Unvexing the VExUS Score – An Overview

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

  1. 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.
  2. 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.
  3. Koratala A, Reisinger N. Venous excess doppler ultrasound for the nephrologist: Pearls and pitfalls. Kidney Medicine. 2022 May 19:100482.
  4. 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.
  5. 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.
  6. Mattoon JS, Berry CR, Nyland TG. Abdominal ultrasound scanning techniques. Small Animal Diagnostic Ultrasound-E-Book. 2014 Dec 2;94(6):93-112.
  7. 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
  8. Dinh V. POCUS101 Vexus ultrasound score–fluid overload and venous congestion assessment.
  9. 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.
  10. 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.
  11. 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.
  12. 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.
  13. 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.
  14. 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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Resuscitative Transesophageal Echo

Resuscitative TEE – the whats, the whys and the hows…. A brief review of the literature, examples of use and a proposed cardiac arrest protocol

Dr. David Lewis

Professor, Dalhousie Department of Emergency Medicine


Download SlidesPoCUS Rounds – TEE – Nov 2022



Further Reading

Introduction to Transesophageal Echo – Basic Technique

   http://pie.med.utoronto.ca/tee/

ACEP NOW – How to Perform Resuscitative Transesophageal Echocardiography in the Emergency Department

 

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PoCUS in Early Pregnancy – a review

PoCUS in Early Pregnancy – a Resident Clinical Pearl (RCP)

Dr. Victoria Landry, R3

Integrated Family Medicine Emergency Medicine Program

Saint John, NB

Edited by Dr. Rawan AlRashed, PoCUS fellow

Copyedited by Dr. Mandy Peach

PoCUS use by the emergency physician for the diagnosis of uncomplicated intrauterine pregnancy have been proven to be affective in expiditing patient management and decreasing the length of stay in the emergency department. In a metanlaysis done by Stein et.al. emergency physiscain performed PoCUS was found to be 99.3% sensitive in ruling out ectopic pregnancy by detecting an Intauterine pregnancy (IUP). In this review, ultrasound findings in the first trimester will be highlighted.

Indication: Confirmed or suspected pregnancy with abdominal pain, vaginal bleeding, syncope, or hypotension(2)

Technique

Start with trans-abdominal ultrasound (TAUS) (1,2)

  • Use abdominal probe (deep penetration, wide field view; use “obstetrics” or “gynecology” preset)
  • Acoustic window is a full bladder (anechoic structure in the near field). Uterus is a homogenous structure beneath bladder
  • Place abdominal probe midline longitudinally/sagitally immediately superior to symphysis pubis with probe marker toward patient’s head. Adjust depth so uterus is in middle of screen. Sweep left and right till uterus disappears in each view.
  • Rotate probe 90° into transverse plane with marker toward patient’s right side. Sweep up and down till uterus disappears in each view.
  • To improve image: Turn the gain down, sweep slowly

Then Consider the use of transvaginal ultrasound (TVUS) if available, and qualified to use  (1)

  • Requires empty bladder, Patient in lithotomy position.
  • Ultrasound gel on probe, latex condom over top (ensure no air bubbles), then sterile lubricant
  • Reference mark toward ceiling (in sagittal orientation), insert 4-5cm into vagina, sweep left and right
  • Turn probe 90° C to be in coronal plane and marker to the right of the patient – sweep anterior and posterior

General principles (1)

  • follow the endometrial stripe (echogenic line within uterus) along its entire course (left to right in longitudinal view, cervix to fundus in transverse view), looking for evidence of a pregnancy
  • You are trying to rule in an intrauterine pregnancy (IUP) (as opposed to rule out an ectopic) – assume all pregnancies are ectopic until proven otherwise(2)

 

Figure 1 – Longitudinal/sagittal view (TAUS): (1)

Figure 2 – Transverse view (TAUS): (1)

Discrimination zone (βHCG levels below which you cannot see an IUP)(2, 3)

  • TVUS – βHCG 1500-2000 mlU/ml
  • TAUS – βHCG 5000-6000 mlU/ml
  • If No definite IUP (NDIUP) above these levels, strongly consider ectopic!

Findings:

Inutrauterine pregnancy

  • The “double ring sign is the earliest sign of a definitive IUP. Diagnosing an intrauterine pregnancy (IUP) requires visualization of all 3 structures inside the uterus. (1,2)
  • Decidual reaction – hyperechoic (white) line in uterus (2) represents endometrium thickening – begins around day 14 post-fertilization (1)
  • Gestational sac – anechoic (black) round area within decidual reaction, contains amniotic fluid, seen at 4-5wks (TVUS), 6wks (TAUS) (2)
  • Yolk sac +/- fetal pole within the gestational sac(2)
    • Yolk sac: circular echogenic layer, looks like a cheerio, visible when gestational sac is 10mm by TVUS (~5-6wks GA), 20mm by TAUS (~6-7wks GA) (1)
    • Fetal pole: echogenic structure; develops around the same time as yolk sac but visualized on US ~1wk later(1)

Figure 3 – Double ring sign(1)

Figure 4 – Double ring sign(4)

Figure 5 – Fetal pole(1)

Measurements

Mean sac diameter

  • Obtain sagittal view of gestational sac, measure height and length of sac using mean sac diameter calculation package, rotate probe 90º to obtain transverse view of gestational sac, measure width of sac
  • MSD (mm) + 30 = Gestational age (days)

 

Crown-rump length (CRL) = Top of skull to base of pelvis(1)

  • >5mm without visible fetal heart = unlikely to proceed to viability
  • CRL (mm) + 42 = gestational age (days)
  • The most accurate method of dating the pregnancy(3)

 

Fetal cardiac activity = proof of live IUP(1)

  • detectable ~6wks on TVUS (fetal pole is >5mm), 7-8wks on TAUS (fetal pole is >10mm) (1)
  • Normal IUP with fetal cardiac activity is reassuring!
    • absence of cardiac activity will likely result in miscarriage, presence of cardiac activity reduces risk of miscarriage (HR >100 consistent with good fetal outcome)
  • Technique(3)
    • Locate fetal pole, optimize depth, turn on M-mode (never doppler as it subjects fetus to high US energy and may be harmful)(1,2), place caliper over beating heart, measure and calculate heart rate
    • Note: must be within gestational sac, well away from uterine wall (don’t confuse with highly vascular decidual reaction)(1)
    • Normal FHR Ranges
      • 6-7wks: 100-120bpm
      • 8wks: 145-170bpm
      • 9+wks: 120-160bpm

 

Other findings and descriptions

No definitive intrauterine pregnancy (NDIUP) (2)

  • if any single criteria of IUP is missing

DDx for NDIUP(2):

  • Early normal pregnancy (βHCG below discrimination zone)
  • Threatened/spontaneous abortion
  • Anembryonic pregnancy (blighted ovum)
  • Molar pregnancy
  • Ectopic pregnancy

Threatened abortion: abnormal bleeding during pregnancy; normal IUP on US(3)

Inevitable abortion: vaginal bleeding with open os; normal IUP or product of conception (POC) near cervix on US(3)

Incomplete abortion: open os with retained POC; US shows anything from debris to embryo; abnormal uterine contents confirms dx(1)

Complete abortion: empty uterus + positive βHCG +/- closed os; same findings as for ectopic therefore requires formal US + serial βHCG(1)

Ectopic pregnancy (3)

  • NDIUP (no definitive intrauterine pregnancy) above βHCG in discriminatory zone
  • Scan adnexa for signs of ectopic
    • Tubal ring sign (thick hyperechoic ring around a tubal mass)
    • Ring of fire sign (also seen in corpus luteum cysts; high velocity flow seen on color doppler around the
    • gestational sac + fetal pole with cardiac activity outside the uterus is diagnostic of an ectopic
  • assess pouch of douglas for free fluid
  • suspicious for ectopic: ectopic mass, fluid in cul de sac, absent IUP, abnormal βHCG pattern (normally rises at least 50% in 48hr period)

Corpus luteal cyst(2,3)

  • develops due to growth, instead of normal regression, of corpus luteum
  • appears very similar to ectopic, but will move with the ovary in response to transducer manipulation instead of independent, tubal ring is thinner and less echogenic, cystic fluid is more clear and anechoic (rather than “clumpy” with echoes)
  • ovarian cyst characteristics: outside the uterus, circular, well circumscribed, do not taper to solid organs

Blighted ovum (anembryonic pregnancy)(1,2)

  • abnormally large gestational sac with no embryonic contents
    • gestational sac >20mm without yolk sac visible à suspect blighted ovum
    • >25mm without yolk sac visible à blighted ovum virtually certain (Eliminates diagnosis of ectopic)
  • Positive βHCG (higher than expected for GA)
  • Confirm with formal US

Molar pregnancy (1,3)

  • Tumor due to uncontrolled proliferation of trophoblasts (cells that surround blastocyst and later become the placenta)
  • Complete mole: no fetal/embryonic tissue; abnormally elevated βHCG >100,000 mIU/ml
  • Partial mole: may contain (abnormal) fetal structures
  • Presentation: hyperemesis, larger uterus than expected, vaginal bleeding, anemia, signs of hyperthyroidism, pregnancy-induced hypertension
  • US: appears as a “snowstorm” or “cluster of grapes” in uterus – fairly homogenous mass full of small, fluid-filled (black) holes; no detectable fetal cardiac activity
  • Needs gyne referral for surgical evacuation(2)

Pitfalls

  • Pseudogestational sac (1, 3)
    • contains no yolk sac, usually more irregularly shaped or pointy-edged than a true gestational sac, border is not as echogenic, and fluid may contain some echoes
    • Intrauterine fluid collections occur in 9-20% of ectopic pregnancies
    • Unless all 3 criteria met for double ring sign, pt requires formal US
  • Extrauterine pregnancy(1)
    • Recognize uterine tissue and always confirm bladder-uterus juxtaposition(2)
  • Interstitial and cornual ectopic pregnancies(1)
    • Rare but dangerous – tend to rupture later therefore produce more rapid hemorrhage than other ectopics
    • Myometrium around interstitial and cornual pregnancies is thin and uneven(2)
    • Measure the “myometrial mantle” (the thinnest part of myometrium around the gestational sac) – should be >5-7mm thick (thinner is concerning for cornual or interstitial ectopic pregnancy) (2)
  • Multiple pregnancies(2)
    • In multiple gestation, each fetus needs to meet the criteria for IUP
    • Heterotopic pregnancies = combined IUP and ectopic pregnancy
      • Risk is 1:30,000 in general population
      • Risk increases to 1:100 with fertility treatment (e.g. IVF)

Figure 7 – Extrauterine pregnancy(1)

Figure 8 – Normal myometrial mantle(1)

Figure 9 – Cornual ectopic pregnancy(1)

Key points(1)

  • False positive IUP can have devastating consequences
  • Any positive βHCG + no definitive IUP = presumed ectopic
    • Pt stable + no free fluid à formal US + quantitative βHCG
      • If no ectopic mass, repeat formal US and βHCG in 48hrs with consideration of patient risk of ectopic pregnancy
      • Follow up with OB to be arranged
    • Always consider other diffrerntail diagnosis for patient presentation before discharging them home.

Figure 10 – Clinical application(2)

 

References:

  1. Socransky, S., &amp; Wiss, R. (2016). Obstetrical EDE. In Essentials of point-of-care ultrasound: The EDE book (pp. 61-90). The EDE 2 Course.
  2. Long, N. (2020, March 02). VanPOCUS: 1st Trimester Obstetrics • LITFL • Ultrasound Library. Retrieved October 15, 2020, from https://litfl.com/vanpocus-1st-trimester-obstetrics/
  3. Dinh, V. (n.d.). Obstetric/OB Ultrasound Made Easy: Step-By-Step Guide. Retrieved October 15, 2020, from https://www.pocus101.com/obstetric-ob-ultrasound-made-easy-step-by-step-guide/
  4. Flores, B., Smith, T., & Joseph, J. (n.d.). OB/Gyn. Retrieved October 15, 2020, from https://www.thepocusatlas.com/obgyn-1

 

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