VOTW: The chamber that bounced back!

Hello all! Check out this week’s VOTW by yours truly!

Hospital course

A 60 y/o M with extensive PMH including ESRD on dialysis and CHF presented to the ED complaining of generalized weakness and SOB. He was hypotensive and anemic. Bedside TTE was performed.

In both parasternal and short axis views seen above, there is a circumferential pericardial effusion surrounding the entire heart.

Parasternal long view: We can see the RV collapse during diastole. How do we know this is diastole? Note that we can see the opening of both the mitral valve and the tricuspid valve to allow for ventricular filling, which occurs during the diastolic phase of cardiac contraction. See clip #1 to see a video of this RV diastolic collapse.

Short axis view: Here we see an example of ‘trampoline sign’, which is the characteristic bouncing motion of the RV. In the image above, we see inversion of the RV wall during diastole (arrow). How do we know this is diastole? Again, note that we can see the opening of the mitral valve in the LV when the RV wall inverts. See clip #2 to see a video of the ‘trampoline sign’.

IVC: In clip #3, we see a very distended plethoric IVC without respiratory variation.

Case Conclusion

The patient was found to have a large pericardial effusion with tamponade. He was stabilized and admitted to cardiology for a pericardial window.

Characteristic Findings of Cardiac Tamponade on POCUS

·       The transition from a pericardial effusion to tamponade is due to the rate of fluid accumulation within the pericardial sac, not the total volume of effusion. The right heart is a low-pressure system and collapses when it is unable to accommodate the acute increase in pressure seen when fluid quickly fills the surrounding pericardial sac.  

·       Thus, the earliest sonographic finding of cardiac tamponade is RA collapse during systole. This is typically followed by RV collapse during diastole, which has both high sensitivity and specificity for cardiac tamponade.

·       A non-collapsible plethoric IVC is the most sensitive sign of cardiac tamponade.

Happy scanning!

Sono team

Resources to review:

·       https://coreultrasound.com/pericardial-tamponade/

·       https://www.acep.org/emultrasound/newsroom/may-2024/cardiac-tamponade

·       https://www.aliem.com/differentiating-pericardial-effusion-tamponade-ultrasound/

·       https://www.emra.org/emresident/article/us-cardiac-tamponade

CIR Union Benefits (July 2025)

Since today is the first day of the new academic year and we have many new faces joining us, I thought it would be a great time to review our union's benefits once again (shout out to our ex-resident Dr. Jeff Yang for his detailed table that he made for POTD a few years back). 

I recommend setting up Direct Deposit at the CIR portal: https://cirmp.novus-360.com/cirmpprod as you can receive your reimbursement back in 7 days after you file a claim, in comparison to 4-6 weeks of a mailed check from the union. 

Professional Education Benefit (also known as CME money)

Our union will pay $1250 annually (benefits renew July 1st every year) with the following caveats:

• Electronic devices are only reimbursed at 75%, up to the full $1250.

• Only 1 electronic device will be reimbursed per year.

• Eligible electronic devices include laptops, phones, tablets. Things that are not eligible include smart watches, phone plans, cameras, eBooks/Kindles.

• Electronic devices must be purchased before the last 6 months of residency. PGY3s, this means you must buy one BEFORE Saturday 12/30 to be reimbursed.

• Interns: you can use this money to pay for your Step 3/Level 3 board exam fees and/or UWorld subscription to study for the exam 

Other things that are eligible include: 

• Audio materials

• Board Exam Fees

• Books and eBooks

• COVID-19 Medical Equipment

• Conferences/Courses

• Dues & Journals for Medical Specialty Society

• Equipment (ie. scrubs, stethoscope, etc.)--FIGS ARE INCLUDED 

• License Application and Examination Fees. Per the Internal Revenue Service, initial medical and/or dental licensing reimbursements are taxable. A 1099 tax statement will be issued to anyone who receives reimbursement for initial licensing totaling $600.00 or more per calendar year.

• Software or electronic medical apps

• Fellowship Application Fee

Discounted Contract Review

Important Information for the graduating PGY3's: 

CIR members are eligible  to receive a review of their post-residency employment contract by a participating lawyer at a substantially discounted rate of $400.

Meal allowances

• $1100 per year, does not roll over

• Places freedom pass accepted at that I’m aware of: 3 in 1, Maimoni, the place next door to Maimoni, Leah’s Kitchen (formerly J&J), D&D, La Strada, Kaff Bakery, and now Bora Bora

• Check balance at next time you buy something at Maimoni Deli or https://my.freedompay.com/MemberServices/BalanceCheck.aspx

Parking

• Opt-in program. Email academic affairs, Robin Gitman and Lindsay Macchia to sign up

• 12 vouchers per month or $36/month (discounted from $54) for unlimited parking

Uberhealth

• $25 limit. Ride must originate from Maimonides.

• Can use 10pm – 5:30am 

• Does not work from your home to Maimo, only the other way around 

• Please be mindful of utilizing this precious resource, as if you use it out of the hour range listed above, the cost of the Uber ride will be deducted from your paycheck (or so we have been told)

Discounts

In addition, CIR in partnership with SEIU (Services Employee International Union), has plenty of discounts through their member portal: https://www.seiumb.com/

Some highlights are: 

• Get a $40 Costco Gift card when you apply for a new membership

• Get up to 40% off on concert/amusement park tickets 

FSA/Commuter Benefits  

• Manage both at https://participant.briweb.com/dashboard

• FSA (flexible spending account): Use pretax money towards healthcare spending. This includes contact lens solution, sunscreen SPF 15+, tampons/liners/pads, OTC medications.

  • These accounts are not the same as HSA. Use-it-or-lose-it by 12/31 each year.

  • You can only add money during enrollment periods which already passed for next year (11/6/23-11/27/23)

• Commuter Benefits: Use pretax money towards transportation. Includes subways, busses, ferries, and trains (e.g. Amtrak). Does not include taxi, uber, tolls. You can change how much you put in before any pay cycle.
   

Benefit

Amount

Comments

PEB (CME)

$1250

Submit claims:

https://cirmp.novus-360.com/cirmpprod

Meal allowance

$1100

Does not rollover

Check balance:

https://my.freedompay.com/MemberServices/BalanceCheck.aspx

Parking

12 vouchers/month or $36/month

Sign up by emailing Robin Gitman and Lindsay Macchia (Academic Affairs)

UberHealth

≤ $25/night

10pm-5:30am or after shift from MMCH

Mental Health

$5,000 / year

Max $200 / visit

Submit claims:

https://cirmp.novus-360.com/cirmpprod

Paid Family Leave

Up to 12 weeks, up to $1131/wk

This is a NY state benefit. For new children, ill family members, family members called in to military.

FutureMoms

N/A

Access OB nurse coach, dietitians, pharmacists, social workers.

Rx Benefit

$5 - $60 copay

ExpressScripts

http://www.express-scripts.com/

Dental

Its… ok. Annual cleanings are covered.

Guardian

http://www.guardiananytime.com/

Vision

$100-125 towards frames/contacts

Davis Vision

http://www.davisvision.com/

Disability

Short term: 60% weekly salary up to $692/wk x 26 wks

Long term: 60% monthly salary up to $3,5000/month

Life

Your beneficiary gets $125,000 if you die. You get $20,000 if your spouse dies.  

Language

Rosetta Stone.

https://www.cirseiu.org/opportunity-to-learn-a-new-language-with-rosetta-stone-2/

Legal

Includes landlord, immigration, bankruptcy issues among others. Refer to following to see if CIR lawyers can cover you.

https://www.cirseiu.org/wp-content/uploads/2016/03/CIRLS-VH-SPD-2014-w-cover.pdf

VBG + Vibes

Our ED has experienced several times when the lab goes down and none of our labs return. On days like these, our team coined the term “VBG + Vibes” to describe the clinical atmosphere. But all jokes aside: is our reliance on VBGs truly justified?

When ICU teams arrive, their residents and fellows sometimes request arterial blood gases (ABGs) instead. While there are certain indications for ABGs—particularly when assessing oxygenation or in unstable patients—a VBG typically provides enough clinical information for most ED decisions.

We also routinely turn to VBGs for electrolytes, especially when a hemolyzed BMP gives us a suspiciously elevated potassium level (e.g., K = 7). If the VBG potassium is normal, we often proceed based on that value. But how accurate and dependable are these VBG electrolytes?

In this POTD, we’ll explore the evidence behind VBG use—its accuracy, limitations, and when it truly matters to make the distinction. Let’s clarify when “VBG + Vibes” is solid clinical practice—and when it might not be enough.

Origins and Uses of VBGs

• Faster, less painful alternative to ABGs for acid–base assessment

• Widely adopted in EDs for evaluating pH, bicarbonate, CO₂, and lactate

• Particularly useful in DKA, sepsis, and undifferentiated shock

• Modern analyzers also provide electrolytes and hemoglobin, expanding utility

VBG vs. ABG 

• Advantages of VBG

  • Easier, safer, and faster to obtain than ABG

  • Less painful; no arterial puncture needed

  • Suitable for most acid–base and perfusion assessments

• Limitations of VBG

  • Cannot measure PaO₂ – use SpO₂ for oxygenation (unless severe hypoxemia suspected)

  • Less reliable at extremes (e.g., shock, hypercapnia >45 mmHg)

  • If VBG PCO₂ is elevated or oxygenation is unclear, follow with ABG

Accuracy of VBG Parameters

• pH & Bicarbonate

  • pH difference vs ABG: ~0.03–0.05 units → clinically negligible

  • Bicarbonate (HCO₃⁻) closely mirrors ABG and serum values (within ~2 mEq/L)

  • Reliable for assessing acidosis/alkalosis, including in DKA and renal failure

• CO₂ (PCO₂)

  • Correlates well when normal or mildly elevated

  • PCO₂ >45 mmHg → correlation worsens, may under- or overestimate PaCO₂ by ±10 mmHg

  • Use VBG to rule out hypercapnia; ABG needed if VBG CO₂ is high or patient is unstable

• Electrolytes

  • Potassium & sodium from VBG strongly correlate with serum values (r > 0.9)

  • Good enough to trust for clinical decisions (e.g., hyperkalemia)

  • Caution: Blood gas analyzers don’t detect hemolysis – falsely elevated K⁺ possible

• Hemoglobin & Hematocrit

  • Reliable from VBG analyzers (via co-oximetry)

  • Sufficient for ED decision-making, including transfusions and anemia eval

• Lactate

  • Venous lactate is accurate for diagnosis and trending in sepsis and shock

  • Normal VBG lactate rules out tissue hypoperfusion

  • Trending must be done using same sample type (venous vs arterial)

Common ED Use Cases

• Diabetic Ketoacidosis (DKA)

  • Venous pH and HCO₃⁻ are adequate to diagnose and monitor DKA

  • VBG electrolytes (Na⁺, K⁺, bicarb, AG) reliably match BMP

  • No need for ABG unless coexisting respiratory failure

• Sepsis

  • VBG lactate + base deficit reflect perfusion status

  • Serial VBGs are reliable for lactate clearance

  • ABG only if oxygenation unclear or patient in severe distress

• Undifferentiated Shock

  • VBG rapidly identifies metabolic or respiratory acidosis

  • Helps differentiate between shock types early

  • ABG may follow if VBG is highly abnormal or clinical picture unclear

When to Use ABG Instead

• Need exact PaO₂ (e.g., ARDS, unclear oxygenation despite high SpO₂)

• Suspected severe hypercapnia or respiratory failure (e.g., altered COPD)

• Mixed acid–base disorder with unclear etiology

• Consultant or protocol explicitly requires it (e.g., trauma base deficit)

Takeaways

• VBG + SpO₂ + clinical judgment is accurate, safe, and efficient in most ED patients

• ABG should be selective, not routine

• Embracing VBGs reduces pain, speeds care, and provides reliable data in:

  • DKA

  • Sepsis

  • Shock

  • COPD/asthma exacerbations

• Knowing when a VBG is enough is essential; use ABG only when it changes management

References:

Kelly, A. M., McAlpine, R., Kyle, E., & Klim, S. (2018). How accurate are blood gas electrolyte measurements? REBEL EM. https://rebelem.com/how-accurate-are-blood-gas-electrolyte-measurements/

LITFL. (2023). VBG versus ABG. Life in the Fast Lane. https://litfl.com/vbg-versus-abg/

Koul, P. A., Khan, U. H., Wani, A. A., Ahangar, A. G., & Ahmad, M. (2024). Venous versus arterial blood gases in patients with COPD exacerbation: A clinical equivalence study. Journal of Emergency Medicine, 66(2), 142–148. https://doi.org/10.1016/j.jemermed.2024.01.003

Zeserson, E., Goodgame, B., Hess, J. D., Satty, T., Walker, C., Diercks, D. B., & Clancy, T. V. (2018). Correlation of venous blood gas and pulse oximetry with arterial blood gas in the undifferentiated critically ill patient. Western Journal of Emergency Medicine, 19(2), 403–408. https://doi.org/10.5811/westjem.2017.11.35191

Gokel, Y., Paydas, S., Koseoglu, Z., Seydaoglu, G., & Tan, M. E. (2000). Comparison of blood gas and electrolyte values in arterial and venous blood samples in patients with uremic acidosis and other acid-base disturbances. American Journal of Nephrology, 20(4), 319–323. https://doi.org/10.1159/000013601