June 13, 2011

A case of bradycardia - biliary disease or acute coronary syndrome?

A middle-aged man comes to the ED with one day history of severe pain in the upper abdomen. He is feeling increasingly uncomfortable and has nausea without vomiting. He appreciates his pain as VAS 7-8. On physical examination he is tender on palpation in the epigastrium, physical examination is otherwise completely normal. You get an ECG with no signs of ischemia but you observe sinus bradycardia at 37 beats per minute.

The lab results unfortunately return a hemolyzed Troponin-T but the LFT (liver functional tests) show ALP=3.2, GGT=8.8, ALT=1.4 and AST=2.3 (slightly elevated, suggesting cholestasis). Could the pain have a cardiac etiology?

Flu in Oakland 1918 Inferior MI and diseases of the upper gastrointestinal tract (gallbladder, stomach/esophagus especially) can present in very similar ways. Besides epigastric pain, patients commonly describe bloating and reflux-like symptoms due to vagal stimulation and gastric distension. Vagus stimulation explains why up to 40% of patients with inferior MI have sinus bradycardia (Bezold-Jarisch reflex). 1st to 3rd degree AV block is also common but how the mechanism of the AV node inhibition is not known.AST was for many years ago the only known cardiac marker. In the 1954 protocols for MI an elevated AST defined an acute coronary syndrome. Which in those days required hospitalization for bed rest mainly! It is a sensitive marker but highly nonspecific. LITFL (as usual) has an excellent article about the use LFTs, especially for the 'cut the crap' based approach of the emergeny physician

All pain and physical stress, especially from stomach and intestines can potentially stimulate the vagus nerve and thereby cause bradycardia. The classical scenario is the elderly patient with gastroenteritis that comes to the ED after a syncope. The relationship between bradycardia and acute cholecystitis has actually been described previously and even given a special name, Cope's sign:

Bradycardia in the case described above turned out to be caused by an underlying acute cholecystitis, the patient had an infusion and was admitted for emergency surgery. A new Troponin T was taken and turned out to be normal. A new ECG revealed normal sinus rythm.

June 12, 2011

Web applications are the software of the future

We all remember those days when Microsoft Office was installed from some 25 or so diskettes and once setup up it was a permanent version not to be updated for a few years. With the Internet, updating became a little easier but you still had to manually download and install. Now that the web-browsers are becoming ever more powerful the software world is being taken over by web applications. Don't be thrown off by the scary term, you most likely are already using web-apps already. Google Docs, Facebook and Twitter are one of many examples. A web application is not installed on your computer since it runs on the web. Instead of opening it from the Start menu you go to a URL and you have it up and running. With a login, it remembers your customized settings and content and hardly any data is written to the hard disk of your computer. You never have to bother if the application is compatible with your operating system or type of computer you have, the browser takes care of it all.

And so we are seeing more and more of web-applications and the classic software you remember installing from diskettes and CDs are now web-based. With the latest web-technologies such as HTML5 and 3D graphics inside the browsers a new era has started and there are no technological barriers for running almost any kind of software as a web-app. Recently audio and video editors have been appearing and Google's body browser (update: now Zygote body browser) is a pioneer for 3D applications as web-app, showing a glimpse of the future. Not even programmers would have believed five years ago that this would ever be possible!

Combined with "cloud computing", this is a gigantic leap in the IT evolution which will completely change the way we work with data. Your data and "software" configuration is accessible wherever you are as long as you're connected to the Internet and even if you're house burns down you can go to the neighbour and continue working with your documents. I like to call this the "mobile office" since you literally have your office desk with all it's tools and papers but in a virtual, electronic format which you can take with you anywhere you go or just open your documents on your mobile. Actually, since you do more than just editing documents and updating your calendar - it's more like having your desktop computer in your pocket. That is true IT power and can save lots of time and effort for the physician. I will later on write more about the mobile office concept and how I use it my self.

Ok, enough of this hallelujah web-app rant, you most likely are asking yourself what does this have to do with the emergency physician?

First of all, you are not any more dependent on a specific operating system. As said earlier, the web-browser is now the most important factor between you and the software (and this is why I hate hospitals that are slow to upgrade the web-browsers, for me it's literally like being forced to work with Windows 3.1). This gives you the opportunity to throw out old habits (I'll be less obscure, stop using MS Windows!) and give way for alternatives. Did you know for example that Linux is a well-established operating system which is free, more secure and stable than Windows  and uses considerably less resources like memory and CPU power - ultimately meaning a faster system. Since Linux is free of virus vulnaribilities it will give you that 10-15% of your CPU which antivirus software normally takes and you will never have to be afraid of crashing your computer because you accidentally pressed that "wrong button". There are many Linux variants but Ubuntu is in my opinion the best one for newbies and has amazed many previous Windows users. It takes only 10 minutes to install and if you're afraid of killing your other OS you can install it parallel to your Win/Mac and choose from the boot screen which one you prefer.

Secondly, your browser is now the bread and butter of your computer and you should really see over if you're having the best one and know how to use it properly. It is beyond the scope of this post to discuss the best browser out there but I can tell you that after years of trying out most of them, Google's Chrome is in my opinion leaving the competitors in smoke. It is fast, stable and incredibly easy to use, yet having very advanced powers under the hood. It's self-updating so you will never have to worry about compatibility or security issues. Add some extensions, you've got a F22 Raptor in your parking slot.

Finally, your valuable documents, pictures, videos and every single information you have collected through the years can now be electronic instead of heaps of papers in the shelves of your office. Imagine having all your articles you've read through the year in a single place, readable from home, work or even your mobile on the train while commuting. With an electronic marker-pen you've highlighted and made notes in those articles that have had the most practicable value to you and in only seconds you can have it back on your screen, just as you left it last time. Having all your emails and documents in a "electronic heap" means it's easily searchable... with a single click you can search through everything you've read or written for the past years. A lost login to the local EMR system, your impersonality notes about ECG reading or just the number of your bank account - it's all right there at the tip of your finger!

You want to relax after work and listen to David Bowie's soothing 80s music? Listen to it at Grooveshark.com and you can search through terabytes of online music and play it right from your screen. If you've created an account you can even play that "dinner playlist" you just created the other day to bring up good memories. You have an ECG which needs to be edited to erase patient ID and resize. Open pixlr.com - an insanely amazing photo-editor which does most if not everything that Photoshop does, completely free of use! You always wanted to try a 3D editor? It's yours if you just click this link! Oh and you have a video that needs the final touch but don't have your laptop with you? Don't worry, you have several to choose from. Oh and they're also free! If you need to create a video-tutorial of something you are doing on your computer, say using your local EMR - guess what, there's a webapp for that too! And if you ever get suspicious, you can even run a viruscheck from a website!!

You get my point. Start building up your collection of web-apps, it is the true beginning of being an IT competent doctor. This post hopefully inspires you, the rest is up to you. In my next posts I will tell you about the Google Apps and the importance of simplicity aka "cockpit approach" to web applications. For me at least, it has stepped up my learning curve more than any other modality.

Still confused? Check out these ultra short videos about webapps:

June 9, 2011

The Toastmasters´ podcasts

In preparation for giving a talk about "IT for emergency physicians" in Kos in september I stumbled upon a great podcast site, The Toastmasters Podcasts. The Toastmasters club needs no introduction but in case you haven't heard about them:

"Toastmasters International (TI) is a nonprofit educational organization that operates clubs worldwide for 
the purpose of helping members improve their communication, public speaking and leadership skills..."

Their podcasts are simply awesome and touch everything you have to know to be a good speaker. Preparation and training is the most important thing you do if you don't want to end up standing in front of your audience with a crimpled tongue and your head full of cotton. Now matter how much you've worked on your slides and notes - if you show up untrained, you WILL fail! So enjoy these great and free podcasts where they feed you full of preparation tips.

The shocked skin - livedo reticularis or cutis marmorata?

A patient in shock will often have a skin-pattern that is hard to forget. This pattern is also seen in the last hours of a moribund patient and almost always post-mortem. "Mottled skin" is the insider slang; it is commonly described as cold, damp/sweaty, pure white with small patchy islands of purple/pink spots in between. This skin pattern, together with the clinical picture, should bring the doctor to the attention of a true emergency where the patient needs immediate care. Physiologically this phenomenon has been explained by peripheral vasoconstriction, an effect of rush of catecholamines in the blood. The body is in a shocked state and strives to move all volume from the periphery to central spaces. If the patient is awake he will most likely be at unease, confused and agitated because of poor CNS perfusion, catecholamines and even pain.

Initially, the purpose of this blogpost was to entertain the reader (hopefully emergency physician) with the one and only truth about the "mottled skin" since it is a common and frightening sight in the ED but vaguely defined. However, it appears that there is no concrete truth in this case, even major sources (Harrison's online, Merck Manual) are silent as the grave. In the end I found some explanations in on of the two holy bibles in emergency medicine, Rosen's emergency medicine, though in the pediatric section (the other is of course Tintinalli's). I want to belive their description also applies to adults:

Compensated shock can be recognized by the presence of pallor. A pale child with a rapid heart rate should always be considered to be in shock until proved otherwise. As cardiac output is further compromised and perfusion to vital organs is decreased, the skin may become mottled. Mottling is manifested by areas of vasoconstriction and vasodilation in a random pattern on the skin. It reflects loss of small vessel integrity and may be similar to what is seen in vital organs during multiple organ system failure. Mottling is usually an ominous sign. It is important to not confuse cutis marmorata with mottling in young infants [...]. Cutis marmorata is a lacy marbling of the skin caused by vascular instability. It is a normal finding and is commonly seen in infants in a cool ambient environment.

Cutis marmorata

src: http://www.eurordis.org/content/dutch-cutis-marmorata-telangiectatica-congenita-cmtc-association is sometimes mentioned along with shock but there are other more common differential diagnoses such as decompression sickness, normal (cold) response in young children and a congenital variant (CMTC). All indicate instability in the vasculature (vasospasm/dilation). The patterns are unfortunately not uniformly defined as seen in the pictures on DermAtlas and NEJM.

Livedo reticularis

src: http://www.sciencephoto.com/images/download_lo_res.html?id=773200433 is also connected with shock, as in this case in BMJs "Images in emergency medicine" series. It confuses however my view of the phenomenon whereas other sources describe livedo as a common pattern of various well-defined, mostly autoimmune, diseases ranging from benign to acute ischemia of the extremities. The skin pattern is sharper than cutis marmorata and the morphology more reticular, as the name indicates.

So after all the browsing I unfortunately didn't come to any intelligent conclusions; for "mottled skin" in the shocked patient, there is no good definition or specific description and differentiation from other similar symptoms pictures of more benign origin. What is clear (as before!) however is that this is a pattern that all emergency physicians must be aware of as it commonly indicates a disaster on its way.