[Chronologic relationship between gastroesophageal reflux and asthma. Simultaneous study of the measured pH and respiratory function].

Unlabelled: The aim of the study was: 1) to define the frequency of gastroesophageal reflux (GER) in asthmatics; 2) to study a possible relationship between episodes of GER and changes in airflow obstruction while maintaining as far as possible physiological conditions. Nineteen consecutive patients (aged 40.3 +/- 19 years) presenting with severe asthma requiring continuous treatment, were studied in a stable period. All treatments were stopped for 12 hours before the examination, except corticosteroids and sustained theophylline. Esophageal pH was measured continuously one hour before and three hours after a standardized meal. Respiratory function was measured every 30 minutes using a miniaturized spirometer which enabled the measurement of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and FEV1-VC ratio: 1) the frequency of pathological GER was defined by a Kaye's score greater than 90 and was 32%; 2) there was no significant correlation between the individual changes in FEV1 and different variables for the pH measured in the 30 mn before the measurement of bronchial obstruction (number of GER episodes, duration of GER, duration of the last GER episode, time of the last GER); 3) we have found no significant difference between the variation of FEV1 above or below 10% of the best FEV1 of each patient in relation to the quality (intensity, duration, delay) of GER episodes recorded 10 minutes before the spirometry.

In Conclusion: in severe asthmatics these results: 1) confirm the high frequency of pathological GER; 2) do not allow the establishment of a direct causal relationship between GER episodes and occurrence of a bronchial obstruction.