Surinder K. Jindal

An attempt has been made to estimate the gross burden of chronic obstructive pulmonary disease (COPD) and its smoking association by reviewing the population studies available from India. Of the 14 studies which were reviewed, there were 11 conducted in general populations. The median values of different prevalence rates (i.e. 5 percent in male and 2.7 percent in female population) were accepted as the most appropriate figures to calculate the overall estimates. The overall M:F ratio was 1.6:1, i.e. 61.6 percent males. The estimated total number of adult patients aged 30 years and above in 1996 were 8.15 million males and 4.21 million females. The smoker:non-smoker ratio in males was assessed at 82.3 percent with an estimated burden of 6.7 millions. When the prevalence rates of COPD and its smoking associations were assessed in three different time periods (before 1970; between 1971-1990; after 1990), the median rates of 1971-1990, when the maximum number of studies were conducted, were nearly the same as the overall rates. However, the total burden as well as the smoking associated COPD, increased with time due to an increase in the eligible base population. In conclusion, these figures can be used to estimate the burden of COPD and its smoking association in India for different statistical analyses.

Inhalation of dusts is an important cause of interstitial lung disease in the tropical countries such as India. While dusts of organic origin, such as the cotton dust causing byssinosis, generally cause bronchial or bronchiolar involvement and hypersensitivity pneumonitis, inorganic metallic dusts cause progressive pulmonary fibrosis. Silicosis, coal workers' pneumoconiosis, and asbestosis are the three most commonly recognized forms of pneumoconiotic pulmonary fibrosis. Pulmonary tuberculosis is an important complication seen in up to 50% of patients of silicosis in some reports from India. The presentation is generally chronic, although acute and accelerated forms of silicosis are known when the exposures are heavy. Breathlessness, dry cough, and general constitutional symptoms are commonly seen. Patients with silicotuberculosis or other forms of infection may also have significant expectoration, hemoptysis, fever, and rapid progression. Respiratory failure and chronic cor pulmonale occur in the later stages. The diagnosis is easily established if the occupational history is available. Dense nodular opacities on chest roentgenograms, which may be large in patients with massive pulmonary fibrosis, are characteristic. Emphysematous changes generally appear in advanced stages or in patients who smoke. Bronchoalveolar lavage and/or lung biopsy may occasionally be required to establish or exclude other causes of interstitial lung disease. Treatment is largely palliative, although a variety of drugs including corticosteroids and procedures such as whole lung lavage have been tried. None of these methods has yet been found successful in the treatment. Preventive safety steps, including removal of the patient from the site of exposure, are the only effective strategies to control disease progression.

Objectives: Information on the spectrum and outcome of acute respiratory distress syndrome (ARDS) in tropical countries is scanty. This study was designed to assess the factors predicting the outcome of ARDS in North India.Methodology: Consecutive patients requiring mechanical ventilation for ARDS over a 2 year period at the Respiratory Intensive Care Unit (RICU) of a tertiary referral hospital were studied. Hospital survival was correlated with age, aetiology, disease severity scores (APACHE III, SAPS II, lung injury score) and organ failure using univariate analysis. Factors significantly influencing mortality were examined by multivariate analysis to identify factors independently affecting outcome.Results: Sepsis (28.6%), followed by malaria (21.4%), were the commonest risk factors. Seven out of eight patients (87.5%) with sepsis died. The presence of sepsis, more than three organ failure prior to admission, APACHE III score > 57 and SAPS II score > 39 were significantly associated with mortality. Only APACHE III score > 57 or SAPS II score > 39 were, however, independently predictive of a poor outcome following multivariate analysis.Conclusions: Sepsis, associated with a very poor outcome, and malaria were important risk factors for the development of ARDS. APACHE III score > 57 or SAPS II score > 39 were associated with increased risk of mortality.