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Showing posts from April, 2014

Bedside focused echocardiography as predictor of survival in cardiac arrest patients: a systematic review.

Methodology Score: 4/5                  Usefulness Score: 4/5
Blyth L, Atkinson P, Gadd K, Lang E. Acad Emerg Med. 2012 Oct;19(10):1119-26.
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This systematic review of 8 studies found that when transthoracic ultrasound is performed during cardiac arrest, the absence of cardiac activity indicates a low but not zero likelihood that a patient will experience ROSC (Negative LR 0.18, Positive LR 4.26). There remains no clear definition of cardiac activity on ultrasound as well as no data on long term patient survival following ROSC; hence, echo should only be used as an adjunct to the pretest probability of patient survival in order to decide when to stop resuscitation efforts.  By: Dr. Michael O’Brien
(Presented December 2013)

Epi lesson: Heterogeneity of Studies in Overviews Heterogeneity refers to differences between patients or differences in the results of different studies and must be carefully evaluated in a meta-analysis to determine if results can be statistically pooled. The …

Effect of heart rate control with esmolol on hemodynamic and clinical outcomes in patients with septic shock: a randomized clinical trial.

Methodology Score: 4/5                  Usefulness Score: 2/5
Morelli A, et al. JAMA. 2013 Oct 23;310(16):1683-91
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This single centre phase 2B trial randomized septic patients still requiring vasopressors after 24hrs of EGDT to esmolol infusions to a target hear rate of between 85-94 or standard sepsis therapy and found overall mortality at 28 days of 49.4% in the esmolol group and 80.5% in the control group representing an ARR of 31% and a NNT of 3.2.  The group agreed that this study, although promising, demonstrated very high baseline mortality numbers, and that a large multicenter study is required to confirm effectiveness and safety of rate control.  By: Dr. Shawn Mondoux

Epi lesson: Phases of a Clinical Trial Clinical trials involving new drugs are classified into four phases with Health Canada and the FDA generally requiring a drug to have passed through Phase 3 before general approval.  Phase 1 trials test the treatment in a small group of healthy people (20-80) to evaluat…

Safe exclusion of pulmonary embolism using the Wells rule and qualitative D-dimer testing in primary care: prospective cohort study.

Methodology Score: 3/5                  Usefulness Score: 2.5/5
Geersing GJ, et al. BMJ. 2012 Oct 4;345:e6564.
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This was a prospective cohort validation study using the Wells clinical decision rule combined with D-dimer to exclude PE in primary care. The study found in their low risk group (Wells ≤ 4 and neg d-dimer) a false negative rate of (1.5%) (95%CI 0.4-3.74%) and Sn = 94.5% (95%CI 86.6-98.8%) Sp = 51%. Our group agreed the results are likely valid but questioned the utility of this protocol effectiveness at impacting emergency referrals.  By: Dr. Nathan Hecht (Presented Dec 2013)

Epi lesson: Screening Tests in the ED Diagnostic tests in the ED are often used to screen many patients for the possibility of severe illness, e.g. ACS in chest pain, SAH in headache, dementia in the elderly. We typically wish to rule-out a condition and such testing must be highly sensitive (SnOut) but will have false positives, e.g Troponin, CT Head, 3DY. In contrast, specialty services may be mo…