Introduction: The diagnosis of diffuse lung disease is still a challenge for the pediatric intensive care physician. Routine clinical examinations and laboratory tests are frequently negative. The objective of this study was to evaluate the diagnostic potential, the impact on therapy and the rate of complications of open lung biopsy in children with undiagnosed diffuse lung disease, respiratory failure and inappropriate response to initial therapy. Methods: From January 1987 to January 1997, 29 children with diffuse pulmonary disease of unknown etiology, respiratory failure (PaO2 /FiO2 < 300) and no response to previous treatments were considered for open lung biopsy. Newborns, children with known chronic pulmonary disease and children with untreatable shock or coagulopathy were excluded. All biopsies were performed by a thoracic surgeon by a microthoracotomy in the lung shown to be the most affected by X-ray examination. Tissue samples were analyzed in terms of cultures, light microscopy, electron microscopy and immunofluorescence microscopy, according to the pathologist's decision. Results: All biopsies (100%) resulted in at least one histological diagnosis and in 20 patients (68.9%) it was obtained a specific diagnosis. The most frequent histological patterns found were: non-specific interstitial pneumonitis with variable degrees of fibrosis in 18 cases; bronchiolitis in eight cases and pulmonary hypertension in three cases. Regarding the most frequent specific diagnosis, six children were found with cytomegalovirus infection, three with Pneumocystis carinii, three with adenovirus and three with respiratory syncytial virus infection. These data induced a change in therapy in 20 children (68.9%). The most frequent changes in therapy were the use of corticosteroids in 14 children and a review of the antibiotic regimen in six patients. Seven patients (24.1%) presented with complications that were easily resolved. There were 13 deaths, probably due to the critical conditions of these patients, all unrelated to the procedure. Conclusions: Open lung biopsy, though an invasive procedure, should be considered in the evaluation of selected children with undiagnosed diffuse lung disease, respiratory failure and with no satisfactory response to previous therapies.

Objective: To provide access to the results of a randomized cross-sectional study conducted by the Brazilian Center for Information on Psychotropic Drugs in 2001. Methods: This survey involved a random sample of individuals ranging from 12 to 65 years of age and residing in the 107 largest cities (over 200,000 inhabitants) in Brazil, which represented 27.7% of the Brazilian population, estimated to be 169,799,170 inhabitants at the time. A total of 8,589 interviews were conducted. The Substance Abuse and Mental Health Services Administration questionnaire, translated and adapted for use in Brazil, was used in the interviews. Results: Of the sample as a whole, 41.1% of the interviewees reported having experimented with tobacco products. The prevalence of daily smokers was 17.4% (20.3% among males and 14.8% among females). We found that 9% of the sample (10.1% of the men and 7.9% of the women) were nicotine-dependent, according to the criteria of the National Household Survey on Drug Abuse. Conclusions: The prevalence of current smoking in the 107 largest cities of Brazil is significantly lower in this decade than was the national prevalence at the end of last century.

Keywords: Smoking/epidemiology; Tobacco use disorder; Smoking cessation.