2010年6月25日 星期五


Alarming Rise in Major Complications from Button Battery Ingestions
Ingestion of large button batteries, particularly lithium cells, accounts for the increase in poor outcomes.

To describe recent trends in button battery ingestions, investigators collected data from the National Poison Data System (NPDS; 56,535 cases reported during 1985–2009), the National Battery Ingestion Hotline (NBIH; 8161 cases during 1990–2008), and all 73 major (life-threatening or disabling) and 13 fatal cases ever reported in the medical literature or to the NBIH.

NPDS data showed no consistent trend in annual frequency of button battery ingestions. However, the proportion of major or fatal cases increased 6.7-fold between the first 3 years (1985–1987) and last 3 years (2007–2009). Children younger than 6 years accounted for 68% of NPDS cases and 62% of NBIH cases; all NBIH fatalities and 85% of major cases were in patients younger than 4 years. In logistic regression analysis of NBIH data, predictors of poor outcome were large battery diameter (20–25 mm; odds ratio, 24.6), age less than 4 years (OR, 3.2), and ingestion of more than one battery (OR, 2.1). During 2000–2009, 92% of major and fatal cases were from ingestion of 20-mm lithium cells. Injuries (e.g., severe burns, esophageal stenosis, bilateral vocal cord paralysis) occurred as soon as 2 hours after ingestion. Most major and fatal cases occurred in children less than 4 years old (92%) and were unwitnessed (56%), and many unwitnessed cases were initially misdiagnosed (46%). The authors present a management algorithm that recommends endoscopic removal of esophageal button batteries within 2 hours of ingestion.

These data are sobering. Physicians should keep button cells high on the list of differential diagnoses for any child who presents with airway obstruction or wheezing, drooling, vomiting, chest discomfort, difficulty swallowing or refusal to eat, or choking or coughing while eating or drinking. Once an esophageal button battery is identified, consultants must be mobilized for emergent removal.

Katherine Bakes, MD
Published in Journal Watch Emergency Medicine June 25, 2010

Citation(s): Litovitz T et al. Emerging battery-ingestion hazard: Clinical implications. Pediatrics 2010 Jun; 125:1168.

2010年6月24日 星期四


Steroid Dosage and Route in Patients Admitted for COPD
Oral low-dose use was associated with less treatment failure than was high-dose parenteral use.

Patients admitted for chronic obstructive pulmonary disease (COPD) usually receive systemic steroids, which have been associated with better outcomes in several prior randomized trials, but the best dose is still in question. Several major clinical practice guidelines recommend low-dose oral steroids.

In a retrospective cohort study, based on data from 414 U.S. hospitals, Massachusetts investigators compared outcomes in nearly 80,000 patients admitted for COPD to non–intensive care unit settings. About 74,000 received parenteral steroids (equivalent to a median dose of 600 mg of prednisone total for the first 2 days), and the rest received oral prednisone (median, 60 mg for the first 2 days). Treatment failure — defined as need for mechanical ventilation after the first 2 days, death, or readmission for COPD within 30 days — occurred in 11% of all patients.

In analyses adjusted for about 50 clinical and demographic variables, as well as propensity scores, treatment failure was 16% lower in patients who received oral low-dose steroids than in those who received parenteral steroids; length of stay and cost were about 10% lower in the low-dose group.

Comment: Although this study was retrospective, its sophisticated analyses convinced editorialists that the results should influence clinical practice and that a randomized controlled trial would be prohibitive in size and cost and is unnecessary. A worrisome secondary finding is that the vast majority of COPD patients received high-dose parenteral steroids, despite the contrary recommendations of major national and international guidelines — including those of the Global Initiative for Chronic Obstructive Lung Disease (GOLD).

Thomas L. Schwenk, MD
Published in Journal Watch General Medicine June 24, 2010

Citation(s): Lindenauer PK et al. Association of corticosteroid dose and route of administration with risk of treatment failure in acute exacerbation of chronic obstructive pulmonary disease. JAMA 2010 Jun 16; 303:2359. (http://dx.doi.org/10.1001/jama.2010.796)

2010年6月22日 星期二

Vertigo 如何診治?

Managing patients with vertigo can be very challenging. This practical summary of the causes and management of "dizziness" is useful. Three types are described:
  1. Episodic becoming chronic-migraine, Meniere's disease (hearing loss, tinnitus, vertigo), benign paroxysmal positional vertigo (BPPV, rotational vertigo lasting a few seconds related to head movements)
  2. Single attack but with residual symptoms-vestibular neuritis (a single, disabling attack that lasts a few days)
  3. Chronic, slowly progressive-polyneuropathies, idiopathic bilateral vestibular failure
Management includes:
  1. Treatment of the specific vestibular condition
  2. Symptomatic treatment of vertigo and nausea
  3. Physical rehabilitation
Source: Practical Neurology 2010;10:129-139

2010年6月18日 星期五


Routine use of oxygen in people who have had a heart attack
Most guidelines for the treatment of people who are having a heart attack recommend that the patient should be given oxygen to breathe. We looked for the evidence to support this practice by searching for randomised controlled trials that compared the outcomes in patients given oxygen to the outcomes for patients given normal air to breathe. We were primarily interested in seeing whether there was a difference in the number of people who died but we also looked at whether administering oxygen reduced pain.

We found three randomised controlled trials that compared one group given oxygen to another group given air. These trials involved a total of 387 patients of whom 14 died. Of those who died, nearly three times as many people known to have been given oxygen died compared to those known to have been given air. However, because the trials had few participants and few deaths this result does not necessarily mean that giving oxygen increases the risk of death. The difference in numbers may have occurred simply by chance. Nonetheless, since the evidence suggests that oxygen may in fact be harmful, we think it is important to evaluate this widely used treatment in a large trial, as soon as possible, to make sure that current practice is not causing harm to people who have had a heart attack.


2010年6月17日 星期四

Syphilis and azithromycin

Treating Syphilis Without Penicillin
A large study finds that a single oral dose of azithromycin can be curative in patients with early syphilis.

Even after all these years, a single dose of intramuscular penicillin G remains the preferred treatment for early-stage syphilis. The usual alternative, oral doxycycline, is problematic because several weeks of treatment are needed, and poor patient adherence can compromise efficacy.

In a multinational randomized nonblinded trial, 517 nonpregnant, HIV-negative adults with primary, secondary, or early latent syphilis received benzathine penicillin G (2.4 million units administered in 2 intramuscular injections) or azithromycin (2 g, administered as four 500-mg tablets). After 6 months, about 75% of patients in each group were judged as cured by the usual serologic standard of a drop in rapid plasma reagin (RPR) titer of 2 dilutions. Four patients had clear treatment failure with a significant rise in RPR titers; all had received azithromycin. Adverse effects, primarily gastrointestinal, were more common in the azithromycin group.

Single-dose azithromycin is an attractive treatment option for syphilis: It can be given under observation, is generally well tolerated, and can also be effective against chancroid, chlamydia, and gonorrhea. This study adds to the evidence that it works for syphilis, but concerns remain. Among them: efficacy in HIV infection, efficacy in pregnancy, and the observation that a mutation encoding for macrolide resistance is rapidly emerging in Treponema pallidum isolates.

Abigail Zuger, MD
Published in Journal Watch General Medicine June 17, 2010

Citation(s): Hook EW III et al. A phase III equivalence trial of azithromycin versus benzathine penicillin for treatment of early syphilis. J Infect Dis 2010 Jun 1; 201:1729.

2010年6月15日 星期二

Statin 的副作用?

Unintended Effects of Statin Drugs
Kidney failure and cataracts were associated significantly with statin use.

Statins lower risk for adverse cardiovascular events, especially in high-risk patients. In this large prospective U.K. cohort study, investigators sought to quantify unintended effects of these widely used drugs.

Of the more than 2 million study participants (age range, 30–84), about 225,000 were new statin users: 160,000 were prescribed simvastatin, 50,000 received atorvastatin, and 15,000 received pravastatin, rosuvastatin, or fluvastatin. Statin use was associated significantly with lower risk for esophageal cancer and higher risks for liver dysfunction (alanine transaminase levels 3x upper limit of normal), myopathy (clinical diagnosis or creatinine kinase level 4x upper limit of normal), acute kidney failure, and cataracts; liver dysfunction and acute kidney failure were dose-dependent. Adverse effects for individual statins were similar, except for liver dysfunction, in which risk was highest for fluvastatin. All excess risks persisted during treatment and returned to normal after drug cessation. Statin use was not associated with risk for osteoporotic fracture, venous thromboembolism, dementia, Parkinson disease, rheumatoid arthritis, or cancers (stomach, lung, breast, colon, kidney, and prostate cancers or melanoma).

Most clinicians are familiar with statin-associated liver dysfunction and myopathy. The results of this study suggest that clinicians should be familiar with and monitor for two more possible statin-associated adverse effects: acute kidney failure and cataracts. In addition, with the exception of esophageal cancer risk, the results are consistent with those of a prior meta-analysis, in which researchers found no association between statin use and cancer risk (JW Cardiol Mar 9 2006).

Paul S. Mueller, MD, MPH, FACP
Published in Journal Watch General Medicine June 15, 2010

Hippisley-Cox J and Coupland C. Unintended effects of statins in men and women in England and Wales: Population based cohort study using the QResearch database. BMJ 2010 May 20; 340:c2197. (http://dx.doi.org/10.1136/bmj.c2197)

2010年6月8日 星期二


Using Clopidogrel with a Proton-Pump Inhibitor
Risks for rehospitalization for myocardial infarction or stent placement were higher with combined therapy.

Studies have suggested that clopidogrel's efficacy is weakened if it is used in combination with a proton-pump inhibitor (PPI), given that the drugs compete for CYP2C19 activity. However, earlier retrospective studies might not have fully accounted for the likelihood that patients who receive PPIs are at higher baseline risk for cardiovascular events than are those who do not.

In this retrospective cohort study, based on U.S. claims data, researchers assessed risks for rehospitalization for myocardial infarction (MI) or stent placement among 2066 patients (mean age, 69) who were discharged from hospitals after MI or coronary stent placement; half the patients received clopidogrel alone, and half received it in combination with a PPI. Propensity scores were used to match patients by baseline cardiovascular risk. During 1 year of follow-up, combined-therapy recipients were more likely than clopidogrel-alone recipients to be rehospitalized for MI or coronary stent procedures (27.6 vs. 14.3 events per 100 person-years) or to be rehospitalized for MI (9.7 vs. 4.1 events per 100 person-years).

Once again, PPIs have been shown to lower the efficacy of clopidogrel. Of note, a few studies have suggested that pantoprazole inhibits CYP2C19 less than other PPIs do and that it does not impair clopidogrel efficacy. In this study, pantoprazole had adverse effects that were similar to those of other PPIs. Discouraging use of PPIs in conjunction with clopidogrel seems prudent.

Jamaluddin Moloo, MD, MPH

Published in Journal Watch General Medicine June 8, 2010

Stockl KM et al. Risk of rehospitalization for patients using clopidogrel with a proton pump inhibitor. Arch Intern Med 2010 Apr 26; 170:704. (http://dx.doi.org/10.1001/archinternmed.2010.34)