Clinical Case: Adverse Reaction to Intravenous Contrast

A 46-year old female was undergoing a CT scan of the abdomen with IV contrast for investigation of abdominal pain when she started to complain of difficulty breathing.

What is the most likely diagnosis?

Read more in Allergic Reaction to Intravenous Contrast on AllergyCases.org.

Image source: Wikipedia, GNU Free Documentation License.

First season of ALF available on Hulu.com for free



First season of ALF is available on Hulu.com for free. Do you remember ALF?

Hulu offers free streaming video of TV shows and movies, primarily from NBC and FOX and their cable networks. The service is ad-supported, with optional registration. Video downloading for offline viewing is not supported. The name Hulu comes from a Mandarin Chinese proverb, in which it means holder of precious things.

References:
Introducing... ALF, Season 1. Hulu Blog.
Hulu, from Wikipedia, the free encyclopedia.

Interesting Articles: A Weekly Review of the "Big Five" Medical Journals

This is a collection of articles I have found interesting in the weekly editions of the "big five" medical journals: NEJM, JAMA, Annals, Lancet and BMJ (a few more journals are included occasionally). The review is a weekly feature of Clinical Cases and Images - Blog. Please see the end of the post for a suggested time-efficient way to stay up-to-date with the medical literature.

------------------

The Relationship of Coffee Consumption with Mortality: No Relationship.
Annals of Int Med, 17 June 2008 | Volume 148 Issue 12 | Pages 904-914

Coffee consumption has been linked to various beneficial and detrimental health effects, but data on its relation with mortality are sparse. The study included 41 736 men and 86 214 women who had 18 years of follow-up for men and 24 years of follow-up for women. Regular coffee consumption was not associated with an increased mortality rate in either men or women.

------------------

Rivaroxaban versus Enoxaparin for Thromboprophylaxis after Hip Arthroplasty: Better and Just as Safe.
NEJM, 06/2008.

This phase 3 trial compared the efficacy and safety of rivaroxaban, an oral direct inhibitor of factor Xa, with those of enoxaparin for extended thromboprophylaxis in patients undergoing total hip arthroplasty.

A once-daily, 10-mg oral dose of rivaroxaban was significantly more effective for extended thromboprophylaxis than a once-daily, 40-mg subcutaneous dose of enoxaparin in patients undergoing elective total hip arthroplasty. The two drugs had similar safety profiles

------------------

Rivaroxaban versus Enoxaparin for Thromboprophylaxis after Total Knee Arthroplasty: Similar Findings to the Study Above.
NEJM, 06/2008.

------------------

Angiotensin II Blockade and Aortic-Root Dilation in Marfan's Syndrome: Effective.
NEJM, 06/2008.

Progressive enlargement of the aortic root, leading to dissection, is the main cause of premature death in patients with Marfan's syndrome. Enlargement is caused by excessive signaling by transforming growth factor β (TGF-β) that can be mitigated by treatment with TGF-β antagonists, including angiotensin II–receptor blockers (ARBs). In a small cohort study of 18 patients, the use of ARB therapy in patients with Marfan's syndrome significantly slowed the rate of progressive aortic-root dilation.

------------------

Are international medical conferences an outdated luxury the planet can’t afford?
Yes or No
BMJ 2008;336:1466 (28 June), doi:10.1136/bmj.a358

------------------

Analysis of NHS at 60: How the NHS measures up.
BMJ 2008;336:1469-1471 (28 June), doi:10.1136/bmj.a385

------------------

Related:
5 Tips to Stay Up-to-Date with Medical Literature
Make Your Own "Medical Journal" with iGoogle Personalized Page
Share iGoogle Tabs with Medical Journals, Podcasts and Gadgets
Text-to-Speech Programs and Continuous Medical Education
Image source: OpenClipArt, public domain.

Video: Bill Gates' Last Day at Microsoft


Bill Gates' Last Day at Microsoft

Link via Digital Inspiration.

Oral Rivaroxaban signals the beginning of the end of Lovenox use for DVT prophylaxis

Rivaroxaban is an oral anticoagulant under development by Bayer; it will be marketed as Xarelto. It acts by inhibiting the active form of coagulation factor X (factor Xa).


Fig 1. The coagulation cascade. Legend: Black arrow = conversion/activation of factor. Red arrows = action of inhibitors. Blue arrows = reactions catalysed by activated factor. Grey arrow = various functions of thrombin. Image source: Wikipedia

According to 2 NEJM studies, a once-daily, 10-mg oral dose of rivaroxaban was significantly more effective for extended thromboprophylaxis than a once-daily, 40-mg subcutaneous dose of enoxaparin (Lovenox) in patients undergoing elective total and knee and hip arthroplasty. The two drugs had similar safety profiles.

Due to the decreased need for monitoring, rivaroxaban is likely to be used to replace warfarin for a number of indications, such as atrial fibrillation.

A related drug, ximelagatran, a direct thrombin inhibitor, was not marketed further due to its potential side-effects, mainly liver toxicity.

Oral rivaroxaban is non-inferior to standard therapy for symptomatic pulmonary embolism (PE) and DVT (NEJM, 2012).

References:

Rivaroxaban versus Enoxaparin for Thromboprophylaxis after Total Knee Arthroplasty. NEJM, 06/2008.
Rivaroxaban versus Enoxaparin for Thromboprophylaxis after Hip Arthroplasty. NEJM, 06/2008.

Related:

An oral anticoagulant in the pipeline. Notes from Dr. RW: Was Lovenox dose intentionally too low (40 mg sq qd instead of 30 mg sq bid)?

A Doctor's Opinion: Why I Started Microblogging on Twitter

As a subscriber of Ev Williams' blog (the founder of Blogger.com), I first heard about Twitter some time ago, a year or two after he left Google. Ev started Twitter with Biz Stone, and I tried the service soon after its launch but "didn't get it." There was too much noise -- too many updates with little valuable information. Twitter looked like a useless distraction at the time.

Combined Feed of Doctors-Twitters

It wasn't until Joshua Schwimmer launched his combined feed of physicians-twitters that I started to think about using Twitter again. Checking the mini posts was not only fun but also potentially useful. Doctors and medical librarians (my other favorite group of bloggers) are busy and often do not have time for long posts. The 140 characters on Twitter are enough to share some interesting bits of information that otherwise would have gone unpublished.


This CommonCraft video explains what a microblogging platform is by using Twitter as an example.

Twitter Patient Reminders

In addition, Twitter may be useful as a daily/weekly reminder to patients with chronic conditions. For example, an allergist can remind his patients with allergic rhinitis of the high pollen counts in late June. Or a cardiologist can text his patients about the findings of a new study. It only takes a doctor's cell phone and patients willing to subscribe to his/her Twitter feed.

News Breaks First on Twitter

Those above are just a few preliminary ideas but it looks like Twitter may not only be fun to use but actually useful. Many A-list tech bloggers have noticed that the news breaks first on Twitter and FriendFeed -- before CNN, and definitely before the evening news. I seldom watch TV nowadays but I have 4 computers that are (potentially) connected 24/7: desktop, laptop, UMPC and MotoQ.

Follow Me On Twitter

It looks like I am one of the newest twitters from the medical blogosphere, following in the footsteps of many others. "ClinicalCases" user name on Twitter was already taken, so I chose "AllergyNotes." You can follow me here: http://twitter.com/allergynotes

Twitter is the Present Day Virtual Doctors Lounge

If you don't use Twitter, you will miss stuff like that:

"KidneyNotes:

It's profoundly weird that Alex, the synthesized Mac voice, pauses occasionally to *inhale.*

Playing with a completely blind Boston Terrier, but you can't tell, since he sees with his nose.

"I AM ALIVE!" he cried out after being twice defibrillated.

When your to-do-lists themselves require a to-do-list, that's your system's way of telling you to file half your tasks in someday/maybe.

If you have 6 containers of water on your tray, you aren't fluid restricted. I don't care what the sign says.

A pale morning, with central park trees reflecting in the fogged glass cube of the apple store."

Twitter is the present day virtual doctors' lounge. If you want to really know how doctors think, you don't have to read Jerome Groopman's books with the same name -- follow the doctors on Twitter.

References:

Blogging, Microblogging and Facebook
Text messaging can help young people manage asthma. How about Twitter and Facebook reminders?
Doctors and Medical Students on Twitter. Kidney Notes.
Eavesdrop on Doctors and Medical Students on Twitter. Kidney Notes.
We're connecting - and wasting time - on Twitter. Mercury News, 06/2008.
So You Want to Microblog (Twitter) With Your Students? Academhack.
Beginner's Guide To Using Twitter. WebGuild.org.

Related reading:

How to make money from Twitter. AllergyNotes.
Twitter badge for Blogger. Blogger Buzz.
Twitter. UBC Health Library Wiki.
Twitter, What Are You Doing? Co-Founder Tells All. NPR.
The Doctor's Room on FriendFeed. Joshua Schwimmer.
10 Reasons Why I Use Twitter. ScienceRoll, 11/2008.
Why I Love Twitter by Tim O'Reilly, 11/2008.
"One of the best decisions I’ve made in my career was to start a blog and a wiki, leaving a paper trail of ideas" http://bit.ly/GX7Z6C

Best Solution for Online Backup: Amazon S3 via Jungle Disk?

After writing a long post on the various ways of local backup, I saw a better solution in the Paul Stamatiou's post about online backup to Amazon S3 via Jungle Disk. S3 (Simple Storage Service) is an online storage web service offered by Amazon.com.

As a disclaimer, I am not against local backup tools and I am planning to continue using at least 3 of them in the future:

1. External hard drive, 500 GB
2. Portable hard drive, 150 GB
3. USB drive, 4 GB

However, an encrypted backup on Amazon S3 looks like a tempting option and is probably the best solution for online backup, at least for now. The service is competitively priced at 15 cents per GB per month. Jungle Disk, which provides the interface to Amazon S3, costs $ 20 (one-time purchase).

I tried this backup solution during the weekend and it works OK. The best way to grasp the concept is to watch the explanatory screencasts from the JungleDisk website.

Initially, I was thinking about using Jungle Disk's virtual drive as just another drive (or a folder) but I gave it up in favor of running backups of a few folders:

1. Scanned documents (in PDF format) and other various files as .doc, .xls, .ppt. The size is about 2 GB.
2. Photos from Picasa, 7 GB.
3. Other various files, such as mp3 and video.

The initial upload took 1 day and 17 hours over a cable connection (upload speed 520 kbits/sec) but the subsequent backup is incremental and it takes much shorter time.

Frequently Asked Questions

Jungle Disk? How can you trust a company with such name?

Yes, I know, it does not sound serious but it goes nicely with Amazon, rain forest, etc. In addition, the company does not have access to your data, which is encrypted before it leaves your computer, and the access to Amazon S3 should be available even if Jungle Disk goes bankrupt.

Can anybody read your online files, tax returns, etc.?

The files are encrypted before they leave your computer and are protected via a password and encryption keys.

What are your thoughts about online backup? Which service do you use?

References:
How do you backup your computer files?
How to backup your medical blog?
Why I Started Using Amazon S3. PaulStamatiou.com.
How I Use Amazon S3. PaulStamatiou.com.
Image source: Wikipedia.

Related:
Amazon S3 Simple Storage Service - Everything You Wanted to Know. Digital Inspiration.
Amazon S3 Buckets Described in Plain English. Digital Inspiration.
Bulletproof Backup Strategies. EfficientMD, 08/2008.
Thoughts on Dropbox from PaulStamatiou.com, 09/2008.
S3 Browser - Freeware client for Amazon S3. User Interface for Amazon S3 Service.
A Round-up of GUI Clients for Amazon S3 Storage & CloudFront. Digital Inspiration, 2009.
Web storage: Amazon S3 is nearly 80% more expensive than Amazon Cloud Drive http://goo.gl/wlgP7

Tundra PA Describes the Annual Salmon Run in Alaska

From Medscape Pre-Rounds:

"An experienced physician assistant moved to the land of the Yupik Eskimo, in southwestern Alaska 7 years ago. Under the pen name "The Tundra PA," she writes about her experiences living and practicing medicine in this unique environment on her blog Tundra Medicine Dreams."

I have enjoyed the Tundra PA writing for almost 2 years. Her latest post provides another fine example:

Fish Camp

"The king salmon (Chinook) are running strong on the lower Kuskokwim River now, and many people have left Bethel and the villages to live in their fish camps.

The salmon run will last for a couple of weeks. During that time, people who live by subsistence must catch a year’s worth of salmon for their family, fillet it, cut it into strips, brine it, dry it, and smoke it.

With over twenty hours of daylight, work goes on almost around the clock."

References:
Fish Camp. Tundra Medicine Dreams.
Physician Assistant Blogs About "Bush Medicine" in Alaska
Image source: Chinook Salmon (also called king, tyee, blackmouth), Wikipedia, public domain.

Guide to mushroom poisoning identification and treatment

From John Halamka of Life as a Healthcare CIO:

"As part of my duties as an Emergency Physician, I do 200 toxicology consultations each year for patients in New England who eat wild mushrooms and seek medical care.

My complete (warning -it's a 21 megabyte Powerpoint) guide to mushroom poisonous identification and treatment is available online."

Image source: Amanita muscaria, from Wikipedia, the free encyclopedia, Creative Commons Attribution-ShareAlike 2.5 Netherlands.

Two of my favorite browsers just had major updates: Firefox 3.0 and Opera 9.5

I use 2 browsers every day: Firefox and Opera. The sequence used to be Opera and Firefox but more on that later. Both browsers just had major updates -- Opera to version 9.5 and Firefox to the hyperhyped (is that a word?) and much anticipated version 3.0.

Opera 9.5

Opera 9.5 is just as solid as it has always been. I like the one-key shortcuts ("Z" to go back, "1/2" to switch tabs) but they are turned off by default in this version so I had to change the settings. The zoom feature is better than the one in Firefox. The browser has a smaller memory footprint and uses less resources when loaded with multiple tabs (30-40+), for example, when I read the 40 newspaper front pages from Newseum. The biggest drawback of Opera? It does not work well with Google services. Firefox feels like it was made for Google (because it was). Opera has other useful features such as sessions and online bookmark synchronization between different computers.

Firefox 3.0

Firefox 3 is a great browser -- much faster than the previous version and it works seamlessly with Gmail, Reader, YouTube, Blogger, etc. The only extensions I have installed are Google Toolbar and Gears (for offline access to Google Docs).

At the beginning of the post, I mentioned that Opera was my browser of choice, then Firefox, but that sequence had reversed. Several years ago, Opera was the first real alternative to Internet Explorer and the major innovator in the browser field. The tabs were first launched in Opera, for example (see the video below). However, Opera does not work very well with Google services, and Google "rules" the online world. Firefox is an excellent browser (with an even better PR team), so if you do not have it on your computer yet, you should give it a try.


Video: Opera browser 12-year history

References:
Web OS May Be Everything You Need for Day-to-Day Work
Portable Firefox on a USB Drive
Newseum Shows Front Pages of 600 Newspapers from Around the World
Largest online database of keyboard shortcuts
Review: Opera 9.5 -- a fine browsing alternative. Computerworld, 06/2008.

Eric Topol on Lessons from Tim Russert's Heart Attack

We have covered the topic before but Eric Topol's video take on the lessons learned from Tim Russert's untimely death is worth a minute of your time (4 minutes, to be exact). Dr. Topol is the former chief of cardiology at Cleveland Clinic and he currently posts regularly on the video blog of TheHeart.org called Topolog:

Lessons From Tim Russert


Blood clot in the left anterior descending artery (LAD). Image source: Wikipedia, public domain.

Related:
MarketWatch: Russert's death is a reminder to be proactive about your health.
Video Interview with Tim Russert's Doctor -- Cause of Death Was a Fresh Clot in LAD

AMA President Diagnosed with Pancreatic Cancer

From Associated Press:

"As a doctor, Ron Davis knew what it meant when he got a diagnosis of advanced pancreatic cancer earlier this year.

Like most of those diagnosed with the disease, Davis' cancer has spread beyond the pancreas, reducing chances for recovery. Surgery wasn't an option.

"As a physician, I know the survival statistics for someone with stage 4 pancreatic cancer," he said. But if the five-year survival is 5 percent, that's not zero... So, never take away someone's hope."


A CT scan of the abdomen shows an ill-defined mass around the pancreatic head and a dilated pancreatic duct in a patient with pancreatic cancer. Source: ClinicalCases.org.

Dr. Ronald M. Davis, M.D., age 52, passed away peacefully at home on Nov. 6, 2008.

References:
AMA president speaks of pancreatic cancer struggle. Associated Press.
Fighting spirit: AMNews interviews Ron Davis, MD. AMNews.
The Team Ron Page.

Skin patch vaccine to prevent travelers' diarrhea

There are more than 6 billion people living around the world but it may be still be surprising that travelers' diarrhea affects as many as 22,000 of them every day.

Travelers' diarrhea (TD) is the most common illness affecting travelers. Each year between 20%-50% of international travelers, an estimated 10 million persons, develop diarrhea. Montezuma's revenge is the colloquial term for any cases of traveler's diarrhea contracted by tourists visiting Mexico. The name humorously refers to Montezuma II (1466-1520), the ruler of the Aztec civilization who was defeated by Hernándo Cortés, the Spanish conquistador. It is estimated that 40% of foreign traveler vacations in Mexico are disrupted by infection.


Image source: Escherichia coli, Wikipedia, public domain.

The most common causative agent is enterotoxigenic Escherichia coli (ETEC). The primary source of infection is ingestion of fecally contaminated food or water.

In a phase II study published in The Lancet, 178 healthy adults (aged 18–64 years) who planned to travel to Mexico or Guatemala were vaccinated before travel, with two skin patches given 2–3 weeks apart. Patches contained either 37·5 μg of heat-labile toxins from E coli (LT) or placebo.

According to the study authors, the vaccine was safe and immunogenic. The 59 LT-patch recipients were protected against moderate-to-severe diarrhea (protective efficacy 75%) and severe diarrhea (protective efficacy 84%). LT-patch recipients who became ill had shorter episodes of diarrhea (0·5 days vs 2·1 days) with fewer loose stools (3·7 vs 10·5) than placebo.

The authors concluded that ETEC diarrhea illness occurring in 10% of cases of TD. The vaccine patch is safe and feasible, with benefits to the rate and severity of travelers' diarrhea.

References:
Use of a patch containing heat-labile toxin from Escherichia coli against travellers' diarrhoea: a phase II, randomised, double-blind, placebo-controlled field trial. The Lancet 2008; 371:2019-2025.
Travelers' Diarrhea. CDC.
Traveler's diarrhea, from Wikipedia, the free encyclopedia.
Top image source: Flickr, Creative Commons license.

Video Interview with Tim Russert's Doctor -- Cause of Death Was a Fresh Clot in LAD


First interview with Tim Russert's doctor. Source: RedLasso. Link via GruntDoc.

On the afternoon of June 13, 2008, Russert collapsed at the offices of WRC-TV, which houses the Washington, D.C. bureau of NBC News, while recording voiceovers for the Sunday edition of Meet the Press. Despite immediate attempts at resuscitation by EMS and transportation to Sibley Memorial Hospital, Russert never regained consciousness and was pronounced dead a short time later at 4:15 p.m.

An autopsy, performed on the day of his death, determined that his history of diabetes mellitus and coronary artery disease led to sudden cardiac death. The immediate cause of death was an occlusive coronary thrombus. On the special reports program, Russert's friend Dr. Michael Newman stated that the autopsy showed coronary artery disease in the left anterior descending artery, and a fresh blood clot was visible on one of these plaques. He had a negative stress test less than 2 months ago.

Tim Russert was in Italy for a family vacation and had just returned home but the autopsy did not show findings of PE. Source: Wikipedia.

Colleague and former NBC anchor Tom Brokaw broke the news on the network Friday: "He will be missed as he was loved -- greatly." Source: CNN.


Blood clot in the left anterior descending artery (LAD)

There is a mnemonic for some of the risk factors for CAD -- OBESE:

Obesity
Blood pressure (hypertension)
Elevated LDL, low HDL
Smoking
Elevated glucose (diabetes)

Related:
What Happened to Russert: The science of sudden cardiac arrest. Newsweek, 06/2008.
Bloggers and Heart Attacks
AltaVista Founder Dies of a Heart Attack at 42
Popular tech blogger Mark Orchant died of heart attack at 50
Image source: Wikipedia, public domain.

Updated: 06/04/2008

How to prepare for the cardiology boards

The cardiology fellows' blog at TheHeart.org features a useful presentation by Dr. Abhinav Goyal (cardiology staff, Emory) called "How To Prepare For The Cardiology Boards."

Here is the link to the PowerPoint presentation (240 KB).

We have covered the less specialized topic of preparing for the ABIM in the past: How to Score Well on the Boards?

This Week's Grand Rounds is Hosted by NHS Blog Doctor

Check out Grand Rounds, the weekly summary of the best posts in the medical blogosphere.

Grand Rounds (GR) has become the contemporary weekly portrait of medicine through the eyes of the medical bloggers. Pre-Rounds is an article series about the hosts of Grand Rounds on Medscape.com. Nick Genes of Blogborygmi, who writes the Medscape column, is the founder of GR and the archive host. I have hosted Grand Rounds 2 times in the past but have not been able to find time to do it again in recent months -- it looks like a deceptively simple task but it takes a lot of work.

This week's edition of GR is compiled by the venerable NHS Blog Doctor -- one of the most popular medical blogs and a well-established institution on the other side of the Atlantic, with its own economic, scientific and political advisers. There is even an American correspondent and, who knows, the blog may one day become something like a mix between the BBC and the TIME magazine. The Blog Doctor caused a lot of concerns when he went on hiatus a few months ago, complicated by fake comments about his premature demise. Luckily for all, the good old (?, judging by the blog header picture) NHS Blog Doctor is back, better than ever, with a huge and well-illustrated edition of Grand Rounds. Spare at least an hour of your time to check the latest and greatest posts from the medical blogosphere.

Image source: NHS Blog Doctor.

Job Search: There's a feed for that?!

An example of power of RSS feeds from Google Reader blog:

"I was having a hard time finding the right job here in Houston. Days would go by without talking to a single recruiter. But then I started using Google Reader to subscribe to custom-made job search feeds for Craigslist, and for oodle.com (which already aggregates feeds from thousands of other classified ad websites).

Soon I found myself flying all over the country interviewing for jobs. The employers always pay for the flights, hotels, rental cars, etc. My job hunt became like an exciting vacation! I've been to New York twice, Milwaukee, Austin, Los Angeles, and Miami. I just accepted an offer in Manhattan with a very competitive salary offer. Google Reader saved me a huge amount of time and effort with the job hunt."

I wonder if you can use the same approach when searching for a job as a physician.

References:
There's a feed for that?! Google Reader blog.

How to Use (and Stop Using) Scheduled Posts in Google Blogger

How Does Scheduling Work?

Google Blogger recently launched the ability to schedule posts for automatic publishing in the future:

"Publishing a post in the future is pretty simple: in the post editor, reveal the Date and Time fields using the “Post Options” toggle and enter a post date and time that is in the future. When you then click the “Publish” button, your post will become “scheduled.” When the date and time of the post arrive, your post will be automatically published to your blog.

Your scheduled posts appear in your Edit Posts list alongside your drafts and published posts. To un-schedule a post, simply save it as a draft any time before it gets published."

What If You Don't Want to Use Scheduling?

I use Google Blogger to publish not only blogs (with posts in reverse chronological order) but also "regular" websites in which the article at the top of the page is not always the newest one. To do this, I often choose a date in the future (for example, 2010) which makes the desired post to stay on top. The "scheduled post" Blogger update eliminated this option but fortunately, there is a workaround:

"We know that some bloggers currently use future post dates in order to keep one post at the top of their blog for a while. Though we recommend that you use a Text page element for this, you can still get this old behavior with just one additional step. First, publish your post with the current date and time. This will publish it to your blog. Then, once it’s published, edit the post to change the date to the future and publish it again. We don’t re-schedule posts that are already published, so the post will stay on your blog but sort to the very top."

References:
New feature: Scheduled Posts. Blogger in draft, 02/2008.
Blogger now schedules future-dated posts. Blogger Buzz, 05/2008.
Image source: Blogger in draft, Google.