This article reviews the effects of aging, tobacco-smoking, chronic bronchitis and emphysema, heart failure, oropharyngeal colonization, aspiration (micro and macro), alcoholism, hepatic cirrhosis, nutritional deficiency, immunosuppression, and environmental factors on the risk of community-acquired pneumonia and its severity. In the second part, the authors review the prophylactic action of anti-influenza and anti-pneumococcus vaccines as well as the role of prevention and treatment of antiviral agents in community-acquired pneumonia.

Keywords: Pneumococcal pneumonia. Influenza. Influenza vaccine. Viral vaccines. Risk factors.

The authors report the case of a 7-year-old girl, with a history of recurrent respiratory infections since five months of age. Immunological evaluation at four years of age revealed a normal level of total serum immunoglobulins, but a deficient humoral response to Streptococcus pneumoniae. Although having all normal IgG subclasses, the patient had inadequate antibody levels to all serotypes tested (1, 3, 5, 6, 9, and 14). Concurrent radiological evaluation showed diffuse atelectasis and bronchiectasis. Patient was started on IVIG, and subsequent chest CT scan revealed resolution of the above-mentioned lesions. To prevent irreversible damage to lung parenchyma, due to recurrent lower respiratory infections, it is important to identify immunocompromised individuals and treat them accordingly.

Keywords: Immunologic deficiency syndromes. Streptococcus pneumoniae.

Objective: To evaluate Light's criteria for drainage in children with parapneumonic pleural effusion. Methods: Prospective cross-sectional study on 85 children who were admitted to Hospital da Criança Santo Antônio, State of Rio Grande do Sul, Southern Brazil, presenting pneumonia with pleural effusion confirmed by chest X-ray and/or chest ultrasonography. The exclusion criteria were: previous drainage, pleural effusions associated with other disorders. The pH analysis was performed with a blood gas analyzer. Glucose and LDH were analyzed by spectrophotometry. The decision to perform pleural drainage was made by the attending physician without the participation of the researchers. Results: Pleural fluid in parapneumonic effusion with pH < 7.2 and glucose < 40 mg/dl presented higher drainage rate than LDH > 1,000 UI/l. The pH and glucose had high specificity (89% and 88%) and above the LDH (65%). The same results were observed when non-purulent fluids were analyzed (pH < 7.2 94%, glucose 88%, LDH 68%). In patients with pH < 7.2 LDH > 1,000 UI/l and glucose < 40 mg/dl predominated fluid with cloudy or purulent aspect. In more than 21% of patients who have indication of drainage by the classic criteria, was found limpid aspect. Conclusions: These data indicate that biochemical test support indication of drainage in children presenting with parapneumonic pleural effusion in non-purulent fluid. The specificity for drainage was 89% for pH and 88% for glucose and around 65% for LDH.

Keywords: Pleural effusion. Pleural empyema. Postural drainage.

Objective: To describe the results of a seven years experience using home oxygen therapy in children with hypoxemia and chronic lung disease. Patients and methods: This is a retrospective and descriptive study carried out at Hospital da Criança Santo Antônio - Porto Alegre-RS, Southern Brazil. The characteristics of the children on home oxygen therapy from January/93 to January/00 were analyzed. Results: Out of the 40 patients studied, 29 (72.5%) were males. At the beginning of home oxygen therapy, the age of the patients ranged from two months to 13 years and six months (mean: 24.8; median: 13), and 18 of them (45%) were less than one year old. The most frequent diseases were: obliterative bronchiolitis (31 cases; 77.5%); chronic obstructive lung disease with aspiration pneumonia (three cases); hypogammaglobulinaemia (two cases); suppurative lung disease (two cases), alveolar proteinosis (one case) and tuberculosis (one case). The length of the last hospitalization before home oxygen therapy was started ranged from nine to 240 days (mean: 63.7 days; median: 50 days). Most of the patients (30; 75%) received oxygen from a concentrator and the remainder from a cylinder. Mean oxygen therapy length ranged from 27 to 1,620 days (median: 392.5 days). There were five deaths from complications of the basic disease and one from accidental removal of the tracheostomy tube. Oxygen use could be discontinued in 19 patients - 15 with obliterative bronchiolitis, two with chronic aspiration pneumonia, one with tuberculosis and one with alveolar proteinosis. Conclusion: Although oxygen was needed for long periods, evolution was satisfactory in most children. Home oxygen for oxygen-dependent is an alternative treatment that allows an early discharge and a quick return to home life.

Keywords: Oxygen inahalation therapy. Anoxemia. Lung obstructive diseases. Home treatment.