Reduced exercise capacity in non-cystic fibrosis bronchiectasis.

OBJECTIVE: Bronchiectasis not due to cystic fibrosis is usually a consequence of severe bacterial or tuberculous infection of the lungs, which is commonly seen in children in developing countries. Our aim was to study its functional sequelae and affect on work capacity in children. METHODS: Seventeen children (7-17 years of age) with clinical and radiological evidence of bronchiectasis of one or both lungs were studied at the Cardiopulmonary Unit of the Tuberculosis Research Centre. Pulmonary function tests including spirometry and lung volume measurements were performed. Incremental exercise stress test was done on a treadmill, and ventilatory and cardiac parameters were monitored. Control values were taken from a previous study. RESULTS: Children with bronchiectasis had lower forced vital capacity (FVC) (1.1 + 0.4 L versus 1.5 + 0.4 L, p = 0.003) and FEV1 (0.95 +/- 0.2 L versus 1.4 +/- 0.3 L, p < 0.002) compared to age- and sex-matched healthy controls. The patient group had significantly higher residual lung volumes (0.7 +/- 0.3 L versus 0.4 + 0.1 L, p < 0.02). At maximal exercise, they had lower aerobic capacity (28 +/- 6 ml/min/kg versus 38 +/- 5 ml/min/kg, p < 0.0001) and maximal ventilation (24 +/- 8 L/min versus 39 +/- 10 L/min, p < 0.001). At maximal exercise, while none of the controls desaturated, oxygen saturation fell below 88% in eight of 17 patients. CONCLUSION: The findings show that children and adolescents with non-cystic fibrosis bronchiectasis have abnormal pulmonary function and reduced exercise capacity. This is likely to interfere with their life as well as future work capacity. Efforts should be made to minimize lung damage in childhood by ensuring early diagnosis and instituting appropriate treatment of respiratory infections.

Pulmonary function in normal south Indian children aged 7 to 19 years.

There are only a few studies that have established reference standards for pulmonary function of Indian children. Reference standards for pulmonary function that are reported for Indian children are mainly from northern and western parts of the country and there is a paucity of data on pulmonary function in normal South Indian children. Therefore, pulmonary function tests (spirometry and maximal expiratory flow rates) were carried out in 469 South Indian healthy children (246 boys and 223 girls) between 7-19 years of age to derive regression equations to predict pulmonary function. The correlations of forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were, in general highest with height followed by weight and age. Peak expiratory flow rate (PEFR), forced mid-expiratory flow (FMF) and forced expiratory flow rates at 25%, 50% and 75% of FVC (FEF25% FVC, FEF50%FVC and FEF75%FVC) were also significantly correlated with physical characteristics (age, height and weight). With a view to find out regression equations to predict spirometric functions based on physical characteristics (age, height and/or weight), the functions were regressed over all possible combinations of regressor variables, i.e. age, height and weight separately for boys and girls. The height influences the prediction equation in males to a great extent, whereas age and weight had greater influence in girls. Regression equations were derived for boys and girls for predicting normal pulmonary functions for children in South India. The pulmonary function measurements in South Indian children were similar to those reported for subjects from Western India and lower than those reported for Caucasians.

Aerobic capacity and cardiopulmonary response to exercise in healthy south Indian children.

OBJECTIVE: To examine the cardiorespiratory response to exercise in healthy South Indian school children. DESIGN: Prospective study. SETTING: Cardiopulmonary Medicine Unit, Tuberculosis Research Center, Madras. SUBJECTS: Data was obtained on 47 girls and 48 boys in the age group 7 to 14 years. INTERVENTION: The children performed a graded maximal exercise stress test on a computerized treadmill system. RESULTS: Maximum oxygen consumption (VO2max) increased significantly at 11 years of age in both sexes but while boys showed a progressive increase beyond 11 years, girls did not. When corrected for weight, only boys at 14 years had a significant increase in VO2max/kg. Boys had higher values of VO2max/kg than girls at all ages. Minute ventilation and oxygen pulse values also increased in both sexes at 11 to 12 years. The VO2max of South Indian children was lower than the predicted values available for North American children when prediction equations based on height were used. However, when regression equations based on weight were used, the predicted values for North American and South Indian boys were similar, though values for the Indian girls were still low. CONCLUSIONS: Nutritional and sociocultural factors may play a role in determining VO2max of children from different populations, rather than ethnic differences alone.

Effect of treatment on maximal expiratory flow rates in tropical eosinophilia.

Maximal expiratory flow rates such as peak expiratory flow rate (PEFR), rates at 25%, 50% and 75% of vital capacity (VE max 25%, VE max 50%, VE max 75%) and forced expiratory flow during the middle half of forced vital capacity (FEF 25-75%) were recorded in 23 patients with tropical eosinophilia (TE) before and after treatment. The mean values of all flow rates were significantly lower (P < 0.001) in untreated TE patients compared to predicted values. After three weeks' treatment with diethylcarbamazine, although there was a significant rise in the mean values of all expiratory flow rates (P < 0.05) except VE max 75% (P > 0.2), all flow rates continued to be significantly lower (P < 0.01) at one month than predicted values.

Prediction equations for maximal voluntary ventilation in non-smoking normal subjects in Madras.

Maximal voluntary ventilation (MVV) was measured in 256 healthy non-smoking adults (132 males, 124 females) aged 15-63 years living in Madras. The mean MVV (+/- SD) in males was 126.7 +/- 31.9 and in females 77.7 +/- 16.4. Regression equations were derived for men and women for predicting maximal voluntary ventilation for adults in South India. MVV in South Indians were similar to those reported for other Indian subjects, but lower than those reported for caucasians.