2010年8月31日 星期二


Calcium Supplementation Is Associated with Excess Risk for Myocardial Infarction
Marginal-to-moderate bone benefits must be weighed against cardiovascular risks.

Evidence suggests that calcium supplements hasten vascular calcification and increase mortality in patients with kidney failure and raise risk for myocardial infarction (MI) in healthy older women. To further investigate the association between supplemental calcium and adverse cardiovascular events, researchers conducted a meta-analysis of 15 double-blind, randomized trials in which participants (mean age at baseline, >40) received calcium supplements (>/= 500 mg daily) or placebo.

Patient-level data were available for five trials involving >8000 participants (77% women; median follow-up, 3.6 years). MIs occurred in 143 participants randomized to calcium supplements and 111 randomized to placebo — a significant difference. Calcium supplementation was not associated with excess risk for stroke or death. Analyses of trial-level data, involving 11 studies with nearly 12,000 patients, yielded findings similar to those that were based on patient-level data.

Calcium supplementation is associated with excess risk for MI. Clinicians should weigh this risk against the marginal-to-modest benefits of calcium supplementation on bone density and fracture risk. Based on current data, the authors estimate that treating 1000 people with calcium supplements for 5 years would prevent only 26 fractures but would cause an additional 14 MIs.

Paul S. Mueller, MD, MPH, FACP
Published in Journal Watch General Medicine August 31, 2010

Bolland MJ et al. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: Meta-analysis. BMJ 2010 Jul 29; 341:c3691. (http://dx.doi.org/10.1136/bmj.c3691)

2010年8月27日 星期五

Alteplase for stroke - up to 4.5 hr

Alteplase Is Effective Up to 4.5 Hours After Onset of Ischemic Stroke
But earlier is better.

On the basis of reports published in September 2008 from two large international studies, professional stroke organizations extended the recommended time between symptom onset and administration of alteplase from 3 to 4.5 hours (JW Emerg Med Sep 24 2008 and JW Emerg Med Sep 15 2008). To assess implementation of the wider treatment window and its effects, investigators analyzed data for nearly 24,000 patients who were included in one of the study's stroke registry from 2002 to 2010.

Overall, 2376 patients received alteplase between 3 and 4.5 hours after symptom onset; the proportion of patients who were treated within this window was three times higher in the last quarter of 2009 than in the first quarter of 2008. Rates of poor outcomes were low: 7.1% of patients treated within 3 hours and 7.4% of those treated at 3 to 4.5 hours had symptomatic intracerebral hemorrhage and 12.3% and 12.0%, respectively, died within 3 months. However, in analyses adjusted for confounding variables, patients treated at 3 to 4.5 hours had significantly higher rates of symptomatic intracerebral hemorrhage (1 extra hemorrhage for every 200 patients) and 3-month mortality (1 extra death for every 333 patients), as well as significantly worse functional outcomes (odds ratio for functional independence, 0.84). Median time from admission to treatment was 65 minutes before and after the reports. The authors conclude that the extended treatment window was implemented rapidly with no overall increase in admission-to-treatment time and that although risk from alteplase was greater when administered at 3 to 4.5 hours, treatment was still beneficial.

Although the U.S. FDA has not yet approved use of alteplase beyond 3 and up to 4.5 hours after onset of ischemic stroke symptoms, this evidence supports a wider treatment window and professional organizations recommend it. Nevertheless, time is brain, and eligible patients should be treated as soon as possible.

Kristi L. Koenig, MD, FACEP
Published in Journal Watch Emergency Medicine August 27, 2010

Citation(s): Ahmed N et al. Implementation and outcome of thrombolysis with alteplase 3–4.5 h after an acute stroke: An updated analysis from SITS-ISTR. Lancet Neurol 2010 Sep; 9:866.

2010年8月20日 星期五

最新版 ICH guidelines

最新版AHA/ASA Guidelines for Management of Spontaneous Intracerebral Hemorrhage。
Guidelines for the Management of Spontaneous Intracerebral Hemorrhage. A Guideline for Healthcare Professionals From AHA/ASA.

2010年8月16日 星期一

超級細菌 (superbug)


NDM-1是一種抗藥性基因,該基因所產生的酵素在2009年底印度新德里發現,全名叫做New Delhi metallo-beta-lactamase 1 。若細菌帶有此基因,其分泌的酵素會分解beta-lactam類的抗生素。NDM-1主要存在於各種革蘭氏陰性細菌,尤其是腸內菌屬的細菌(Enterobacteriaceae),例如Escherichia coli 與Klebsiella pneumoniae等等。細菌一但含有這種抗藥性基因,所有的beta-lactam類抗生素都對它沒有效,所以這些細菌常常被形容為超級細菌(superbug)。可能有效的藥物只剩下tigecyclinecolistin





1. Emergence of a new antibiotic resistance mechanism in India, Pakistan, and the UK: a molecular, biological, and epidemiological study. Lancet Infect Dis. 2010 Aug 10.

2. Characterization of a new metallo-beta-lactamase gene, bla(NDM-1), and a novel erythromycin esterase gene carried on a unique genetic structure in Klebsiella pneumoniae sequence type 14 from India. Antimicrob Agents Chemother. 2009 Dec;53(12):5046-54.

2010年8月14日 星期六


Digital Nerve Block: One Injection Is as Good as Two
Preliminary data support use of a single-injection method for fingertip injuries and infections.

The traditional method of digital nerve block involves two subcutaneous injections with the dorsal approach to block the four digital nerves at the base of the finger. An alternative approach involves a single subcutaneous injection of 2 to 3 mL of local anesthetic on the palmar surface at the base of the digit just distal to the proximal skin crease, followed by massage of the anesthetic into the area. Researchers conducted a multicenter, randomized controlled trial to compare these two methods in 76 patients older than 16 years who presented to three emergency departments in the U.K. with fingertip injuries or infections that required local anesthesia.

The proportion of patients who were adequately anesthetized did not differ significantly between the one-injection and two-injection groups at 5 minutes (76% and 65%) or at 10 minutes (89% and 82%). Clinician satisfaction scores were significantly higher for the one-injection technique (mean, 8.1 vs. 6.8 on a 10-point scale).

Comment: The authors could not recruit the intended 500 patients to adequately power the study, in part because many clinicians preferred the subcutaneous method and adopted it as their normal practice. This simple single-injection approach works beautifully to anesthetize the distal finger; however, because this method does not block the dorsal branches of the digital nerve, it might be less effective for injuries proximal to the distal-interphalangeal joint.

Diane M. Birnbaumer, MD, FACEP
Published in Journal Watch Emergency Medicine August 13, 2010

Citation(s): Cannon B et al. Digital anaesthesia: One injection or two? Emerg Med J 2010 Jul; 27:533.