Predicting deterioration in previously healthy infants hospitalized with respiratory syncytial virus infection

Objective. To estimate the incidence of clinical deterioration leading to i ntensive care unit transfer in previously healthy infants with respiratory syncytial virus (RSV) infection hospitalized on a general pediatric unit an d, to assess the hypothesis that history, physical examination, oximetry, a nd chest radiographic findings at time of presentation can accurately ident ify these infants. Study Design. A virology database was used to identify and determine the di sposition of all children less than or equal to 1 year of age admitted to t he Children's Hospital at Strong (CHaS) with RSV infection during the 1985 to 1994 respiratory seasons. Index patients were all previously healthy, fu ll-term infants admitted initially to the general inpatient services at CHa S or Rochester General Hospital, a second University of Rochester teaching hospital, whose clinical deterioration led to transfer to the pediatric int ensive care unit (PICU). These infants were matched retrospectively (for ye ar and date of infection, sex, chronologic age, and race) with two hospital ized controls who did not require PICU transfer. Chest radiographic finding s, respiratory rate (RR), O-2 saturation, and presence of wheezing at time of presentation to the emergency department (ED) were compared. Results. During the study years, 542 previously healthy, full-term infants were admitted to the general pediatric unit at CHaS with proven RSV infecti on. Ten (1.8%; 95% confidence interval, 0.9%, 3.4%) were transferred subseq uently to the PICU, primarily for close monitoring of progressive respirato ry distress. Data for these patients and 7 patients transferred from Roches ter General Hospital to the PICU at the CHaS were compared with those for c ontrol patients. The mean RR in the ED (63 vs 50), and O-2 saturation in th e ED (88% vs 93%) were modestly abnormal in cases compared with controls. W heezing on examination at time of presentation and chest radiographic findi ngs did not differ between the two groups. A RR >80 and an O-2 saturation < 85% at time of presentation each had a specificity >97% for predicting subs equent deterioration. Each parameter, however, had a sensitivity less than or equal to 30%. Conclusion. Clinical deterioration requiring PICU admission is an uncommon occurrence in previously healthy infants admitted to a general pediatric in patient unit with RSV infection. Extreme tachypnea and hypoxemia were both associated with subsequent deterioration; however, only a small proportion of patients who clinically deteriorated presented in this way. The clinical usefulness of these parameters, therefore, is limited.