A while back I linked a study demonstrating that antibiotics, when prescribed for bronchitis, prevented pneumonia. Now comes this study in Chest showing that antibiotic treatment in the ambulatory setting for “lower respiratory tract infections” (essentially bronchitis) is associated with decreased mortality and decreased hospitalization rates. An accompanying editorial points out the methodologic problems, suggests alternative explanations for the findings and calls for more research.
Friday, July 10, 2009
Rethinking the anti-antibiotic dogma
Update in Anesthesia---a virtual physiology text
Although posted as an educational reference for anesthesiologists this is an excellent resource for anyone involved in the care of critically ill patients.
Thursday, July 09, 2009
ECMO for refractory respiratory failure?
It may be beneficial in selected adult patients according to this paper in the Archives of Surgery. It would be indicated and available in only a very select group of patients.
Diabetic retinopathy and cardiac dysfunction
Lifetime Medical Television
Every Sunday in the late 1980s and early 1990s Lifetime Television, the network for women, became Lifetime Medical Television, the network for physicians. Back in the days before the Web this was the only option for viewing presentations on medical topics right from the comfort of home. I was glued to the set all day many Sundays. I took notes. When I couldn’t watch I set my VCR. There were few if any accredited CME offerings but the content was excellent. The pharma ads, directed to physicians, were attractive and clever, much better than the DTC ads of today. In the videos that follow is a montage of promos, openings and ads with shots of some of LMT’s all star cast. I spotted HJ Swann, Robert Rakel, Bernie Lown and Roger Bone, all of whom were frequent hosts.
Tuesday, July 07, 2009
Cardiologists---not so greedy after all?
After I challenged Doug Bremner for claiming that all angioplasty (by which he meant, primarily, coronary stenting) was useless and should be eliminated from future health care budgets he updated his post thusly:
[...Even so they are still estimated to be about 1/3 which is too many and some cardiologist lately have gone to jail for performing PCI on people with little or no heart disease. So my initial statement that 25 billion dollars could be saved is not correct. It is more like, um, 8 billion.]
So the question Dr. Bremner and I now have on the table is not whether to cut out all stent procedures, but whether one third could be slashed from the budget. We're getting closer but we need to examine a little more rigorously what the clinical trials said about that third. They are the folks who have stable coronary disease. Neither the BARI 2D nor the COURAGE trial showed a reduction in major events with stenting as compared to medical therapy. But what else was learned from the two studies? First, both trials addressed the lowest risk stable angina patients. If the patients were too high risk they simply were not included for study. Second, many medically managed patients in both groups crossed over to revascularization---around 30% in courage and around 40% in BARI 2D. In other words many patients failed medical therapy. That's not to say it was inferior to PCI, because many PCI patients had to have repeat revascularizations. It is to say that many stable CAD patients initially managed medically will develop legitimate indications for unblocking their arteries sooner or later. In fact, the authors of the very paper Dr. Bremner was referring to (the BARI 2D trial, or at least I think it was—Dr. Bremner didn't provide the citation) said this in their discussion section:
It is important to note that all the patients who were assigned to receive medical therapy underwent careful clinical monitoring, and 42.1% had changes in the clinical course that called for later revascularization during 5 years of follow-up. In clinical practice, the initial treatment strategy for a patient with diabetes and coronary disease rarely remains constant over a 5-year period.
In the real world these stable patients get stented for better angina relief, which study after study shows is a benefit of revascularization even if major events are not reduced. So when Dr. Bremner calls for a denial of PCI for these patients he can't base it on evidence. He has to make a value judgment about whether the better quality of life these patients would experience is worth it. Will Obama's “comparative effectiveness” panels make similar value judgments?
Now if Dr. Bremner will concede that some stable angina patients have a legitimate need for PCI for symptom relief not afforded by optimal medical therapy then we can reduce this discussion down to the real question: how many of those revascularizations are truly unnecessary? How many cardiologists yield to the oculostenotic reflex and stent lesions just because they're there and because they can, in stable minimally symptomatic patients? There's little doubt such non-evidence based stenting takes place, but we don't know how much, do we? Without such numbers how can Dr. Bremner begin to estimate they monies potentially saved by eliminating non-evidence based PCI?
Maybe Dr. Bremner's problem is that he uses the same EBM pyramid as Marcia Angell. He seems to have gotten his information from this article in Business Week. Lets hope the folks in the Obama administration who evaluate comparative effectiveness spend a little more time reading the NEJM.
The new evidence pyramid
Monday, July 06, 2009
Consensus Algorithm for medication choices and titrations in DM 2
Bundle branch blocks and fascicle blocks
Classification, diagnosis and clinical implications reviewed in the American Journal of Emergency Medicine.
Another tool to help determine the duration of anticoagulation
Sunday, July 05, 2009
More on Salmonella and mycotic aneurysms
Dr. Sanders commented:
I published a similar case in a very different forum, the New York Times Magazine. I think the case gives a sense of how this might unfold in real time...
The patient presented with fever, back pain and confusion. The resolution of the case:
The radiologist called as soon as the scan was done. There was no abscess on the spinal cord, but the patient's aorta had weakened and the pressure of the blood flow had caused the tube to bulge like a worn garden hose. He was also concerned that this weak spot had sprung a leak....
...the patient was rushed to the operating room.
The left side of his abdominal cavity was filled with blood, and parts of the normally thick tube of the aorta were in tatters. The surgeon quickly replaced the shredded portion of the aorta and sent the dissected bits to the lab. Under the microscope, it became clear what had caused all of this man's symptoms. The tissue had been invaded by a bacterium -- an unusual type of salmonella, one usually found in uncooked pork. This bug -- salmonella choleraesuis...
So what is Salmonella choleraesuis? I have always been confused by the taxonomy of Salmonella. In my post I mistakenly said:
Species associations, according to the brief review, tend to be enteritidis and typhimurium.
Well, after a little digging it turns out that those aren't species. They're serotypes, also known as serovars. (I plan to make the correction). Salmonella choleraesuis is indeed a species. One popular classification denotes this species, which contains many serotypes and is also called Salmonella enterica, as the one which accounts for virtually all human Salmonella infections. The patient in the New York Times report apparently had an unusual organism acquired from uncooked pork, so maybe the name choleraesuis, referring to pigs, denotes something more specific in another classification. I've consulted Cecil, Robbins pathology and a micro textbook and am still more than a little confused.
That's all beside the point of Dr. Sanders's article but one distinction does bear emphasis. This situation, bacteremia causing vascular infection complicated by mycotic aneurysm, is not the same thing as enteric fever, aka typhoid fever.
Image: Salmonella invading cultured human cells. Public domain. Source Wikipedia.
Anesthesia Tutorial of the Week
Learning resources on a variety of topics in anesthesiology and critical care.
Witnessed collapse, two rescuer CPR, arrival of AED
Notice how long she fiddled around checking for air movement and getting a barrier device to give the two initial breaths. The healthy looking guy who collapsed probably had greater than 95% of his hemoglobin saturated with oxygen. Why not dispense with the rescue breaths? They only delayed the initiation of compressions.
But the sequence was performed in accordance with the AHA guidelines which can be accessed here.
At the University of Arizona for years they have been teaching it this way.
The perfect megacode
AHA instructional video, V fib arrest, BLS transitioning to ACLS
Keep in mind the emerging controversy about rescue breathing in adult arrest of suspected cardiac origin.
Full text ACLS guidelines in Circulation here.
Saturday, July 04, 2009
Stent placement for atherosclerotic renal artery stenosis
Not beneficial in terms of either renal function or blood pressure in this multicenter randomized trial. Stenting was associated with complications. According to an editorial note the study was underpowered.
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