April 28th, 2014
Selections from Richard Lehman’s Literature Review: April 28th
CardioExchange is pleased to reprint this selection from Dr. Richard Lehman’s weekly journal review blog at BMJ.com. Selected summaries are relevant to our audience, but we encourage members to engage with the entire blog.
NEJM 24 Apr 2014 Vol 370
High vs. Low BP Target in Patients with Septic Shock (pg. 1583): The New England Journal has put so many good articles online first lately that I’ve left myself with thin pickings this week. This big French study of blood pressure targets in septic shock has been on the website for some weeks, and I didn’t comment on it sooner because I have only ever treated a single patient for septic shock in my working life. At the time I was a house officer on a urology ward. Despite my best efforts over a day and a night, he survived. Physiological emergencies cause a flow of adrenaline: there is an urge to do everything possible. A mean blood pressure of 65mm Hg doesn’t seem enough to keep anyone’s kidneys working, so this trial used adrenaline (epinephrine) or noradrenaline to push it up to a target of 80 or 85 in the intervention group. But these patients did no better than those whose BPs stayed at 65 or 70.
JAMA 23/30 Apr 2014 Vol 311
Effect of the Use of Ambulance-Based Thrombolysis on Time to Thrombolysis in Acute Ischemic Stroke (pg. 1622): Reading this week’s JAMA makes me think we need better outcomes research in stroke medicine. Two papers in this neurology-themed issue are devoted to systems changes aimed at reducing event-to-needle times for stroke; i.e. shortening the time between the actual event and the moment when tissue plasminogen activator reaches the cerebral circulation. One moment the leather-clad young RAF pilots are lounging in the sunshine drinking tea and smoking their pipes: the next moment the siren sounds and they are racing to their Spitfires to shoot down bandits. Never did so many owe so much to so few. But is this really true of crash teams for stroke? In this PHANTOM-S trial, ambulances in Berlin were set up with their own CT scanners, at a cost of a million euros each, and manned by teams trained to give tPA. Berliners giving a history suggesting Schlaganfall would rapidly hear the siren of an approaching Ambulanz; they would be whisked into the scanner; images would be relayed to waiting radiologists; and if there was clot, the tPA would go in before the vehicle reached the hospital door. This happened some weeks and not others. In the active weeks, alarm-to-treatment time was reduced by 25 minutes. Although the trial went on for 18 months and covered a catchment of 1.3 million people, it could not demonstrate any improvement in mortality. Never did so few owe so little to so many?
Door-to-Needle Times for Tissue Plasminogen Activator Administration and Clinical Outcomes in Acute Ischemic Stroke Before and After a Quality Improvement Initiative (pg. 1632): Meanwhile in the USA Gregg Fonarow and colleagues were trying out a new in-hospital protocol for reducing door-to-needle time in ischaemic stroke. All Get With The Guidelines (GWTG)—Stroke hospitals were encouraged to participate and each hospital received a detailed tool kit, including the 10 key strategies, protocols, stroke screening tools, order sets, algorithms, time trackers, patient education materials, and other tools. This massive effort across more than a thousand hospitals resulted in a reduction of median door-to-needle time from 77 to 67 minutes, and was associated with a before-and-after reduction in all-cause in-hospital mortality from 9.93% to 8.25%, and a rise of 5% in the number of patients discharged to their own homes. Note that we cannot know how much of this was due to any part of this complex intervention.
JAMA Intern Med April 2014 Vol 174
Different Time Trends of Caloric and Fat Intake Between Statin Users and Nonusers Among U.S. Adults (OL): Since taking a statin, I have got fatter. I am part of a trend, according to an analysis of data from the National Health and Nutrition Examination Survey, 1999 through 2010 (N.B. I’m keeping the American “through” here because it is a useful construction). “Caloric and fat intake have increased among statin users over time, which was not true for nonusers. The increase in BMI was faster for statin users than for nonusers.” So far, so incontestable: this was a thoroughly conducted survey. But now for the speculation: “Efforts aimed at dietary control among statin users may be becoming less intensive. The importance of dietary composition may need to be reemphasized for statin users.” We’ve no idea whether this is actually true of this population, let alone individuals within it. It certainly isn’t true for me. I’ve always just eaten what I enjoy: I just need more exercise.