RESUMO

During the last 20 years, an association between respiratory syncytial virus (RSV) bronchiolitis or pneumonia in infants and abnormal pulmonary function later in childhood has been established. Study designs have varied considerably, but most investigators have used an observational approach in which children with early bronchiolitis or pneumonia are identified and pulmonary function is measured later in childhood. Decreased forced expiratory flows at mid-lung volumes and increased airway reactivity have been demonstrated consistently in most studies. Few studies, however, have addressed the issue of whether the early symptomatic RSV infection caused the subsequent abnormalities in pulmonary function. An atopic tendency does not appear to explain the underlying association between early RSV infection and subsequent abnormal pulmonary function. Evidence suggests that infants with symptomatic bronchiolitis have an underlying deficit in pulmonary function that might contribute to the abnormalities documented later in childhood. The issue of causation could be addressed by intervention studies in which RSV is prevented or treated and differences in pulmonary function are observed. Several small prospective studies of children enrolled in early controlled trials of ribavirin treatment of RSV lower respiratory tract infection have not consistently demonstrated differences between infants in treated and control groups. Larger studies of the effect of ribavirin treatment, immunoglobulin prophylaxis, or immunization (when it becomes available) on subsequent pulmonary function and airway hyperreactivity may resolve this important issue.

Assuntos

Assuntos

RESUMO

A 3-year prospective, blinded, multicenter study was done to assess the efficacy of early ribavirin intervention in mild respiratory syncytial virus illness in children with bronchopulmonary dysplasia or with congenital heart disease. A cohort of 178 children younger than 36 months of age with bronchopulmonary dysplasia or congenital heart disease were followed. Forty-seven infants whose respiratory syncytial virus infection resulted in mild symptoms of less than or equal to 72 hours' duration received ribavirin (n = 20) or water placebo aerosol (n = 27) either in a hospital or at home. Outcome measures included respiratory and analog score, room air oxygen, saturation, and oxygen flow needed to maintain saturation at greater than or equal to 91%. No difference in age, gender, family size, passive smoking, baseline oxygen saturations in room air, or duration of symptoms before treatment was found between groups. After 3 days of therapy, ribavirin produced a greater rate of improvement of analog scores (p = less than or equal to 0.001), lower oxygen requirements (p = 0.01), and higher oxygen saturation (p = 0.01). Respiratory scores and total hospital days did not differ significantly between the groups. Treatment failure occurred in 2 of 20 children (10%) in the ribavirin group versus 5 of 27 children (18%) in the placebo group, a nonsignificant difference. No child required assisted ventilation or had an adverse reaction. We conclude that early ribavirin therapy may help to reduce morbidity from respiratory syncytial virus infection in high-risk young children.

Assuntos

RESUMO

We measured ventilatory responses to progressive isocapnic hypoxia and to hyperoxic hypercapnia (CO2) using rebreathing techniques in 16 parents of infants with autopsy-confirmed sudden infant death syndrome (SIDS) and 18 control parents matched for age, sex, and body size. Response to ventilatory loading was assessed by repeating the CO2 test with an inspiratory flow-resistive load (16 cm H2O/L/sec). During loaded and unloaded CO2 tests, respiratory effort was also assessed by measuring the pressure generated in the first 0.1 second (P0.1) of the subsequent inspiratory effort after brief manual occlusion of the inspiratory line. Ventilatory responses of the parents of victims of SIDS to chemical and mechanical stimulation were not significantly different from those of control parents. Responses in both groups were similar to previously reported normal values. There was a linear increase in ventilation (VE) in response to hypercapnia and hypoxia and in P0.1 in response to hypercapnia. We found expected increases in P0.1/PCO2 and decreases in VE/PCO2 slopes during loaded breathing in all subjects, but no difference between groups. We conclude that parents of SIDS victims have normal ventilatory chemosensitivity and respiratory drive.

Assuntos

RESUMO

Concern about the long-term sequelae of bronchiolitis has been raised through studies of children hospitalized for bronchiolitis, but the long-term sequelae of mild bronchiolitis have not been studied. We assessed the hypothesis that 25 children with mild bronchiolitis (index subjects) were at greater risk for abnormalities of pulmonary function or airway reactivity to cold air between the ages of 8 and 12 years than were randomly selected, matched controls. There were no consistent differences in pulmonary function or airway reactivity between index and control groups. Airway hyperreactivity was found in five control subjects and three index subjects, and all children with symptomatic asthma were identified by cold air challenge. Our data suggest that children with a history of mild bronchiolitis are not at increased risk between ages 8 and 12 years for airway hyperreactivity or for abnormalities in pulmonary function.

Assuntos