Yoon Ki Han

Fractional exhaled nitric oxide and impulse oscillometry in children with allergic rhinitis.

Purpose Airway inflammation, bronchial hyper-responsiveness (BHR), and bronchodilator response (BDR) are representative characteristics of asthma. Because allergic rhinitis (AR) is a risk factor for asthma development, we evaluated these 3 characteristics in AR using measurement of fractional exhaled nitric oxide (FeNO), a methacholine challenge test (MCT), and impulse oscillometry (IOS). Methods This study included 112 children with asthma (asthma group), 196 children with AR (AR group), and 32 control subjects (control group). We compared pulmonary function parameters and FeNO levels among the 3 groups. The AR group was subdivided into 2 categories: the AR group with BHR and the AR group without, and again pulmonary function and FeNO levels were compared between the 2 subgroups. Results FeNO levels were more increased in the AR and asthma groups than in the control group; within the AR group, FeNO was higher in the AR group with BHR than in the AR group without. The BDR was more increased in the AR group than in the control group when percent changes in reactance at 5 Hz (Δ X5) and reactance area (Δ AX) were compared. In the AR group, however, there was no difference in Δ X5 and Δ AX between the AR group with BHR and the AR group without. Conclusions Reversible airway obstruction on IOS and elevated FeNO levels were observed in children with AR. Because elevated FeNO levels can indicate airway inflammation and because chronic inflammation may lead to BHR, FeNO levels may be associated with BHR in AR. IOS can be a useful tool for detecting lower airway involvement of AR independent of BHR assessed in the MCT.

Effect of breastfeeding on lung function in asthmatic children.

Effect of breastfeeding on the protective effect on asthma has been studied extensively but remains controversial. Studies regarding the effect of breastfeeding on lung function have also been conflicting. The aim of this study was to determine the influence of breastfeeding on lung function in asthmatic children. We included 555 patients who visited Severance Childrens Hospital Allergy Clinic with asthma. Pulmonary function, its bronchodilator response (BDR), fractional nitric oxide, and sputum eosinophils were measured. Parents completed questionnaires with information on feeding practices, family history of allergic disease, exposure to tobacco smoke, and presence of pets. Breastfeeding duration was categorized as not breastfed, breastfed <6 months, and breastfed ≥6 months. Within the asthma group, we stratified by atopic sensitization. We also investigated whether exclusivity of breastfeeding had any modifying effect on lung function. In the asthma group, ratio of forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) significantly increased according to breastfeeding duration: 86.6 ± 8.7 for not breastfed group, 87.2 ± 8.6 for <6 months group, and 88.8 ± 7.7 for ≥6 months group. Within asthma group, only the nonatopic subjects showed a significant increase of FEV1/FVC, maximal midexpiratory flow, and decrease of maximal response to BD according to breastfeeding duration. Increase in FEV1/FVC was seen in the exclusive breastfeeding for ≥6 months group compared with those partially breastfed but FVC was significantly lower in those exclusively breastfed <6 months group compared with those partially breastfed. BDR decreased with breastfeeding duration in the nonatopic asthma group. In conclusion, longer duration of breastfeeding appears to have a favorable effect on lung function in asthmatic children, especially in nonatopic subjects.

Prognostic Usefulness of Eosinopenia in the Pediatric Intensive Care Unit

Eosinopenia, a biomarker for infection, has recently been shown to be a predictor of adult mortality in the intensive care unit (ICU). Our study assessed the usefulness of eosinopenia as a mortality and an infection biomarker in the pediatric ICU (PICU). We compared the PICU mortality scores, eosinophil count and percentage at ICU admission between children who survived and those who did not survive and between children with infection and those without infection. A total of 150 patients were evaluated. The initial eosinophil count and percentage were significantly lower in the group that did not survive when compared to those that did survive (P < 0.001; P < 0.001). However, there was no significant difference in the eosinophil count and percentage seen in patients with and without infection. Eosinopenia, defined as an eosinophil count < 15 cells/µL and an eosinophil percentage < 0.25%, (hazard ratio [HR]: 2.96; P = 0.008) along with a Pediatric Index of Mortality (PIM) 2 (HR: 1.03; P = 0.004) were both determined to be independent predictors of mortality in the PICU. The presence of eosinopenia at the ICU admission can be a useful biomarker for mortality in children, but is not useful as a biomarker for infection.

Clinical implication of exhaled breath temperature measurement in pediatric asthma

Correspondence to: Yoon Hee Kim https://orcid.org/0000-0002-2149-8501 Department of Pediatrics, Gangnam Severance Hospital, 211 Eonju-ro, Gangnam-gu, Seoul 06273, Korea Tel: +82-2-2019-3350, Fax: +82-2-3461-9473, E-mail: YHKIM@yuhs.ac • This research was supported by Kuhnil academic research fund. Received: September 6, 2016 Revised: October 13, 2016 Accepted: October 15, 2016