Reduction In Peak Expiratory Flow Research Articles

Respiratory Health and PM10Pollution: A Daily Time Series Analysis

This study evaluated changes in respiratory health associated with daily changes in fine particulate pollution (PM10). Participants included a relatively healthy school-based sample of fourth and fifth grade elementary students, and a sample of patients with asthma 8 to 72 yr of age. Elevated PM10 pollution levels of 150 micrograms/m3 were associated with an approximately 3 to 6% decline in lung function as measured by peak expiratory flow (PEF). Current day and daily lagged associations between PM10 levels and PEF were observed. Elevated levels of PM10 pollution also were associated with increases in reported symptoms of respiratory disease and use of asthma medication. Associations between compromised respiratory health and elevated PM10 pollution were observed even when PM10 levels were well below the 24-h national ambient air quality standard of 150 micrograms/m3. Associations between elevated PM10 levels, reductions in PEF, and increases in symptoms of respiratory disease and asthma medication use remained statistically significant even when the only pollution episode that exceeded the standard was excluded. Concurrent measurements indicated that little or no strong particle acidity was present.

Can a Low or Moderate Dose of Inhaled Budesonide Replace Oral Non-Steroidal Anti-Asthma Treatment?

The efficacy of inhaled budesonide was assessed as an adjunct to and as a replacement for oral bronchodilators in an open study of 27 asthmatic patients. The patients had been treated regularly with oral bronchodilators but not with oral inhaled, or nasal steroids during the 2 3 months prior to the study. The study consisted of four treatment periods: 1, oral bronchodilator plus inhaled placebo for 1 week; 2, oral bronchodilator plus 400 micrograms inhaled budesonide twice daily for 3 weeks; 3,400 micrograms inhaled budesonide twice daily for 3 weeks; 4,200 micrograms inhaled budesonide twice daily for 3 weeks. Lung function measurements increased when budesonide was included with oral bronchodilators and there was a corresponding decrease in symptoms and rescue inhaler usage. Removal of oral bronchodilators from therapy did not significantly alter lung function and symptoms, whereas decreasing the dose of budesonide produced a slight reduction in peak expiratory flow and an increase in inhaled bronchodilator consumption.

Peak expiratory flow in symptomless elderly smokers and ex-smokers.

Values of peak expiratory flow (PEF) in 142 current smokers (116 men, 26 women) and 108 ex-smokers (88 men, 20 women) aged 55 or over were compared with the predicted values obtained in lifelong nonsmokers of the same age range. None of the subjects had been liable during childhood or subsequently to expectoration, lower respiratory tract infection, wheeze, or shortness of breath. Observed values of PEF were expressed as differences from predicted. Analysis of the relation between smoking state and ventilatory function in the men disclosed significant reductions of PEF in current smokers, the deficits increasing with the amount smoked from a mean of 48.1 l/min in those smoking fewer than 20 cigarettes a day to 73.3 l/min in smokers of 20 or more a day. Significant reductions of PEF were also found in women who were currently smoking (mean 47.4 l/min) and in male ex-smokers of 20 or more cigarettes a day (mean 27.8 l/min). There was no significant reduction of PEF in male or female ex-smokers of fewer than 20 cigarettes a day. These findings suggest that factors besides smoking are concerned in the development of irreversible airflow obstruction.

Outcome of respiratory illness occurring in the first year of life.

This paper describes the outcome of respiratory illness presented by a birth cohort of infants in the first year of life who were born to mothers in two inner London group general practices in terms of the ventilatory capacity measured at their fifth birthday. A history of two or more episodes of "lower" respiratory illness in the first year of life was associated with a significant reduction in peak expiratory flow when compared with those who had no such history. Boys had significantly higher peak flow rates than girls; those whose parents were in manual occupations had significantly lower peak flow rates than those whose parents were in non-manual occupations. There was a significant interaction between sex and social class.

Increased bronchial hypersensitivity after early and late bronchial reactions provoked by allergen inhalation.

The non-specific bronchial reactivity following bronchial allergen challenge was studied in 40 patients with allergic bronchial asthma, particularly in subjects without definite late reactions 6 h after the provocations (reduction in peak expiratory flow or forced expiratory volume in 1 s of less than 15% of the control value at this time). Among a group of 21 patients submitted to bronchial provocation tests, 13 carried out maximal exercise tests 6 and 1 week after the allergen challenge. In another group of 19 patients, the bronchial hyperreactivity to methacholine was assessed before and 6 h and 1 week after challenge. Two patients with a dual response (early & late) reacted with bronchial obstruction to the exercise. Exercise tests performed after 1 week did not provoke asthma in any patient. In the methacholine group a marked increase in responsiveness to methacholine 6 h after the provocation was observed in those patients with a dual response who were tested and in those with equivocal late reactions and even in three patients with an isolated immediate reaction. The increases responsiveness was still present in many patients 1 week after challenge. The airway caliber did not influence the degree of responsiveness to methacholine. Nor did the degree of responsiveness have any influence on the patterns of reactions observed after allergen exposure. It was concluded that in some individuals exposure to the relevant allergen predisposes them to exercise-inducible bronchial obstruction. Further, it was confirmed that non-specific bronchial reactivity can be increased not only in patients with late responses - both definite and equivocal--but also in some patients with immediate reactions alone.(ABSTRACT TRUNCATED AT 250 WORDS)