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.

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Volume Status Assessment in ED: Beyond the Vitals

Posted on June 8, 2022 by Rawan Alrashed

Dr. Rawan Alrashed (@rawalrashed)

PEM Physician

PoCUS Fellow

Reviewed and edited by: Dr. David Lewis

Case

A 55 year old man known to have hypertension, diabetes, atrial fibrillation, chronic kidney disease presenting with 1 week H/O fever, SOB, chest pain, cough, fatigability, looking distressed on exam with HR 110, SpO2 of 86% on RA and BP of 87/45. No audible crackles or gallop rhythm, bilateral pitting edema noticed.

So, you are asking yourself should your next step be Fluids or Diuresis ??

Background

Patient presenting to the emergency department as critically ill with shock status presents a challenge in the initial hour to balance their fluid requirements with their volume status to reach an improvement in hemodynamics without causing harm.

Volume status assessment and fluid responsiveness have been investigated using multiple measures ranging from physical examination to laboratory work up to invasive measures. Despite all that, no single or multiple factor have been sensitive or specific enough to guide further fluid management. Currently, PoCUS is progressing widely in aiding the emergency physician to take a decision in assessing patient’s fluid vs vasopressor vs diuretic needs and guide further resuscitation. PoCUS is noninvasive, readily available, reproducible test that can be augmented with other measures to guide fluid management (1).

Pathophysiology

To simplify fluid responsiveness, patients are assessed on accordance of the Frank-Starling curve. Patients will respond to fluid administration if they are on the ascending portion of the Starling curve and no benefit will be added if they are at a plateau where more harm can occur which is difficult to be predict form physical examination solely (2).

Figure 1: Frank Starling Law

Fluid Challenge

Traditionally volume responsiveness has been assessed by small fluid bolus challenge. A safer alternative to this is passive leg raise (PLR) which is an autotransfusion where you mobilize about 300-500 ml of intravascular volume from the lower limb to the heart by raising the patient legs from 0^o to 45^o. A Pre-Post assessment of stroke volume within 30-90 sec from PLR can be done to measure the difference where change of 10% consider to be responsive.

This have been shown to have a sensitivity of 77% to 100%, and a specificity of 88% and 99% (1).

Figure 2: Passive Leg raising technique (uptodate)

Volume Status Assessment

PoCUS have been used in volume status assessment and fluid responsiveness using multiple surrogates which can be classified as follows for simplification:

Cardiac PoCUS: core and advanced.
Stroke volume Assessment: VTI of LVOT/Carotid artery.
Vascular Assessment: IVC, IJV.
Venous Congestion: Hepatic, portal, & intra-renal doppler.
Lung PoCUS.

1) Cardiac PoCUS

The target of Cardiac PoCUS is to assess for possible causes of hypotension and shock status using the RUSH or SHoC protocol (3).

Figure 3: SHoC Protocol (3).

2) Cardiac Output Assessment

Two measures can be used to assess fluid responsiveness: the left ventricular outlet tract (LVOT) and the carotid artery where you assess the velocity time integral (VTI) representing the column of blood passing through the vessel through time. This can be used as surrogate of fluid responsiveness before and after the PLR where a change of 10-15% consider as fluid responsive (4).

a. LVOT measurements

Cardiac output variation of greater than 14% has a high positive predictive value for the patient being fluid responsive while values less than 10% are associated with a high negative predictive value (1)

Cardiac output (mL/min) = Stroke Volume (mL/cycle) x Heart Rate (bpm)

Stroke Volume= LVOT area x LVOT VTI

PoCUS Technique (4)

Using the cardiac phased array probe to get apical 5 chamber view and parasternal long axis view.
Apical five chamber view, with visualization of the LVOT (A).
Pulsed wave Doppler interrogation of the LVOT. The interrogation window is placed just above the aortic valve, and the line of interrogation is positioned parallel to the long-axis of the LVOT itself (B).
Measuring the area under the curve of the LVOT Doppler waveform to derive the velocity time integral (C) .
Diameter of the LVOT, measured from a parasternal long-axis view (D)

Figure 4: Stroke volume measurement at the LVOT.

b. Common Carotid Artery

Two measurement are applied to the carotid artery: the carotid blood flow and the corrected carotid flow time index. These measure are recently established in the field of cardiac output assessment and accuracy is still under debate with further studies needed.

The carotid blood flow is the integral of blood volume that is ejected through the carotid artery with each cardiac cycle. An increase of carotid blood flow by 20% after PLR is indicative of fluid responsiveness with a sensitivity of 94% and specificity of 86% (6).

The corrected carotid flow time index (CFTI) representing the flow time between the onset of systole and the closure of the aortic valve as the duration of the full cardiac cycle. A change in the CFTI of 25% following PLR was found to have high specificity but a low sensitivity accordingly a cutoff values of 10% to 15% are more typical, still further studies are needed to specify the accurate cut off value (4).

PoCUS Technique (4,5)

a. The linear transducer is placed at approximately at the level of the thyroid cartilage, with the orientation marker pointed toward the patient’s head (A).

b. The Carotid artery identified in long-axis and the bulb before the bifurcation visualized and the doppler is applied within 2–3 cm proximal to the carotid bulb, interrogation line (green) has also been angled to make it more parallel to the long-axis of the artery.

c. The Doppler angle correction cursor is placed parallel to the direction of blood flow with insonation angles <60° .

d. Carotid artery Doppler waveform with measurement of the systolic flow time (SFT) and total cycle time (CCT).

e. Calculate the corrected flow time index using the following formula (Figure-5):

CFTI=SFT/√CCT

f. Calculate the carotid blood flow using velocity time integral tracing and carotid diameter (Intima to intima) then apply it in this formula (Figure-6):

blood flow=π×(carotid diameter)2/4×VTI×heart rate

Figure-5: Corrected Carotid Flow Time Index Measurement (4).

Figure-6: Carotid Blood Flow measurement (5).

3) Vascular Assessment

a. Inferior vena cava (IVC)

Measurements of IVC diameter and respiratory variation with the collapsibility index as a predictor of fluid responsiveness was found to be having pooled sensitivity and specificity of 63% and 73% respectively (7).

PoCUS Technique (8)

Use the curvilinear or phased array probe.
placed in the sub-xiphoid space with the transducer flat against the abdomen identifying RA and gradually fanning the probe until the intrahepatic IVC can be identified.
The probe is then rotated 90 degrees with the marker toward patient head to obtain the IVC in long axis view.
IVC diameter is measured 2 cm inferior to the cavo-atrial junction or about 1 cm inferior to the branching of the hepatic veins (Figure 7).
M-mode can be used to track IVC collapse during inspiration in spontaneously breathing patients.

Figure-7: IVC and measurement of respiratory variation (Collapsibility Index)

Measurements:

Collapsibility Index (Caval Index)

The collapsibility index=(maximal vessel diameter – minimal vessel diameter)÷maximal vessel diameter

It has been demonstrated that venous collapsibility may be inversely proportional to CVP: a 1 mmHg change in central venous pressure correlates to about 3.3% change in IVC collapsibility (9).

IVC diameter (cm)	CI (%)	CVP (mmHg)
<1.5	100%	<0-5	Volume depleted
1.5-2.5	>50%	<10	Less predictive of responsiveness
1.5-2.5	<50	>10	Less predictive of responsiveness
>2.5	0%	>20	Volume overload

Important to note that sole interpretation of the IVC for volume assessment was found to be poorly correlating and thus should be used in conjunction with other measures and integrated on patient presentation (9).

b. Internal Jugular Vein (IJV)

Internal jugular vein is used for the assessment of the central venous pressure in comparable way to IVC. A small study of non-ventilated patients who were simultaneously undergoing CVP monitoring, a mean IJV diameter of 7 mm correlated with a CVP of 10 mmHg (8).

Collapsibility index of the IJV with change of 39% consider the patient as volume depleted but this carries a limitation of the intrabdominal/ intrathoracic pressure effects (4).

PoCUS Technique

Use the linear Probe
Identify the IJV in transverse plane then rotate the probe 90^o toward the patient head.
Image of IJV is obtained where it narrows into a paintbrush appearance (Figure 8).
The height where the IJV tapers correlates with jugular venous distension.
The IJV diameter is measured using M-mode through several respiratory cycles, and the end expiratory diameter is used as the final measurement.

Figure-8: Internal Jugular vein

4)Venous Congestion (VEXUS):

This includes assessment of the Hepatic/Portal/Intrarenal veins wave forms which has been correlated to the level of venous congestion thus estimating the end organ volume effects.

Hepatic Vein Doppler mainly reflects the right atrium filling pattern, portal and intrarenal venous Doppler provide additional information about right atrial filling pressure and its correlation with congestive organ injury (10).

PoCUS Technique (9)

Hepatic Vein Doppler

The probe is placed over the liver in the subcostal position to visualize the middle hepatic vein. Pulsed-wave Doppler is used 2-4 cm from where the hepatic vein drains into the IVC.

Findings: The waveform of the hepatic vein is reversed with higher velocities seen in diastole in states of volume overload. In severe volume overload, retrograde flow is seen in systole (Figure 9)

Figure-9: Hepatic vein doppler different wave forms (11).

Portal Vein Doppler

Moving towards the portal vein, the transducer is placed in the right mid-axillary line

Findings: Flow through the portal vein is normally monophasic, but in the presence of hypervolemia, pulsatility will be present. This can be quantified using the pulsatility index where a pulsatility index greater than 50% indicates severe volume overload.

Figure 10: Portal vein doppler wave forms (11).

Intra-renal Doppler

The curvilinear transducer is placed on the posterior axillary line

Findings: A normal Doppler waveform is continuous. With increasing venous congestion, there is a decrease in the systolic component of the wave with progression to biphasic (systolic/diastolic phases), and with severe renal congestion, there is complete absence of systolic flow showing only diastolic phase.

Figure 11: Intra-renal doppler wave forms (11).

Figure-12: the change in the venous doppler according to progression of venous congestion (10).

Figure -13: VExUS grading system for venous congestion using IVC and different venous doppler wave form for categorization.

5)Lung Ultrasound

A meta-analysis showed that LUS is 88% sensitive and 90% specific for acutely decompensated heart failure and was more sensitive at detecting pulmonary edema than CXR (8).

Another meta-analysis determined the sensitivity and specificity of ultrasound for detection of pleural effusions as 93% and 96% respectively. The sensitivity approaches 100% with pleural effusions >100 mL in volume (8).

PoCUS Technique

Use the linear or curvilinear probe.
In longitudinal plane, along the midclavicular, midaxillary line then the posterior-lateral point.

Findings:

B-lines are hyperechoic vertical lines extending from the pleura down to the bottom of the US image (Figure 14). Two or fewer B-lines in each section is considered normal
Pleural effusion can be identified with presence of V-sign (extension of vertebral line proximal to the diaphragm (Figure-15) .

Figure 14: B-Lines

Figure 15: Pleural effusion

Case Conclusion

Patient was found to have reduced LV function with Dilated IVC and CI of 15%, VExUS grade 2. Assessment of COP after PLR didn’t show a proper change thus patient was started on diuretic and respiratory support with consideration of inotropic support.

Conclusion

The table below (8) shows a summary of the evidence related to the different used marker for volume assessment from physical exam to the use of PoCUS. Thus, it is imperative that we do not rely on one single tool, but rather integrate both pertinent physical examination and POCUS findings for better probability of coming to the right decision.

References

Pourmand A, Pyle M, Yamane D, Sumon K, Frasure SE. The utility of point-of-care ultrasound in the assessment of volume status in acute and critically ill patients. World J Emerg Med. 2019;10(4):232-238. doi:10.5847/wjem.j.1920-8642.2019.04.007.
Praveen P., Shanmugam L., Prasath, P. A review of role of lung ultrasound and clinical congestion score in acute left ventricular failure. International Journal of Advances in Medicine. 2020;7. 720. 10.18203/2349-3933.ijam20201130.
Atkinson P, Bowra J, Milne J, et al. 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 – CORRIGENDUM. CJEM. 2017;19(4):327. doi:10.1017/cem.2017.31.
Millington SJ, Wiskar K, Hobbs H, Koenig S. Risks and Benefits of Fluid Administration as Assessed by Ultrasound. Chest. 2021;160(6):2196-2208. doi:10.1016/j.chest.2021.06.041.
Ma IWY, Caplin JD, Azad A, et al. Correlation of carotid blood flow and corrected carotid flow time with invasive cardiac output measurements. Crit Ultrasound J. 2017;9(1):10. doi:10.1186/s13089-017-0065-0.
Marik PE LA, Young A, Andrews L. The use of bioreactance and carotid Doppler to determine volume responsiveness and blood flow redistribution following passive leg raising in hemodynamically unstable patients. Chest. 2013;143(2):364-370. doi:10.1378/chest.12-1274.
Long E, Oakley E, Duke T, Babl FE. Does Respiratory Variation in Inferior Vena Cava Diameter Predict Fluid Responsiveness: A Systematic Review and Meta-Analysis. Shock (Augusta, Ga). 2017;47(5):550-559.
Kearney, D., Reisinger, N., & Lohani, S. (2022). Integrative Volume Status Assessment. POCUS Journal, 7(Kidney), 65–77.
Argaiz Eduardo R, Koratal A., Reisinger N. Comprehensive Assessment of Fluid Status by Point-of-Care Ultrasonography. Kidney360 Aug 2021, 2 (8) 1326-1338; DOI: 10.34067/KID.0006482020.
Galindo P, Gasca C, Argaiz ER, Koratala A. Point of care venous Doppler ultrasound: Exploring the missing piece of bedside hemodynamic assessment. World J Crit Care Med. 2021;10(6):310-322. Published 2021 Nov 9. doi:10.5492/wjccm.v10.i6.310.
Dinh, V. (n.d.). Vexus ultrasound score – fluid overload and venous congestion assessment. POCUS 101. Retrieved March 29, 2022, from https://www.pocus101.com/vexus-ultrasound-score-fluid-overload-and-venous-congestion-assessment/.

A Peanut Problem or Pimple Popper Predicament

Posted on April 12, 2022 by Mandy Peach

A Peanut Problem or Pimple Popper Predicament – A Resident Clinical Pearl

Grace Dao PGY1

Family Medicine, Dalhousie University

Saint John, NB

Reviewed by: Dr. Chris Vaillancourt

Copyedited by: Dr. Mandy Peach

Case Presentation

A 30-year-old otherwise healthy female presented to the ED with concerns about an “allergic reaction” to peanut butter. She reported that she woke 30 minutes prior to her presentation in the ED with a severely swollen red and disfigured lip. Her face had looked normal upon going to bed the evening prior. Her last meal was a peanut butter sandwich, which she eats frequently without difficulty. She described having some “wheezes” and “chest tightness” to the triage RN. When seen by writer, she denied any trouble breathing. She denied any issues the night prior before going to bed. She denied any GI upset, such as cramping, nausea, vomiting or diarrhea. Besides the swollen lip, she denied noticing any other skin changes; she denied any itchy sensation. Past medical history was unremarkable; she had no history of prior allergic reaction and no known allergies. She took no medications. Review of systems was negative, besides she noted that there was pimple at the base of her nose that she had “popped” yesterday.

On exam, all vitals were within normal limits besides a HR of 110. Respiratory exam revealed no obvious stridor or increased work of breathing; there was no swelling of the tongue or uvula on inspection of the mouth, clear air entry and exit were appreciated bilaterally. A faint wheeze was appreciated bilaterally. Cardiovascular and abdominal examinations were within normal limits. A skin exam revealed a diffusely red and swollen upper lip, with skin the above the vermillion border also showing swelling and redness. Increased erythema/pus at the R nostril sill was appreciated in the area of the previously popped pimple. The lip was tender and very warm to the touch.

With 2 system involvement (lip swelling and wheezes on respiratory exam); she was treated as anaphylaxis initially and given 0.5 mg Epinephrine IM, which did not lead to any change in her symptoms. However, it would be quite unusual for an IgE mediated reaction to present this late after ingestion. A peanut allergy especially, as most of these present before age 3.

Initial bloodwork showed a normal CBC, Cr and electrolytes. CRP was elevated at 67.1. Due to no change in symptoms with anaphylaxis treatment and concerns re an infectious etiology a CT facial bones was ordered after discussion with the radiologist on call. CT report showed a broad zone of cellulitis with an evolving central abscess. ENT was consulted who reported that incision and drainage was required, and that the infection likely came from the popped pimple. They performed an incision and drainage of the abscess in the ED, took wound cultures and started empiric antibiotics, and arranged for outpatient follow-up. In discussion with the ENT, it was noted that this presentation is typical of CA-MRSA cellulitis, and, thus, antibiotics to cover MSRA were required.

Anaphylaxis

While not the outcome in this case, it is important to be familiar with the various constellation of symptoms/signs that make anaphylaxis a likely and the initial management of this “can’t miss” diagnosis, which are outlined in the included figures^1,2.

Lip Cellulitis and Abscess

Interestingly, after this case, a case study of a similar presentation was found in the literature where a MRSA lip infection was initially misdiagnosed as angioedema/anaphylaxis³. The diagnosis was discovered later, after the patient was unresponsive to anaphylaxis treatment and a history of a popping a pimple on their chin the day prior was elicited. Because Methicillin-resistant Staphylococcus aureus (MRSA) soft tissue infection also has a characteristic presentation of erythema, edema, and often, areas of fluctuance it can have a similar appearance to the typical angioedema that can be found in anaphylaxis.

See Reference 3. This CT was performed after incision and drainage; thus, no abscess is appreciated

While it is important to be vigilant towards the presentation of anaphylaxis, cellulitis is another diagnosis that it important not to miss⁴. Like other infections, complications of cellulitis include bacteremia, endocarditis, septic arthritis, osteomyelitis, metastatic infection, sepsis and toxic shock syndrome. In patients with suspected erysipelas or cellulitis it is important to consider the possibility of an abscess, which requires incision and drainage. Findings in keeping with a skin abscess would be a painful, erythematous, fluctuant nodule.

The central face is not the most common area to develop cellulitis; however, it is an important area to recognize cellulitis. Untreated cellulitis in this area, can lead to septic cavernous thrombosis because the veins in this region are valveless.

Other diagnoses to consider for angioedema without history consistent with IgE mediated reaction or infection:

Hereditary or acquired angioedema
Mast cell disorder
Idiopathic angioedema

Bottom Line: Always consider anaphylaxis in someone with apparent lip angioedema. However, it is also important to keep infection on the differential for a swollen lip, particularly if symptoms are not responding to therapy. Asking about prior injuries/skin lesions in the previous days can help clarify likelihood of infection. Also, as a personal takeaway, I should probably stop popping pimples.

References:

Sampson, H. A. , Munoz-Furlong A., Campbell, R.L., et al. (2016). Second symposium on the definition and management of anaphylaxis: Summary report: Second National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network Symposium. J Allergy Clin Immunol 2006; 117:391. https://doi.org/10.1016/j.jaci.2005.12.1303
Campbell, R.L. & Kelso, J.M. (2021). Anaphylaxis: Acute diagnosis. UpToDate. Retrieved December 30th, 2021 from : https://www.uptodate.com/contents/anaphylaxis-acute-diagnosis?search=anaphylaxis&topicRef=392&source=see_link#H1929228973
Lucerna, A. R., Espinosa, J., & Darlington, A.M. (2015). Methicillin-resistant Staphylococcus Aureus Lip Infection Mimicking Angioedema. The Journal of Emergency Medicine 49 (1), 8-11 https://doi.org/10.1016/j.jemermed.2014.12.022.
Spelman, D. & Baddour, L.M. (2021). Cellulitis and skin abscess: Epidemiology, microbiology, clinical manifestations, and diagnosis. UpToDate. Retrieved January 2^nd, 2022 from: https://www.uptodate.com/contents/cellulitis-and-skin-abscess-epidemiology-microbiology-clinical-manifestations-and-diagnosis?search=cellulitis%20&source=search_result&selectedTitle=3~150&usage_type=default&display_rank=2#H1368100182

Cover image from: https://www.uptodate.com/contents/an-overview-of-angioedema-clinical-features-diagnosis-and-management?search=angioedema&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1

A Case of Smoke Inhalation Injury

Posted on February 14, 2022 by Mandy Peach

A Case of Smoke Inhalation Injury – A Medical Student Clinical Pearl

Emmanuel Hebert

MD Candidate, Class of 2022

Dalhousie Medicine New Brunswick

Reviewed by Dr. Matthew Greer

Copyedited by Dr. Mandy Peach

Case

A 54-year-old Male presents to the emergency room via EMS. He woke up at nighttime to his house on fire. He says he woke up coughing due to the smoke and was able to crawl out of the house while ablaze and called EMS. He was then transported to the hospital. He also reports that his voice is more rough than usual and that he has pain on his back.

Past Medical History: Unremarkable

Medications: No prescriptions medications.

Physical Examination: Patient is seen wearing a non-rebreather mask with an oxygen rate of 12L/min. He appears well and is in no acute distress. He has singed scalp hair and appears flushed. The patient’s vitals are HR-110, BP-125/80, Temp-36.5, O2 sat- 99%. Patient weighs 130 kg. His back appears very red but there are no open lacerations or blisters. There is good air entry bilaterally with no adventitious sounds or wheeze. There is soot in the mouth as far back as can be visualized. The oropharynx is dry and mucous contains soot.

Figure 1: First degree burns on the back.

Initial bloodwork:

WBC: 10×10^9/L
Hgb: 135
Plt: 300×10^9/L
Na: 135
K: 4
Glu: 6
Carboxyhemoglobin: 5%
EtOH: Neg

What is the differential diagnosis of dysphonia?

-Acute laryngitis

-Functional dysphonia

-Tracheal Injury

-Injury to recurrent laryngeal nerve

-Caustic ingestion, smoke inhalation injury, blister chemical agents

-Neck masses (benign and malignant) [5,7]

Smoke Inhalation Upper Respiratory Tract Injury

Definition: Inhalation injury refers to damage to the respiratory tract or lung tissue from heat, smoke, or chemical irritants carried into the airway during inspiration [1].

Damage to the airway can be broken into three different affected zones with their own clinical consequences:

Upper Airway

The leading injury in the upper airway (above the vocal cords) is thermal injury due to heat exchange in the oro- and nasopharynx.
Injuries occurring early include erythema, ulcerations, and edema.
It is for this reason that aggressive fluid resuscitation should be avoided as the edema resulting from the heat transfer, can be compounded with fluid resuscitation, resulting in a further compromised airway. [2]

Tracheobronchial

Injuries to the tracheobronchial system occurs due to the chemical makeup of the smoke. When smoke stimulates the vasomotor and sensory nerve endings, neuropeptides get released which cause bronchoconstriction and vasodilation. Due to this inflammatory response, a loss of plasma proteins and fluid from the intravascular space into the alveoli and bronchioles ensues. This causes alveolar collapse and causes a VQ mismatch resulting in hypoxia. [3]

Parenchymal Injury

Injuries to the parenchyma occur because of the above mechanism resulting in alveolar collapse, which then cause increased transvascular fluid flux, a decrease in surfactant, and a loss of hypoxic vasoconstriction and therefore impaired oxygenation. [3]

Figure 2. Mechanisms of smoke inhalation injury in tracheobronchial area [4]

Management

Patients with smoke inhalation injuries are also at risk for carbon monoxide poisoning. It is for this reason that carboxyhemoglobin is used to assess degree of carbon monoxide toxicity. The treatment for this is 100% oxygen via non-rebreather. Another treatment that can be used is hyperbaric therapy. Choice of hyperbaric therapy should be made in consultation with a hyperbaric specialist and patient must be stable prior to transport. [3]

One of the earliest decisions to make in the management of patients with suspected smoke inhalation injuries is whether to secure the airway. In patient whom the airway is non-patent or there is an obstruction, the decision is easy to either attempt intubation via endotracheal tube or secure a surgical airway. The decision is less straight forward when the patient does not seem to be having any difficulties with ventilation and oxygenation. In the case of smoke inhalation injury, early intubation can be lifesaving. [6] This is due to the delayed fashion of bronchoconstriction in addition to the thermal changes that result from heat/smoke inhalation. Clinical judgement must be used however, to avoid intubating everyone prematurely. There are several red flag symptoms that physicians can use to assess whether a patient with smoke inhalation injury requires prophylactic intubation. [5]

Indications for early intubation:

Signs of airway obstruction: hoarseness, stridor, accessory respiratory muscle use, sternal retraction
Extent of the burn (TBSA burn > 40-50%)
Extensive and deep facial burns
Burns inside the mouth
Significant edema or risk for edema
Difficulty swallowing
Signs of respiratory compromise: inability to clear secretions, respiratory fatigue, poor oxygenation or ventilation
Decreased level of consciousness where airway protective reflexes are impaired
Anticipated patient transfer of large burn with airway issue without qualified personnel to intubate en route

Back to the case:

Due to our patient having progressive hoarseness, as well as soot throughout his oropharynx, the decision was made to secure his airway before it became too difficult to do so. A discussion was had with the patient about the risks and benefits to intubation and sedation while the inflammatory response could take its course and he consented to the procedure. Using rapid sequence intubation, rocuronium, a paralytic was used at a dose of 1mg/kg=130mg and propofol was used as a sedative at 1mg/kg=130mg. Fentanyl was used for analgesia at a dose of 1mcg/kg= 130mcg.

Due to the complexity of intubating a patient with possible impending upper airway collapse, it is important to have the best person available for intubation with one pass and ENT should be consulted so that a surgical airway can be obtained. One should also consider awake intubation due to high risk of upper airway occlusion. With this patient, a video laryngoscope was used to place the endotracheal tube.

Figure 3: Video laryngoscopy of an airway with smoke inhalation injury

During the intubation, it was seen that the tissue surrounding the airway was quite edematous with black soot present as well. This was an impending airway collapse! The endotracheal tube was placed, and the patient was monitored in the ICU overnight. As expected, edema ensued and oropharynx, tongue became edematous. The patient was stabilized on propofol drip over the next 2 days and was extubated on the third day post intubation.

Key Takeaways

Early identification of smoke inhalation injury is critical to survival.
The longer delay of intubation is, the harder it becomes. Consider awake intubation.
Red flag symptoms: Respiratory distress, respiratory depression, or altered mental status, Progressive hoarseness, Supraglottic or laryngeal edema/inflammation on bronchoscopy or NPL, Full thickness burns to face or perioral region, Circumferential neck burns, Major burns over 40-60% of body surface
Early intubation=lower mortality

References:

Woodson CL. Diagnosis and treatment of inhalation injury. In: Total Burn

Care, 4 ed, Herndon DN (Ed), 2009.

Sheridan RL. Fire-Related Inhalation Injury. N Engl J Med 2016; 375:1905.
Rehberg S, Maybauer MO, Enkhbaatar P, et al. Pathophysiology, management and treatment of smoke inhalation injury. Expert Rev Respir Med 2009; 3:283.
Herndon, D. N. (2018). 16. In Total burn care (pp. 174–183). essay, Elsevier.
ABLS Provider Manual. (2019). Ameriburn.org
Cioffi WG, Mason AD Jr, et al. The risk of pneumonia in thermally injured patients requiring ventilatory support. J Burn Care Rehabil 1995; 16:262.
Reiter R, Hoffmann TK, Pickhard A, Brosch S. Hoarseness-causes and treatments. Dtsch Arztebl Int. 2015;112(19):329-337. doi:10.3238/arztebl.2015.0329

Department of Emergency Medicine | Saint John

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