Sustaining the implementation of an evidence-based guideline for bronchiolitis. 
To describe the changes occurring over a 3-year period after implementation of an evidence-based clinical practice guideline for the care of infants with bronchiolitis.  Before and after study.  Children's Hospital Medical Center, Cincinnati, Ohio.  Infants 1 year or younger admitted to the hospital with a first-time episode of typical bronchiolitis.  The guideline was implemented January 15, 1997.  Data on all patients discharged from the hospital with bronchiolitis, from January 15 through March 27, in 1997, 1998, and 1999, were stratified by year and compared with data on similar patients discharged from the hospital in the same periods in the years 1993 through 1996.  Patient volumes, length of stay for admissions, and use of specific laboratory and therapeutic resources ancillary to bed occupancy.  After implementation of the guideline, admissions decreased 30% and mean length of stay decreased 17% (P<.001).  Nasopharyngeal washings for respiratory syncytial virus were obtained in 52% fewer patients (P<.001); 14% fewer chest x-ray films were ordered (P<.001).  There were significant reductions in the use of all respiratory therapies, with a 17% decrease in the use of at least 1 beta(2)-agonist inhalation therapy (P<.001).  In addition, 28% fewer repeated inhalations were administered (P<.001); mean costs for all resources ancillary to bed occupancy fell 41% (P<.001); and mean costs for respiratory care services fell 72% (P<.001).  An evidence-based clinical practice guideline for the care of patients encountered in major pediatric care facility has been successfully sustained beyond the initial year of its introduction to practitioners in southwest Ohio.