INFLUENCE OF TREATMENT ON PEAK EXPIRATORY FLOW ACID ITS RELATION TO AIRWAY HYPERRESPONSIVENESS AND SYMPTOMS

Background - Despite effective treatments, the morbidity and mortality of obstructive airways disease (asthma and COPD) remains high. Home monitoring of peak expiratory dow (PEF) is increasingly being advocated as an aid to better management of obstructive airways disease. The few available studies describing effects of treatment on the level and variation of PEF have involved relatively small numbers of subjects and did not use control groups.Methods - Patients aged 18-60 years were selected with PC20 less than or equal to 8 mg/ml and FEV(1)Results - Improvements in PEF occurred within the first three months of treatment with BA + CS and was subsequently maintained: the mean (SE) increase in morning PEF was 51 (8) l/min in the BA + CS group compared with no change in the other two groups. Similarly, afternoon PEF increased by 22 (7) l/min. Diurnal variation in PEF (amplitude %mean) decreased from 18.0% to 10.2% in the first three months of treatment with BA + CS. Within-subject relations between changes in diurnal variation in PEF and changes in PC20 were found to be predominantly negative (median rho-0.40) but with a large scatter. Relations between diurnal variation ation in PEF and changes in symptom scores, FEV(1), and bronchodilator response were even weaker.Conclusions - In patients with moderately severe obstructive airways disease, PEF rates and variation are greatly improved by inhaled corticosteroids. Since the relation of diurnal PEF variation with PC20 symptoms, FEV(1), and bronchodilator response were all weak, these markers of disease severity may all provide different information on the actual disease state. PEF measurements should be used in addition to the other markers but not instead of them.</p

INFLUENCE OF TREATMENT ON PEAK EXPIRATORY FLOW ACID ITS RELATION TO AIRWAY HYPERRESPONSIVENESS AND SYMPTOMS

Background - Despite effective treatments, the morbidity and mortality of obstructive airways disease (asthma and COPD) remains high. Home monitoring of peak expiratory dow (PEF) is increasingly being advocated as an aid to better management of obstructive airways disease. The few available studies describing effects of treatment on the level and variation of PEF have involved relatively small numbers of subjects and did not use control groups. Methods - Patients aged 18-60 years were selected with PC20 less than or equal to 8 mg/ml and FEV(1) Results - Improvements in PEF occurred within the first three months of treatment with BA + CS and was subsequently maintained: the mean (SE) increase in morning PEF was 51 (8) l/min in the BA + CS group compared with no change in the other two groups. Similarly, afternoon PEF increased by 22 (7) l/min. Diurnal variation in PEF (amplitude %mean) decreased from 18.0% to 10.2% in the first three months of treatment with BA + CS. Within-subject relations between changes in diurnal variation in PEF and changes in PC20 were found to be predominantly negative (median rho-0.40) but with a large scatter. Relations between diurnal variation ation in PEF and changes in symptom scores, FEV(1), and bronchodilator response were even weaker. Conclusions - In patients with moderately severe obstructive airways disease, PEF rates and variation are greatly improved by inhaled corticosteroids. Since the relation of diurnal PEF variation with PC20 symptoms, FEV(1), and bronchodilator response were all weak, these markers of disease severity may all provide different information on the actual disease state. PEF measurements should be used in addition to the other markers but not instead of them

Peak flow variation in childhood asthma:Relationship to symptoms, atopy, airways obstruction and hyperresponsiveness

Although home recording of peak expiratory flow (PEF) is considered useful in managing asthma, little is known about the relationship of PEF variation to other indicators of disease activity, We examined the relationship of PEF variation, expressed in various ways, to symptoms, atopy, level of lung function, and airways hyperresponsiveness;ess in schoolchildren with asthma. One hundred and two asthmatic children (aged 7-14 yrs) recorded symptoms and PEF (twice daily) in a diary for 2 weeks after withdrawal of all anti-inflammatory maintenance medication, PEF variation was expressed as amplitude % mean, as standard deviation and coefficient of variation of all recordings, and as low % best (lowest PEF as percentage of the highest of all values). Atopy and level of forced expiratory volume in one second (FEV1) % predicted were not significantly related to PEF variation, The provocative dose of histamine causing a 20% fall in FEV1 (PD20) and symptom scores were significantly, but weakly, related to PEF variation, The index, low % best, proved easy to calculate and effective in identifying a short-term episode of reduced PEF. We conclude that peak expiratory flow variation in children with stable, moderately severe asthma is significantly, but weakly, related to symptoms and airways hyperresponsiveness, These three phenomena, therefore, all provide different information on the actual disease state, Expressing peak expiratory flow variation as low % best is easy to perform and appears to be clinically relevant

INTERPRETATION OF SKIN-TESTS TO HOUSE DUST MITE AND RELATIONSHIP TO OTHER ALLERGY PARAMETERS IN PATIENTS WITH ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY-DISEASE

Background: The relationships between allergic symptoms after exposure to house dust, allergy parameters (skin test to house dust mite [HDM], total IgE, HDM-specific IgE, and blood eosinophil counts), and several confounding variables (age, sex, smoking habits, and airway hyperresponsiveness) were evaluated in 235 patients with asthma and chronic obstructive pulmonary disease (COPD). Results: Skin tests had higher diagnostic value (sensitivity plus specificity) for symptomatic allergy than specific IgE (1.45 versus 1.36) or total IgE (1.16). The other allergy parameters gave no additional information on symptoms once the skin test was known. Expressing the skin test relative to the histamine control proved slightly better than uncorrected wheal size, but this probably has limited clinical value. The best cutoff level for a positive skin test was 0.7 when the histamine wheal size was accounted for by division, -6 mm when subtraction was used, and 7 mm for absolute wheal size. These cutoff levels proved equally applicable in various subgroups of patients with asthma and COPD. Only the skin test and female sex were independent predictors of allergic symptoms. Conclusion: We conclude that skin tests to HDM are better predictors for clinical allergy than total or specific IgE levels and eosinophil count, and that they are applicable in most patients with asthma and with COPD