Early clinical, pulmonary function and blood gas studies in victims of Bhopal tragedy

Clinical, Pulmonary function and blood gas studies carricd out in 129 symptomatic toxic gas exposed individuals 1-3 months after exposure had revealed that pulmonary function measurements such as FVC, FEV1 and FMF 25-75% were significantly lower in toxic gas exposed subjects and 57 subjects (44.2%) had ventilatory impairment. The predominant type of ventilatory defect was combined obstruction and restriction. Of these 57 subjects, 5 (9%) had severe respiratory impairment. With increasing severity of exposure, there was a tendency for a higher proportion of subjects to have increasing impairment in pulmonary function and this trend was significant statistically (P<0.001). Isolated small airway disease was present in 9 (7%) subjects. 20.3% of patients with normal physical findings and 19.1% with normal chest roentgenograms had abnormal pulmonary junction. Arterial hypoxemia and ventilatory abnormalities were predominant in severely exposed patients. Further studies are required to identify the subgroup o/patients with Reactive Airways Dysfunction Syndrome. Long term follow-up is essential to categorise the pulmonary syndromes due to toxic gas exposure

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 Cardiopulmonaly 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 we 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 lie 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

Maximal expiratory flow rates in South Indian sportsmen.

The maximal Expiratory Flow Volume (MEFV) loop is superior to peak expiratory Flow Rate (PFR) and Forced Expiratory Volume in one second (FEV1) in that it describes total information during Forced Vital Capacity (FVC) test. MEFV loop was utilised to identify ventilatory adaptation in lungs of sportsmen. Twenty non-smoking sportsmen who were active participants in athletics at inter-university and interstate level were selected for the study. After a thorough clinical examination MEFV loop was recorded in the sitting posture using a computerised (P. K. Morgan (U.K.) pulmonary function test equipment and x-y recorder. When the results were analysed, it was found that mean PFR was 7.89 ± 0.29 L/S and flow rates of air at 25 % (V max 25 %) 50 % (V max 50%) and 75% of FVC were 7.12 ± 0.29 L/S, 5.18 ± 0.27 L/S and 2.87 ± 0.24 L/S respectively. Mean Forced Mid Flow (FMF) was 5.09 ± 0.24 L/S. When compared to the predicted values of our laboratory, the mean percentage predicted values of these parameters were as follows : PFR=102.5%, vmax 25% = 107.0%, vmx 50% = 110.7%, vmax 75% = 134.2% and FMF 114.2 %. It is evident from these results that sportsmen have increasingly higher flow rates at terminal part of FVC curve. Mean Flow Volume Loop drawn for the sportsman fails on the right side of the predicted normal curve, indicating thereby that the airways are patent even at every low lung volumes to let the air flow out at faster rate. This may be due to adaptation to habitual ventilatory training on the air ways, especially small airways, in sportsmen

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 caucasions

Maximal respiratory flow rates in tropical eosinophilia

Maximal expiratory flow rates such as Peak Expiratory Flow Rate (PEFR), rates at 25%, 50% and 75% of forced vital capacity (VE 25%, VE 50% and VE 75%) were studied in twenty untreated tropical eosinophilia (TE) patients. All measurements were significantly lower in patients with TE compared to their mean predicted values. These data suggest that inflammation of airways is an important mechanism of pathophysiology of tropical eosinophilia

Correlation of lower respiratory tract inflammation with changes in lung function and chest roentgenograms in patients with untreated tropical pulmonary eosinophilia

Forty-one patients with untreated tropical pulmonary eosinophilia (TPE) were studied to determine whether there was any relationship between lower respiratory tract inflammation and either changes in lung function or abnormalities in chest roentgenograms. Total number of inflammatory cells in bronchoalveolar lavage (BAL)fluid, consisting of alveolar macrophages, lymphocytes, eosinophils and neutrophils had significant negative correlations with transfer factor (TLCO) (r=-0519, p<0.001), transfer coefficient (KCO) (r=-0.3!2, p<0.05) and total lung capacity (TLC) (r=-0.352, p<0.05). The absolute count of eosinophils in BAL fluid had a signifiant negative correlation with TLC0 (r=-0.430, p<0.01) and KC0 (r=-0.300, p=0.05), but not with forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) or TLC. However, the absolute count of alveolar macrophages had a significant negative correlation with FVC (r=-0.343, p<0.05), FEVI (r=-0.341, p<0.05) and TLC (r=-0.305, p<0.05), but not with TLC0 or KCO. The total number of lymphocytes had a negative correlation with TLC (r=-0.315, p<0.05). There was no correlation between the types of cells recovered in BAL/fluid and changes in chest radiographs as assessed by the IL0 classification for occupational lung diseases. These data suggest that there may be a dissociation of pulmonary pathophysiological changesproduced by different inflammatory cells in the lower respiratory tract. Macrophages and lymphocytes may produce more harm to the lung, as evidenced by significant negative correlations of these cells with lung volumes

Arterial hypoxemin in acute tropical pulmonary eosinophilia

Arterial oxygen tensions were estimated in 48 acute tropical eosinophilic patients. Twenty (42%) had PaO2 of less than 80 mmHg, though 18 had only mild hypoxemia (PaO2 -70-80 mmHg). A smoker had PaO2 of less than 60 mmHg. The single breath carbon monoxide transfer factor (TLCO) was lowered in 42 (88%) patients. The PaO2 correlation with both FEV1% and TLCO percent predicted was not strong. Obstructive ventilatory and diffusion defects may not be the main mechanisms of hypoxemia in these patients

Reference values and prediction equations for maximal expiratory flow rates in non-smoking normal subjects in Madras

Maximal Expiratory Flow Rates such as Peak Expiratory Flow Rate (PEFR). rates at 25%, 50% and 75% of forced vita) capacity (V max 25%, V max 50% and V max 75%) and forced expiratory flow during the middle half of forced vital capacity (FEF 25-75%) were measured in 273 healthy non-smoking adults (144 males, 129 females) aged 15-63 years living in Madras. Regression equations were derived for men and women for predicting maximal expiratory flow rates for adults in South India. Expiratory Flow Rates at lower lung volumes in men were similar to those reported for caucasians, but higher than those reported for western Indian Subjects. However, in women the flow rates were similar to those of western Indians and lower than those of caucasians, probably due to indoor air pollution since childhood. These data may suggest that expiratory flow rates at lower lung volumes may not show ethnic variability

Aerobic capacity and cardio-pulmonary responses 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: Cardiopulmo nary Medicine Unit, Tuberculosi s Research Center, Ma dras. Subjects: Data was obtained on 47 girls an d 48 boys in the age group 7 to 14 years. Intervention: The children performed a graded maximal exercise stress test on a compute rized treadmill system. Results: Maximum oxygen consumption (VO2max) increased significa ntly at 11 years of a ge in both sexes b ut while boys sho wed 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 venti lation and oxygen pulse values also increased in both sexes at 11 to 12 year s. The VO2max of South Indian children was lower than the predicte d values available for North American children w hen 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. Nutri tional and sociocul tural factors may play a role in determining VO2max of children from different pop ulations, rather than ethnic differences alone. significa ntly at 11 years of a ge in both sexes b ut while boys sho wed 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 venti lation and oxygen pulse values also increased in both sexes at 11 to 12 year s. The VO2max of South Indian children was lower than the predicte d values available for North American children w hen 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: Nutri tional and sociocul tural factors may play a role in determining VO2max of children from different populations, rather than ethnic differences alone