Clinical Aspects of Pneumonia with Tachypnea in Pediatric Patients with Influenza H1N1

Choi, Bo Geum; Lee, Dong Won; Kim, Yeo Hyang; Hyun, Myung Chul; Lee, Hee Jung

Abstract

PURPOSE
We evaluated the clinical/laboratory characteristics and progress of pediatric patients hospitalized for pneumonia and laboratory-confirmed H1N1 influenza infection.
METHODS
A total of 101 patients were enrolled. They were divided into 2 groups: group 1 with a fast respiration rate for age (n=66) and group 2 with an appropriate respiration rate for age (n=35). We retrospectively reviewed the medical charts to collect data on the hospitalized patients.
RESULTS
Patients were significantly older in group 1 than in group 2 (median age, 7 vs. 4 years, p<0.001) and 59.0% were between 6 and 8 years of age. Sixteen patients (24.2%) in group 1 had underlying medical conditions, most of whom had asthma, and 50 were previously healthy. Oxygen saturation on admission day was significantly lower in group 1 than in group 2 (92% vs. 98%, p<0.001) and 42 patients (63.6%) in group 1 had hypoxia (oxygen saturation <= 92%). The frequency of lymphopenia was significantly higher in group 1 than in group 2 (n=59 vs. 11, p<0.001). Some patients in group 1 received systemic corticosteroid therapy, intravenous immunoglobulin infusion and oxygen supplement (n=28, n=16, n=48, respectively). The frequency of systemic corticosteroid therapy and oxygen supplement was higher in group 1 than in group 2 (p<0.001 for each).
CONCLUSION
H1N1 influenza infection complicated by pneumonia can cause severe illness in previously healthy children more than 6 years old and in children with uncontrolled allergic disease. Multi-center studies are needed to evaluate the clinical and epidemiologic characteristics of pediatric patients with 2009 H1N1 influenza.