PoCUS Fellowship Rounds: Near-Syncope

Posted on October 30, 2023 by David Lewis

Dr. Chew Kiat Yeoh

EMSJ DalEM PoCUS Fellow

Privacy note: This is case is imaginary and includes components from various cases seen by the author over the last 5 years. It is presented in this way for educational purposes.

PoCUS For Maxillary Sinusitis

Posted on October 30, 2023 by David Lewis

PoCUS Clinical Pearl by Dr. Chew Kiat Yeoh

DalEM PoCUS Fellow

Reviewed by: Dr. David Lewis

Background

Acute rhinosinusitis is an inflammatory disease of nasal mucosa and paranasal sinuses. It is one of the most common ED presentations and fifth most common diagnosis for which antibiotics are prescribed (1).
It affects more than 30 million adult each year (2).
Accurate diagnosis of acute maxillary sinusitis based on clinical examination is unreliable (3) because the signs/symptoms are nonspecific.
Although radiographic imaging improves diagnostic accuracy, it is not recommended in uncomplicated sinusitis (4) due to radiation risk, additional costs, and time.

How accurate is PoCUS in identifying maxillary sinusitis?

Gold standard for diagnosing maxillary sinusitis is positive fluid culture obtained from sinus puncture (5). However, this method is invasive, unnecessary, and often not easily accepted by patient.
Ultrasound has been used to diagnose acute maxillary sinusitis as it is rapid, safe, and non-invasive.
Ultrasound is very sensitive in identifying fluid in sinus cavities, with accuracies more than 90% for the diagnosis of maxillary sinusitis have been reported in otolaryngology (ENT) practices.
While the result from ENT practices might not be applicable to the ED setting due to different patient demographic and severity of disease. When PoCUS performed by Emergency Physician compared to CT in ED patients with suspected maxillary sinusitis, the sensitivity and specificity are 81% and 89%, respectively, for diagnosis of maxillary sinusitis (7). The agreement between the two methods was 86%.
Study using MRI as gold standard, ultrasound was found to have 64% sensitivity and 95% specificity, compared to 73% sensitivity and 100% specificity for plain XR (6).
Overall – ultrasound is sensitive in detecting fluid in sinus cavities and highly accurate (>90%) in diagnosing maxillary sinusitis.

Scanning Technique

Position: sitting upright or lean slight forward to ensure sinus fluid if present, would layer out against the anterior wall.
Probe: High frequency (4 to 12 MHz) linear array transducer with adequate depth penetration (5-7cm) to visualize the entire sinus cavity Or phased-array probe if depth required.
Scan the maxillary sinus in between lateral nose and zygoma in at least two planes: transverse & sagittal (Figure 1).
Always scan the contralateral normal side is for comparison.

Ultrasound Features

Normal Ultrasound Appearance of Maxillary Sinus

The Ultrasound Appearance of Maxillary Sinusitis

If the sinus cavity is fluid filled (complete or partial), the ultrasound signal will be able to penetrate through the thin hyperechoic anterior wall, and the surrounding walls (posterior, medial, lateral) of the sinus will be visualized and seen as a bright echogenic line.
Positive Ultrasound finding : Presence of posterior wall echo >3.5 cm from the initial echo (3) (anterior maxillary wall)

Partially Filled: Partial Sinusogram

Completely Filled: Complete Sinusogram

The significance of the Pathology and how can PoCUS add value?

More than 1 in 5 antibiotics prescribed in adults are for sinusitis. It is the fifth most common diagnosis which antibiotics is prescribed.
Rhinosinusitis is a common disorder, however, only 50% of patients presenting to the acute care setting with sinus symptoms have acute bacterial sinusitis.
Although, ultrasound is not accurate as CT and MRI, it is a more practical adjunct bedside tool that can be rapidly, safely and routinely used to assess those with sinus symptoms and for diagnosing uncomplicated sinusitis in acute care settings and could potentially reduce unnecessary over prescription of antibiotic use.

Pearls and Pitfalls

Ultrasound is not helpful in differentiating between a viral and or bacterial sinusitis.
Positive sinusogram can also be caused by significant mucosal thickening, polyps, fluid-filled cysts, masses and blood from facial trauma or sinus fractures. All these can be mistaken for acute sinusitis.
Technical failure includes inadequate depth setting to properly visualize the posterior wall and improper position(supine).

References

Summary E. Otolaryngology – Head and Neck Surgery Antimicrobial treatment guidelines for acute bacterial rhinosinusitis. 2004;130(January):1-45. doi:10.1016/j.otohns.2003.12.003
Rosenfeld RM, Andes D, Bhattacharyya N, et al. Clinical practice guideline : Adult sinusitis. Published online 2007:1-31. doi:10.1016/j.otohns.2007.06.726
Varonen H, Mäkelä M, Savolainen S, Läärä E, Hilden J. Comparison of ultrasound , radiography , and clinical examination in the diagnosis of acute maxillary sinusitis : a systematic review. 2000;53:940-948.
Aring ANNM, Chan MM. Acute Rhinosinusitis in Adults. Published online 2011:1057-1063.
Carolina S, Sur- N, Hospital HF, Cen- HM, Carolina S. Maxillary sinus puncture and culture in the diagnosis of acute rhinosinusitis : The case for pursuing alternative culture methods. Published online 2000:7-12. doi:10.1067/mhn.2002.124847
Puhakka T, Heikkinen T, Makela MJ, et al. Validity of Ultrasonography in Diagnosis of Acute Maxillary Sinusitis. Arch Otolaryngol Head Neck Surg 126(12):1482–1486, 2000.
Price D, Park R, Frazee B, et al. Emergency department ultrasound for the diagnosis of maxillary sinus fluid. Acad Emerg Med. 2006;13(3):363-4

EM Grand Rounds: Transesophageal Echo in the ED

Posted on October 3, 2023 by Janeske Vonkeman

Dr. Kavish Chandra MD, CCFP (EM)

Ultrasound in Tonsillitis – Submandibular Approach (Transcutaneous)

Posted on September 12, 2023 by Janeske Vonkeman

PoCUS Clinical Pearl by Dr. Rawan Makhdom

DalEM PoCUS Fellow

Reviewed by Dr. D Lewis

Copy Edited by Dr. D Lewis

Pdf Download: EMSJ RMakhdom Ultrasound in Tonsillitis – Submandibular Approach

Case

A 33-year-old gentleman presents to the ED with a history of fever and sore throat for the past week.

Seven days ago, he was diagnosed with tonsillitis and started on Amoxicillin but showed no clinical improvement.

Three days ago, his antibiotic was changed to Azithromycin.

At his present visit, he is febrile with a complaint of sore throat and muffled voice.

Background

Tonsillitis is an infection or inflammation of the tonsils. The tonsils are areas of lymph tissue on both sides of the throat, above and behind the tongue. They are part of the immune system, which helps the body fight infection. Tonsillitis is usually self-limiting, with most patients recovering within 4 to 10 days. Tonsillitis is usually viral, but can be bacterial e.g., strep throat and in rare cases, a fungus or a parasite can cause tonsillitis. The main symptoms of tonsillitis are a sore throat, and swollen tonsils. Symptoms may also include a fever, a congested or runny nose, swollen lymph nodes, a headache, and trouble swallowing.

Figure 1: Normal vs Inflamed Tonsils. (Mayoclinichealthsystem.org)

Peritonsillar Abscess (PTA) is one of the most common deep neck space infection
PTA is a potentially life-threatening complication if not treated.
Blind aspiration can lead to eroding or extending of the pus into the deep tissues of the neck, carotid sheath, or posterior mediastinum.

Can PoCUS help?

The ability of clinicians to reliably differentiate PTA from peritonsillar cellulitis (PTC) by physical examination alone is limited. (2)
Both conditions can have overlapping clinical presentations and findings; however, these 2 conditions have very different treatment regimens.
Blind needle aspiration is the typical method of choice to diagnosis a PTA, has also been found unreliable with a reported false-negative rate of 10% to 24% (2)
So, POCUS can help to differentiate and can also help with needle aspiration!

Endocavity Approach (Intraoral)

Figure 2: Ultrasound of Normal Tonsil using Endocavity Approach. (Google images)

Technique:

The probe is placed into the mouth against the affected tonsil to visualize any adjacent collection.
The transducer should be covered with either a condom or a finger from a sterile glove filled with ultrasound gel.
A topical anesthesia can be applied (spray) to the oropharynx prior to the examination.

Advantages:

It can aid the efficacy and safety of aspiration by localizing the area of pus and visualizing the relationship of the abscess to the carotid artery.

Disadvantages:

Not all EM providers have access to an endocavity probe.
The patient may also have trismus or difficulty opening their mouth wide enough to accommodate the endocavity probe.
Some patients simply cannot tolerate the oral ultrasound.

Submandibular Approach (Transcutaneous)

Technique:

Curvilinear/ linear probe was placed under the patient’s mandible.
Marker toward the patient’s ear.
Fanned to locate the tonsils.
Transverse plane/longitudinal plane (1,5).

Figure 3: Submandibular Approach for Scanning Tonsils using High Frequency Probe. (Brown Emergency Medicine brownemblog.com)

Endocavity vs Submandibular Approach

Comparing the two different techniques, intraoral had a sensitivity and specificity of 91% and 75% while transcervical (TCU) had a sensitivity and specificity of 80% and 81% (4).

PTA PoCUS Pearl

When there is doubt, evaluate the contralateral side.
Locate the internal jugular vein and carotid artery and fan the transducer cephalad.
with the tonsil appearing laterally and adjacent to the hyperechoic oropharyngeal space.
Ask the patient to swallow.
Using color Doppler can help identify vascular flow from the internal carotid as well as inflamed tonsillar tissue.
As most PTAs are superior and posteriorly located, these will appear deep on transcutaneous views.

Figure 4: Ultrasound of PTA using Linear Probe. (SJRHEM)

Figure 5: Ultrasound of PTA using Curvilinear Probe. (SJRHEM)

Figure 6: Another Ultrasound of PTA using Linear Probe. (SJRHEM)

References

Mathew Lecuyer “What is that hot potato voice? POUCS for the PTA” 3 May, 2019. http://brownemblog.com/blogposts/2019/4/24/ptaultrasound
Michael Secko MD a, et al. “Think Ultrasound First for Peritonsillar Swelling.” The American Journal of Emergency Medicine, 23 Jan. 2015. sciencedirect.com/science/article/abs/pii/S0735675715000339.
Matti Sievert, et “the value of transcutaneous ultrasound in the diagnosis of tonsillar abscess: A retrospective analysis” 6 Dec, 2021. https://www.sciencedirect.com/science/article/abs/pii/S0385814621001279
Daniel J. Kim MD a ,et “Test Charcteristics of ultrasound for the diagnosis of peritonsillar abscess: A systematic review and meta-analysis” 10 Jan, 2023. https://onlinelibrary.wiley.com/doi/full/10.1111/acem.14660
Hiroshi Hori, MD, et “The effectiveness of transcutaneous cervical ultrasonography for diagnosing peritonsillar abscess in patient complaining of sorethroat” 22 Jan, 2021. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7796778/

Unvexing the VExUS Score – An Overview

Posted on April 22, 2023 by David Lewis

Unvexing the VExUS Score – An Overview

PoCUS Clinical Pearl

Dr Steven Chen

DalEM PoCUS Elective

PGY2 Internal Medicine, University of Toronto

Reviewed: Dr David Lewis

Copyedited: Dr David Lewis

Introduction:

The pursuit of a rapid and objective measure of volume status has always been a vexing problem for clinicians as proper fluid management is pivotal for patient outcomes. In recent years, there has been increased attention towards the concept of “fluid-responsive” as liberal fluid boluses can often be associated with poor outcomes as a result of systemic congestion. ¹

In the POCUS community, while Inferior Vena Cava (IVC) measurements have promise in assessing central venous pressure, the subsequent translation towards “volume responsiveness” has been met with many other limitations. For one, it did not account for venous congestion at other organ levels such as the pulmonary, renal, or hepatic systems. ^2,3

Venous excess ultrasound (VExUS) is a growing bedside ultrasound-based approach that aims to provide a more comprehensive assessment of venous congestion. This was initially described by Beaubien-Souligny et al. (2020) from a post-hoc analysis correlating ultrasound grading parameters with risk in development of AKI in cardiac surgery patients.⁴ The protocol serves to assess multiple sites of venous congestion, including the IVC, hepatic veins, portal veins and intrarenal veins. By assessing congestion in these multiple sites, the VExUS score has gained attraction in providing a more comprehensive assessment of systemic congestion. ^4,5

View Acquisition:

The VExUS protocol is composed of four main components outlined below:

IVC diameter
Hepatic Vein Doppler Assessment
Hepatic Portal Vein Doppler Assessment
Intrarenal Vein Doppler Assessment

This can be performed using either the curvilinear probe (preferred) or the phased array probe. The patient should be positioned flat and supine on the bed to acquire the views. The table below depicts some suggested views where larger regions of the veins may be accessible for pulse wave doppler gating in reference to standardized sonography protocols. ^6,7

Note: Reviewing the basics of pulse wave doppler will be needed prior to completing VExUS scans (not covered in this article).

Interpretation:

Interpretation of the VExUS grading system is well summarized in diagram below (sourced from POCUS101⁸) and takes some practice to differentiate normal from abnormal waveforms. Pulse wave doppler assessment is pursued only if the inferior vena cava is found plethoric, defined as greater or equal to 2cm. ^4,5

Each of the hepatic, portal and renal veins are subsequently examined and classified as normal, mildly congested, or severely congested. The VExUS system has four grades: Grade 0 represents no congestion in any organ, Grade 1 represents only mild congestive findings, Grade 2 represents severe congestive findings in only one organ, and Grade 3 represents severe congestive findings in at least two out of three organ systems.^4,5

Source: POCUS101⁸

Some sample waveforms are shown below with comments to help with distinguishing normal from abnormal waveforms.

Evidence:

VExUS has also been shown to be reliable and reproducible, with good interobserver agreement in trained individuals and correlation with other measures of volume status such as central venous pressure.^4,5 As the technique is growing in the POCUS literature, below is a table summarizing several recent studies exploring its application across numerous settings.

Study	Purpose	Results
Beaubien-Souligny W, et al. (2020)⁴ Post-hoc analysis of a single centre prospective study in 145 patients	Initial model of VExUS grading system looking at association in development of AKI in cardiac surgery population	Association with subsequent AKI: HR: 3.69 CI 1.65–8.24 p = 0.001; +LR: 6.37 CI 2.19–18.50 when detected at ICU admission, which outperformed central venous pressure measurements
Bhardwaj V, et al. (2020)⁹ Prospective cohort study of 30 patients in ICU setting	Prospective study on application of VExUS scoring on staging of AKI in patients with cardiorenal syndrome	Resolution of AKI injury significantly correlated with improvement in VExUS grade (p 0.003). There was significant association between changes in VExUS grade and fluid balance (p value 0.006).
Varudo R, et al. (2022)¹⁰ Case report of ICU patient with hyponatremia	Application of VExUS in case report as rapid tool to help with volume status assessment in patient with complex hyponatremia	Overall VExUS grade 2, prompting strategy for diuresis with improvement
Rolston D, et al. (2022)¹¹ Observational study of 150 septic patients in single centre	VExUS score performed on ED septic patients prior to receiving fluids with chart review done to determine if there is association with poorer outcomes	Composite outcome (mortality, ICU admission or rapid response activation): VExUS score of 0: 31.6% of patients VExUS score of 1: 47.6% of patients VExUS score >1: 67.7% of patients (p: 0.0015)
Guinot, PG, et al. (2022)¹² Prospective observational study of 81 ICU patients started on loop diuretic therapy	Evaluation of multiple scores to predict appropriate diuretic-induced fluid depletion (portal pulsatility index, renal venous impedance index, VExUS)	Baseline portal pulsatility index and renal venous impedance index were found to be superior predictors compared to VExUS. The baseline VExUS score (AUC of 0.66 CI95% 0.53–0.79, p = 0.012) was poorly predictive of appropriate response to diuretic-induced fluid depletion.
Menéndez‐Suso JJ, et al. (2023)¹³ Cross-sectional pilot study of 33 children in pediatric ICU setting	Association of VExUS score with CVP in pediatric ICU	VExUS score severity was strongly associated with CVP (p<0.001) in critically ill children.
Longino A, et al. (2023)¹⁴ Prospective validation study in 56 critically ill patients	Validation looking at association of VExUS grade with right atrial pressure.	VExUS had a favorable AUC for prediction of a RAP ≥ 12 mmHg (0.99, 95% CI 0.96-1) compared to IVC diameter (0.79, 95% CI 0.65–0.92).

Pitfalls:

It should be kept in mind that numerous factors may affect interpretation of VExUS gradings.

For the IVC component, increased intra-abdominal pressure can affect measurements independently of the pressure in the right atrium or may be affected by chronic pulmonary hypertension. The hepatic vein may not show significant changes even in severe tricuspid regurgitation if the right atrium can still expand and contract normally. In thin healthy people and those with arteriovenous malformations, the portal vein can have a pulsatile flow without venous congestion. It is also important to note that for patients with underlying disease renal or liver parenchymal disease, venous doppler recordings may be less reliable. ^3-5

Outside of physiologic factors, another limitation is the need for adequate training and familiarity in performing and interpreting the technique. While VExUS is fairly well protocolized, it requires proficiency with pulse wave doppler to perform accurately. As with any new technique, there is a risk of variability in technique and interpretation. To avoid misinterpretation, it is important to consider repeat tracings to ensure consistency of results and to consider findings within the overall clinical context of the patient.

Bottom line:

VExUS is a non-invasive ultrasound method for assessing venous congestion across multiple organ systems. While there are several physiologic limitations and results need to be used in adjunct with the clinical picture, studies have shown promise for VExUS to be incorporated as part of a physician’s toolkit to help with clinical decision making. ^3-5

References

Atkinson P, Bowra J, Milne J, Lewis D, Lambert M, Jarman B, Noble VE, Lamprecht H, Harris T, Connolly J, Kessler R. International Federation for Emergency Medicine Consensus Statement: Sonography in hypotension and cardiac arrest (SHoC): An international consensus on the use of point of care ultrasound for undifferentiated hypotension and during cardiac arrest. Canadian Journal of Emergency Medicine. 2017 Nov;19(6):459-70.
Corl KA, George NR, Romanoff J, Levinson AT, Chheng DB, Merchant RC, Levy MM, Napoli AM. Inferior vena cava collapsibility detects fluid responsiveness among spontaneously breathing critically-ill patients. Journal of critical care. 2017 Oct 1;41:130-7.
Koratala A, Reisinger N. Venous excess doppler ultrasound for the nephrologist: Pearls and pitfalls. Kidney Medicine. 2022 May 19:100482.
Beaubien-Souligny W, Rola P, Haycock K, Bouchard J, Lamarche Y, Spiegel R, Denault AY. Quantifying systemic congestion with point-of-care ultrasound: development of the venous excess ultrasound grading system. The Ultrasound Journal. 2020 Dec;12:1-2.
Rola P, Miralles-Aguiar F, Argaiz E, Beaubien-Souligny W, Haycock K, Karimov T, Dinh VA, Spiegel R. Clinical applications of the venous excess ultrasound (VExUS) score: conceptual review and case series. The Ultrasound Journal. 2021 Dec;13(1):1-0.
Mattoon JS, Berry CR, Nyland TG. Abdominal ultrasound scanning techniques. Small Animal Diagnostic Ultrasound-E-Book. 2014 Dec 2;94(6):93-112.
Standardized method of abdominal ultrasound [Internet]. Japanese society of sonographers. [cited 2023Apr12]. Available from: https://www.jss.org/english/standard/abdominal.html#Longitudinal%20scanning_2
Dinh V. POCUS101 Vexus ultrasound score–fluid overload and venous congestion assessment.
Bhardwaj V, Vikneswaran G, Rola P, Raju S, Bhat RS, Jayakumar A, Alva A. Combination of inferior vena cava diameter, hepatic venous flow, and portal vein pulsatility index: venous excess ultrasound score (VExUS score) in predicting acute kidney injury in patients with cardiorenal syndrome: a prospective cohort study. Indian journal of critical care medicine: peer-reviewed, official publication of Indian Society of Critical Care Medicine. 2020 Sep;24(9):783.
Varudo R, Pimenta I, Blanco JB, Gonzalez FA. Use of Venous Excess UltraSound (VExUS) score in hyponatraemia management in critically ill patient. BMJ Case Reports CP. 2022 Feb 1;15(2):e246995.
Rolston D, Li T, Huang H, Johnson A, van Loveren K, Kearney E, Pettit D, Haverty J, Nelson M, Cohen A. 204 A Higher Initial VExUS Score Is Associated With Inferior Outcomes in Septic Emergency Department Patients. Annals of Emergency Medicine. 2021 Oct 1;78(4):S82.
Guinot PG, Bahr PA, Andrei S, Popescu BA, Caruso V, Mertes PM, Berthoud V, Nguyen M, Bouhemad B. Doppler study of portal vein and renal venous velocity predict the appropriate fluid response to diuretic in ICU: a prospective observational echocardiographic evaluation. Critical Care. 2022 Dec;26(1):1-1.
Menéndez‐Suso JJ, Rodríguez‐Álvarez D, Sánchez‐Martín M. Feasibility and Utility of the Venous Excess Ultrasound Score to Detect and Grade Central Venous Pressure Elevation in Critically Ill Children. Journal of Ultrasound in Medicine. 2023 Jan;42(1):211-20.
Longino A, Martin K, Leyba K, Siegel G, Gill E, Douglas I, Burke J. Prospective Validation of the Venous Excess Ultrasound “(VExUS)” Score.