Expert Panel Report 2: Guidelines for the Diagnosis and Management of Asthma

Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma

Exacerbations occur commonly in patients with moderate or severe chronic obstructive pulmonary disease (COPD) but factors affecting their severity and frequency or effects on quality of life are unknown. We measured daily peak expiratory flow rate (PEFR) and daily respiratory symptoms for 1 yr in 70 COPD patients (52 male, 18 female, mean age [+/- SD] 67.5 +/- 8.3 yr, FEV1 1.06 +/- 0.45 L, FVC 2.48 +/- 0.82 L, FEV1/FVC 44 +/- 15%, FEV1 reversibility 6.7 +/- 9.1%, PaO2 8.8 +/- 1.1 kPa). Quality of life was measured by the St. George's Respiratory Questionnaire (SGRQ). Exacerbations (E) were assessed at acute visit (reported exacerbation) or from diary card data each month (unreported exacerbation). In 61 (87%) patients there were 190 exacerbations (median 3; range, 1 to 8) of which 93 (51%) were reported. There were no differences in major symptoms (increase in dyspnea, sputum volume, or purulence) or physiological parameters between reported and unreported exacerbations. At exacerbation, median peak flow fell by an average of 6.6 L/min (p = 0.0003). Using the median number of exacerbations as the cutoff point, patients were classified as infrequent exacerbators (E = 0 to 2) or frequent exacerbators (E = 3 to 8). The SGRQ Total and component scores were significantly worse in the group that had frequent exacerbations: SGRQ Total score (mean difference = 14.8, p < 0.001), Symptoms (23.1, p < 0.001), Activities (12.2, p = 0.003), Impacts (13.9, p = 0.002). However there was no difference between frequent and infrequent exacerbators in the fall in peak flow at exacerbation. Factors predictive of frequent exacerbations were daily cough (p = 0.018), daily wheeze (p = 0.011), and daily cough and sputum (p = 0.009) and frequent exacerbations in the previous year (p = 0.001). These findings suggest that patient quality of life is related to COPD exacerbation frequency.

Effect of exacerbation on quality of life in patients with chronic obstructive pulmonary disease.

National Asthma Education and Prevention Program.

Background: A rich microbial environment in infancy protects against asthma [1], [2] and infections precipitate asthma exacerbations [3]. We compared the airway microbiota at three levels in adult patients with asthma, the related condition of COPD, and controls. We also studied bronchial lavage from asthmatic children and controls. 

Principal Findings: We identified 5,054 16S rRNA bacterial sequences from 43 subjects, detecting >70% of species present. The bronchial tree was not sterile, and contained a mean of 2,000 bacterial genomes per cm2 surface sampled. Pathogenic Proteobacteria, particularly Haemophilus spp., were much more frequent in bronchi of adult asthmatics or patients with COPD than controls. We found similar highly significant increases in Proteobacteria in asthmatic children. Conversely, Bacteroidetes, particularly Prevotella spp., were more frequent in controls than adult or child asthmatics or COPD patients. 

Significance: The results show the bronchial tree to contain a characteristic microbiota, and suggest that this microbiota is disturbed in asthmatic airways.

https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0008578&type=printable

Disordered Microbial Communities in Asthmatic Airways

Objective: To study the association between upper and lower respiratory viral infections and acute exacerbations of asthma in schoolchildren in the community. Design: Community based 13 month longitudinal study using diary card respiratory symptom and peak expiratory flow monitoring to allow early sampling for viruses. Subjects: 108 Children aged 9-11 years who had reported wheeze or cough, or both, in a questionnaire. Setting: Southampton and surrounding community. Main outcome measures: Upper and lower respiratory viral infections detected by polymerase chain reaction or conventional methods, reported exacerbations of asthma, computer identified episodes of respiratory tract symptoms or peak flow reductions. Results: Viruses were detected in 80% of reported episodes of reduced peak expiratory flow, 80% of reported episodes of wheeze, and in 85% of reported episodes of upper respiratory symptoms, cough, wheeze, and a fall in peak expiratory flow. The median duration of reported falls in peak expiratory flow was 14 days, and the median maximum fall in peak expiratory flow was 81 1/min. The most commonly identified virus type was rhinovirus. Conclusions: This study supports the hypothesis that upper respiratory viral infections are associated with 80-85% of asthma exacerbations in school age children. Key messages Key messages In this study common cold viruses were found in 80-85% of reported exacerbations of asthma in children Rhinoviruses, which cause most common colds, accounted for two thirds of viruses detected Analysis of diary cards also showed large numbers of similar but less severe episodes that may also be viral in origin

/pdf/community-study-of-role-of-viral-infections-in-exacerbations-19j3dejnc5.pdf

P. Symington

Papers

Community study of role of viral infections in exacerbations of asthma in 9-11 year old children.