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Biomedical subjects

C J Warburton

Publications and source records attributed to C J Warburton.

13 recordsLinked to original sources

Effect of primary-care spirometry on the diagnosis and management of COPD.

Primary-care spirometry has been promoted as a method of facilitating accurate diagnosis of chronic obstructive pulmonary disease (COPD). The present study examined whether improving rates of diagnosis lead to improvements in pharmacological and nonpharmacological management. From 1999 to 2003, the current authors provided an open-access spirometry and reversibility service to a local primary-care area, to which 1,508 subjects were referred. A total of 797 (53%) had pre-bronchodilator airflow obstruction (AFO). Of the subjects who underwent reversibility testing, 19.3% were no longer obstructed post-bronchodilator. The results and records of a subgroup of 235 subjects with post-bronchodilator AFO were examined. Of the 235 subjects, 130 received a new diagnosis, most commonly COPD. The patients with COPD were significantly undertreated before spirometry and testing led to a significant increase in the use of anticholinergics (37 versus 18%), long-acting beta-agonists (25 versus 8%) and inhaled steroids (71 versus 52%). More than three quarters of smokers received smoking cessation advice but very few were referred for pulmonary rehabilitation. In conclusion, primary-care spirometry not only increases rates of chronic obstructive pulmonary disease diagnosis, but it also leads to improvements in chronic obstructive pulmonary disease treatment. The use of bronchodilator reversibility testing in this setting may be important to avoid misdiagnosis.

Adult↗

Leukotriene receptor antagonists for non-cystic fibrosis bronchiectasis.

BACKGROUND: Leukotriene receptor antagonists are a new class of drug that were initially identified for use in asthma. As they have an effect on neutrophil mediated inflammation, they may be of benefit in bronchiectasis. OBJECTIVES: To determine whether leukotriene receptor antagonists have any additive benefit over and above conventional treatment for bronchiectasis (usually consisting of antibiotics and postural drainage). SEARCH STRATEGY: The Cochrane Airways Group clinical trials register derived from MEDLINE, EMBASE and hand searching of major journals was searched using the terms:Bronchiec* AND leukotrien* OR anti-leuk* OR cysteinyl, Bronchiec* AND monteluk*, Bronchiec* AND zafirluk* SELECTION CRITERIA: Only randomised, controlled trials were considered DATA COLLECTION AND ANALYSIS: The results of searches were analysed by both authors MAIN RESULTS: No randomised, controlled trials were identified REVIEWER'S CONCLUSIONS: Further research is required to establish any benefit from the use of leukotriene antagonists in bronchiectasis.

Acetates↗

Surgery vs non-surgical treatment for bronchiectasis.

BACKGROUND: Standard treatment for bronchiectasis comprises postural drainage and various regimes of antibiotic therapy. If the disease is confined to localised areas of lung, surgical resection of the affected segments is often performed. OBJECTIVES: To assess the benefit of surgical resection compared with standard ("conservative") treatment. SEARCH STRATEGY: The Cochrane Airways Group trials register derived from MEDLINE, EMBASE and hand searching of major journals was searched using the terms [bronchiect* AND surg* OR resection OR lobect* OR pneumonect* OR segementect*]. SELECTION CRITERIA: Only randomised, controlled trials were considered DATA COLLECTION AND ANALYSIS: The titles, abstracts and citations were independently reviewed by the two reviewers to assess potential relevance for full review. STATISTICAL CONSIDERATIONS Not applicable MAIN RESULTS: No randomised or controlled clinical trials were found, other than case series or case-controlled studies. REVIEWER'S CONCLUSIONS: Surgical treatment of bronchiectasis is widely used, but there appear to be no randomised controlled trials. It is not possible to provide an unbiased estimate of its benefit compared to conservative therapy.

Adult↗

Environmental exposure to air pollution and allergens and peak flow changes.

Laboratory-based studies have shown that ozone and nitrogen dioxide can potentiate the effect of allergen in sensitized asthmatic subjects, but it is not known whether this interaction is important under natural exposure conditions. Thirty-five subjects with clinical diagnoses of asthma or chronic obstructive pulmonary disease and with a provocative dose causing a 20% fall in forced expiratory volume in one second methacholine <12.25 micromol (using the Yan method) kept peak expiratory flow (PEF) records for a 4-week period during late summer, with concurrent measurement of spore and pollen counts and pollution levels. Multiple regression analysis was then used to determine the effect on PEF of aeroallergen, and of the interaction between aeroallergen and pollutant levels. A statistically significant interaction was demonstrated between total spore count and ozone, but not nitrogen dioxide. Mean PEF fell in association with increasing spore count (same-day and 24-h lag level) and PEF variability increased with increasing spore count (24-h lag level only); both changes were greater the higher the prior ozone level. These results suggest that ozone can potentiate the effect of aeroallergens in subjects with bronchial hyperreactivity under natural exposure conditions. However, the effect was small, and the clinical significance of the interaction requires further study.

Adult↗

A comparison of performance of two personal sampling heads for cotton dust.

Cotton dust sampling for monitoring worker exposure was traditionally performed by work area sampling. A change to an exposure limit based on personal sampling has recently been agreed. The choice of sampling head for personal monitoring exposure was hampered by the use of two different sampling heads in the major epidemiological studies of textile workers which had incorporated personal sampling techniques. The purpose of this study was to compare the results of exposure measurements using these two sampling heads. This study has examined the performance of the two sampling heads, by performing dual sampling on cotton operatives during normal working activities. Each operative included wore two samplers randomly allocated to left or right side. A minimum of 200 minutes of sampling was accepted and the relative concentrations calculated. The IOM total dust sampler produced repeatedly higher measurements than the Manchester head. The ratio overall was 1.33 (95% C.I. 1.20-1.49). The performance was similar across the ranges of dust exposure from low (< 1 mg/m3-ratio 1.28), medium (1-3 mg/m3-ratio 1.43) to high exposure (> 3 mg/m3-ratio 1.24). The two heads give reproducibly proportionate dust measurements with approximately 30% greater results obtained with the IOM total dust sampler. Either dust sampling head could be used for worker monitoring and the results adjusted accordingly for reference to the Maximum Exposure Limit.

Dust↗

Chronic bronchitis in textile workers.

BACKGROUND: Exposure to cotton is known to produce a specific occupational disease known as byssinosis. A large population of textile workers was investigated to determine whether such exposure was also associated with chronic bronchitis once other possible aetiological factors had been accounted for. METHODS: A total of 2991 workers were investigated for the presence of symptoms compatible with chronic bronchitis. An MRC adapted respiratory questionnaire and MRC definition of chronic bronchitis were used for diagnostic labelling. Current and lifetime exposure to dust was estimated by personal and work area sampling, and the use of records of retrospective dust levels previously measured over the preceding 10 years. Airborne endotoxin exposure was measured using a quantitative turbidometric assay. Lung function tests were performed to measure forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). A control group of workers exposed to man-made fibre textiles was identified. The comparative prevalence of chronic bronchitis in the two populations was assessed, allowing for sex, age, smoking habit, and ethnic origin. Two case referent studies were also performed; cases of chronic bronchitis were separately matched with controls from the cotton and control populations to determine the effect of the symptomatic state on lung function. RESULTS: After controlling for smoking (pack years), workers in a cotton environment were significantly more likely to suffer from chronic bronchitis and this was most marked in workers over 45 years of age (odds ratio 2.51 (CI 1.3 to 4.9); p < 0.01). Regression analysis of all possible influencing parameters showed that cumulative exposure to cotton dust was significantly associated with chronic bronchitis after the effects of age, sex, smoking, and ethnic group were accounted for (p < 0.0005). In the intra-cotton population case control study a diagnosis of chronic bronchitis was associated with a small decrement in lung function compared with controls: percentage predicted FEV1 in cases 81.4% (95% CI 78.3 to 84.6), controls 86.7% (84.9 to 88.5); FVC in cases 89.9% (95% CI 87.0 to 92.9), controls 94.6% (92.8 to 96.4). After controlling for cumulative past exposure and pack years of smoking the effect of the diagnostic state remained significant for both FEV1 (p < 0.01) and FVC (p < 0.05). CONCLUSIONS: Chronic bronchitis is more prevalent in cotton workers than in those working with man-made fibre and exposure is additive to the effect of smoking. The diagnosis of chronic bronchitis is associated with a small but significant decrement in lung function.

Adult↗

Gastropleural fistula due to gastric lymphoma presenting as tension pneumothorax and empyema.

The formation of a gastropleural fistula is an uncommon complication of a number of conditions. The case of a patient with gastropleural fistula, as a complication of gastric lymphoma, is presented. The patient developed a tension pneumothorax and empyema. On cytological examination of the empyematous fluid, the presence of food debris aided diagnosis. The patient died 2 days after a total gastrectomy. The development of this complication in gastric lymphoma appears to have a particularly poor prognosis.

Aged↗

Functional upper airways obstruction: two patients with persistent symptoms.

Functional upper airways obstruction is caused by vocal cord dysfunction and classically occurs in paroxysms closely resembling acute asthmatic attacks. We present two cases in which the symptoms and signs of the vocal cord dysfunction demonstrate very little variability with time. We suggest that as part of this disorder, a syndrome of chronic unremitting symptoms may occur.

Adolescent↗

Effects of air pollution on symptoms and peak expiratory flow measurements in subjects with obstructive airways disease.

BACKGROUND: Evidence from laboratory studies suggests that air pollution can produce bronchoconstriction and respiratory symptoms in selected subjects, but the relevance of these findings to exposure to natural pollution is unclear. This study was performed to determine whether air pollution at typical levels found in the UK has demonstrable effects on respiratory function and symptoms in subjects with airways disease. METHODS: Seventy five adult patients with diagnoses of asthma or chronic obstructive pulmonary disease (COPD) were studied for a period of four weeks during which they kept records of their peak expiratory flow (PEF) rates, symptoms (wheeze, dyspnoea, cough, throat and eye irritation), and bronchodilator use. Thirty six patients in whom the provocative dose of methacholine causing a 20% fall in FEV1 was below 12.25 mumol were classified as reactors. Ambient air pollution was measured with absorption spectroscopy. RESULTS: There were modest but significant increases in PEF variability, bronchodilator use, and wheeze with increasing sulphur dioxide levels; bronchodilator use, dyspnoea, eye irritation, and minimum PEF readings were related to ozone levels. In the subgroup of reactors falls in mean and minimum peak flow and increases in wheeze, dyspnoea, and bronchodilator use were associated with increases in levels of both sulphur dioxide and ozone. Some associations were seen with pollution levels on the same day, but for others the pollution effects appeared to be delayed by 24 or 48 hours. Pollution levels did not breach the WHO guide levels during the course of the study. CONCLUSIONS: Increases in environmental levels of ozone and sulphur dioxide are associated with adverse changes in peak flow measurements and both ocular and respiratory symptoms in subjects with obstructive airways disease. Although the peak flow and symptom changes were modest, they occurred at pollution levels below current WHO guide levels.

Adult↗

Domiciliary air filtration units, symptoms and lung function in atopic asthmatics.

Air infiltration units (AFUs) incorporating a high efficiency particulate air filter are theoretically able to remove almost all potential airborne allergens. This may have implications for subjects with allergic lower respiratory disease. AFUs were placed in the living room of 12 atopic asthmatics, and the internal filters were inserted and removed in a double-blind fashion. No difference in subjective symptom scoring, spirometry or bronchial reactivity was demonstrated. Peak expiratory flow rate (PEFR) variability was significantly improved from baseline readings, and there was a trend towards higher mean PEFRs when the filters were present in the AFU. Trends towards lower levels of airborne micro-organisms were also demonstrated when the filters were present, however no effect upon total airborne dust and airborne Der pI could be demonstrated.

Air Conditioning↗

A study of the performance and comparability of the sampling response to cotton dust of work area and personal sampling techniques.

In order to compare and contrast the sampling response to cotton dust of two forms of dust sampling 85 work areas were identified over a 2-year period for investigation in eight Lancashire spinning mills. Three hundred and five work area dust samples were undertaken and 252 personal dust samples were performed. Operatives who spent a minimum of 80% of their working shift in the area in which work area sampling was also performed were selected for personal sampling. Work area dust exposures have recently shown an upward trend, with highest concentrations occurring in the ring spinning room (median 1.15 mg m-3, range 0.82-2.06). Personal dust samples showed a reduction in dust exposures as cotton processing progressed, from a high in the opening room (median value of 6.24 mg m-3, range 1.0-41.5) to a minimum of 1.02 mg m-3 (range 0.30-0.93) in the winding room. The ratio of measured personal sampling dust exposure to work area sampling exposure was used to compare the relative performance of the two techniques. This ratio was highest in the early processes. There was a 7.8-fold difference in measurement between the two techniques in the opening processes, falling to 4.9 in carding and 4.2 in the other card-room processes. However in ring spinning the ratio was only 1.4, suggesting a degree of comparability in the methods at this stage of processing. The value rose to 2.5 for the last stage (winding). Respiratory disease is known to occur predominantly in the early stages of processing (opening and carding) where high dust concentrations are found using the personal technique. These data support the use of personal sampling for setting exposure limits to cotton dust in preference to the current recommended method using work area sampling techniques, which may significantly underestimate dust exposure in the high risk work areas and is outdated.

Dust↗