Advances in the clinical applications of exhaled nitric oxide measurements.

J Breath Res. 2012 Jun 7;6(4):047102

Authors: Taylor DR

Abstract
This article focuses on recent data which highlight the clinical settings in which exhaled nitric oxide (F(E)NO) is potentially helpful, or not, as a clinical tool. It is becoming clearer that, selectively applied, F(E)NO measurements can provide reliable clinical guidance, particularly when values are low. Such values are associated with high negative predictive values (>90%). Increased F(E)NO levels are associated with much more modest positive predictive values (75%-85%) and these are less reliable. These general principles apply when diagnosing steroid responsiveness in relation to asthma, chronic cough, and COPD. Although randomised trials do not support routine use of exhaled NO measurements in uncomplicated bronchial asthma, there is evidence that in patients with difficult asthma, or asthma associated with pregnancy, F(E)NO enhances overall management, and the decision to commence or increase inhaled steroid therapy (yes/no) may be made more accurately. Exhaled NO is potentially relevant in the assessment of occupational asthma (serial measurements) and also in diagnosing bronchiolitis obliterans in lung transplant patients.

PMID: 22677703 [PubMed - as supplied by publisher]

Prevalence, risk factors, activity limitation and health care utilization of an obese, population-based sample with chronic obstructive pulmonary disease.

Can Respir J. 2012 May;19(3):e18-24

Authors: Vozoris N, O'Donnell DE

Abstract
BACKGROUND: To estimate the prevalence and determine the risk factors and health associations among individuals with combined chronic obstructive pulmonary disease and obesity.
METHODS: Canadian national health survey data from 1994 to 2007 (n=650,000) were used. The presence of COPD was based on health professional-diagnosed self-report. The presence of obesity, defined by body mass index ≥30 kg⁄m2, was identified using self-reported and measured height and weight. Hospitalization, homecare use, physical activity assessments and socioeconomic data were all self-reported.
RESULTS: In 2005, the prevalence of obesity in COPD (n=3470) and non-COPD (n=92,237) individuals was 24.6% and 17.1%, respectively (P<0.0001). In contrast to the non-COPD group, in which obesity prevalence increased by 38% over 14 years, obesity prevalence increased by only 5% in people with COPD over this same time period. Female sex was the only independent risk factor for obesity in COPD. Previous smoking, residing in Atlantic Canada and the Territories, and low education level were independent risk factors for obesity in the non-COPD group, but not in the COPD group. The odds of physical activity limitation and health care utilization were significantly higher among obese individuals with COPD compared with nonobese COPD and obese non-COPD groups.
CONCLUSIONS: The prevalence of obesity was higher in COPD, and exceeded that of the larger non-COPD group throughout the 13-year observation period. The presence of obesity in COPD was associated with significantly higher risk of severe activity limitation and increased health care utilization. The combination of obesity and COPD has major implications for health care delivery that has not been previously appreciated.

PMID: 22679617 [PubMed - in process]

Influence of macrolide maintenance therapy and bacterial colonisation on exacerbation frequency and progression of COPD (COLUMBUS): Study protocol for a randomised controlled trial.

Trials. 2012 Jun 9;13(1):82

Authors: Uzun S, Djamin RS, Kluytmans JA, Van't Veer NE, Ermens AA, Pelle AJ, Mulder P, van der Eerden MM, Aerts JG

Abstract
ABSTRACT: BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterised by progressive development of airflow limitation that is poorly reversible. Because of a poor understanding of COPD pathogenesis, treatment is mostly symptomatic and new therapeutic strategies are limited. There is a direct relationship between the severity of the disease and the intensity of the inflammatory response. Besides smoking, one of the hypotheses for the persistent airway inflammation is the presence of recurrent infections. Macrolide antibiotics have bacteriostatic as well as anti-inflammatory properties in patients with cystic fibrosis and other inflammatory pulmonary diseases. There is consistent evidence that macrolide therapy reduces infectious exacerbations, decreases the requirement for additional antibiotics and improves nutritional measures. Because of these positive effects we hypothesised that maintenance macrolide therapy may also have beneficial effects in patients with COPD who have recurrent exacerbations. The effects on development of bacterial resistance to macrolides due to this long-term treatment are unknown. Until now, studies investigating macrolide therapy in COPD are limited. The objective of this study is to assess whether maintenance treatment with macrolide antibiotics in COPD patients with three or more exacerbations in the previous year decreases the exacerbation rate in the year of treatment and to establish microbial resistance due to the long-term treatment. Methods/design The study is set up as a prospective randomised double-blind placebo-controlled single-centre trial. A total of 92 patients with COPD who have had at least three exacerbations of COPD in the previous year will be included. Subjects will be randomised to receive either azithromycin 500 mg three times a week or placebo. Our primary endpoint is the reduction in the number of exacerbations of COPD in the year of treatment. DISCUSSION: We investigate whether long-term therapy with macrolide antibiotics can prevent exacerbations in patients with COPD. Additionally, our study aims to assess the effect of long-term use of macrolide on the development of antimicrobial resistance and on inflammatory parameters related to COPD. We believe this study will provide more data on the effects of macrolide treatment in patients in COPD and will add more knowledge on its working mechanisms. Trial registration www.clinicaltrials.gov NCT00985244.

PMID: 22682323 [PubMed - as supplied by publisher]

Diagnostic accuracy of primary care asthma/COPD working hypotheses, a real life study.

Respir Med. 2012 Jun 6;

Authors: Lucas AE, Smeenk FJ, Smeele IJ, van Schayck OP

Abstract
Misdiagnoses are inevitable when working hypotheses of asthma/COPD of General Practitioners (GPs) are not checked by spirometry. To reduce misdiagnoses, Asthma/COPD-support services (AC-services) offer support by performing spirometry assessed together with written medical history by consulting pulmonologists. RESEARCH QUESTIONS: Which criteria do GPs use to justify their asthma/COPD working hypotheses? How do diagnostic assessments by an AC-service change GPs' working hypotheses? Do GPs' justifications for their working hypotheses influence the extent to which working hypotheses correspond with diagnoses given by an AC-service? METHOD: We investigated the working hypotheses of 17 GPs for 284 patients with respiratory problems and their justifications: "clinical symptoms", "office spirometry", or "specialist's correspondence". Working hypotheses were compared with diagnoses given by an AC-service, and the influence of the different justifications categories on diagnostic accuracy of the working hypotheses was described. RESULTS: 49% of the working hypothesis were only based on clinical information, 21% were also based on office spirometry. For 30% additional specialist information was available. 50% of the working hypotheses were confirmed by the AC-service. The working hypothesis asthma was confirmed more frequently (62%) than the working hypothesis COPD (40%). The justifications for the working hypotheses given by GPs did not influence these results. CONCLUSION: Diagnostic assessments of the AC-service differed significantly from the working hypotheses of GPs, even when these were based on previous specialists' correspondence or on office spirometry. To optimize the diagnoses in primary care, diagnostic support of an AC-service is recommended for all primary care patients with respiratory problems.

PMID: 22682550 [PubMed - as supplied by publisher]