Jason A. Pietryga MD, Presenter: Nothing to Disclose

Terrance T. Healey MD, Abstract Co-Author: Nothing to Disclose

Thomas K. Egglin MD, Abstract Co-Author: Nothing to Disclose

John Albert Pezzullo MD, Abstract Co-Author: Nothing to Disclose

Philip Chan MD, Abstract Co-Author: Nothing to Disclose

Kimberle Chapin MD, Abstract Co-Author: Nothing to Disclose

The purpose of this study is to describe the initial chest radiographic (CXR) findings of pediatric patients with documented novel swine-origin influenza A (H1N1) infection, to determine the prognostic significance of findings on the initial CXR and to evaluate the clinical significance of a negative initial CXR.

An IRB-approved, HIPAA-compliant retrospective search of the medical record identified pediatric patients who had documented influenza A (H1N1) infection and a CXR obtained at initial presentation. Initial CXR and subsequent chest CTs were reviewed by three board-certified radiologists and a consensus was reached. The electronic medical record was reviewed and data concerning demographics, treatment, hospital course and outcome was recorded. Initial CXR findings were correlated with clinical course and outcome to determine the prognostic significance of imaging findings. The data was analyzed using chi square and fishers exact test as appropriate.

127 pediatric patients (82 M, 45 F, mean age 7 years) with documented influenza A (H1N1) infection and a CXR obtained at the time of initial presentation were identified. The most common presenting complaints were fever (70%), cough (46%), vomiting (10%) and seizure (5%). 32% of the initial CXR were negative. 39% of the initial CXR demonstrated prominent peribronchial markings with hyperinflation, 27% airspace disease ( 21% involved 1 lobe, 3% 2 lobes, and 3% all lobes), 3% low lung volumes, 3% lobar collapse, 2% pneumomediastinum, and 1% pneumothorax. 1 chest CT was performed which demonstrated multifocal consolidation. No specific findings on the initial CXR were indicative of a poor prognosis; however, a negative initial CXR was associated with decreased ICU admission [9% with a negative CXR versus 27% with a positive CXR (p=0.037), NPV 90%] and nebulizer treatment requirement [35% with a negative CXR versus 61% with a positive CXR (p=0.01), NPV 66%].

This is the largest cohort of pediatric patients presenting with documented influenza A (H1N1) infection to date which shows a negative CXR portends a good prognosis while there are no specific findings on CXR that were predictive of a poor outcome.

This is the largest cohort of pediatric patients presenting with documented influenza A (H1N1) infection to date. A negative CXR portends a good prognosis, while no finding predicted a poor outcome.

Pietryga, J, Healey, T, Egglin, T, Pezzullo, J, Chan, P, Chapin, K, Pediatric Novel Swine-origin Influenza A (H1N1) Infection: Chest Radiographic Findings and Prognostic Implications.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9009683.html