Publications

INTRODUCTION

Secondhand smoke (SHS) contains respiratory irritants and has the potential to adversely affect adults with chronic obstructive pulmonary disease (COPD), but few studies have evaluated the impact of SHS on COPD.

METHODS

We used data from 72 nonsmoking participants in a cohort study of COPD. Urine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) was measured as an indicator of longer term SHS exposure, whereas urine cotinine was assessed as a measure of more recent exposure. The impact of SHS exposure on COPD-related health status was examined using multivariate linear regression (controlling for age, sex, race, educational attainment, and smoking history). Health status was measured using a validated COPD severity score, reported dyspnea, a standard health status measure (Short Form-12), and activity restriction.

RESULTS

The urine NNAL-to-creatinine ratio (per interquartile increment) was associated with greater COPD severity (mean score increase 1.7 points; 95% CI 0.6-2.8; p = .0003). Higher urine NNAL was also related to greater dyspnea, poorer physical health status, and more restricted activity (p < or = .05 in all cases). When considered simultaneously, longer term exposure (NNAL) had a greater negative impact on COPD status than shorter term exposure (cotinine).

DISCUSSION

Urine NNAL can be used to estimate longer term SHS exposure and negatively affects a number of health outcomes among adults with COPD. Screening for and prevention of SHS exposure among persons with COPD may be beneficial.

BACKGROUND

Agitation affects up to 70% of older people with dementia. Valproic acid derivatives have been used for the past 10 years to control agitation in dementia, but no systematic review of the effectiveness of this treatment has been published to date. A systematic review of 2004 examined three randomised, placebo-controlled trials of the effect of valproate therapy on older people with dementia who were agitated. The review was updated (October 2008) to include two additional studies.

OBJECTIVES

To determine whether evidence supports the use of valproate preparations in the treatment of agitation of people with dementia.

SEARCH STRATEGY

The Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (CDCIG), The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL and LILACS were searched on 7 February 2008 using the terms: valproic OR valproate OR divalproex* . The CDCIG Specialized Register contains records from all major health care databases (The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS) as well as from many trials databases and grey literature sources.

SELECTION CRITERIA

Randomized, placebo-controlled trials with concealed allocation where agitation and dementia of participants were assessed

DATA COLLECTION AND ANALYSIS

1. Two reviewers extracted data from published trials 2. Odds ratios of average differences were calculated 3. Only "intention to treat" analyses were included 4. Analysis compared participants treated with valproic acid with controls

MAIN RESULTS

Meta-analysis in 2004 of the pooled results was limited because of the following problems.In Porsteinsson 2001, although the physicians having direct responsibility for patient care were blinded, a non-blinded physician, who had no direct contact with these physicians, adjusted divalproex sodium dosage on the basis of reports from blinded raters and from confidential laboratory reports. Therefore, because the physician who controlled therapy knew which patients were receiving divalproex, the trial did not satisfy the criterion of concealed allocation.In Tariot 2001, 54% of the treated patients dropped out compared with 29% of control patients. Of all treated patients, 22% dropped out because of adverse effects, and the study had to be discontinued prematurely.The third trial (Sival 2002) had a cross-over design. No results from the first phase of the study were available, and although the statistical section stated, "the t-test for independent samples is used to analyse the two-period cross-over trial", because the samples were not independent - they are the same patients in the treatment and placebo groups - a question must be raised about the correctness of the analyses.The valproate preparation used in the trials varied - one used short-acting sodium valproate, one long-acting divalproex sodium, and the third early-onset acting divalproex sodium. Average doses differed (480 mg/d - 1000 mg/d), as did duration of therapy (3 weeks - 6 weeks), and ways of evaluating patients and their response to therapy.A limited meta-analysis, pooling the results concerning adverse effects (Porsteinsson 2001, Tariot 2001) revealed the following: sedation occurred more frequently in patients treated with valproic acid than in controls. Urinary tract infection was more common among patients treated with valproic acid than controls.An updated systematic review (October 2008) of two new studies (Tariot 2005, Herrmann 2007) applied meta-analysis to the effect of valproate on agitation in demented patients and also combined these studies with the earlier reports to examine adverse effects among valproate treated patients. Because the study of Herrmann et al involved a cross-over design, only those results from the first part of this study were included in the updated review.The new meta-analysis of pooled results showed no improvement of agitation among valproate treated patients, compared with controls, and showed an increase in adverse events (falls, infection, gastrointestinal disorders) among valproate treated patients.

AUTHORS' CONCLUSIONS

The updated review corroborates the earlier findings that valproate preparations are ineffective in treating agitation among demented patients, and that valproate therapy is associated with an unacceptable rate of adverse effects. More research on the use of valproate preparations for agitation of people with dementia is needed. On the basis of current evidence, valproate therapy cannot be recommended for management of agitation in dementia.

UNLABELLED

Although stress plays an important role in chronic widespread pain syndromes, such as fibromyalgia, the underlying mechanism has remained elusive. We have recently demonstrated, in a model of chronic widespread pain, that prolonged enhancement of immune mediator hyperalgesia, induced by unpredictable sound stress, requires a contribution of both the sympathoadrenal (epinephrine) and the hypothalamic-pituitary adrenal (corticosterone) neuroendocrine stress axes. Because this stress protocol produced sustained elevation of plasma epinephrine, in the current study we tested the hypothesis that the sympathoadrenal axis also plays a role in maintenance of symptoms in this model of chronic widespread pain. After establishment, adrenal medullectomy abolished the enhancement of epinephrine-induced cutaneous and muscle hyperalgesia. Administration of stress levels of epinephrine to adrenal medullectomized rats reconstituted the pain phenotype. These observations suggest that the sympathoadrenal stress axis plays a major role in the induction as well as maintenance of stress-induced enhancement of mechanical hyperalgesia, mediated by prolonged elevation of circulating epinephrine.

PERSPECTIVE

We present data showing mechanical hyperalgesia persisting for up to 28 days after exposure to sound stress, with evidence that the sympathoadrenal axis mediator epinephrine plays a major role. These findings could have clinical implications with regard to novel potential treatments for chronic widespread pain syndromes, such as fibromyalgia.

BACKGROUND

Deep hypothermic circulatory arrest (DHCA) is commonly used for complex cardiac operations in children, often with selective cerebral perfusion (SCP). Little data exist concerning the real-time effects of DHCA with or without SCP on cerebral metabolism. Our objective was to better define these effects, focusing on brain oxygenation and energy metabolism.

METHODS

Piglets undergoing cardiopulmonary bypass were assigned to either 60 minutes of DHCA at 18 degrees C (n = 9) or DHCA with SCP at 18 degrees C (n = 8), using pH-stat management. SCP was administered at 10 mL/kg/min. A cerebral microdialysis catheter was implanted into the cortex for monitoring of cellular ischemia and energy stores. Cerebral oxygen tension and intracranial pressure also were monitored. After DHCA with or without SCP, animals were recovered for 4 hours off cardiopulmonary bypass.

RESULTS

With SCP, brain oxygen tension was preserved in contrast to DHCA alone (p < 0.01). Deep hypothermic circulatory arrest was associated with marked elevations of lactate (p < 0.01), glycerol (p < 0.01), and the lactate to pyruvate ratio (p < 0.001), as well as profound depletion of the energy substrates glucose (p < 0.001) and pyruvate (p < 0.001). These changes persisted well into recovery. With SCP, no significant cerebral microdialysis changes were observed. A strong correlation was demonstrated between cerebral oxygen levels and cerebral microdialysis markers (p < 0.001).

CONCLUSIONS

Selective cerebral perfusion preserves cerebral oxygenation and attenuates derangements in cerebral metabolism associated with DHCA. Cerebral microdialysis provides real-time metabolic feedback that correlates with changes in brain tissue oxygenation. This model enables further study and refinement of strategies aiming to limit brain injury in children requiring complex cardiac operations.