

Assessing for diastolic dysfunction is best achieved with an apical four chamber view and involves two measurements: mitral inflow and tissue doppler. Mitral inflow velocity is measured by placing pulsed-wave doppler at the mitral valve leaflet tips. During diastole, there are two surges of blood flow through the mitral valve. The first is Early filling immediately after the valve opens (E wave), representing ventricular relaxation. The second wave comes from the Atrial kick (A wave). In normal diastolic function, the E wave should be larger than the A wave because most of the blood enters the ventricle during relaxation, with the atrial kick subsidizing this.

Look at the diagram below to see how the E/A wave changes with the different grades of diastolic dysfunction. In our patient, the A wave was larger than the E wave so we knew this patient had grade 1 diastolic dysfunction, i.e. impaired relaxation. This happens when the stiff ventricle no longer pulls most of the blood in with relaxation (as relaxation is impaired), so the atrial kick does most of the diastolic filling. Our patient was admitted to cardiology for IV diuresis and medical optimization.

For patients whose E wave is larger than their A wave, it can be unclear whether this is a normal, pseudonormal or restrictive pattern. Tissue doppler can help further assess whether this. Place the doppler gate at the mitral valve annulus to assess left ventricular muscle relaxation. As diastolic dysfunction worsens, the ability of the left ventricle to relax will progressively worsen. Looking at the diagram below again, we see that in normal diastolic function the e' wave will be larger than the a', but as the ventricle loses its ability to relax the e' wave will get smaller. If the e' is the same size or smaller than the a' this represents diastolic dysfunction. 

diastolic dysfunction

Learning Points:

  • Heart failure with preserved ejection fraction makes up half of the patients with heart failure.
  • HFpEF can be assessed in the apical four chamber view by evaluating the mitral valve inflow at the leaflet tips and tissue doppler at the annulus.
  • The E wave is blood flow through the mitral valve during early diastole and the A wave is during the atrial kick.
  • In one study, sensitivity and specificity of diagnosing clinically significant diastolic dysfunction was 92% and 69% respectively for emergency physician conducted echocardiography (1).

References

This post was written by Megan Jackson, PGY1 at UCSD Emergency Medicine Residency Program, Charles Murchison, MD and Amir Aminlari MD

Case # 21: A 28 Year Old With Shortness of Breath

echo d sign

 

A previously healthy 28-year-old male presents to the Emergency Department complaining of one month of fatigue, shortness of breath, and dyspnea on exertion. These symptoms were preceded by symptoms of a viral illness which initially improved; however, he had recurrence of symptoms two weeks ago. He was seen at urgent care five days ago and was given steroids and albuterol without improvement. The patient otherwise denies any infectious symptoms, leg swelling, or risk factors for pulmonary embolus or deep vein thrombosis.  

VS: T: 97.7F    BP: 129/87.    HR: 109     RR: 16.    SP02: 95%

Patient is alert and oriented, non-toxic in no distress, and behaving appropriately. Cardiac exam shows a RRR, no murmurs, rubs, or gallops. Lung exam is consistent with shallow breaths and dyspnea with conversation, otherwise lungs are CTAB with no wheezing, rales, or rhonchi. The patient has no chest wall tenderness, no JVD, and no lower extremity edema.

You perform a bedside ECHO and you see the following. What do you see and what is your most likely diagnosis? What is your next step in management?

apical 4 rv strain
psla rv strain
pssa rv strain

Answer and Learning Points

Answer:

In all three cardiac views, there is dilation of the right side of the heart. In the parasternal short axis you see septal bowing into the left side of the heart, also known as the “D” sign (named after the shape of the left ventricle). These findings are indicative of elevated right sided pressure, or right heart strain, which can be seen in conditions such as acute pulmonary embolism, pulmonary hypertension, COPD, and right ventricular infarction. Given the relatively thin free wall of the right ventricle, the likely cause of right heart strain in the above scenario is an acute process.

The patient had a CT scan that revealed extensive pulmonary emboli in all segmental and subsegmental arterial divisions of the lung with findings consistent with pulmonary artery hypertension and severe right heart strain. The EKG obtained had evidence of right heart strain including right axis deviation and diffuse T-wave inversions. The patient was started on heparin and admitted to the ICU.

Learning Points

  • The reported sensitivity and specificity of echocardiography in demonstrating right heart dysfunction are around 56% and 42% respectively (1)
  • Described features of right heart dysfunction include (2)
    1. Dilation of the right ventricle
      • The RV normally appears triangular-shaped and is two-thirds the size of the LV in apical four view (3)
    1. Interventricular septal flattening
      • AKA the “D sign” on parasternal short view or paradoxical septal motion on apical four view
    1. Right ventricular hypertrophy (right ventricular free wall thickness >5mm in diastole)
      • When present, implies some degree of chronicity to the inciting hemodynamic insult
    1. Right ventricular hypokensia
      • Typically quantified as a tricuspid annular plane systolic excursion, as measured by M-mode from the apical 4 chamber view, <1.6 cm
    1. Plethoric vena cava

References

  1. He, H., et-al. Computed tomography evaluation of right heart dysfunction in patients with acute pulmonary embolism. J Comput Assist Tomogr. 2006;30 (2): 262-6.
  2. Rudski, L.G., et al. Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography. (2010) Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography. 23 (7): 685-713
  3. Mallin, M, Dawson, M. Introduction to Bedside Ultrasound: Volume 2. Emergency Ultrasound Solutions, 2013. Apple Books. https://books.apple.com/us/book/introduction-to-bedside-ultrasound-volume-2/id647356692. Accessed April 17th, 2020.


The following authors contributed to this post:

Danika Brodak, MD; Amir Aminlari, MD; Rachna Subramony, MD; Colleen Campbell, MD

Ultrasound-guided supra-inguinal fascia iliaca block: a cadaveric evaluation of a novel approach

fascia iliaca block

Background

Regional anesthesia of the fascia iliaca is well-documented to be a successful way to control acute pain from hip fractures in the emergency department, particularly in those patients at high risk of complications from repeated doses of IV opioids. However, the majority of existing descriptions on technique for performing fascia iliaca blocks focus on approaching from inferior to the inguinal ligament, relying on supra-inguinal spread to block the lateral femoral cutaneous nerve in the iliac fossa. This study aims to investigate the utility in performing suprainguinal injection of anesthetic agents directly into the iliac fossa to provide regional anesthesia.

Ultrasound-guided supra-inguinal fascia iliaca block: a cadaveric evaluation of a novel approach

Clinical Question

Does injecting dye superior to the inguinal ligament provide significant uptake of dye in the femoral, LCFN, and ilioinguinal nerves in cadaveric models?

Methods & Study Design

• Design 

This is an informational study made to illustrate the utility of an alternative supra-inguinal approach for providing regional anesthesia in those patients presenting with acute hip or knee pain.

• Population 

Bilateral injections of 20 mL of 0.25% aniline blue dye were administered to six unembalmed cadavers, for a total of 12 injections available for analysis.

• Intervention 

Bilateral injections of 20 mL of 0.25% aniline blue dye were administered to six unembalmed cadavers via an ultrasound guided approach, and dye uptake was analyzed in anatomic nerve distributions.

Steps of superior approach to fascia iliaca block:

  • Place sterile probe over the inguinal ligament, close to the anterior superior iliac spine
  • Orient linear probe in parasagittal oblique orientation (superior aspect facing medially)
  • Rock the probe so beam faces laterally to enhance fascia iliaca
  • Move probe infero-medially along the line of inguinal ligament until femoral artery is imaged
  • Moving probe supero-laterally helps identify anterior inferior iliac spine (site of rectus femoris attachment)
  • As you move laterally, you see “rising” of ilium towards transducer
  • Identify deep circumflex artery 1-2cm superficial to fascia iliaca
  • Needle introduced 2-4cm inferior to inguinal ligament, and advanced through the fascia iliaca at the level of inguinal ligament.
  • “pop” as needle passes through fascial iliaca and into the iliacus muscle
  • Needle withdrawn to the fascia, and position confirmed by 1cc of local anesthetic.
  • Injection of fluid produces a“lens”that appears. The fluid should then hydro-dissect as it migrates into the iliac fossa
  • End point is when local anesthetic passes freely superiorly over the iliacus muscle and into the iliac fossa.

• Outcomes  

Dye uptake in the femoral, lateral femoral cutaneous nerve, and ilioninguinal nerves after supra-inguinal injection.

Results

    • There was extensive spread of dye identified in the iliac fossa. (50 to 144mm of spread)
    • 10 out of 12 injections also resulted in spread into the thigh along the femoral nerve
    • The femoral nerve was surrounded by dye in all cases
    • The LFCN was identified bilaterally in 5 cadavers, but one cadaver lacked both LFCN. LCFN was surrounded by dye in all cases in which it was present.
    • It is important to realize that the ilioinguinal nerve has significant anatomic variation. The ilioinguinal nerve passed over iliac crest onto iliacus muscle and re-emerged into the abdominal wall anteriorly in 8 cases. In the other four cases it remained in the abdominal wall. It was stained blue 7 out of 8 times in this procedure as it passed over iliac crest.

Strength & Limitations

    • There was no comparison group in this study (supra-inguinal approach was used in all cases).
    • There were significant anatomic variations between cadavers. One cadaver was found to have no lateral femoral cutaneous nerve. There were also significant anatomic variations in positioning of the ilioinguinal nerve.
    • Throughout the article, there were multiple references that the authors institution has performed over 150 supra-inguinal fascia iliata blocks without any short term complications, however no retrospective data was available in the article to confirm this.
    • Low sample population (6 cadavers, 12 nerve blocks)

Authors Conclusion

“Our cadaveric dye-injection study confirms that the ultrasound-guided supra-inguinal approach result in significant spread of injectate with simultaneous involvement of both the femoral nerve and LFCN, in the iliac fossa, in the all the cadavers in which we identified theses nerves by dissection.”

Our Conclusion

This article outlines an interesting alternative approach to providing regional anesthesia for acute pain control of the hip or knee. The majority of existing descriptions on technique for performing fascia iliaca blocks focus on approaching from inferior to the inguinal ligament, relying on supra-inguinal spread to block the lateral femoral cutaneous nerve in the iliac fossa. This study demonstrates consistent bathing of the LFCN and femoral nerve with dye in cadaveric subjects with a supra-inguinal approach. However, this study does not directly demonstrate superior efficacy of the suprainguinal approach when compared to infrainguinal fascia iliaca block. Further patient-oriented studies would be needed to make such a suggestion.

The Bottom Line 

Ultrasound guided suprainguinal fascia iliaca injection of dye in cadaveric subjects shows consistent and significant uptake of injectate of the femoral nerve and LFCN in the iliac fossa. Further studies are needed to show if this provides improved analgesia as compared to the conventional infrainguinal approach. 

Authors

This post was written by Casey Smith, MD. Review and further commentary was provided by Danika Brodak, MD, Emergency Ultrasound Fellow at UCSD and Amir Aminlari, MD, Ultrasound Faculty at UCSD.

References

  1. Hebbard P, Ivanusic J, Sha S. Ultrasound-guided supra-inguinal fascia iliaca block: a cadaveric evaluation of a novel approach. Anaesthesia. 2011;66(4):300‐305. doi:10.1111/j.1365-2044.2011.06628.x

 

Case # 16: The Smoking Gun

A 32 year-old woman with history of pleurisy and systemic lupus erythematosus presented to the emergency department with three weeks of shortness of breath and pleuritic chest pain, acutely worse one day prior to arrival.

She flew into San Diego three days prior to her hospital presentation. She became dyspneic when walking from her hotel bed to the bathroom. On review of systems, she did endorse 3 weeks of right lower leg cramping. She denied fever/chills, cough, back pain, or history of blood clots. She was tachypneic and speaking in short phrases upon arrival.

Vitals: T: 98.3, HR: 130, BP: 142/88, RR: 24, SpO2 97% on RA

A bedside ultrasound ECHO and lower extremity scan was preformed.  What do you see?

 

ezgif.com-video-to-gif
RV strain gif
dvt gif 2

Answer and Learning Points

Answer

These ultrasound images show an apical 4 chamber and parasternal short view of the heart, as well as a right lower extremity DVT. The apical 4 chamber demonstrates right ventricular dilation with bowing of the septum into the left ventricle. The parasternal short illustrates “D sign” with right ventricular dilation and bowing/flattening of the interventricular septum leading to decreased left ventricular systolic function. Both views indicate right heart strain in the setting of likely pulmonary embolism. The right lower extremity showed a noncompressible right femoral vein, indicating DVT.

TPA was prepared and ready to give incase patient had worsening hemodynamic instability. She was fortuantley able to tolerate further imaging without HD compromise; CT angio confirmed the diagnosis of pulmonary embolism in bilateral main pulmonary arteries extending into all 5 lobes. Half dose TPA was administered and the patient was admitted to the ICU.

Learning Points

    • Identification of right ventricular dilatation on point-of-care echocardiography for the diagnosis of pulmonary embolism has a sensitivity of 50%, but a specificity of 98%1
    • Patients who present normotensive but have signs of cardiac dysfunction secondary to a PE are classified as submassive, and thrombolytic therapy should be considered2
    • When combining echocardiogram with lower extremity ultrasound, the sensitivity and specificity of cardiac US are 91% and 87%, respectively. Venous US shows a lower sensitivity 56%, but higher specificity 95% than cardiac. When cardiac and venous US are both positive the specificity increases to 100%, whereas when at least one was positive the sensitivity increased to 95.3
    • There is a broad differential of patients presenting to the emergency department with chest pain and shortness of breath. Point-of-care transthoracic cardiac ultrasound in the ED is an effective tool to promptly diagnose acute pulmonary embolism with right heart strain, and rapidly guide management.4,5 This patient with a history of lupus and pericarditis could have presented with cardiac tamponade, and ultrasound did show a small circumferential pericardial effusion, but did not show a collapsing right ventricle that would be expected in tamponade (instead, a dilated RV is seen).6
 

Author

Nicolas Kahl, MD. Emergency Medicine Resident. UCSD Department of Emergency Medicine.

Jessica Oswald, MD. Clinical Faculty, UCSD Department of Emergency Medicine. 

Sukhdeep Singh, MD. Clinical Faculty, UCSD Department of Emergency Medicine. Director of POCUS, El Centro Regional Medical Center.

References

  1. Dresden S, et al. Right Ventricular dilatation on bedside echocardiography performed by emergency physicians aids in diagnosis of pulmonary embolism. Ann Emerg Med; 2014 Jan; 63(1):16-24
  2. Malik Sonika et al. Advanced Management Options for Massive and Submassive Pulmonary Embolism. USC US Cardiology Review. 2016 Feb. 
  3. Nazerian P, et al.Diagnostic accuracy of focused cardiac and venous ultrasound examinations in patients with shock and suspected pulmonary embolism.Intern Emerg Med. 2018 Jun;13(4):567-574
  4. Fields JM, et al. Transthoracic Echocardiography for Diagnosing Pulmonary Embolism: A Systematic Review and Meta-Analysis.J Am Soc Echocardiogr. 2017
  5. Kahl N, et al. Point-of-care Ultrasound Diagnosis of Pulmonary Embolism with Thrombus in Transit.Clin Pract Cases Emerg Med. 2019 Feb; 3(1): 11–12.
  6. Singh, S., et al., Usefulness of right ventricular diastolic collapse in diagnosing cardiac tamponade and comparison to pulsus paradoxus.Am J Cardiol, 1986. 57(8): p. 652-6.

Case # 15: When Lines Go Wild

A 35 year old woman with sickle cell disease presented to the emergency department with localized swelling and pain near her port site. The pain started two days prior to arrival, when she was at an infusion center and her port was found to be inaccessible by the staff. She stated that the staff were unable to draw back any blood. She denied shortness of breath, chest pain, fever, or any other skin changes aside from the swelling.

Vitals: T: 97.8, HR: 64, BP: 144/80, RR: 16, Sat: 96% on RA

A bedside ultrasound ECHO was preformed to evaluate the distal tip of the port.  What do you see?

Answer and Learning Points

Answer

These ultrasound images show an apical 4 view of the heart. There is a hyperechoic mass in the right atrium that does not shadow, suggestive of a line thrombosis. A CT angio confirmed the diagnosis, showing a large clot adhered to the distal tip of the catheter.

Learning Points

    • Catheter-related complications are common and are the cause of significant morbidity and mortality for patients that have chronic indwelling lines. Symptomatic rates are reported to be 5% with asymptomatic rates increasing to nearly 20%(1).
    • Typical imaging beings with an upper extremity ultrasound. However, challenges arise as compression is unattainable when dealing with subclavian vessels(2). CT can improve the sensitivity and specificity(3).
    • In our case, a DVT ultrasound would not have been adequate, as the port is inserted over the subclavian vessel. However, a clot located in the heart can be easily detected on a cardiac echo. A CT angio was used to confirm there was a clot adhered to the line, but no pulmonary embolism.
    • Ultrasound can be used to evaluate for RV strain and at times may note RA thrombosis (such as in this case), clots in transit, and can be helpful in evaluating lines that extend into the right atrium/right ventricle.  

Ultrasound findings of clots on the cardiac echo:

Non-adhered clots will typically be floating/tumbling with cardiac motion. Since they are non-calcified, shadowing does not typically occur.

Right Atrial Thrombus
Dr. Scheels. The POCUS Atlas. http://www.thepocusatlas.com/

This can be difficulty to distingue from other masses, such as an atrial myxoma. However the correct clinical context is able to help.

Atrial Myxoma
Dr. Russell. The POCUS Atlas. http://www.thepocusatlas.com/

Using echo to check line placement/wire tips is not uncommon. Obtaining an apical 4 view as done in this case, one can evaluate the right atrium and right ventricle.


Dr. Ftacnikova et al. 3D ECHO 360. http://3decho360.com/cc19/

Author

Sukhdeep Singh, MD. Clinical Faculty, UCSD Department of Emergency Medicine. Director of POCUS, El Centro Regional Medical Center

References

  1. Verso M, Agnelli GJ. Venous thromboembolism associated with long-term use of central venous catheters in cancer patientsJ Clin Oncol 2003; 21: 3665–3675.
  2. Sartori M, Migliaccio L, Favaretto E, et al. Whole-Arm Ultrasound to Rule Out Suspected Upper-Extremity Deep Venous Thrombosis in Outpatients. JAMA Intern Med. 2015;175(7):1226–1227. doi:10.1001/jamainternmed.2015.1683
  3. Gita Yashwantrao Karande, Sandeep S. Hedgire, Yadiel Sanchez, Vinit Baliyan, Vishala Mishra, Suvranu Ganguli, Anand M. Prabhakar
    Cardiovasc Diagn Ther. 2016 Dec; 6(6): 493–507. doi: 10.21037/cdt.2016.12.06

Point-of-Care Ultrasonography for Evaluation of Acute Dyspnea in the ED

Background

Dyspnea is a common presenting symptom in the emergency department, and early diagnosis of underlying disease pathology is crucial in rapid intervention and treatment. Laboratory and radiological tests aid in the diagnosis, but often these results take time.1-3 Additionally, chest radiographs and chest CTs, the most common radiological tests in the evaluation of dyspnea, have several disadvantages including radiation risks and high costs. Unlike these modalities, point-of-care ultrasound (PoCUS) is cheap with no radiation risk, highly accurate, and has better sensitivity in detecting pneumothorax, pneumonia, and pleural effusions than CXR.4-7 In addition to being accurate and reliable, PoCUS can be performed rapidly to aid in early diagnosis and treatment of patients.

Point-of-Care Ultrasonography for Evaluation of Acute Dyspnea in the ED

Clinical Question

What is the feasibility and diagnostic accuracy of PoCUS for the management of acute dyspnea in the ED?

Methods & Study Design

  • Design:

Prospective, blinded, observational study

  • Population:

This study was conducted at Careggi University Hospital, a university-affiliated teaching hospital.

  • Inclusion Criteria:

Patients over the age of 18 with acute dyspnea of any degree. 

  • Exclusion Criteria:

Patients with dyspnea of traumatic origin, and those that were discharged from the emergency department after evaluation. 

  • Intervention:

All patients were primarily assessed by 2 separate emergency physicians with vital signs, history, physical exam, and EKG.

One physician performed a Lung, Cardiac, and IVC PoCUS.

One physician performed a standard workup using any combination of Chest X-Ray, Chest CT, Echocardiogram, labs, or Arterial Blood Gas.

Both physicians were asked to make up to 2 diagnoses based on their results.

Possible diagnoses: Heart Failure, Acute Coronary Syndrome, Pneumonia, Pleural Effusion, Pericardial Effusion, COPD/asthma, Pulmonary Embolism, Pneumothorax, ARDS/ALI, Other.

  • Outcomes

Primary: 

Accuracy of diagnosis:

Follow-up chart review determined the reference diagnosis. Results were compared to the diagnosis obtained from the ultrasound group and the standard workup group.

Secondary: 

Time to final diagnosis for both groups was recorded.

Time for Ultrasound completion was recorded.

Results

3,487 total patients → 2,683 included in study

Average time to complete US: 7±2 min

Average time to Diagnosis:

Ultrasound: 24 ± 10 minutes

ED: 186 ± 72 minutes

Variable Sensitivity - Ultrasound Sensitivity - Standard
Heart Failure 88 (85.1-90.6) 77.3 (73.7 – 80.6)
COPD/asthma 86.6 (84.2-89.2) 92.2 (90.1-94)
Pulmonary Embolism 40 (30.1-50.6) 90.5 (82.8-95.6)
  • Point-of-care ultrasound had an increased sensitivity in detecting heart failure compared to standard workup.
  • Point-of-care ultrasound had a decreased sensitivity in diagnosing COPD/asthma and pulmonary embolism compared to standard workup.

There were no differences in the sensitivity or specificity of ultrasound vs. standard workup in all other diagnoses.

Strength & Limitations

Strengths

Adequate sample size obtained for most diagnoses.

Gold standard diagnosis was reviewed by two separate emergency medicine physicians.

Limitations

Ultrasound sonographers focused only on those patients with dyspnea, while the treating physicians were responsible for other patients in the ED.

This likely increased the time to diagnosis for emergency physicians in the standard workup group.

Patients discharged from the hospital were not included in study.

Average age of patient population was 71, but patients 18 and over were accepted.

ARDS patient studies were underpowered.

Authors Conclusion

“Integrated ultrasound methods could replace the current first diagnostic approach to patients presenting with dyspnea, allowing a drastic reduction in costs and diagnostic times.”

Our Conclusion

Point-of-Care Ultrasound in patients with dyspnea provides us with quick information to begin treatment before other laboratory and radiological tests become available. While this study showed that ultrasound was superior to the standard workup in detecting heart failure, it was slightly inferior to the standard workup in detecting COPD/asthma, and significantly inferior to standard workup in detecting pulmonary embolism. The authors speculated that with the inclusion of a DVT ultrasound study would improve the sensitivity for detecting PEs greatly.  

There have been other studies demonstrating increased sensitivity using ultrasound in patients to diagnose pneumonia and pleural effusions compared to chest x-ray. This study contributed to our knowledge of the accuracy of ultrasound in undifferentiated dyspnea by demonstrating its accuracy in these other important diagnoses. The study shows that PoCUS can guide and the emergency physician’s workup, help risk-stratify, can help us to begin treatment quickly, and improveflow and efficiency in the ED. 

The Bottom Line

Although PoCUS won’t replace a standard workup in many cases, PoCUS can rapidly and accurately aid in determining the underlying diagnosis in patients presenting to the ED with undifferentiated dyspnea and may lead to quicker treatment times and improved flow in the emergency department. 

Authors

This post was written by Marissa Wolfe, MS4 at Stony Brook University. Review and further commentary was provided by Amir Aminlari, MD, Ultrasound Faculty at UCSD.

References

  1. Mulrow CD, Lucey CR, Farnett LE. Discriminating causes of dyspnea through clinical examination. J Gen Intern Med. 1993;8(7):383-392. 
  2. Schmitt BP, Kushner MS, Wiener SL. The diagnostic usefulness of the history of the patient with dyspnea. J Gen Intern Med. 1986;1(6):386-393. 
  3. Nielsen LS, Svanegaard J, Wiggers P, Egeblad H. The yield of a diagnostic hospital dyspnoea clinic for the primary health care section. J Intern Med. 2001;250(5):422-428. 
  4. Lichtenstein D, Mezière G. Relevance of lung ultrasound in the diagnosis of acute respiratory failure: the BLUE protocol. Chest. 2008;134(1):117-125. 
  5. Reissig A, Copetti R, Mathis G, et al. Lung ultrasound in the diagnosis and follow-up of community-acquired pneumonia: a prospective, multicenter, diagnostic accuracy study. Chest. 2012;142(4): 965-972. 
  6. Zanobetti M, Poggioni C, Pini R. Can chest ultrasonography replace standard chest radiography for evaluation of acute dyspnea in the ED? Chest. 2011;139(5): 1140-1147. 
  7. Nazerian P, Volpicelli G, Vanni S, et al. Accuracy of lung ultrasound for the diagnosis of consolidations when compared to chest computed tomography. Am J Emerg Med. 2015;33(5):620-625.