BACKGROUND: During arterial line sampling, 2 to 3 times of deadspace volume (from sampling port to catheter tip) are discarded to obtain accurate arterial blood gas variables. In this study, minimal discard volume was determined to decrease unnecessary blood loss. METHODS: Eighty patients scheduled for elective cardiac surgery were included. Two consecutive studies were conducted, in which the radial arterial line was placed with 20-gauge catheter. Once patients had stable hemodynamics, 5.5 times the deadspace of 1.5 ml was discarded before the sampling to obtain control value. In first study (n = 50), deadspace volume was fixed to 1.5 ml. After that, 1, 1.5, 2 and 2.5 times the deadspace were discarded in random before the sampling. In second study (n = 30), discard volume was fixed to 2 times the deadspace. The deadspace volumes were 1.5, 3.5 and 5.5 ml. Samples were analyzed for pH, PaCO2, PaO2, HCO3-, Na+, K+, Ca++ and hematocrit. RESULTS: In first study of fixed deadspace, there was no statistical difference in blood gas variables between discard volume of 2.5 ml and control value. In second study of fixed discard volume, the difference in blood gas variables was statistically significant only between deadspace volume of 1.5 ml and control value. CONCLUSIONS: The optimal discard volume was 2.5 times the deadspace to obtain accurate blood gas variables while decreasing unnecessary blood loss during arterial line sampling. On the other hand, when deadspace was larger than 3.5 ml, discard volume of 2 times the deadspace was sufficient.
Catheters ; Hand ; Hematocrit ; Hemodynamics ; Humans ; Hydrogen-Ion Concentration ; Thoracic Surgery ; Vascular Access Devices

PURPOSE: Adherence to treatment with inhaled corticosteroids (ICS) is a critical determinant of asthma control. The objective of this study was to assess factors that determine adherence to ICS therapy in children with asthma. METHODS: Fifty-eight children with asthma, aged 5 to 16 years, used ICS with or without a spacer for 3 months. Adherence rates as measured from questionnaires and canisters, asthma symptom scores, and inhalation technique scores were assessed every 30 days. The degree of supervision by caregivers was assessed at day 30. RESULTS: Adherence rates measured using canisters were lower at day 60 than at day 30 (P=0.044) and did not change thereafter (74.4%+/-17.4% at day 30, 66.5%+/-18.4% at day 60, and 67.4%+/-22.2% at day 90). Adherence rates at days 60 and 90 and during the total study period were significantly different when measured by using questionnaires versus canisters (P<0.001, P=0.022, and P=0.001, respectively). In the comparison of adherence rates repeatedly measured at days 30, 60, and 90 and adherence rates during the total study period among the 3 groups, adherence rates in the high-degree supervision group were significantly higher than those in the low-degree supervision group (82.0+/-16.0 vs. 66.1+/-14.5, 75.4+/-14.4 vs. 56.2+/-18.4, 75.0+/-18.3 vs. 55.0+/-19.7 [P=0.027]; 77.9+/-12.2 vs. 59.1+/-11.4 [P=0.021]) after adjustment for sex and age. CONCLUSION: The level of caregiver supervision is an important factor affecting adherence to ICS therapy in children with asthma. Therefore, a high degree of supervision may be required to increase adherence to ICS therapy in children with asthma.
Adrenal Cortex Hormones* ; Asthma* ; Caregivers ; Child* ; Humans ; Inhalation ; Organization and Administration*

PURPOSE: The roles of gut microbiota on the natural course of atopic dermatitis (AD) are not yet fully understood. We investigated whether the composition and function of gut microbiota and short-chain fatty acids (SCFAs) at 6 months of age could affect the natural course of AD up to 24 months in early childhood.METHODS: Fecal samples from 132 infants were analyzed using pyrosequencing, including 84 healthy controls, 22 transient AD and 26 persistent AD subjects from the Cohort for Childhood Origin of Asthma and Allergic Diseases (COCOA) birth cohort. The functional profile of the gut microbiome was analyzed by whole-metagenome sequencing. SCFAs were measured using gas chromatography-mass spectrometry.RESULTS: Low levels of Streptococcus and high amounts of Akkermansia were evident in transient AD cases, and low Clostridium, Akkermansia and high Streptococcus were found in children with persistent AD. The relative abundance of Streptococcus positively correlated with scoring of AD (SCORAD) score, whereas that of Clostridium negatively correlated with SCORAD score. The persistent AD group showed decreased gut microbial functional genes related to oxidative phosphorylation compared with healthy controls. Butyrate and valerate levels were lower in transient AD infants compared with healthy and persistent AD infants.CONCLUSIONS: Compositions, functions and metabolites of the early gut microbiome are related to natural courses of AD in infants.
Asthma ; Butyrates ; Child ; Clostridium ; Cohort Studies ; Dermatitis, Atopic ; Fatty Acids, Volatile ; Gas Chromatography-Mass Spectrometry ; Gastrointestinal Microbiome ; Humans ; Infant ; Metabolomics ; Metagenome ; Oxidative Phosphorylation ; Parturition ; Streptococcus

BACKGROUND: A US Food and Drug Administration (FDA)-approved drug methacholine chloride (Provocholine®) was recently introduced to Korea where it is now widely used in clinical practice. We aimed to evaluate the prevalence, risk factors and cutoff value of bronchial hyperresponsiveness (BHR) to Provocholine in 7-year-old children. METHODS: Six hundred and thirty-three children from the Panel Study on Korean Children who visited 16 regional hospitals were evaluated. Skin prick tests, spirometry and bronchial provocation tests for Provocholine as well as a detailed history and physical examinations were performed. The bronchial provocation test was reliably performed on 559 of these children. RESULTS: The prevalence of ever-diagnosed asthma via medical records was 7.7%, and that of current asthma (wheezy episode in the last 12 months + diagnosed asthma by physicians) was 3.2%. The prevalence of BHR to Provocholine was 17.2% and 25.8%, respectively, for a PC20 < 8 and < 16 mg/mL. The risk factors for BHR (PC20 < 16 mg/mL) were atopic dermatitis diagnosis and current dog ownership, whereas those for current asthma were allergy rhinitis diagnosis, a history of bronchiolitis before the age of 3, recent use of analgesics/antipyretics and maternal history of asthma. The BHR prevalence trend showed an increase along with the increased immunoglobulin E (IgE) quartile. The cutoff value of PC20 for the diagnosis of current asthma in children at age 7 was 5.8 mg/mL (sensitivity: 47.1%, specificity: 87.4%). CONCLUSIONS: BHR to Provocholine (PC20 < 8 mg/mL) was observed in 17.2% of 7-year-olds children from the general population and the cutoff value of PC20 for the diagnosis of current asthma was 5.8 mg/mL in this age group. The risk factors for BHR and current asthma showed discrepancies suggesting different underlying mechanisms. Bronchial provocation testing with Provocholine will be a useful clinical tool in the future.
Animals ; Asthma ; Bronchial Hyperreactivity ; Bronchial Provocation Tests ; Bronchiolitis ; Child* ; Dermatitis, Atopic ; Diagnosis ; Dogs ; Humans ; Hypersensitivity ; Immunoglobulin E ; Immunoglobulins ; Korea ; Medical Records ; Methacholine Chloride* ; Ownership ; Physical Examination ; Prevalence* ; Rhinitis ; Risk Factors* ; ROC Curve ; Sensitivity and Specificity ; Skin ; Spirometry ; United States Food and Drug Administration

PURPOSE: It is controversial whether indoor pet exposure is either a risk or protective factor developing sensitization to pet allergens or asthma. Therefore, we investigated whether indoor pet ownership entails a risk for the development of asthma and sensitization in childhood. METHODS: The Panel Study of Korean Children (PSKC) is a general-population-based birth cohort study that recruited 2,078 mother-baby dyads in Korea between April and July of 2008. Among 1,577 children who were followed up in 2015, 559 underwent skin prick tests, spirometry and bronchial provocation tests using Provocholine. Having a cat or a dog and the prevalence of asthma were evaluated by using self-reported questionnaires and physicians’ medical records. RESULTS: During infancy, the rate of dog ownership was 4.5% (71 of 1,574) and that of cat ownership was 0.5% (8 of 1,574). Of the subjects, 7.9% (n=109) currently had at least 1 dog and 2.5% (n=34) had at least 1 cat. Pet ownership during infancy was associated with sensitization to cats or dogs (adjusted odds ratio [aOR], 4.24; 95% confidence interval [CI], 1.29–13.98), wheezing within 12 months (aOR, 5.56; 95% CI, 1.65–18.75) and current asthma (wheezing episode in the last 12 months+diagnosed asthma by physicians) (aOR, 6.36; 95% CI, 1.54–26.28). In contrast, pet ownership during the last 12 months was not associated with sensitization to cats or dogs or current asthma. CONCLUSION: Indoor pet exposure during infancy can be critical for developing sensitization to cats or dogs and asthma in childhood. Avoidance of pet exposure in early life may reduce sensitization to cats or dogs and development of asthma.
Allergens ; Animals ; Asthma ; Bronchial Provocation Tests ; Cats ; Child ; Cohort Studies ; Dogs ; Humans ; Infant ; Korea ; Medical Records ; Methacholine Chloride ; Odds Ratio ; Ownership ; Parturition ; Pets ; Prevalence ; Protective Factors ; Respiratory Sounds ; Risk Factors ; Skin ; Spirometry

PURPOSE: Data are lacking on the association between the allergic rhinitis (AR) phenotype and sensitization to specific allergens or bronchial hyperresponsiveness (BHR) in children. We here investigated risk factors and comorbidities, including sensitization to specific allergens and BHR, for the AR phenotype by AR and its Impact on Asthma (ARIA) classification in a general population-based birth cohort study. METHODS: We enrolled 606 children aged 7 years from the Panel Study of Korean Children. The AR phenotype was assigned in accordance with the ARIA classification in children. Skin prick tests and Provocholine provocation test were performed. Risk factors and comorbidities for AR phenotypes were then analyzed. RESULTS: The prevalence of mild and moderate to severe AR in our study cohort was 37.2% and 8.8%, respectively. Recent use of analgesics or antipyretics and current cat ownership were associated with the risk of mild persistent AR. Sensitizations to Dermatophagoides Pteronyssinus (Der p), Japanese hop and cat were associated with moderate to severe persistent AR. Children with moderate to severe AR had a higher risk of current asthma and BHR compared to mild AR cases (adjusted odds ratio [aOR], 5.26; 95% confidence interval [CI], 1.77–15.62). Moderate to severe AR with allergic sensitization was associated with the highest risk of BHR (aOR, 11.77; 95% CI, 3.40–40.74). CONCLUSIONS: Moderate to severe-persistent AR is more closely related to respiratory comorbidities and sensitizations than mild AR. Stratifying the AR phenotype by ARIA classification may assist in disease management.
Allergens ; Analgesics ; Animals ; Antipyretics ; Asian Continental Ancestry Group ; Asthma ; Bronchial Hyperreactivity ; Cats ; Child ; Classification ; Cohort Studies ; Comorbidity ; Dermatophagoides pteronyssinus ; Disease Management ; Humans ; Methacholine Chloride ; Odds Ratio ; Ownership ; Parturition ; Phenotype ; Prevalence ; Rhinitis, Allergic ; Risk Factors ; Skin