Commentary by Michael Poles MD, Associate Editor, Clinical Correlations
Another week, another set of shortcuts, so let’s take a quick look around the world of medical happenings. A quick trip into the strange. The blogosphere presented the story of Mr. Paul Karason. Why did we hear about Mr. Karason? Well, he is blue. No, not sad, but really blue. His skin is tinged blue from chronic usage of colloidal silver as an alternative medicine remedy. While completely unproven, some people use colloidal silver as a panacea, but especially for prophylaxis against infection. Elsewhere, we learned of the impregnation of Jamie Lynn Spears. Ms. Spears is Britney Spears’ sister, and while her pregnancy should be completely unimportant to the world, it highlights the very important problem of teen pregnancy; Ms. Spears is only 16 years old, and as we know, teen pregnancy continues to be a major social problem. I would therefore like to use this as a segue into a short mention of abstinence-only teaching of sex-ed. Over the years, we have learned of multiple studies that provided evidence that abstinence-only teaching, as supported by the present administration, is ineffective. Thankfully, there are now 14 states that are refusing abstinence-only funding from the federal government and, are instead teaching comprehensive sex-ed in a more scientifically-based and more effective manner.
Ok, out of politics and into the journals. The Annals of Internal Medicine provides us with a recommendation statement on Screening for Carotid Artery Stenosis by the U.S. Preventive Services Task Force. In this recommendation, they acknowledge that although stroke is a leading cause of death and disability in the United States, a relatively small proportion of strokes is due to carotid artery stenosis. The USPSTF therefore recommends against screening for asymptomatic carotid artery stenosis (without neurologic signs or symptoms, including a history of TIAs or stroke) in the general adult population. When screening is required, the most feasible test for severe stenosis is duplex ultrasonography. So how does this compare with the recommendations from other groups? In 2006, the American Heart Association/American Stroke Association released similar recommendations. Likewise, this year, the American Society of Neuroimaging also recommended against screening in unselected populations but advised that screening of adults age 65 years or older with 3 or more cardiovascular risk factors should be considered. In comparison, the Society for Vascular Surgery recommended ultrasonography screening for individuals age 55 years or older with cardiovascular risk factors, such as a history of hypertension, diabetes mellitus, smoking, hypercholesterolemia, or known cardiovascular disease.
JAMA provides us with a randomized controlled trial comparing Ventilation-perfusion scanning and CT pulmonary angiography in the evaluation of patients with suspected pulmonary embolism. The authors performed this noninferiority study at 4 Canadian and 1 US hospital and included 1417 patients with likely acute pulmonary embolism. The primary outcomes were the subsequent development of symptomatic PE or proximal DVT 3 months after initial testing in patients in whom pulmonary embolism had initially been excluded. The authors found that 19.2% in the CT angiography group and 14.2% in theV/Q scan group were diagnosed as having PE in the initial evaluation period. Of those in whom PE was considered excluded, 0.4% randomized to CT angiogram and 1.0% who received a V/Q scan developed venous thromboembolism in follow-up. They therefore concluded that CT angiogram was not inferior to V/Q scan in ruling out acute PE. However, significantly more patients were diagnosed with pulmonary embolism using CT angiography.
Finally, in an article published by the Lancet, we hear that bowel purging with polyethylene glycol or sodium phosphate may not be necessary before bowel surgery. The authors randomized 1431 patients who were going to have elective colorectal surgery to either receive mechanical bowel preparation or not. They found that the rate of anastomotic leakage did not differ between groups; leakage occurred in 4.8% patients who had mechanical bowel preparation and 5.4% in those who did not. Still, patients who had mechanical bowel preparation had fewer abscesses after anastomotic leakage than those who did not. The authors therefore suggest that we can safely give up purging before colorectal surgery and allow those patients to have a normal meal on the day before the operation.