Pulmonary surfactant, a soap-like substance, which has been shown to line the alveoli of the lung is responsible for the stable co-existence of alveoli of varied sizes. It has the unique capacity to change surface tension with area. Inactivation or depletion of surfactant material leads to various pulmonary disorders. In this overview, the important role of surfactant in mechanics of breathing, methods of assessment of surfactant activity and the factors affecting the lung surfactant properties are discussed.

Peak expiratory flow rate of 880 Indian subjects (456 males and 424 females), fulfilling the criteria of normalcy, was determined for different age and height groups, using the Wright's peak flow meter. The values of correlation coefficient between PEFR and age and PEFR and height were calculated to find out regression line on age and height. Using the authors' own regression equation, the value of PEFR was calculated for a standard male and standard female, and this was compared with available data of other workers. It was concluded that the mean value of PEFR would be more or less equal in the persons of same height and age of the different continents.

A sample of 456 males and 424 females was selected randomly from among healthy northern Indian subjects and their peak expiratory flow rate was determined by the Wright's peak flow meter to evaluate the effect of various factors influencing it. There was a significant difference of PEFR in both the sexes. The correlation of PEFR with the age was negative in both the sexes, and with anthropometric measurements (height, weight and body surface area) it was positive. Low socio-economic status and moderately or over-crowded area of residence were found to decrease PEFR. Smokers were found to have significantly lower value of PEFR in comparison to nonsmokers. The duration of smoking was found to be a more important factor than the amount of tobacco smoked per day in impairing PEFR. It was also noted that PEFR tended to decline more rapidly among the smokers than the nonsmokers after the age of 40 years. Other factors like type of job (sedentary or hard manual worker) and dietary habit did not show any significant effect on PEFR.

Thirty-one asthmatic patients from a general hospital were taken up for the study. Patients were randomly assigned to either TEP-SA one tablet B.I.D. or salbutamol 4 mg T.I.D. After two weeks of therapy the patients were switched over to the second drug. Patients were assessed on 8th, 15th, 22nd and 29th day of treatment. Results showed TEP-SA and salbutamol both significantly reduced the number of attacks and increased PEFR over pretreatment values. Statistical evaluation of difference in respect to all the parameters of assessment between the two drugs was not significant. Both the drugs were equally well tolerated by all the patients.

This study was conducted to find out the bacteriology, incidence of anaerobic infection and drug sensitivity of anaerobes in cases of empyema. Thirty cases of thoracic empyema were taken for study. Pleural exudate obtained by thoracentesis was subjected to culture examination under careful laboratory conditions. Culture results of aspirated fluid showed isolation of anaerobes in 10 (33.3%). aerobes in seven (23.3%), mixed infection in six (20.0%), and sterile culture in seven (23.3%) cases. Thus, the incidence of anaerobic infection was 53.3%. Bacteroids fragilis was isolated in a maximum number of five cases. Antibacterial activity of antibiotics studied showed rifampicin having maximal effect followed by kanamycin. All bacteria were resistant to erythromycin.

An open study of sodium 2 mercapto ethane-sulphonate (MESNA) daily over 10 days was done in 30 subjects with chronic lung diseases and sputum production. While 13 of them showed improvement, five deteriorated clinically. There was a reduction in sputum quantity in 11 subjects; sputum viscosity improved in all over two hours and in 26 subjects progressively. Moderately severe side effects were seen in six of 24 subjects in whom complaints like burning chest pain, increased dyspnoea, vomiting, headache, and giddiness were observed. There was significant decrease in FEV1 and FVC (but not PEF) which was maximal at 20-40 minutes and reversed later. MESNA aerosol merits further evaluation as a mucolytic in subjects with serious disease.