Tuesday, April 11, 2006

Pet Peave: popular press articles that don't link to their sources

The New York Times Online has an article titled 'Blasting of Kidney Stones Has Risks, Study Reports'. The article mentions the journal (The Journal of Urology) and the first author (Dr. Amy Krambeck). Would it have been so difficult to link to the abstract in the online version?

" SWL has revolutionized the management of nephrolithiasis and it is a preferred treatment for uncomplicated renal and proximal ureteral calculi. Since its introduction in 1982, conflicting reports of early adverse effects have been published. However, to our knowledge the long-term medical effects associated with SWL are unknown. We evaluated these adverse medical effects associated with SWL for renal and proximal ureteral stones.

Materials and Methods
Chart review identified 630 patients treated with SWL at our institution in 1985. Questionnaires were sent to 578 patients who were alive in 2004. The response rate was 58.9%. Respondents were matched by age, sex and year of presentation to a cohort of patients with nephrolithiasis who were treated nonsurgically.

Results
At 19 years of followup hypertension was more prevalent in the SWL group (OR 1.47, 95% CI 1.03, 2.10, p = 0.034). The development of hypertension was related to bilateral treatment (p = 0.033). In the SWL group diabetes mellitus developed in 16.8% of patients. Patients treated with SWL were more likely to have diabetes mellitus than controls (OR 3.23, 95% CI 1.73 to 6.02, p <0.001). Multivariate analysis controlling for change in body mass index showed a persistent risk of diabetes mellitus in the SWL group (OR 3.75, 95% CI 1.56 to 9.02, p = 0.003). Diabetes mellitus was related to the number of administered shocks and treatment intensity (p = 0.005 and 0.007).

Conclusions
At 19 years of followup SWL for renal and proximal ureteral stones was associated with the development of hypertension and diabetes mellitus. The incidence of these conditions was significantly higher than in a cohort of conservatively treated patients with nephrolithiasis. "

Before people panic (or call lawyers), please consider that this is one study, retrospective, with a 59% response rate, using older lithotripsy technology (as the NYT article points out, modern machines use less energy and are able to focus it more precisely.



Sunday, March 5, 2006

Vaccines, Mercury, and Autism--New Data

My smart wife tells me that this article is really big news: Early Downward Trends in Neurodevelopmental Disorders Following Removal of Thimerosal-Containing Vaccines (pdf). I've quoted the entire abstract below:

"Contemporaneously with the epidemic rise in neurodevelopmental disorders (NDs), first observed in the United States during the 1990s, the childhood immunization schedule was expanded by the U.S. Centers for Disease Control and Prevention (CDC) to include several additional thimerosal-containing vaccines (TCVs). On July 7, 1999, a joint recommendation was made by the American Academy of Pediatrics (AAP) and the U.S. Public Health Service (PHS) to remove thimerosal from vaccines. A two-phase study was undertaken to evaluate trends in diagnosis of new NDs entered into the Vaccine Adverse Event Reporting System (VAERS) and the California Department of Developmental Services (CDDS) databases on a reporting quarter basis, from 1994 through 2005. Significant increasing trends in newly diagnosed NDs were observed in both databases 1994 through mid-2002. Significant decreasing trends in newly diagnosed NDs were observed in both databases from mid-2002 through 2005. The results indicate that the trends in newly diagnosed NDs correspond directly to the expansion and subsequent contraction of the cumulative mercury dose to which children were exposed from TCVs through the U.S. immunization schedule."

The big news is the last sentence: trends in newly diagnosed ND's [ed: autistic spectrum disorders] correspond directly to the expansion and subsequent contraction of the cumulative mercury dose to which children were exposed from TCVs through the U.S. immunization schedule.

There were suspicions during the time that vaccines contained Thimerisol that it was responsible for an associated increase is the so-called autistic spectrum disorders. The suspicion was based on reports of increases in autism in the community. These were explained away by the observation that diagnosis had become much better during the same time period and the fact that scientific data supporting such a link were of very poor quality. Nonetheless, many parents chose to forgo immunization of their children out of concern that vaccination would increase their risk of autism or related disorders. Skipping immunization did not increase their risk of infectious disease because of herd immunity, up until enough members of a population are unprotected and disease can once again propagate among the non-immunized.

There are ongoing flame wars among blogs about this issue, but his article should cause many of those involved to rethink their position.



Tuesday, February 28, 2006

MAC: Maximum Anesthesia Care?

Injury and Liability Associated with Monitored Anesthesia Care: A Closed Claims Analysis.:

"Analysis of closed malpractice claims associated with monitored anesthesia care showed a high severity of patient injuries, comparable to claims associated with general anesthesia. Severe respiratory depression from an absolute or relative overdose of medications used for sedation was the most common damaging mechanism. Burn injuries due to fires from the use of electrocautery in the presence of supplemental oxygen represented a surprisingly high proportion of all monitored anesthesia care claims (17%)."

[Via Anesthesiology]



Tuesday, February 7, 2006

Smoking Cessation Before Surgery Encouraged

"According to a new comprehensive review of existing studies in the February issue of Anesthesiology, surgical patients who are nonsmokers, or who stop smoking prior to surgery, tend to fare better in the recovery period than smokers. This is in addition to the benefit seen during the actual surgery, when anesthesia is safer and more predictable in nonsmokers due to better functioning of the heart, blood vessels, lungs and nervous system.

Add to all of this another bonus: smokers who have quit around the time of surgery may have fewer problems with nicotine withdrawal after the operation than they would have if they had tried to quit at other times. This may be due to medications and therapies commonly used during surgery and recovery, which may suppress nicotine withdrawal symptoms. Even if patients do have problems with nicotine withdrawal after surgery, they can safely receive help such as nicotine patches."

I think this is noteworthy because, in terms of complications, we used to think that one would need to quit smoking for at least six weeks before surgery for there to be any benefit. Though that may still be true, this review seems to indicate that if someone were to quit around time of surgery, their chances of success are better.

[via Newswise]


Sunday, January 1, 2006

Prilosec and C.Diff?

Reading a blog far afield of medicine, then to the Washington Post, I cam across an interesting nugget on C. Diff. The JAMA published an article on December 21, 2005 titled Use of Gastric Acid–Suppressive Agents and the Risk of Community-Acquired Clostridium difficile–Associated Disease [abstract]. In two population-based case-control studies:

" The incidence of C difficile in patients diagnosed by their general practitioners in the General Practice Research Database increased from less than 1 case per 100 000 in 1994 to 22 per 100 000 in 2004. The adjusted rate ratio of C difficile–associated disease with current use of proton pump inhibitors was 2.9 (95% confidence interval [CI], 2.4-3.4) and with H2-receptor antagonists the rate ratio was 2.0 (95% CI, 1.6-2.7). An elevated rate was also found with the use of nonsteroidal anti-inflammatory drugs (rate ratio, 1.3; 95% CI, 1.2-1.5). "

A teleconference is planned for January 18th to discuss these results as part of the new Author-in-the-room series.



Saturday, December 24, 2005

Mythbusters: On Being An Organ Donor

The Iowa Charles City Press has a nice piece titled Myth busters on being an organ donor which addresses the following myths:

"Myth: Doctors will not try to save my life if they know I want to be a donor.
Myth: People can recover from brain death.
Myth: Minorities should refuse to donate because organ distribution discriminates by race.
Myth: The rich and famous on the U.S. waiting list for organs get preferential treatment.
Myth: I am too old to donate organs and tissues.
Myth: My family will be charged for donating my organs.
Myth: Donation will disfigure my body.
Myth: Organs are sold, with enormous profits going to the medical community.
Myth: Marrow donation is painful. "

Please read and pass along...and 'yes' I'm an organ donor.



Thursday, December 22, 2005

More proof: people don't change (doctors are people)

Disciplinary Action by Medical Boards and Prior Behavior in Medical School

"Conclusions In this case-control study, disciplinary action among practicing physicians by medical boards was strongly associated with unprofessional behavior in medical school. Students with the strongest association were those who were described as irresponsible or as having diminished ability to improve their behavior. Professionalism should have a central role in medical academics and throughout one's medical career."

Another report of H5N1 resistance to Tamiflu

NEJM Case Report: Oseltamivir Resistance during Treatment of Influenza A (H5N1) Infection [free full text]

Tight glycemic control in Type I diabetes reduces risk of cardiovascular disease

NEJM:Intensive Diabetes Treatment and Cardiovascular Disease in Patients with Type 1 Diabetes

"Results During the mean 17 years of follow-up, 46 cardiovascular disease events occurred in 31 patients who had received intensive treatment in the DCCT, as compared with 98 events in 52 patients who had received conventional treatment. Intensive treatment reduced the risk of any cardiovascular disease event by 42 percent (95 percent confidence interval, 9 to 63 percent; P=0.02) and the risk of nonfatal myocardial infarction, stroke, or death from cardiovascular disease by 57 percent (95 percent confidence interval, 12 to 79 percent; P=0.02). The decrease in glycosylated hemoglobin values during the DCCT was significantly associated with most of the positive effects of intensive treatment on the risk of cardiovascular disease. Microalbuminuria and albuminuria were associated with a significant increase in the risk of cardiovascular disease, but differences between treatment groups remained significant (P≤0.05) after adjusting for these factors."



Thursday, November 24, 2005

NEJM: The Origins of Pandemic Influenza--Lessons from the 1918 Virus

The Origins of Pandemic Influenza--Lessons from the 1918 Virus [free full text]

"...monitoring of the sequences of viruses isolated in instances of bird-to-human transmission for genetic changes in key regions may enable us to track viruses years before they develop the capacity to replicate with high efficiency in humans. Knowledge of the genetic sequences of influenza viruses that predate the 1918 pandemic would be extremely helpful in determining the events that may lead to the adaptation of avian viruses to humans before the occurrence of pandemic influenza. We could then conduct worldwide surveillance for similar events involving contemporary avian viruses. "



Friday, June 17, 2005

Review: Chronic Stable Angina

The NEJM has a very nice review article titled Chronic Stable Angina.
"It is useful to classify therapeutic drugs into two categories: antianginal (anti-ischemic) agents and vasculoprotective agents. Although medications for angina are widely used, therapy to slow the progression of coronary artery disease, to induce the stabilization of plaque, or to do both is a newer concept and these forms of treatment are underprescribed."



Saturday, June 11, 2005

NEJM -- Two-Years after Endovascular Repair of Abdominal Aortic Aneurysms

Very interesting Dutch study on Two-Year Outcomes after Conventional or Endovascular Repair of Abdominal Aortic Aneurysms in the NEJM. This is the first study to look at prolonged survival (2 years) after placing a tube stent into a dilated abdominal aorta (aneurysm) to prevent rupture. We know that early survival is better with the stent vs. open repair. But what about after the first month? This study shows that after two years, the survival is about the same:

" The cumulative rates of aneurysm-related death were 5.7 percent for open repair and 2.1 percent for endovascular repair. This advantage of endovascular repair over open repair was entirely accounted for by events occurring in the perioperative period, with no significant difference in subsequent aneurysm-related mortality. "

To try to explain this, the authors discuss the following possibilities:

"There may be two possible explanations for the convergence of survival curves in our study. One is that patients who have survived the stress of open repair may be somewhat less likely to die in the first few months after surgery than patients who have undergone endovascular repair, since the latter group has not been subjected to a conventional surgical procedure.
...[snip]...
Another possible explanation for the convergence of survival curves is the failure of endovascular repair to prevent rupture of the aneurysm."

I wonder about a third possibility: did patients having an open repair make lifestyle change that those having the less stressful endovascular repair did not? I ask because one of the frustrations in taking care of patients with vascular disease is the extent to which they do NOT change their eating or smoking habits and so need to come back for yet another procedure at yet another time. The study lists baseline characteristics (55% smoked in the open group and 64% smoked in the endovascular repair group. Half in each group had hyperlipidemia), but no characteristics are given at the two year point. Can the lack of survival advantage after endovascular repair be explained by differences in rates of smoking, hyperlipidemia, and other risk factors at two years?

And thanks to the power of Google, I've sent the lead author an e-mail with just this question!

8: 00 A.M., the lead author writes back:

"We haven't studied that in this 2-year analysis but it is part of our long-term study."

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