PV Card: Focused 1st Trimester Pregnancy Transvaginal Ultrasound

Screen Shot 2014-12-31 at 2.59.44 PMEarly 1st trimester pregnancies can be challenging to risk stratify when patient present with bleeding or pain. The pregnancy may be still too early for transabdominal ultrasonography, which was covered in last week’s PV card. The same authors, Drs. Matt Lipton, Mike Mallon, and Mike Stone provide a great bedside clinical reference tool on performing the focused transvaginal ultrasound in pregnancy.


PV: Focused 1st Trimester Pregnancy Transvaginal Ultrasound

Pregnancy Transvaginal Ultrasound 1

Pregnancy Transvaginal Ultrasound 2

Pregnancy Transvaginal Ultrasound 3

You can download this PV card:  [MS Word] [PDF]

Author information

Scott Kobner

Medical student

New York University School of Medicine

ALiEM-EMRA Social Media and Digital Scholarship Fellow

Founder, EdintheED.com

The post PV Card: Focused 1st Trimester Pregnancy Transvaginal Ultrasound appeared first on ALiEM.

Ultrasound for Verification of Endotracheal Tube Location

ETT_Lubricate copyIn patients undergoing emergent tracheal intubation, there is currently no universally accepted gold-standard test to confirm the location of the endotracheal tube (ETT) [1]. End-tidal carbon dioxide (CO2) detection is the best of the tests that are routinely utilized to confirm ETT placement, however, it has been shown to have an error rate as high as 1/10 for proper determination of ETT location in emergency intubations [2]. As a result, multiple modalities are necessary to confirm ETT location, which can delay mechanical ventilation and other treatments. The lack of a single, reliable test to confirm ETT placement can potentially lead to confusion regarding the location of the tube. This confusion can result in both unrecognized esophageal intubations (“false positive”), as well as successful tracheal intubations that are subsequently removed (“false negative”), subjecting the patient to further unnecessary attempts at airway management. Both scenarios can lead to disastrous consequences.

The advent of point-of-care ultrasound (POCUS) has led to a potential solution to this problem. Over the past decade, emergency physicians, anesthesiologists, and others have studied the ability of POCUS to determine ETT location either during or immediately following laryngoscopy. Multiple approaches have been utilized including transtracheal at the suprasternal notch (Figure 1), transcricoid, and also assessments of lung sliding at the visceral-parietal pleural interface and the diaphragms.

Figure 1: Transverse placement of the high-frequency linear transducer over the trachea just cephalad to the suprasternal notch. Image courtesy of Werner et al. [3]

Recently, in the Canadian Journal of Anesthesia, Das et al published a systematic review and meta-analysis to definitively answer the question about transtracheal ultrasound’s accuracy in confirming ETT placement [4].

Inclusion criteria

  • Studies evaluating the diagnostic accuracy of transtracheal ultrasound in confirming ETT location AND
  • Results of the index test (POCUS) verified with that of a gold standard (capnography) AND
  • Studies that enrolled living adult humans


Eleven studies encompassing 969 intubations were analyzed. The pooled sensitivity and specificity for the detection of proper ETT placement with US were:

  • Sensitivity: 98% (95% C.I. 97-99%)
  • Specificity: 98% (95% C.I. 95-99%)
  • Positive Predictive Value: 99.5%
  • Negative Predictive Value: 93.8%
  • + Likelihood Ratio: 46
  • - Likelihood Ratio: 0.0157

Of these 11 studies, 3 examined elective intubations and a sensitivity analysis was performed to exclude these trials. This resulted in an aggregate sensitivity and specificity of POCUS in emergency intubations of:

  • Sensitivity: 98% (95% C.I. 97-99%)
  • Specificity: 94% (95% C.I. 86-98%)

As with all meta-analyses, the robustness and applicability of the results are highly dependent on the quality of the included trials. Eight of the included trials were judged to have a low risk of bias (using the QUADAS-2 tool [5]) and the aggregate sensitivity and specificity was:

  • Sensitivity: 98% (95% C.I. 97-99%)
  • Specificity: 98% (95% C.I. 95-100%)

Fine Print

The heterogeneity between the included studies was determined using the inconsistency index (I2) and found to be in the mild-moderate range. However, further inspection into the variability between studies showed 9 different confirmatory findings on POCUS that were used to determine ETT location, including:

  • One air-mucosal interface = tracheal intubation.
    • Two air-mucosal interfaces = esophageal intubation.
  • Two hyperechoic reverberation artifacts inside trachea = tracheal intubation.
    • Two hyperechoic reverberation artifacts inside esophagus = esophageal intubation.
  • Bullet sign”= tracheal intubation (figure 2)
  • Double track sign” = esophageal intubation (figure 3).
  • Snowstorm sign” = tracheal intubation [6]
  • Dynamic opening of the esophagus by the ETT seen on US performed during laryngoscopy = esophageal intubation. (See video 2)
  • Brief flutter deep to the thyroid cartilage = tracheal intubation

Proof is in the pudding


FIGURE 2: Success! Tracheal intubation visualized on ultrasound (bullet sign). Reverberations are seen in the anterior portion of the lumen of the trachea, just posterior (or deep) to the anterior wall.

VIDEO 1: Dynamic (real-time, concurrent with laryngoscopy and ETT placement) video showing successful tracheal placement of ETT.


FIGURE 3: The “Double Tract” sign indicating esophageal intubation.

VIDEO 2: Dynamic video showing placement of ETT into the esophagus (located in left paratracheal location in approx 70% humans).

Transducer Placement Location

While many of these sonographic findings are similar (and some are exactly the same), there is no consistent sonographic finding that is widely accepted amongst investigators. Another source of heterogeneity is in the transducer type and placement. The following locations were used in the included studies:

  • Immediately cephalad to suprasternal notch: 8
  • Cricothyroid membrane: 1
  • Both suprasternal notch and cricothyroid membrane: 2

Six studies used high frequency linear probes, while 5 studies used low frequency curvilinear probes. The precise frequencies used in the various studies were:

  • 3.75 MHz: 3
  • 3-5 MHz: 1
  • 5-10 MHz: 1
  • 7-10 MHz: 2
  • 9-12 MHz: 1
  • 10 MHz: 2
  • No frequency noted: 1

At this time, POCUS can (and should) be utilized as an adjunctive method as part of a multimodal approach to verify ETT location. It has an added benefit in cases where end-tidal CO2 detection is less reliable, such as cardiac arrest. Future studies of POCUS verification of ETT location should attempt to standardize the approach and type of equipment (transducer, settings, frequency, etc), and should utilize a technique that will not interfere with attempts at direct laryngoscopy.

ALiEM Copyedit
Pre-Publication Critique
Expert Peer Review

Author information

Mark Favot, MD

Mark Favot, MD

Assistant Professor of Emergency Medicine,

Wayne State University School of Medicine.

Co-Director, Emergency Ultrasound Fellowship,

Detroit Medical Center/Wayne State University.

The post Ultrasound for Verification of Endotracheal Tube Location appeared first on ALiEM.

I am Dr. Haney Mallemat, ED Intensivist and Lecturer on the Go: How I Travel Smarter

How I Work Smarter Logo Dear productivity aficionados, today we have a special treat. Dr. Haney Mallemat (@CriticalCareNow) is our guest. However, he has decided to go rogue and approached ‘how to work smarter’ from a very different angle. We are thrilled he did. Dr. Mallemat is a rising star in the world of critical care and emergency medicine. He started off by securing board certifications in Emergency Medicine, Internal Medicine, Critical Care, and Echocardiography. Now, only 5 years out of his Critical Care fellowship, Dr. Mallemat already has a place among the FOAM greats and a position as Assistant Professor at University of Maryland. Those who have listen to him talk will know he has the rare ability to take complex topics and break them down into understandable concepts. This has earned him the “Outstanding Teaching Award” two years in a row (2012-2013) at his home institution. You can hear his great talks on the RAGE Podcast, EMRAP, Ultrasound Podcast, PHARM Podcast, to name a few. However, it’s not all podcasting. Dr. Mallemat also lectures both nationally and internationally, and today he graciously shares his wisdom about how to get from point A to point B, with style.

  • Name: Haney Mallemathaney mallemat headshot Small
  • Location:  Baltimore, MD
  • Current job:  ½ Emergency Physician, ½ Intensivist
  • One word that best describes how you work: Fervently
  • Current mobile device: iPhone 5s / iPad mini
  • Current computer: MacBook 13”

I am a huge fan of ALiEM’s How I Work Smarter series, so I was elated when Lauren Westafer (@Lwestafer) and my mentor, Chris Doty (@PoppasPearls) nominated me to give my take on “How I work smarter”. There’s only one problem, so many incredibly smart people have already written extensively about how they work smarter I don’t think I have anything groundbreaking novel to add. Instead I’ve asked Dr. Lin if I can write about “How I Travel Smarter”. Let me explain…

I’ve been doing a lot of traveling over the past few years. Traveling is a lot of fun but I also have to stay productive while on the road; especially when some destinations require a day’s worth of travel (e.g., #SMACC Gold Coast). One of my greatest challenges to staying productive is being able to fit everything I need into my small travel bag (see below). I also don’t have an office, so I have to bring my office with me everywhere I go. So here are some tips and tricks that I’d like to share with you in no particular order of importance.

Packing for the Trip:

travel smarter
Dr. Mallemat’s Travel Gear (click for larger image).
He has no financial disclosures with regard to any of the products named.

  • Travel Bag – Pic Ref: A 
    • Let’s start off with my (small) travel bag: I like to keep my workbag as small as possible. This forces me to bring only essential items and allows me to be compact, practical, and efficient. My bag is by InCase and is perfect for me, but there is no shortage of choices out there. If I’m traveling internationally and I want to bring a few extra things to the plane (e.g., sweater, food, etc.) I opt to go with a messenger style bag with good padding for my laptop just in case it gets tossed around.
  • Pencil Case (and no, it’s not for pencils) - Pic Ref: B
    • This is the cheapest item in my travel bag, but it is the MOST essential. A simple pencil case is a good place to store all your wires, cables, adapters, extra batteries, flash drive etc. Having this case ensures that everything is in one place and doesn’t clutter the rest of my bag with wires. Plus, you can add a little bit of your own flair and style (did someone say Hello Kitty?)

Mobile Computing:

  • Multiple Desktop Feature (Mission Control in OS X; sorry Windows users, this is for MAC only)
    • In my home office I use multiple computer screens to multi-task and get work done. I’ll have one computer screen with Keynote or PowerPoint, a second screen with a video editing program, and a third screen with a web browser. This allows me to see all my work at the same time. Since I can’t bring all these computer screens on a plane, I use the desktop feature of MAC OS X. This feature allows me to have multiple programs open on different “virtual screens” that I can easily toggle between. If you’re good with the MAC’s trackpad, then it only requires one “swipe” to get between “desktops”. If I’m not making any sense here then please watch the video in the link provided and everything should become clearer.
    • If you prefer having physical screens, then try Duet. This allows you to hook up your iPhone or Ipad up to your Mac and turn it into another display. I’ve been using this a lot recently and I love it. Pair it up with a Mountie and this will turn your laptop into a powerful workflow device.
  • Large Capacity Memory Stick or Portable External Hard-Drive - Pic Ref: F
    • More and more of our data is being stored in the cloud however you don’t always have access to the cloud… even though you may be flying through them. I always have a physical backup of my all my lectures, important articles, music, movies, etc. I recommend investing in a high-capacity portable external hard drive. I use this one, which has a 1 TB capacity. Don’t want to lug around a portable drive, well how about a high capacity flash-drive? I just bought a 128 GB capacity stick for only $50! Now if you’re saying “I’ll just keep everything stored locally on my hard drive” you cannot always trust your computer (ask me how I know that). I always keep my important information on an external drive so I can access my work, even if is from someone else’s computer should my computer malfunction or crash.
  • Travel Router - Pic Ref: L
    • Some hotels only allow one device to link to their network at a time, but this is a huge problem if you have multiple devices that need wifi access. So when I travel, I always bring a portable travel router I use the Satechi Smart Travel Router. I like this router for several reasons:
      1. It becomes a “hot spot” that all my devices connect to.
      2. It has a port for USB charging so I don’t need an extra charger to lug around.
      3. It is also has an international converter built in.

Three features in one? C’mon… that’s pretty awesome.

  • Portable USB Docking Station with Multiple Ports - Pic Ref: E
    • My MacBook pro only has two USB ports and this is usually not enough. So I have a USB docking station what allows me to use multiple peripherals. Docking stations are small and cheap, but are essentials if you have a lot of peripherals to plug in when you travel.

Staying Charged:

  • Fluxbot Mobile Charge - Pic Ref: K
    • Batteries on peripheral devices (e.g., iPhones and iPads) can deplete very quickly while traveling so it’s important to always have backup energy. There are many portable battery options, but I found one recently that really impressed me, the Fluxmob. This battery plugs directly into the wall to recharge itself, but the really neat thing here is that it also doubles as an adapter for charging the device directly. This means you don’t have to bring both an external battery and a charging block adapter. The Fluxmob is also really small so it only takes up little space in my bag.
  • Batteries - Pic Ref: N 
    • There are lots of reasons to bring a couple of extra new batteries with you on your travels, here’s two reasons:
      1. Batteries will fail you and you should be ready for that.
      2. Other people’s batteries will fail them, and you’ll be a hero when bailing them out with a fresh set of batteries.

Killing It at the Venue: 

  • Bring Multiple Versions of your Presentations
    • If you are traveling to give a talk, always have multiple versions of your presentations prepared prior to leaving (this is yet another reason to have lots of physical storage available). All the major presenter programs allow you to export native files to various file formats and having this file redundancy is essential and will save you when you least expect it. For example, I prepare for disaster by creating multiple versions of the same presentation. I make a version in Keynote ’09, Keynote 6, PowerPoint, and PDF. Keynote even allows you to export a file into a QuickTime format; this is a video file with all the animations preserved. Having extra versions allows me the flexibility of not using your computer for the presentation should you need to use the computer at the conference or if your computer crashes prior to the presentation. The worst-case scenario is having a PDF version that you can flip through because all computers have a PDF viewer. Another major reason to have all your presentations backed up is that you never know when another speaker will drop out and you’ll be called upon to give an emergency “fill in” talk. It is for this reason that I always carry all my talks with me at all times (and in multiple file formats). People remember the person who comes through in a pinch and you’re sure to be invited back.
  • Wireless Remote - Pic Ref: G
    • If you are presenting at a conference you should always bring your own wireless remote. Many presenters rely on the conference organizers to provide all the necessary equipment required for their presentations. This strategy works out fine until it does not, so be prepared for anything and that’s why I always bring my own wireless remote loaded with brand new batteries. I use the R800 by Logitech for several reasons: 1) it has a great range so I can walk around the room without loosing the signal, 2) it has green laser which is easier for people to see than a red laser, 3) it has a built in count-down timer that you can set and vibrates when you have 5, 2, and zero minutes. The R800 fits comfortably in my hand and is very lightweight for travel.
  • Video Adapters - Pic Ref: M
    • If you are presenting at a conference you should never rely on the local venue to have the necessary adapters for your computer. Consider packing your own VGA adapter for your computer. I also recommend an HDMI adapter because many venues are switching to projectors with HDMI inputs. If you are using a MAC, learn how to set it up when it is plugged into the AV equipment.
    • If you are using your own computer (especially a Mac) I suggest you become a pro at setting up your computer with the projector because some AV people do not know how to troubleshoot through every computer. Search YouTube for your particular computer.
  • Never Be Forgotten. Bring Business Cards - Pic Ref: J
    • Email, blogs, and social media are the new business cards for networking, but I still have some business cards. Someone once explained to me the power of someone finding a business card in a suit or bag months after meeting the person. People tend to remember those with business cards and I still think there is something special about giving someone your card. You don’t need anything fancy or cute on the card, just simply your name, email, twitter handle, and institution. These are very cheap but they’ve worked for me.

Resting Up: 

  • Noise-Canceling Headphones  - Pic Ref: C 
    • Let’s face it you can’t always predict how quiet the plane, train, or automobile will be and there will always be someone on a cell phone telling the entire plane his or her business. A good pair of noise cancelling headphones is essential when traveling. Not only will these allow you to get some high quality work done, but they also allow you to catch up on some restful sleep. If you haven’t tried noise-cancelling headphones before, they really do work. Many noise cancelling headphones are not only good for blocking out sound but their audio is pretty good too when listening to podcasts or music. There are lots of brands and options to choose from including in ear vs. over the ear headphones, wired versus Bluetooth, rechargeable versus disposable battery, so I recommend heading to a store where you can try these on and see what sounds and works best for you.
  • Blindfold and Earplugs - Pic Ref: D
    • It is important to be productive while traveling, but getting rest is just as important. I always pack a pair of ear plugs and a blind fold to block out the outside world. Even the best noise canceling headphones will allow some sound in, but with both the ear plugs and the headphones I never hear a thing and the blindfold keeps out the light and lets me sleep.

Who would you love for us to track down to answer these same questions?

For How I Work Smarter:
  1. Ben Smith (@UltrasoundJelly)
  2. Sam Ghali (@em_resus)
  3. Michael Winters (@critcareguys)

For How I Travel Smarter:

  1. Mike Stone (@bedsidesono)
  2. Scott Weingart (@emcrit)
  3. Mike Mallin (@UltrasoundPod)
  4. Matt Dawson (@UltrasoundPod)

Author information

Benjamin Azan, MD

Benjamin Azan, MD

Emergency Medicine Resident

Icahn School of Medicine at Mount Sinai

Founder/Editor of foambase.org

The post I am Dr. Haney Mallemat, ED Intensivist and Lecturer on the Go: How I Travel Smarter appeared first on ALiEM.

MEdIC Series | The Case of the Returning Traveller

Many residents and medical students are engaging in international medical activities. Before departing many do (or should) undergo pre-departure training but how prepared are medical learners to return on the other end? Many struggle with “reverse culture shock”.  This month’s ALiEM MEdIC series case considers how we might help a learner returning from an international elective. Please join us in discussing the case this month, we would love your thoughts and advice.


P.S. Teresa Chan, Brent Thoma, Sarah Luckett-Gatopoulos, and I would also like to invite you all to register for the ALiEM MEdIC pre-conference workshop at SMACC.  Come out and be part of a LIVE version of the ALiEM MEdIC case development and release for a special SMACC version of the case series!

MEdIC Series: The Concept

Inspired by the Harvard Business Review Cases and initially led by Dr. Teresa Chan (@TChanMD) and Dr. Brent Thoma (@Brent_Thoma), the Medical Education In Cases (MEdIC) series puts difficult medical education cases under a microscope. On the fourth Friday of the month, we pose a challenging hypothetical dilemma, moderate a discussion on potential approaches, and recruit medical education experts to provide “Gold Standard” responses. Cases and responses are be made available for download in PDF format – feel free to use them! If you’re a medical educator with a pedagogical problem, we want to get you a MEdIC. Send us your most difficult dilemmas (guidelines) and help the rest of us bring our teaching to the next level.

The Case of The Returning Traveller

by Amy Walsh (@docamyewalsh)

Olivia hadn’t seen her friend Miguel in a few weeks as he had been away on an international elective. He was really interested in global health and this was his second trip to Africa in the last year. She saw him leaving the locker room and hoped to catch him before they started their shift. She quickly walked down the hall of the emergency department and called out, “Hey Miguel, welcome back!”

He turned around with a big smile. Olivia was excited to hear about his trip and asked, “Do you have time to grab a beer after work and tell me about Ghana?”

“Sure, I’d love to! It was such a great experience. The people are incredible and I felt like we really made a difference. I’ll even bring my computer so I can show you some photos!”

They made plans to meet up after their shift at a local pub. As they walked into the department, Miguel noticed that the waiting room was unusually empty. It was typically quite busy on a Friday evening. He figured that although it was slow and he may not get to see much, this would actually be a great shift to transition back to western emergency medicine.


Olivia was in the staff lounge getting ready to leave for the evening. As she packed her bag Miguel quietly walked into the lounge and sat down, looking quite upset, almost angry. This was odd, she thought. He seemed so happy earlier.

“What’s wrong? What happened?” she asked, genuinely concerned.

“It’s just so hard to come back and see how wasteful we can be with our resources. And how incredibly entitled some of our patients are. There just seems to be a general lack of respect towards the system and towards physicians. You wouldn’t believe what just happened, Olivia! The father of my last patient got incredibly upset with me because he had to wait 20 minutes to be seen by a doctor. His daughter had a very minor bump on the head with one episode of vomiting. Perfectly fine now with a normal neuro exam and negative CT head criteria. Yet he is demanding we obtain imaging and get some bloodwork done… and my attending just signed off for all that unnecessary testing! It makes me so angry!”

“It’s just wild how quickly I forgot how different things are back home. People in Ghana wait for hours in the heat to see a physician and when they do, they’re incredibly grateful that you took the time to see them. And at the end of the day there were usually still lines of people waiting to be seen that we simply didn’t have the time or resources to evaluate. No one received unnecessary testing. No one argued with our treatment plan. It’s just so hard to gain perspective again. How do we not realize how lucky we are to be living in a country where we have clean water to drink and 24/7 access to world-class healthcare? It’s sobering really.”

Olivia was overwhelmed by how upset Miguel was. She had never had the experience of working abroad and didn’t have much knowledge of other healthcare systems or cultural practices. She didn’t know how she could help Miguel get through this.

Key Questions

  1. How do you cope with culture shock after your international experiences?
  2. What advice would you give Miguel as he transitions back to his normal residency work
  3. What strategies do you use in working with demanding and entitled patients?

Weekly Wrap Up

As always, we posted the expert responses and a curated commentary derived from the community responses one week after the case was published. This time the two experts are:

  • Dr. Jennifer Thompson, RN, MD, Senior Resident, McMaster University EM Residency Program
  • Dr. Susan Shaw, RN, Masters Candidate (UCSF) International Health

On March 6, 2015 we will post the Expert Responses and Curated Community Commentary for the Case of The Returning Traveller. After that date, you may continue to comment below, but your commentary will no longer be integrated into the curated commentary.  That said, we’d love to hear from you, so please comment below!

All characters in this case are fictitious. Any resemblance to real persons, living or dead, is purely coincidental. Also, as always, we will generate a curated community commentary based on your participation below and on Twitter. We will try to attribute names, but if you choose to comment anonymously, you will be referred to as your pseudonym in our writing.

Author information

Eve Purdy, BHSc

Eve Purdy, BHSc

Medical student

Queen's University in Kingston, Ontario, Canada

Student editor at BoringEM.org

Founder of manuetcorde.org

The post MEdIC Series | The Case of the Returning Traveller appeared first on ALiEM.

PV Card: Focused 1st Trimester Pregnancy Transabdominal Ultrasound

Screen Shot 2014-12-31 at 2.24.08 PMAlthough history, physical, and lab tests are obtained for patients with first trimester vaginal bleeding and abdominal pain, none compare to the utility of bedside ultrasonography. Today’s PV card reviews the transabdominal approach to the focused pregnancy ultrasound and was written by Drs. Matt Lipton, Mike Mallon, and Mike Stone.


PV Card: Focused 1st Trimester Pregnancy Transabdominal Ultrasound

First Trimester Pregnancy Transabdominal Ultrasound 1

First Trimester Pregnancy Transabdominal Ultrasound 2

First Trimester Pregnancy Transabdominal Ultrasound 3

You can download this PV card:  [MS Word] [PDF]

Author information

Scott Kobner

Medical student

New York University School of Medicine

ALiEM-EMRA Social Media and Digital Scholarship Fellow

Founder, EdintheED.com

The post PV Card: Focused 1st Trimester Pregnancy Transabdominal Ultrasound appeared first on ALiEM.

Ultrasound For The Win: 46F with Right Abdominal and Flank Pain #US4TW

Welcome to another ultrasound-based case, part of the “Ultrasound For The Win!” (#US4TW) Case Series. In this peer-reviewed case series, we focus on a real clinical case where bedside ultrasound changed the management or aided in the diagnosis. In this case, a 46-year-old woman presents with acute right-sided abdominal and flank pain.


An otherwise healthy 46-year-old female presents to the ED with 6 hours of right-sided abdominal pain. She complains of pain in the right lower quadrant radiating to the right flank. She is noted to be febrile, but appears well. Review of systems is positive for dysuria, but she denies nausea, vomiting, diarrhea, vaginal discharge or bleeding. She denies history of abdominal surgeries. On examination, she has tenderness to palpation at the right lower quadrant without rebound or guarding and no CVA tenderness.


BP: 123/65 mmHg
P: 87 
RR: 20 
O2: 100% room air
T: 38.7° C (101.7° F)


  • Appendicitis
  • Ectopic pregnancy
  • Gastroenteritis
  • Nephrolithiasis
  • Ovarian torsion
  • Pyelonephritis
  • Urinary tract infection

Labs were significant for a leukocytosis (WBC 18.8), and the pregnancy test was negative. A Computed Tomography (CT) with intravenous contrast to look for appendicitis was ordered. A urinalysis was positive for leukocytes, small blood, 620 white blood cells/hpf, and many bacteria.

At this point in the patient’s workup, it was change of shift and the patient was signed out as “follow-up CT to rule out appendicitis; if negative treat for urinary tract infection/pyelonephritis.”

The oncoming provider, upon re-evaluating the patient, performed a point-of-care focused renal ultrasound.


Fig. 1a. Ultrasound of the right kidney reveals moderate hydronephrosis.

Fig. 1b. Right kidney with moderate hydronephrosis (blue arrow). Renal cortex (#), medullary pyramid (+), and renal sinus (*) can also be identified.

Fig. 2. Right kidney with color doppler, confirming no flow in anechoic areas consistent with hydronephrosis.

Fig. 3. Normal left kidney with no evidence of hydronephrosis.


The images obtained show the standard views that should be obtained when performing a focused point-of-care renal study. A curvilinear probe is used and positioned in a coronal plane. These views should be very familiar to emergency physicians, as they are similar to the right upper quadrant (RUQ) and left upper quadrant (LUQ) views of a FAST. Both kidneys are scanned fully in both planes, using the liver and spleen as your acoustic windows.

The primary indication for performing a focused bedside renal study in the Emergency Department is to look for hydronephrosis, which is classified into one of three grades – mild, moderate, or severe. Mild hydronephrosis appears as a dilation of the renal pelvis, moderate hydronephrosis as a dilation of the renal pelvis and calyces, and severe hydronephrosis as a ballooning of the calyces and thinning of the renal cortex [1].


Fig. 4. Grading of Hydronephrosis: Mild (A), Moderate (B), and Severe (C).

A common pitfall is mistaking normal renal vasculature for hydronephrosis, both of which will appear anechoic (black) on a B-mode or grayscale clip. Placing color doppler over the area will help to distinguish these from one another. Renal vasculature will demonstrate flow with color doppler, whereas hydronephrosis will remain anechoic without flow.


Fig. 5. Common Pitfall. Anechoic areas that may look suspicious for mild hydronephrosis (A) but light up with Color Doppler (B), indicative of renal vasculature rather than hydronephrosis.


Given the findings of moderate right-sided hydronephrosis on the point-of-care ultrasound, the CT was changed from a contrast study to a non-contrast flank CT study, given the concern for an obstructed and infected stone.

The CT abdomen and pelvis revealed a large, 7.37 mm obstructing renal calculus in the mid right ureter with upstream moderate hydroureteronephrosis and perinephric stranding due to infectious or inflammatory etiology.

Fig. 6. CT showing 7.37 mm obstructing renal calculus in the mid right ureter


The patient was given IV antibiotics, and urology was consulted. She was taken to the OR for cystoscopy and right ureteral stent placement for urgent decompression. On post-op day 3, the patient was discharged to home in stable condition, afebrile, and with her pain well controlled.

Patients presenting to the ED with flank or kidney pain account for over 2 million annual ED visits in the US [1]. CT is often the initial imaging study of choice given its high sensitivity (97%) and specificity (96%) for diagnosing nephrolithiasis [2]. However, there has been a concerning 10-fold increase in the use of CT for diagnosis of kidney stones over the past 15 years, with no change in frequency of diagnosis or hospital admissions [3].

Point-of-care renal ultrasound can play a vital role in the diagnosis and management of patients who present to the ED with abdominal or flank pain. The primary indication for renal ultrasound in the ED is to assess for hydronephrosis, an indirect sign of ureteral obstruction. Although ultrasound is poorly sensitive for directly imaging stones, one study revealed that resulting hydronephrosis may be easier to identify in patients with larger stones (90% sensitivity for detecting hydronephrosis with stones >6 mm, compared with 75% sensitivity with stones <6 mm) [4]. This can be reassuring in the clinical setting of uncomplicated ureterolithiasis, as smaller stones are likely to pass on their own without intervention, and “missing” hydronephrosis with these smaller stones is unlikely to change clinical outcomes.

A recent large multicenter study published in the New England Journal of Medicine found that ultrasonography should be used as the initial imaging modality for patients with suspected nephrolithiasis, with further imaging studies performed based on the findings and discretion of the clinician [5]. Patients enrolled in the study were randomized to one of three initial imaging modalities:

  1. Point-of-care ultrasonography by an emergency physician
  2. Radiology-performed ultrasonography
  3. CT

Comparison of the three groups at 30 days showed no statistically significant difference in high-risk diagnoses with complications, serious adverse events, pain control, return ED visits, hospitalizations, or diagnostic accuracy [5].

In this case, the point-of-care ultrasound and clinical picture gave concern for complicated ureterolithiasis (i.e. a potentially obstructed and infected stone requiring urologic intervention), and thus a CT was rightfully obtained.


  1. Consider ultrasonography as the initial imaging modality in patients who present with a strong suspicion for nephrolithiasis, especially in younger and female patients.
  2. Although CT has a higher sensitivity for kidney stones than ultrasonography, this increased sensitivity does not necessarily improve diagnostic accuracy or decrease serious adverse events [5].
  3. Point-of-care ultrasonography by Emergency Physicians for identifying hydronephrosis has a moderate sensitivity (72.6%) and specificity (73.3%), with much higher sensitivity (92.7%) in those with additional ultrasound fellowship training [1].
  4. The use of color doppler can help distinguish hydronephrosis from normal renal vasculature.

*Note: All identifying information and certain aspects of the case have been changed to maintain patient confidentiality and protected health information (PHI).

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Author information

Jeffrey Shih, MD

Jeffrey Shih, MD

Assistant Editor, Ultrasound for the Win Series,

Academic Life in Emergency Medicine;

Emergency Ultrasound Fellow,
Instructor in Emergency Medicine,
Yale University School of Medicine

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