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… We plan to cover 2 articles in this week’s update. Here are their comments in full.

Two recent articles in JACC talk about coronary artery calcium. Be sure to hear the summaries in Update 6 later this week. We asked the lead author, Dr. Jim Min and our own Dr. David Maron for their opinions about this. One of these studies would seem to support and one call into question the following recommendation of the American College of Cardiology and American Heart Association that states: �For the symptomatic patient, exclusion of measurable coronary calcium may be an effective filter before undertaking invasive diagnostic procedures or hospital admission. Scores <100 are typically associated with a low probability (2%) of abnormal perfusion on nuclear stress tests, and 3% probability of significant obstruction (= 50% stenosis) on cardiac catheterization.� It seems both the cardiologists we spoke to are of the same mind, however.

Keeping Up: “In JACC this week, you found that progression of CAC score from zero to > 0 took an average of four years. This study was done on asymptomatic patients. If a symptomatic patient comes to the ED, has negative serial ECGs and biomarkers, and a CAC score of zero within the past four years, would you feel comfortable sending that person home without further stress testing? An article in press in Annals of (see ) found that a CAC score of zero done at presentation in symptomatic patients safely predicts a very low risk group safe for discharge. Can the results of your study be applied in this way yet, or should we wait for ED-based studies that specifically address this question?”

Dr. Min: “I would caution folks to not extrapolate our findings to the ED acute chest pain patients, as prior studies have demonstrated a non-negligible rate of obstructive stenosis in these pts despite a zero calcium score (10-15%). I think that contrast-enhanced CT angiography would be more definitive, or else whatever is standard-of-care at the practicing site (e.g. nuclear stress testing).”

Dr. Maron: “A score of zero does not guarantee the absence of disease, so I would NOT rely on a CAC score of zero to discharge a patient (even though a score of zero has a great prognostic value). There are too many reports of people with zero scores who go on to have ACS that it is not reliable. I couldn�t say it better than this paper does [referring toGottlieb I et al. The Absence of Coronary Calcification Does Not Exclude Obstructive Coronary Artery Disease or the Need for Revascularization in Patients Referred for Conventional Coronary Angiography. J Am Coll Cardiol February 2010;55:627�34, which will be discussed this week in Update 6].

Looks like we need to be cautious about how we use coronary artery calcium scoring in the ED setting! Better listen to Update 6 coming up this week to hear both articles!

… All his comments on his recent JAMA article would not fit in the Update 5 audio. Check them out here!

Keeping Up: What do you see as the most important advantage for emergency physicians in using lactate clearance over ScvO2 as the third tier of goal-directed therapy?

Dr. Jones: “Our view of the importance of our findings is that lactate clearance is a much more generalizable and readily available method of assessing oxygen delivery. This will allow physicians who don�t have access to specialty monitoring such as ScvO2 to have a reliable method to assess oxygen delivery. Additionally, our experience is that the use of the ScvO2 catheter often takes the focus off the patient due to the process and trouble shooting required by the catheter.”

Keeping Up: Why do you think the lactate clearance group had improved mortality, since the treatment each group received was the same? Was it chance alone or do you have a hunch what might have made the difference?

Dr. Jones: “As far as the mortality, it is certainly possible that the benefit of LC is that it could impact care at multiple levels, not just the third node. It is possible that the clinicians’ focus was re-directed to the patients in the LC group. It is also certainly possible that this difference was just due to chance.”

…It’s really fun to practice !

Which is better for measuring oxygen delivery in sepsis: lactate clearance or ScvO2? Does rapid, lights-and-sirens EMS transport make a difference in trauma outcome? What are five simple, proven ways to reduce central venous catheter infections? How well does a rapid influenza test perform in kids with H1N1? Is oseltamivir safe in kids < 12 months? Can we use biomarkers to avoid full sepsis work-up in febrile newborns? Which is better when sedating with ketamine: atropine, glycopyrrlolate, or no anticholinergic? Is there any new evidence for using dexamethasone in bacterial meningitis? Should we use compression only CPR in kids? How well does ultrasound of the IVC predict central venous pressure?

…OK, so this is not that important unless you drink loads of coffee and are looking for reasons to justify your habit.

ACEP custom briefings cited a new AHA abstract to be presented this Friday that found heavy (>4 cups/day) coffee drinking reduced the risk of supraventricular arrhythmias such as SVT, atrial fibrillation, atrial flutter. I think the only thing questionable about this study is whether or not 4 cups/day is really that heavy. As my mug says, “A morning without coffee is like sleep.” I don’t know about you, but the fog just starts to lift after cup #4. Coffee drinkers, feel vindicated and slosh back another cup! are publicly available for your perusal. This landmark study was P461.

…Key CV, ID, and venous thromboembolism articles in this updateStanding up normally causes transient tachycardia. Could this be used to unmask long QT syndrome? How much does CT perfusion stress imaging add to normal CTA? How well does a 320-row CT scanner perform in scanning for CAD in a single heartbeat? If the coronary calcium score is zero, is the patient safe for discharge? How often does H1N1 cause myocardial dysfunction or fulminant myocarditis? Does procalcitonin aid us in the ED for detecting bacterial infection in febrile patients? Could procalcitonin reduce antibiotic use in ICU patients? How accurate is rapid DNA testing for bacterial infection compared with blood culture? Do we really need a follow-up ultrasound in 5-7 days if the ultrasound in the ED is negative in patients with possible DVT? How well does attribute matching perform in predicting which patients are very low-risk for PE? Find out all these answers in this episode of Keeping Up!