Brought In By Ambulance, #1: Vagal maneuvers in SVT

In this section, we will highlight EBM queries targeted to the prehospital care of patients.


Without further ado...
You respond to a call-out for "palpitations." You arrive on-scene to find a middle-age female patient who is awake, well-oriented, and talking to you in complete sentences. She is complaining of her heart "fluttering," and reports feeling somewhat short of breath and anxious. She reports a prior history of palpitations without a clear working diagnosis. Cardiac leads are placed, and the monitor shows a well-organized narrow-complex rhythm with rate in the 160s. Her BP is stable. Her skin appears warm and well-perfused. As the EMT's are working on establishing IV access, you wonder how effective vagal maneuvers are in terminating SVT.

Clinical Question:

Which vagal maneuver, if any, should be used to terminate SVT?

Literature:

In two studies, the authors found that the valsalva maneuver was more successful in terminating SVT than carotid massage or ice-to-face. In one case series, valsalva was able to terminate SVT in 54% of patients. These study authors also found that a right carotid massage was slightly more efficacious than a left carotid massage in terminating SVT (17% vs 5%). Attempting to provoke the diving reflex with ice had the same efficacy as the right carotid massage (17%)¹.

A second study of prehospital treatment of SVT found that valsalva was more efficacious if the patient was supine, the maneuver was sustained for 15 seconds, and a pressure of 40mm Hg was obtained. The study again found that valsalva was more successful than carotid sinus massage and the ice-to-the face technique².

In a third study, there was a trend toward valsalva being more effective than carotid sinus massage.  Valsalva had a success rate of 19.4% vs 10.5% for carotid sinus massage, though these figures did not reach statistical significance. When initial carotid massage did not resolve the SVT, valsalva was able to convert in 16.9% cases, versus 14% when carotid massage was used after failed valsalva.  Overall, the conversion rate was 27.7%³.

Valsalva maneuver is inherently safer than a carotid massage, as there is no risk of causing decreased carotid perfusion or dislodging clot. The most difficult part is ensuring full patient participation, especially in pediatric patients. One method that has been suggested to promote valsalva in pediatric patients is asking the child to blow through a straw. Several reports also suggest that valsalva maneuver is more efficacious than carotid massage in terminating SVT. There is also limited data to suggest that a right carotid massage is better than a left carotid massage. Given that Valsalva is safer and may be more efficacious, attempts at terminating SVT should begin with Valsalva.

Take home points:

- In available reports, valsalva maneuver appears to be the most efficacious of vagal maneuvers in terminating SVT. It may be effective anywhere from 20-50% of the time.

References:

1. Mehta D, Wafa S, Ward DE, Camm AJ. Relative efficacy of various physical manoeuvres in the termination of junctional tachycardia. Lancet. 1988;1(8596):1181.

2. Smith G, Morgans A, Boyel M. Use of the Valsalva manoeuvre in the prehospital setting: a review of the literature. Emerg Med J. 2009 Jan;26(1):8-10

3. Lim SH, Anantharaman V, Teo WS, Goh PP, Tan AT. Comparison of treatment of supraventricular tachycardia by Valsalva maneuver and carotid sinus massage. Ann Emerg Med. 1998 Jan;31(1):30-35

Contributed by Steven Hung, PGY-2

#FOAMed Digest No. 4: Butter My Biscuit, Baby

Welcome back, to the brand new edition of the WUEMR FOAMed Digest. Get out your Tintinalli’s and strap in, because we’re going back to basics today. It’s all about the bread and butter. The things any PGY-2 setting off to an overnight Saturday shift in the Deuce should have down cold…yet us seniors still screw up on the daily.

FOAMed…ENGAGE!

Three Stars:

1. If my last shift at Children’s is any indication, the season is upon us – pharyngitis in every exam room. Casey Parker over at Broome Docs (a blog authored by EPs & GPs practicing in rural Australia), presents a magnificent summary of the data surrounding rapid strep swabs, antibiotic use for symptom relief, and antibiotic use for preventing secondary complications of strep. As always, be sure to check out the original literature for yourself. And don’t miss Minh Le Cong’s excellent counterpoint in the comments, which is also well-referenced.

2. What’s your record for most C-collars cleared in one shift? (When you hit double-digits, then we can talk.) The best tools in our arsenal for clearing C-spine in low-risk patients remain the Canadian C-spine and NEXUS instruments. But which one should you use? Do you even remember which criteria belong in each rule, or do you find yourself trying to apply the “Canadi-EXUS” criteria, like I do? Luckily for us, Alayna Hawling at BoringEM authored an excellent rundown and comparison – with a pretty flowchart!

3. As much as you want to start the fist-pumping and beer-chugging as soon as you drop that tube past the cords, your work with the intubated patient is not done, my friend! We’ve already touched on our persistently poor rates of achieving adequate analgesia & sedation in the intubated patient. Another part of quality post-intubation care is knowing what to do if your ventilated patient acutely decompensates. Check out Chris Cresswell’s summary of the DOTTS mnemonic over at EM Tutorials.

(EXTRA CREDIT: He also included a link to Scott Weingart’s notes regarding care of the crashing ventilated patient, which are well worth a look.)

Oldie But Goodie:

There’s been some e-mail discussion lately among our attendings regarding the best way to clean lacs prior to closure. Back in February, Ken Milne at the Skeptic’s Guide (along with Eve Purdy, a rockstar med student and creator of the excellent Manu et Corde blog) published a piece dedicated to breaking down the dogma of management of simple lacerations. Tap water vs sterile water, sterile gloves vs clean gloves, to sew or not to sew…it’s all covered here. Plus there’s links to other excellent FOAMed resources regarding wound care dogma.

F(FN)OAMed:

The good folks over at EB Medicine recently published a stem-to-stern guide to UTI diagnosis and management in the ED, all based on best available evidence. A bit lengthier than your average blog post, but incredibly high-yield and well worth your time. It’s a bit difficult for me to place a direct link here, but you can find it simply by logging into your account at EBMedicine, following the link to browse issues of Emergency Medicine Practice, and opening the July 2014 issue on UTI.
(As always, contact your friendly neighborhood Social Media Committee member if you need help obtaining access to EB Medicine resources.)

The Gunner Files:

1. Hard to get through a Deuce shift without breaking out the prochlorperazine at least once. We’ve all seen patients get jittery, agitated, or downright whacky following its use. Does Benadryl help? A PharmD expert at ALiEM has a good lit review of the topic.

2. Short and sweet: some diabetic medications are more likely to cause harmful hypoglycemia after overdose than others. Quick table-based rundown over at ALiEM.

3. It is asthma season, and you may find yourself in the worst-case-asthma-scenario of impending need for intubation. Check out this post from The Kings of County regarding care for the sick asthmatic, including intubation and mechanical ventilation issues.

4. FOAMed is taking the world by storm! Does the UK College of Emergency Medicine launching a dedicated FOAMed site mean it’s officially gone mainstream? Don’t worry – we were all into FOAMed before it was cool. But seriously, check out this vodcast on diagnostics in EM, and not feel quite so much increase in sphincter tone when Carpenter or Cohn pimp you on likelihood ratios or Bayesian analysis.

5. Another classic from the Skeptic’s Guide, this time addressing another oh-so-common ED complaint: renal colic. Fluids? Flomax? Any good evidence for either? In news that will surprise no one, Ken Milne is skeptical.

Never stop learning,

Sam Smith, PGY-3

Anaphylaxis: I can't breathe!

On an EMS ride along, you respond to a dispatch for a patient having an allergic reaction to some food.  You arrive on scene and find the patient having difficulty speaking and having stridor, in clear respiratory distress.

Clinical Question:

What is the ideal treatment of anaphylaxis?

Literature:

The lifetime prevalence of anaphylaxis is estimated between 0.5-2% with mortality rates ranging between 0.65%-2%, resulting in approximately 1500 deaths annually.  When fatal, death usually occurs minutes after contact with the trigger.  Fatal food reactions usually caused respiratory arrest 30-35 minutes after initial contact.

The first line treatment is epinephrine since it counters many of the symptoms of anaphylaxis.  As an alpha-receptor agonist, it reverses peripheral vasodilation and reduces edema.  The beta-receptor activity dilates bronchial airways, increases myocardial contraction, suppresses histamine and leukotriene release, inhibits mast cell activation.

There are several methods for epinephrine injection.  In a study comparing IM vs subcutaneously route, it found that an IM injection of epinephrine in the anterolateral aspect of the thigh achieved a higher and faster plasma epinephrine concentration peak.  IM injection into the deltoid of the arm as well as subcutaneous injection into the deltoid had lower and longer time to peak concentrations.  The greater blood supply to the vastus lateralis muscle is theorized to account for this difference.  The IM injection site also offers a greater margin of safety as well as ease of administration compared to IV epinephrine.  The IM dose of epinephrine can be repeated in 5-15 minutes if symptoms are not improving.  IV epinephrine has been associated with fatal cardiac arrhythmias and myocardial infarction and should be reserved for those unresponsive to conventional treatment in a controlled setting.

The recommended dose of epinephrine IM is 0.3-0.5mg of 1:1000 epinephrine (0.3-0.5 ml).  For pediatric patients, the recommended dosage is 0.01mg/kg.  Initial resuscitation should also include a bolus of normal saline given the vasodilatory effects of anaphylaxis.

Antihistamines are considered second line treatment.  H1 blockers such as diphenhydramine can be given to alleviate cutaneous symptoms, however it does not acutely treat the life threatening aspects of anaphylaxis.  There is little evidence to support the routine use of H2 blockers.  Steroids can also be given, although there is also weak evidence for their use.  In theory, steroids are used to prevent a biphasic reaction (when symptoms resolve, but recur within 1-72h) but there is little evidence that it is effective in reducing biphasic reactions.  Many providers will give a one time dose of methylprednisolone 1-2mg/kg in the ED, which is generally considered sufficient.  Bronchodilators can also be given if the patient is wheezing, experiencing dyspnea, or coughing.

Take home points:

-First line treatment for anaphylaxis is epinephrine 0.3-0.5mg IM in anterolateral thigh
-IV fluids should be given to counteract vasodilation
-H1 blocker may provide symptomatic relief, however is not first line therapy
-Bronchodilators may provide symptomatic relief
-H2 blockers have not been proven to be effective
-Steroids have not been proven to be effective

References:

1)Pumphrey RS. Lessons for management of anaphylaxis from a study of fatal reactions. Clin Exp Allergy. 2000;30(8):1144-1150
2) Soar J, Pumphrey R, Cant A, Clarke S, Corbett A, Dawson P, Ewan P, Foex B, Gabbott D, Griffiths M, Hall J, Harper N, Jewkes F, Maconochie I, Mitchell S, Nasser S, Nolan J, Rylance G, Sheikh A, Unsworth DJ, Warrell D. Emergency treatment of anaphylactic reactions – guidelines for healthcare providers. Resuscitation. 2008 May;77(2):157-69
3) Simons FE, Ardusso LR, Bilò MB, Cardona V, Ebisawa M, El-Gamal YM, Lieberman P, Lockey RF, Muraro A, Roberts G, Sanchez-Borges M, Sheikh A, Shek LP, Wallace DV, Worm M. International consensus on (ICON) anaphylaxis. World Allergy Organ J. 2014 May;7(1):9
4) Simons FE, Gu X, Simons KJ. Epinephrine absorption in adults: intramuscular versus subcutaneous injection. J Allergy Clin Immunol. 2001 Nov;108(5):871-3.
5) Zilberstein J, McCurdy MT, Winters ME. Anaphylaxis. J Emerg Med. 2014 Aug;47(20):182-7

Contributed by Steven Hung, PGY-2

#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

Blunt Abdominal Trauma in Pediatric Patients: A Clinical Decision Rule

A school-age child was brought to the ED by the mother following involvement in an MVC during which the child was restrained with a lap belt.  The child initially complained of abdominal pain while eating, but currently has no complaints, stable vital signs, and a benign abdominal exam.  The mother is concerned and wonders if her child should get imaging.  This prompts you to investigate whether there are any evidence based clinical decision rules for imaging in pediatric blunt abdominal trauma.

Clinical question: 

Do all children with blunt abdominal trauma necessitate abdominal imaging?  Is there a clinical decision rule that can help guide physician and parent shared-decision making when weighing risks vs benefit in evaluation of pediatric patients following blunt abdominal trauma?

Literature:

Injuries secondary to blunt abdominal trauma contribute to a large degree of morbidity in the pediatric patient population.  In assessing these patients following trauma, CT scans have become the reference standard for diagnostic of traumatic injury.  However, we must also weigh the risk of exposing patients to increased dosage of radiation and increasing their risk of radiation-induced malignancy.  This is especially true in the pediatric population given their rapidly developing bodies as well as their propensity to have a continued lifetime of exposure to medical radiation through future diagnostics.  

Clinicians, especially those not accustomed to regularly seeing pediatric patients, trauma patients, or more specifically pediatric trauma patients, often (anecdotally) err on the side of obtaining advanced imaging to assess patients following blunt abdominal trauma.  Dr. James Holmes and his colleagues in the PECARN (Pediatric Emergency Care Applied Research Network) group derived a clinical decision rule to help guide decision making when considering imaging in the pediatric patients.  Using a large, prospective study in 20 EDs, they identified a 7 point rule based solely on history and physical data to help risk stratify the pediatric blunt abdominal patient.  In patients who have no evidence of abdominal wall trauma or a seatbelt sign, a GCS >14, no abdominal tenderness on PE, no thoracic wall trauma, no complaint of abdominal pain, no absence or decreased breath sounds, and no vomiting, the risk of intra-abdominal injury requiring intervention is extremely low (0.1%).  

While these findings require external validation before likely widespread use, they have benefit for current ED practitioners for several reasons.  First, they used a patient oriented outcome of injury requiring intervention rather than a diagnostic outcome of any intra-abdominal injury, so that some patients who perhaps had injury but went on to have a stable clinical course and never received imaging were not a source of bias.  Secondly, their 7 findings were based solely on history and physical findings, something that is available to any clinician regardless of location or resources.  This eliminated the exclusion of validity to centers able to perform FAST scans or obtain more rapid lab results.  It also likely further decreased the “miss rate” for significant intra-abdominal injury when the clinical decision rule is supplemented by these diagnostic studies.  Finally, their rule is not meant as a hard “rule” to force a physician’s hand in obtaining a CT on a patient who carries 1 or 2 of their H&P risk factors.  It is meant to guide the conversation and critical decision process in weighing the radiation exposure risk versus the inherent injury risk when deciding how to continue the workup of the presenting child.  0.1% is a lower risk of injury the risk of a radiation induced malignancy in a young child.  However, as more risk factors accumulate, that may mitigate the difference in risk percentage, increasing the possible benefit of obtaining the CT.

Take home:

All patients, especially pediatric patients are sensitive to the ionizing radiation of medical imaging.  Risk stratifying pediatric patients with decreased likelihood of significant intra-abdominal injury can help physicians to have informed discussions with patients and their guardians and help to decrease the number of CT scans ordered on low risk patients and their exposure to unnecessary radiation.

References:

1) Holmes, JF, et al.  Identifying Children at Very Low Risk of Clinically Important Blunt Abdominal Injuries.  Annals of Emergency Medicine.  2013. 62: 107-16

Kindly contributed by Michael Galante, PGY-3.