Tuesday, January 29, 2008

Stroke Treatment

I have been very interested in the recent advances in targeted therapy using ultrasound contrast agents (bubble technology). It has been known for a few years that micro bubbles filled with gas can be safely administered IV to image many organs in the body using conventional sonography and harmonic imaging.
The idea of filling these bubbles with other medications along with the gas, and adding proteins to allow the bubbles to target specific tumors or clots is not new, and research continues along these lines. I am hopeful that in the near future, Sonographers may be intimately involved in treatment as well as diagnosis of conditions likely to respond to this form of targeted delivery.
As an American, I am very disturbed by the FDA's decision to black box Definity and Optison; agents used to opacify the heart for wall motion abnormalities. In the EU, ultrasound contrast has been safely used for years for evaluating liver lesions, trauma, echocardiography, and vascular imaging. Contrast is only approved in the USA for LVO (left ventricular opacification). I find this extremely disturbing. Many cardiologists are protesting this black box warning because of flawed evidence concerning a very minor number of events where contrast was a party to the treatment or evaluation of the patient.
I register this protest because the potential life saving benefits that ultrasound contrast has to offer outweighs the potential negative side effects. The FDA has made a very poor case regarding the black box warning, and the ultrasound community is responding. The potential future benefits of contrast in the ED, and in routine imaging are limitless in my opinion.
Uses in the EU include:
* Trauma and organ damage with bleeding due to trauma
* Ischemia to almost any organ
* Perfusion surveillance (kidney transplants, etc)
* Torsed testicles or ovaries
* Lesion categorization in the liver and other organs
* Differentiation of clot from living tissue/tumor
These are routine uses in the EU. Why the hell is the USA balking at adding contrast to our vast arsenal of life saving drugs? My guess is political and financial manipulations. It is always about the money.
Here is an interesting discussion about one companies struggle to produce an agent with potential to treat stroke patients:
ImaRx Therapeutics, Inc. recently issued a progress report on its TUCSON (Transcranial Ultrasound in Clinical SONoLysis) United States Food and Drug Administration clinical trial involving patients with acute ischemic stroke. TUCSON is a randomized, placebo controlled clinical trial to evaluate the safety, tolerability and effectiveness of a ImaRx’s microbubble-based agent MRX-801. Administration of MRX-801 and ultrasound imaging is being used as an adjunctive therapy to the conventional method of administration of tissue plasminogen activator (tPA) for treatment of two different cohorts of patients with acute ischemic stroke.
Take care,

Saturday, January 12, 2008

Job Security

Greetings gentle readers,
I saw patients yesterday for the first time this year at a great hospital. I had a horrible case that I will will never forget involving a kindergarten teacher. Tune in next week for that one.
Right now I want to give "Thanks" for obesity.
"Self indulgence is the product of prosperous society" I paraphrase one writer who tips the scales over 350 pounds.
As a Sonographer, I say it is job security. How many times are we called to the ED to R/O DVT, or gallstones in the obese? We may grumble, but it pays the mortgage. The following link describes one person's latest diatribe about the greatness of being obese.
WASHINGTON (AFP) - As adult obesity balloons in the United States, being overweight has become less of a health hazard and more of a lifestyle choice, the author of a new book argues.
Burps... Gimme a break
"Obesity is a natural extension of an advancing economy. As you become a First World economy and you get all these labor-saving devices and low-cost, easily accessible foods, people are going to eat more and exercise less," health economist Eric Finkelstein told AFP."
As a sonographer, I know that part of my job is taking care of the obese. I never council people on their eating habits because that is not my job. I must point out that from an ergonomic point of view, treating the obese is a challenge to my aging body. The techniques of imaging the "TDS" patients are much different from other studies. We all groan when reading the height and weight of a patient on a request: 380 pounds, 5'1", and wish we could slap that request back in the box.
Never you mind though, as the post says, obesity is here to stay. I call it job security.

Friday, January 4, 2008

This kind of emergency is too common...

The following is from an emergency physicians BLOG posting which happens quite a bit in the ED.
" Last night in the ER...
....was very busy. And "busy" in a good way. Lots of codes and respiratory distress. Not so much "weak and dizzy" and "TMD (todo me duele)". The kind of night that reminds you why you chose emergency medicine as a specialty, and not primary care.
Anyhoo, there was this one guy...
A 36 yo morbidly obese Samoan man with a past medical history of diabetes, hypertension, and has lots of 'bad habits', was brought in by paramedics complaining of chest pain which started 10 minutes prior to the 911 call. He was sitting on the sofa watching reruns on TV when he suddenly felt a tightening in his chest. He got up to get a cup of water, and the pain got worse. Then he felt weak and lightheaded so he sat down on the nearest chair. He then called for his wife, and she took one look at him and called 911.
In the field EMS established a very tiny finger IV (because 'his veins could not be accessed secondary to excessive adipose tissue.' i.e. he was too fat). They gave him an aspirin, and after he denied using Viagra, a nitroglycerin sublingual. Immediately thereafter his blood pressure dropped from 150s systolic to low 80s. He became very diaphoretic (lots of sweating), and short of breath.
Upon ED arrival the patient was alert and oriented, but very agitated sitting upright on the gurney, in moderate/severe respiratory distress. He weighed about 450 pounds, and was extremely diaphoretic, and c/o worsening SOB. EKG could not be obtained by the paramedics because the stickers wouldn't stick to the body for all the sweat. Also, the patient was so agitated and anxious that a good reading couldn't be obtained even when the EKG leads were held in place by assistants.
In the ED we attempted to obtain an EKG...for over 20 minutes. We cannot make a diagnosis of acute MI requiring thrombolytics if we cannot obtain an EKG. Afterall, there are other deadly causes of chestpain, some of which absolutely cannot be treated with thrombolytics (or else you kill the patient). It's one thing for someone to die. It's another thing to kill them. So we worked to obtain that EKG...over, and over, and over, and over again.
During this time we worked to establish a better IV with ultrasound guidance."
Here is where I need to jump in. Ultrasound is very useful for line placement and other procedures. I teach ED physicians line placement procedures at my school. We practice on phantoms instead of real human volunteers, and the procedure works well for subclavians, and other veins when obesity or other issues arise making placement difficult.
I would also be called in to perform an echocardiogram in a situation like this (where getting the EKG is problematic) to look at basic cardiac function, and try to see if there were any heart wall motion abnormalities. Granted in this patient the echo would not be very diagnostic, but it would be worth a try. I also train ED physicians to perform basic echocardiography useful in cases like this.
More often than not, I would also be called upon to look for DVT if the patient were in respiratory distress, but even this procedure is difficult in the morbidlly obese. Just some thoughts for a cold January day. To continue with the article please click on the link below.
Have a great day,