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I'm a Physician. My speciality is Critical Care and Infectious Diseases. I'm also a Tech geek, an avid Apple fan & enjoy traveling, fine dining and tea drinking. 

Saturday
Mar102012

AXILLARY ARTERIAL LINES

Hemodynamic monitoring of critically ill patients is incomplete without Arterial catheters. These allow us to have accurate blood pressure monitoring and ease of checking Arterial blood gases. 

Traditionally radial artery has been used most extensively. Since pulsations from the artery can easily be palpated on arm, it is the most readily accessible artery for this procedure. 

With Ultrasound guidance becoming standard of care for all vascular procedures, we have better alternatives than radial artery. Though radial arterial line is also best done using Ultrasound, the relatively small size of the vessel and its proximity to the wrist, makes is very vulnerable to malfunction and inaccuracy. In my experience, radial arterial catheters are good for 24-48 hours in most patients. There is also convincing data that blood pressure measurements from radial artery, may not be as accurate as femoral arterial catheters. 

Axillary artery is larger and easily accessible via ultrasound guidance. It is close to pectoralis minor muscle which divides it into three parts. I favor Axillary Artery for arterial puncture and arterial catheter placement in most critically ill patients. 

Most patients have this artery very superficial (0.5 to 2.0cm) beneath the skin and with ultrasound it is easy to differentiate it from the Axillary vein. Either compressibility method or color doppler can be used for this purpose. In Axilla the axillary artery is surrounded by the Brachial plexus. This is usually more proximal and risk of nerve injury is minimal if procedure is done properly. 

Use ultrasound to scan the arm to assess the size and anatomy of the axillary artery. If artery size is too small (less than 0.2cm) it may be difficult to canulate with guide wire. In those cases femoral artery is better (usually its diameter is larger). It is important to scan and obtain images prior to scrubbing in for the procedure. 

Keep the patient's arm at 90 degrees. After full sterile precautions are taken, local anesthesia can be given with lidocaine at the site. Using a needle (e.g. Argon Arterial Line) from the kit, axillary artery can be accessed easily under real time ultrasonographic guidance. Arterial blood is pulsatile and bright red. Using Seldinger technique guidewire is passed in the artery. Needle is then removed leaving guidewire in the vessel. Always check the position of the guidewire with ultrasound, it should be easily visible in the cross sectional and logitudinal views. Arterial catheter is then guided over the guidewire and guidewire is removed. Arterial line is then secured with sutures and dressed. 

If done properly, there is a 99% chance of successful access to the axillary artery on first attempt. In comparison to Femoral artery, I find it easier to manipulate the guidewire as it has a relatively straight path. Femoral artery goes beneath the inguinal ligament and in some patients, guidewire gets stuck in that path. 

With our population getting obese, femoral artery access is relatively difficult (abdominal panus covers the groin). In obese patients femoral artery is also deeper. Even in most morbidly obese patients, axillary artery is still less than 2.5cm deep as medial side of arm doesn't gain as much subcutaneous fat. 

Axillary Artery blood pressure (like Femoral Artery) is more accurate than radial artery, as these are more central vessels. Since the catheters are long, there is very little chance of it losing waveform or inaccuracy with prolonged use. I have not had had to remove a single one of these for malfunction so far. Infection risk is also minimal if strict sterile precautions are used.

There is a common misconception that Axillary Artery puncture or catheterization has risks of compromising arm circulation. This is not true. Axillary Artery has six major branches and collateral circulation is provided via Dorsal Scapular, Subscapular, Anterior and posterior humeral circumflex artery to the arm. As long as procedure is done proximally (close to axilla above the Teres minor muscle), it is very safe. Care should be taken in Brachial artery punctures (Axillary Artery become brachial artery below the Teres Minor muscle) as there can be a risk of arm ischemia. 

I find Axillary Arterial punctures and catheterizations a very important tool for hemodynamic monitoring of critically ill patients in my ICU (Intensive Care Unit). With ultrasound use, it is very easy, safe and can be used effectively to provide better care to our patients. 

If anyone is interested in learning this procedure, I can upload a video of the proper technique. Just leave a comment below. 

 

Saturday
Jun052010

iPad ~ Is it really better than a laptop?


Macbook 13" with an iPad

Now that I've owned an iPad for a little over a month, I'm ready to compare. Most of us do believe that it is a new product category and cannot be compared to traditional computers. But if I'm doing my routine San Francisco to New York city travel, would I carry an iPad or my Macbook?

iPad is Better

Here is a list of things where iPad rocks:

More Portable than Laptop

As you can guess by the picture (iPad vs a 13" Macbook) iPad is significantly smaller and lighter. This is a big advantage during travel.

Quick On/Off

iPad is quick to turn on & off. Due to long battery life, it rarely requires to be shut down. It's OS takes less time to load than any kind of laptop.

Great Battery Life

iPad battery lasts 10-12 hours of active use. Makes it ideal for long flights as I'm never looking to charge it in a plane or at the Airport Gates. This is not that big an issue with the newer Macbooks, but my Macbook Pro's (3 years old) battery life is just around 3 hours.

Easy Airport TSA Screening

US Airport security considers iPad different from Laptop i.e. unlike a laptop (which requires removal from a bag during the scanning) an iPad can be inside the luggage. It is easily recognized by the scanners. I have had no trouble during my multiple trips this year.

No Heated Laps

Anyone who has used a Macbook for a considerable time knows how burning hot they can get. This has given birth to devices like Raindrop’s iLap and Brookstone’s ePad. Good News! iPad doesn’t get hot at all, no matter how long you use it.

Faster with Multi-touch screen

iPad is very fast due to Apple's A4 processor. Everything opens and closes in a flash. Browsing becomes extra fun with speed and responsive touch screen. I really like double clicking the main screen which zooms in the text of the webpage hiding all the ads (on the sides & top)

Reading is more fun

Though iPad hasn't got the 'paper like' or E-ink kindle display, iBooks screen brightness can be dimmed to reduce the LED back-lit considerably. iPad has revolutionized how we read newspapers, magazines and books. Even Kindle has an application for iPad. UK newspaper Financial Times has a great application, seems I'm holding the actual newspaper. Wired's first iPad edition has been a huge hit too.

As a physician one of my favorite applications is Mekentosj's Papers. It can bring all the medical literature journals and papers in an electronic format. PDF opens full screen and can be arranged by journals, authors and different categories. I'm no longer dependent on print versions which easily get lost. In a way it allows carrying entire research library all the time with easy one click sharing of articles.

Portable Media

Games, Music, Movies and Pictures are all kind of more fun due to iPad's gorgeous screen. I wonder who would buy Brookstone's digital picture frame now? Though I'm not an avid gamer, those who have tried games on iPad seem to love it.

Laptop is Better


Ok now what are the areas which make me miss a laptop?

Productivity

iPad is a great way to consume content, but creating it can be challenging. Though Apple's iWork suite for iPad is very impressive, it just wouldn't allow all the features of the desktop version. I recently tried making a medical presentation on iPad's Keynote, it was difficult. I couldn't add notes, format text etc.

Lack of Physical KeyBoard

Touch screen keyboards are fancy, but any serious typing or work is still better on a real keyboard. iPad works flawlessly with bluetooth wireless keyboard, but who wants to carry an extra device? iPad is too big to hold vertically and type. Landscape typing on screen requires a case which props it up to 30-45 degree angle. This isn't a major problem though, I can easily type long emails on iPad but still prefer a physical keyboard (faster & easier)

Multi-Tasking
Now this changes with new iPad OS later this year. Currently iPad only runs one application at a time i.e. creating a presentation and you have to close Keynote again and again to get pictures or browse the web for content. It seriously impairs productivity.

Lack of Built-in Camera

This certainly isn't a major drawback as most of us carry cell phones with cameras. For others (like my wife) video conferencing as integral part of computing, so it maybe another reason to keep your laptop

The Bottom Line


Like a lot of Apple products, iPad isn't offering anything which isn't available in other forms of computers. However, the way it integrates multi-touch, portability, speed and e-reading in a small device is incredible. It has a tremendous potential in so many ways. In the health-care industry we would likely be able to view X-rays, lab results and full EMR's on iPads in future. We use it already in our patient rounds daily to look up relevant medical literature or drug information.

Ultimately its not about getting everything in one device, its about giving a great user experience and iPad does it very well.

Saturday
Feb202010

Best Drug Databases for iPhone

In the old days Physicians used to have a big thick book on their desk called "Physicians Desk Reference" to reference any drug. It is difficult to remember all the common adverse effects of medications. PDA's are very popular among medical community since it is easy to look up drug information and avoid errors.

With iPhone and App store, we have access to several great drug databases. Here is my list of the best ones:

The Best

UpToDate : (Web App) UpToDate is one of the best medical websites and it has partnered with Lexi-Comp for drug information. Any drug search pulls up Lexi's drug information. Lexi-Comp is one of the most authentic drug databases. It gives a very detailed account of everything including adverse effects of medications with relative percentages.

UpToDate requires a prescription (individual or institutional). It is available currently only as a web application and not as a native iPhone Application, though later is rumored to be released soon.  

Lexi-Comp iPhone Application : Lexi-Comp has individual and instituitional iPhone Applications for drug database. These also require subscription and give access to the same incredible drug database as I mention above in UpToDate section.

Free Applications

Epocrates : Epocrates has been around for a while and has improved over time. It is very basic and is available as a native free iPhone application. A unique feature is pill identification i.e. pill numbers, shape, color can be used to identify any pill without a label. It also has Pill pictures (see left).

It is good for physicians, nurses and even non health care providers for quick knowledge about a medicine including its side effects. However for physicians desiring detailed information, Lexi-Comp and Micromedex (iPhone app coming soon) are better alternatives.

 

Medscape : Free iPhone Application is by WebMD. To me its the best free drug application. Its faster than Epocrates and offers similar information. I particularly like its drug interaction tool.

Medscape application is a lot more than just drug database. It also pulls up WebMD news and has references for a variety of diseases and medical procedures. I'm very impressed with how much this application offers for a free App.

It has a CME section as well. Great interface, user friendly and that makes it a must have medical Application.  

 

Honorable Mentions

Drugs & Medications : Reasonably good for $1

iPharmacy : Also costs $1, but again why pay when a better database is available for free as 'Medscape'

Drugs & Medications: $20. Good reviews on iTunes but I haven't tried it.

Take the Poll below to rate your favorite. If there is a better application, share it in the comments area. 

 

Tuesday
Feb162010

Why Apple is the Future Of Technology

People often think that I'm an Apple fan and has been one always. Actually I only recently started using Apple products. Growing up in South Asia, we were surrounded by Windows running machines. I never saw an Apple computer till I came to US few years ago.

There is no doubt that Windows revolutionized the personal computers back in the 90's. Windows 95 and NT were pretty good, but the later versions compromised the ease of use to complex functionality. A simple task became tougher and tougher. I remember countless nights fixing errors and formatting my system many times. 

Microsoft somehow doesn't get the idea that users want to do things quickly and painlessly. Security has been a major concern with the need for a good anti-virus agent a must. These anti-viruses are never perfect and use system resources. I, however, haven't tried Windows 7 yet and am hoping its better than its predecessors. 

Microsoft's browser Internet explorer has also been left far behind with the likes of Firefox, Safari and Google Chrome. These newer browsers are inherently faster, more secure and versatile. I think Microsoft has to make some major decisions if it wants to retain its position as the biggest software company. 

Apple's biggest advantage is that its a hardware + software company. It makes a world of a difference if you make computer hardware customized to specific tasks and then write softwares for it. Apple's Mac operating system is very basic but does a wonderful job in providing users a trouble free, fast and secure system. First time I used Mac OS X, it took me literally no time to master it. Its so simple to learn and pretty stable. I do not run any anti-virus software since the operating system is relatively immune to viruses and spam. Mac's dock is a great way to have your most frequently running programs easy to access. 

Apple also writes great software for most common tasks like iLife, iWork and iTunes. These are either part of the system or available at very reasonable costs. One thing which needs a little improvement is Apple's mail program. Its very basic and for most professional users Microsoft's Entourage (part of the Office for Mac) is a better alternative. 

Innovation is Apple. Who would have thought that Apple would trump all portable mp3 players by introduction of an iPod? It wasn't even known for creating such devices. Today mp3 player is almost synonymous to an iPod. I gifted an iPod nano to my wife a few years ago and since then we have purchased around 4 others. If you look around, you would see 1 in 5 people around you has one. People give credit to Steve Jobs for such brilliant ideas, but in reality most of Apple's greatest products like new Macbooks, iMac, iPods and iPhone are all the brilliance of Jonathan Ive. He designed these revolutionary products which we all enjoy everyday. 

If I look back, June of 2007 is when my life suddenly changed and so did for so many else. iPhone was launched and all of a sudden we were doing things on our phones that we had never imagined before. As a physician I think it made me a much better doctor. I was able to pull up drug information, check medical literature and explain things to my patients better than I had ever done before. Practicing medicine in hospitals is all about communication and its so easy to communicate with other physicians. iPhone camera is good for taking pictures of skin lesions for future follow-up. 

As an Intensivist (ICU doctor) I'm very excited about Airstrip's 'Critical Care' application (not yet FDA approved) which will allow me to see my patient's bedside monitors on the iPhone in real time. I wouldn't have to wait to be paged when one of my patient suddenly develops Ventricular tachycardia. I hope someone develops an Application for hospital paging system, so I don't have to carry multiple pagers. A lab 'push' notification system for critical care labs will be very useful too. 

Apple's iPad has had mixed reviews so far, with excitement and disappointment. I find it hard to imagine how something running the same OS and softwares as an iPhone but having a bigger screen, will fail. It would simply enhance the iPhone experience by a larger LCD screen, full screen multi-touch and faster speed. 

iPad is not meant to replace desktops, laptops and smart phones. Having all the above three, I still think there is a need for another gadget that is lighter than Macbook Pro and would be ideal for traveling, e-book reading and maybe for use at my hospital. I have not met anyone who has used an iPad and hasn't been impressed with its speed and functionality. 

Unless Apple drastically changes its ways, I think it will continue to lead the computer, music/media and smart phone industry. The secret lies in company's ability to introduce products which are simple to use, fast, reliable and have the best design. Some say their products are expensive, I disagree. I purchased my Macbook Pro 3 years ago, it still works perfectly whereas a windows laptop (HP Pavilion) for me lasted only 1.5 years. You pay the price for a superior hardware, great OS + software environment and products that simply last longer. This is why Apple is and will be the future of technology.