Is it in? Well, flush the line

Clinical Scenario: 

You are working in the TCC when an ESRD patient presents with fever and hypotension, RN’s are able to attain a small IV, but knowing the patient will need abx and IVF, you prepare to place a central venous catheter (CVC). Under ultrasound guidance you place a triple lumen catheter.  You aspirate dark red blood and are confident it is venous. The follow up chest xray shows a cvc with an awkward course to the heart. You send off a blood gas, and are setting up to tranduce the line.  While waiting, you wonder is there another method to confirm CVC placement?

Literature Review:
Approximately three million CVC’s are placed every year in the US. Complication rates vary by source but the most commonly cited rate is around 10%, including arterial puncture, hematoma, pneumothorax, chylothorax, arrhythmia and air embolus . The use of ultrasound during CVC placement has reduced the complication rate to around 3%.  (1) In 2010 Liu et al described the novel use of bedside ultrasound (2D) and a saline flush,to confirm catheter placement in the SVC. The method involves flushing 10ml saline throught the most distal CVC port, while performing a cardiac ultrasound either in the subxiphoid or parasternal view. 

Horowitz et al 

Flushing of the saline causes immediate turbulence in the right atrium and ventricle, that is easily viewable on ultrasound.(1) Prekker et al also reported on using this technique with success, adding that saline can be flushed immediately after venous puncture but before the guide wire or CVC is placed. (2) In 2014 Horowitz et al performed a prospective blinded study testing whether flushed saline under cardiac US could accurately confirm femoral line placement.  In their study, all patients had an arterial line and a femoral CVC placed, then a blinded EM physician performed subxyphoid cardiac ultrasound while a provider flushed either the arterial line or venous CVC. The EM physician would either say "venous" or "arterial" based on the presence of a + flush sign (See image) . The study results showed 100% sensitivity and 90.3% specificity. (3) In other words, the presence of +flush test was always associated with venous CVC. There were zero incidences of an arterial flush being identified as venous. However, approx 10% of venous CVC's were incorrectly identified by negative flush test (specificity 90.3%). 

Take home points:
Rapid assessment of CVC placement can be achieved by saline flush and cardiac ultrasound. A +flush sign has been shown to be 100% sensitive for a venous CVC. However more studies are needed at this time as most literature is focused on case series, with only one prospective randomized study. 

Submitted by Louis Jamtgaard, PGY-3 @Lgaard
Faculty Reviewed by Deb Kane

References

1) Liu et al. Evaluation of proper above-the-diaphragm central venous catheter placement: the saline flush test. Am J Emerg Med. 2011 Sep;29(7):842.e1-3. doi: 10.1016/j.ajem.2010.06.025. Epub 2010 Sep 25.

2) Prekker ME Rapid confirmation of central venous catheter placement using an ultrasonographic "Bubble Test".Acad Emerg Med. 2010 Jul;17(7):e85-6. doi: 10.1111/j.1553-2712.2010.00785.x.

3) Horowitz R¹The FLUSH study--flush the line and ultrasound the heart: ultrasonographic confirmation of central femoral venous line placement. Ann Emerg Med. 2014 Jun;63(6):678-83. doi: 10.1016/j.annemergmed.2013.12.020. Epub 2014 Jan 15.

Subchorionic Hematoma: incidental finding or early risk?

Clinical Scenario:

A 20 yo G1P0 at 6wk1day by LMP presented with vaginal bleeding.  She had onset of bleeding 1 hour prior to arrival, soaked through 1 pad.  She was seen at her OB earlier that day (prior to onset of bleeding) and had an US which showed +FHR.  Transabdominal and transvaginal ultrasound showed an IUP with +FHR of 120 BPM (image below).  Her beta hCG was 72,813 and she was Rh+.  Hypoechoic material was seen surrounding the gestational sac, consistent with subchorionic bleeding.  The patient was given return precautions and instructed to follow-up with her OB in 48 hours.  You wonder if should have given any specific precautions regarding subchorionic hematoma?

#FOAMed Digest No.5: But This One Goes to 11

Time once again for your mid-week blast of FOAMy goodness from around the interwebs. There’s no particular subject today; instead we’re going to highlight some of the better podcasts/vodcasts that updated this week. Podcasts are great. They break up the monotony of reading (and the monotony of mundane things like laundry, grocery shopping, training for this damn marathon…). For the more distractible among us, they usually come in easily-digestible 20-30 minute morsels. They expose you to different presentation styles, and allow you to match a face and a voice with the big names in FOAMed. Most of them also feature written show notes with references as well, which allows you both to reinforce the things you learned while listening, and also to dig deeper into topics you’re interested in.

Fun for the whole family!

Three Stars:

1. I think FOAMcast, authored by residents and EM social media savants Jeremy Faust and Lauren Westafer, might be the first example of “metaFOAM.” They peruse the FOAM world for interesting recent posts, then integrate that information with relevant material from the most popular EM textbooks (i.e., “Rosenalli”), other relevant blogs/podcasts, primary literature, and even Rosh Review questions. This week they use a post from ALiEM on calcium channel blockers vs beta blockers for A-Fib as a jumping-off point for a discussion on ED management of A-Fib and A-Flutter. There’s links to vodcasts from Scott Weingart and Amal Mattu on narrow-complex tachydysrhythmias, and plenty of cited references from the primary literature (including one from our own Brian Cohn!). It’s good stuff.

2. Speaking of the Godfather of ED EKG, Dr. Mattu has two quick cases for you to ponder. Remember: T-wave inversion does not always mean cardiac ischemia!

Remember: Gotta think tox in a seemingly unprovoked wide complex tachycardia!

3. Steve Carroll at EM Basic provides an excellent analysis of the ED management of asymptomatic hypertension, including references to the relevant ACEP Clinical Policy document and other FOAMed resources.

Oldie But Goodie:

Chris Nickson, creator and administrator of Life in the Fast Lane, gave an excellent talk at the original SMACC conference in March 2013 with the confidence-inspiring title, “All Doctors are Jackasses.” Why are we jackasses? Because we don’t do enough to understand how we think and how we make decisions, and this leads us to make errors. Watch Nickson’s lecture and begin to understand how to remedy this situation.

(EXTRA CREDIT: Links in the show notes to the other SMACC talks in the “Mind of the Resuscitationist” plenary by Weingart, Cliff Reid, and Simon Carley.)

F(FN)OAMed:

By this point you guys all know how awesome EM:RAP is, but this week is particularly relevant because Herbert & Co. just released an “EM:RAP Mini” segment about the newly-published “Ultrasonography versus Computed Tomography for Suspected Nephrolithiasis” trial in the New England Journal. For those of you that aren’t familiar, this was a study in which we participated, and our own Drs. Aubin and Griffey are authors on the paper! An excellent summary of this paper is found on the Emergency Medicine Ireland blog, with a link to download the EM:RAP Mini segment in the show notes.

The Gunner Files:

1. Time to synthesize the knowledge you gained about non-surgical management of pediatric appendicitis at Journal Club last month. Dr. Cohn is back with another excellent EMJClub podcast along with Drs. Trehan and Horst, summarizing the primary literature.

2. EMin5 is back at it with a review of the four types of shock, in a little over four minutes.

3. From the Maryland Critical Care Project, an excellent lecture from Neuro Critical Care and ED intensivist Dr. Wendy Chang describing the ED management of status epilepticus. She covers the gamut from first-line benzos to second-line AEDs and third-line agents for initiation of therapeutic coma.

4. The good people at the All NYC EM blog posted a lecture given during their conference day by the FOAMed superstar Dr. Haney Mallemat. He covers all the basics of ultrasound evaluation of pericardial effusion and tamponade, even ultrasound-guided pericardiocentesis.

5. In case you’re not familiar, US Air Force Pararescuemen, a.k.a. “PJs,” are the ultimate badasses. Just look at it this way: think becoming a SEAL is tough? PJ training has an even higher failure rate. But I digress.

Former PJ and critical care flight retrieval medic Mike Lauria is now in medical school, and is making a bit of a splash in the FOAMed community as an expert on training, thinking, and operating in high-stress environments. Scott Weingart recently interviewed him on EMCrit about the concept of “mental toughness,” how that translates from the combat realm to the ED, and how to incorporate it into physician training. Really interesting stuff.

That Others May Live,

Sam Smith, PGY-3

#FOAMed Digest No. 3: You Need Me On That Wall

Emergency Medicine physicians practice in a unique environment. We must synthesize plans for  diagnosis, management, and disposition while utilizing input from almost every subspecialty, and the ED is the ultimate proving ground for diagnostic tests and treatment modalities of every sort. Unsurprisingly, a fair deal of controversy and debate exists regarding the optimum management of patients. (For reference, see any Trauma Case Conference featuring Drs. Schuerer and Aubin.) The “best evidence” is often poor evidence. We in Emergency Medicine retain the rebellious spirit of our founders, and are always looking for new and innovative techniques. Some physicians are too quick to jump on the bandwagon, and others lag behind the curve when it comes to adopting new practices.

The selections this time around are not meant to tell you the best way to do things. The algorithms and practice patterns suggested are not universally adopted, written in textbooks, or taught as part of any standard curriculum. They are meant to promote thought, to prompt you to read the primary literature for yourself, to encourage you to seek the opinions of other experts on the subject, and to form your own conclusions. Hopefully they will inspire you to suggest new ideas to your seniors and attendings during your next shift – or even question ideas you think are unsound. Maybe, just maybe, they will even inspire a new research or QI project. FOAMed is by design perfectly adapted to assist you in this quest.

Ramblers, let’s get ramblin’.

Three Stars:

1. Ken Milne at the Skeptic’s Guide to Emergency Medicine pretty much sets the bar when it comes to FOAMed of the latest EBM topics. He asks his clinical questions in the PICO format, he applies a rigorous quality checklist when analyzing the available literature, and includes in his discussion other FOAMed experts (including on occasion our very own Chris R. Carpenter, a.k.a. “Captain Cranium”). This episode he turns his skeptical eye to a topic sure to generate heated discussions for years to come: tPA for stroke.

2. If there’s anyone that looms larger in the ED Critical Care world than Weingart, it’s Resuscitationist Extraordinaire Cliff Reid. His lecture from the SMACC Gold conference hit resuscitation dogma like an A-bomb, leaving irradiated bits of unfounded practice patterns strewn about the Outback countryside.

(EXTRA CREDIT: Reid’s talk from the original SMACC conference, “Making Things Happen,” should be required viewing for anyone wanting to be a Trauma Senior someday.)

3. If pediatric surgeons have come to accept ultrasound as a stand-alone diagnostic method for appendicitis, maybe there’s hope that someday ultrasound can also be used as a radiation-sparing technique for diagnosis of small bowel obstruction. Academic Life in EM has an excellent run-down of the technique and comparative research studies.
(EXTRA CREDIT: The book Evidence-Based Emergency Care, authored in part by our own Captain Cranium Chris R. Carpenter, has a chapter dedicated to the inferiority of plain films for SBO diagnosis. You can read it for free online via Becker Library.)

Oldie But Goodie:

I think here in a few more years this will reach “accepted standard practice” level, and maybe even “textbook” level, but it’s not there yet. It should be: there’s good evidence to show kayexelate doesn’t work, and may even cause harm. Let Weingart and the PaperChase fellows from EM:RAP give you the ammunition you need to stand up to any pesky floor seniors.

F(FN)OAMed:

In a very enlightening segment from this month’s EM:RAP, Rob Orman interviews a community ED practitioner, Dr. Cameron Berg, regarding his hospital’s new Accelerated Diagnostic Protocol for low-risk chest pain. While his exact algorithm hasn’t been externally validated and probably isn’t ready for prime-time at our shop, the evidence-based and pragmatic approach is certainly worth considering. And he provides links to almost all of his references in the show notes!

The Gunner Files:

1. The “Research & Reviews” segment on Life in the Fast Lane is worth checking out every week. A group of some of the brightest minds in the FOAMed world get together and spoon-feed us summaries some of the most relevant, practice-changing, or downright strangest papers in the EM literature.

2. Josh Farkas over at PulmCrit wrote an excellent piece laying out his argument for super-high-flow NC (think 30-45L!) as an acceptable method of preoxygenation before RSI. It’s also got a good rundown of apneic oxygenation using NC (which we all should be doing every time), and an enlightening counterpoint from the grand maester of ED Critical Care, Scott Weingart.

3. Pediatric EM expert Sean Fox provides an excellent summary of the neonatal ALTE on his blog Pediatric EM Morsels.

4. Two EM airway heavyweights, Rich Levitan and Reuben Strayer, slug it out in the ultimate Direct Laryngoscopy vs Video Laryngoscopy debate, posted to the Prehospital and Retrieval Medicine podcast hosted by Minh Le Cong.

5. All of us will be the bearer of the -07 phone at some point, and that means you better have your act together when discussing decision-making capacity. Bill Johnston, EMT-P and author of the excellent blog Prehospital Wisdom, shares his fundamentally sound and no-bullshit method for determining capacity in the field.

In the words of Ken Milne: “Meet ‘em, greet ‘em, treat ‘em, and street ‘em!”

Sam Smith, PGY-3

Imaging in Renal Colic

You are working in the Emergency Department when a 30ish year-old female is wheeled by, clasping on to her right flank and clearly in pain.  You head into the room and find out that she had the acute onset of right flank pain that has been coming and going for the last hour.   She is otherwise healthy and denies any prior history of renal stones.  Thinking that this is probably a kidney stone, you order some pain medication, a UA, and a urine pregnancy test.  She is (thankfully) not pregnant and has 2+ blood in her UA.

You log back in to order your next diagnostic test of choice.  You start to click on “renal stone protocol CT” but pause…  and think to yourself: “Do I need to irradiate this woman to make the diagnosis?  Will the results of the CT scan change my management in some way?  What are the alternatives?”

Clinical Question #1:

Does a CT scan change management in cases of suspected uncomplicated renal colic?

                

The Literature:

There are several smaller studies that addressed whether a CT scan changes the clinical management in a patient where there is a high suspicion for renal stone.

                

Zwank et. al. [1] published a prospective observational study addressing this question.  The study enrolled providers caring for 93 “clinically stable” patients  > 18 yo with abdominal or flank pain, > 18 years of age and the  “most likely diagnosis” of renal colic.   Patients at higher risk of complication, i.e. those with a history of chronic kidney disease, nephrectomy, renal transplant, UTI, prior renal stones, were excluded from the study.  Prior to the CT, providers were surveyed as to what their top 3 differential diagnoses were and whether they thought that the CT scan might change management.    In the end, 62/93 patients who were scanned were diagnosed with renal colic (as a side note only 84% of these had hematuria on UA).   Five (5.3%) patients received an alternative diagnosis after CT scan – two ovarian cysts, one ovarian tumor, diverticulitis, and mesenteric edema.  Of the 16 patients where CT scan was obtained even though the provider thought it was very unlikely to change management, 10 had symptomatic renal stones and reportedly none had a change in management (unclear why the disparity if a diagnosis was not reach in 6/16 cases).    On this small pool of data, the authors conclude that “This result indicates that providers who are confident with the diagnosis of renal colic and who do not anticipate benefit from a CT scan can trust their low pre-test probability or ‘gestalt’ of low likelihood of benefit and should strongly consider not ordering a CT scan.” 

                

Another way of framing the question about whether CT scans change management in patients thought to have renal colic is to examine the incidence of alternative diagnoses that are found on CT in these patients.   In their prospective study, Pernet et. al. [2] examined this question by following the CT diagnosis of 155 patients with suspected uncomplicated renal colic (i.e. exclusion of patients with compromised renal function, UTI, fever, suspected bilateral renal stones).  118/155 (77%) were found to have uncomplicated stones, while 10 (6%) of these patients were found to have alternative diagnoses after CT.  These diagnoses included large calculi needing urology intervention, pyelonephritis, biliary colic, appendicitis, ileitis, small bowel obstruction and intra-renal hemorrhage.  Though a similar proportion of alternative diagnoses were found in this study when compared with Zwank et. al. above, these authors argue that CT(low-dose radiation) should be performed in cases of predicted uncomplicated renal colic because of the proportion of alternative diagnoses that mandated other intervention or hospitalization.  They further argue, that the population of patients which people would least want to irradiate (young women) are also the most likely to have some alternative diagnoses.   

Clinical Question #2:

Given that stones requiring urologic intervention and alternative diagnoses are found on CT imaging, how does ultrasound measure up as an imaging modality?

The Literature:

An older article in the British Journal of Radiology published in 2001  [3] [around the advent of use of CT and Ultrasound for diagnosis of renal calculi as opposed to intravenous urography (IVU)] prospectively evaluated the sensitivity and specificity of non-contrast CT and ultrasound for renal calculi.  They prospectively enrolled 62 patients with suspected uncomplicated renal colic.  These patients underwent both renal ultrasound and CT scan.  The gold standard was stone recovery or urological intervention.  43 (69%) of patients with suspected renal colic were confirmed by the “gold standard”.  Ultrasound showed 93% sensitivity and 95% specificity in the diagnosis of ureterolithiasis, while CT showed 91% and 95%.    Alternative pathology was found in six patients (~ 10%).  These alternative pathologies were cholelithiasis, cholecystitis, ovarian torsion, adnexal masses and appendicitis.  Both CT and ultrasound detected these, with the exception of the case of appendicitis, which was detected by CT scan alone.  Given advances in imaging technology, it is likely the sensitivity of CT has increased with time, but this is an impressive comparison.

Another study compared KUB + ultrasound versus CT scan for detection of clinically significant renal stones [4].   This was a retrospective study of 300 patients evaluated with KUB, US, non-contrast CT or some combination of the above for renal colic.  The study is overall very confusing because of the number of combinations of imaging modalities that patients had.  Despite this, one interesting observation was that among 147 patients who underwent KUB and/or US and CT scan, 22 had a normal KUB or US (unclear what proportion had what) and a CT scan positive for stone.  Of these, mean stone size was < 5 mm suggesting that this was a population of patients who was unlikely to need any type of urologic intervention.

Along the same lines of sensitivity of ultrasound for renal stones requiring urologic intervention, two separate studies examined the incidence of urologic intervention needed in patients with “normal” renal ultrasounds [5, 6].  In one of these studies (Yan et. al.) ,  they prospectively followed 341 patients with renal colic who were evaluated with ultrasound.   Of the 105 (30.8%) patients were classified as “normal”, none had urologic intervention in the following 90 days.  Alternative pelvic pathologies were identified on ultrasound (such as ovarian cysts and pregnancy) but there was no avenue for direct comparison with CT in this study.  A similar study from Edmonds et. al. retrospectively reviewed the records of all patients undergoing renal ultrasound for suspected nephrolithiasis over the course of a year.  Of a 352/817 (43%) that were classified as “normal”, only 2 patients (0.6%) required urologic intervention in the following 90 days.  They did not comment on alternative diagnoses.

Take home:

Renal ultrasound is a reasonable initially imaging modality for patients with suspected uncomplicated renal colic.  While we are overall pretty good an predicting who has renal colic based on history and exam (~ 60- 70% of all patients with this as a suspected diagnosis had imaging confirming it in the above studies), we should keep in mind that anywhere between 5 – 10% of these patients will have an alternative diagnosis requiring alternative management.   Ultrasound is good at picking up these alternative diagnoses as well.

References:

1. Zwank et. al. “Does computed tomographic scan affect diagnosis and management of patients with suspected renal colic?” American Journal of Emergency Medicine 32 (2014) 367–370

2. Pernet et. al. “Prevalence of alternative diagnoses in patients with suspected uncomplicated renal colic undergoing computed tomography: a prospective study.” CJEM. 2014 Feb 1;16(0):8-14.

3. Patlas et. al. “Ultrasound vs CT for the detection of ureteric stones in

patients with renal colic”. The British Journal of Radiology, 74 (2001), 901–904

4. Ekici and Sinanoglu. “Comparison of conventional radiography combined

with ultrasonography versus nonenhanced helical computed

tomography in evaluation of patients.” Urol Res (2012) 40:543–547

5. Yan et. al. “Normal renal sonogram identifies renal colic patients at low risk for urologic intervention: a prospective cohort study” CJEM 2014:1-8.

6. Edmonds et. al.  “The utility of renal ultrasonography in the diagnosis of renal colic in emergency department patients” CJEM 2010;12(3):201-6.

Kindly submitted by Maia Dorsett, PGY-3.

#FOAMed Digest No. 2: Breathless Love

Welcome back! Fresh new FOAMy goodness for you, this time with an emphasis on airway and pulmonary care. Let’s do it!

Three Stars:

1. No way around it: “Delayed Sequence Intubation” is the new hotness. If you want to be one of the cool kids, you better get on board. I’ll let the more graphically-minded folks at EMCurious lay it all out for you with a prototypical case. Don’t miss the links – more excellent FOAMed resources on DSI.

(And Weingart’s seminal paper on the subject is required reading at this point.)

(And, oh yeah, ketamine does NOT increase ICP. Let’s use these two systematic reviews 1 & 2 to stop the foolishness already.)

2. Someday you will need to perform a cricothyrotomy. Accept it as reality, and do everything you can to prepare for it. Start here, with Weingart’s lecture on the surgical airway delivered at the SMACC Gold conference last fall. This page from the EMCrit blog has compiled all sorts of great surgical airway resources from around the FOAMed world all in one spot, including can’t-miss stuff about the scalpel-finger-bougie technique and Weingart’s pre-intubation checklist. You should probably add it to your favorites list now.

3. Wouldn’t be a FOAMed Digest without getting a little off-topic, and Rick Body’s recent contributions over at St. Elmyn’s regarding ACS & “low-risk” chest pain in the ED are too good to pass up. Great post analyzing his recent paper, which concluded ED physicians simply aren’t capable of ruling out ACS in chest pain patients with an acceptable accuracy using only the clinical exam. Dr. Body also gives you a run-down of how to properly utilize high-sensitivity troponin in his talk from SMACC Gold.

(Link to Body's paper here.)

Oldie But Goodie:

By the end of our Ultrasound rotation, we can all diagnose pneumothorax with ultrasound at the bedside. It’s time to take it next-level. A-lines, B-lines, pneumonia vs edema…the experts at the Ultrasound Podcast help you figure it all out in a two-part 1 & 2 podcast.

F(FN)OAMed:

Sanjay Arora and Mike Menchine, hosts of the PaperChase segment on EM:RAP, summarize the current literature about how terrible we are at adequately sedating patients after RSI. Roc lasts longer than Sux – the patients won’t be able to tell us they need sedation!

(Links to relevant papers in the show notes.)

The Gunner Files:

1. Brett Sweeny at EMDocs provides an exhaustive review of FOAMed resources regarding permissive hypotension in trauma. Great lectures and podcasts from some of the brightest minds in EM & trauma surgery.

2. We’re seeing it already – asthma cases are starting to pile up over on the SLCH side. Luckiliy for you, Pediatric EM rockstar Andy Sloas just published an excellent podcast on the evaluation and management of asthma in the Peds ED.

3. Next time you’re consulting Ortho or Plastics for a hand injury, sound like you know what you’re talking about. The folks over at EMin5 hit you with the quick rundown on the neuro exam of the hand.

4. Last week, St. Elmyn’s helped the rooks get up to speed when it came to dealing with the dyspneic patient in the ED (and I bet the seniors learned a thing or two as well). This time, get your mind right when faced with a syncopal patient.

5. Who doesn’t love infographics? And if they actually help us learn something about managing septic patients, that’s just a bonus! Very well done by EMCurious, with embedded links to the relevant studies!

6. New podcast from R.E.B.E.L.EM, summarizing the results of a meta-analysis just published this month in Annals which concluded prehospital application of NIPPV in patients with severe respiratory distress regardless of cause reduced need for intubation (NNT 8) and in-hospital mortality (NNT 18). 

w00t prehospital medicine!
(Original pub here.)

That’s all, folks! Go get your learn on!

Sam Smith, PGY-3