A predictive model can be used to identify children who need a chest x-ray during a work-up for lower respiratory infection, E. Melinda Mahabee-Gittens, M.D., and her colleagues reported.
The variables include age, respirations, oxygen saturation, and, for younger children, nasal flaring. “The model that we derived is not intended to replace the judgment of a skilled clinician,” said Dr. Mahabee-Gittens of the University of Cincinnati. “Rather, it may help to inform clinical decision making such that children with pneumonia are evaluated promptly and children without pneumonia are spared unnecessary chest radiography.”
They evaluated 510 children aged 2–59 months who presented at an emergency department with symptoms of lower respiratory tract infection. All of the patients had cough; 72% had fever; 45% had rapid or labored breathing; 20% had wheezing; and 18% had noisy breathing. All of the children received a chest x-ray; only 44 (8.6%) had radiographic evidence of pneumonia (Clin. Pediatr. 2005;44:427–35).
Patients with and without pneumonia differed significantly in four respects: age (21 months vs. 15 months); respiratory rate (50 breaths/min vs. 43 breaths/min); oxygen saturation (95% vs. 98%); and, for children that were younger than 12 months, nasal flaring (23% vs. 8%).
When the variables included age older than 12 months, respirations more than 50 breaths/min, and oxygen saturation 96% or less, the predictive model had a 97% specificity and a likelihood ratio of 6.1. The model also was highly specific for children younger than 12 months with the addition of nasal flaring.
Michele G. Sullivan