Reference values for respiratory system impedance using impulse oscillometry in healthy preschool children / 소아과

PURPOSE: The normal values for lung resistance and lung capacity of children, as determined by impulse oscillometry (IOS), are different for children of different ethnicities. However, reference values there is no available reference value for Korean preschool children have yet to be determined. The aim of the present study was to determine the normal ranges of IOS parameters in Korean preschool children. METHODS: A total of 133 healthy Korean preschool children were selected from 639 children (aged 3 to 6 years) who attended kindergarten in Seongnam, Gyeonggi province, Korea. Healthy children were defined according to the European Respiratory Society (ERS) criteria. All subjects underwent lung function tests using IOS. The relationships between IOS value (respiratory resistance (Rrs) and reactance (Xrs) at 5 and 10 Hz and resonance frequency (RF)) and age, height, and weight were analyzed by simple linear and multiple linear regression analyses. RESULTS: The IOS success rate was 89.5%, yielding data on 119 children. Linear regression identified height as the best predictor of Rrs and Xrs. Using stepwise multiple linear regressions based on age, height, and weight, we determined regression equations and coefficients of determination (R2) for boys (Rrs5=1.934-0.009xHeight, R2=12.1%; Xrs5=0.774+0.006xHeight-0.002xAge, R2=20.2% and for girls (Rrs5=2.201-0.012xHeight, R2=18.2%; Xrs5=-0.674+0.004xHeight, R2=10.5%). CONCLUSION: This study provides reference values for IOS measurements of normal Korean preschool children. These provide a basis for the diagnosis and monitoring of preschool children with a variety of respiratory diseases.

Obstructive sleep apnea syndrome in children: Epidemiology, pathophysiology, diagnosis and sequelae / 소아과

The prevalence of pediatric obstructive sleep apnea syndrome (OSAS) is approximately 3% in children. Adenotonsillar hypertrophy is the most common cause of OSAS in children, and obesity, hypotonic neuromuscular diseases, and craniofacial anomalies are other major risk factors. Snoring is the most common presenting complaint in children with OSAS, but the clinical presentation varies according to age. Agitated sleep with frequent postural changes, excessive sweating, or abnormal sleep positions such as hyperextension of neck or abnormal prone position may suggest a sleep-disordered breathing. Night terror, sleepwalking, and enuresis are frequently associated, during slow-wave sleep, with sleep-disordered breathing. Excessive daytime sleepiness becomes apparent in older children, whereas hyperactivity or inattention is usually predominant in younger children. Morning headache and poor appetite may also be present. As the cortical arousal threshold is higher in children, arousals are not easily developed and their sleep architectures are usually more conserved than those of adults. Untreated OSAS in children may result in various problems such as cognitive deficits, attention deficit/hyperactivity disorder, poor academic achievement, and emotional instability. Mild pulmonary hypertension is not uncommon. Rarely, cardiovascular complications such as cor pulmonale, heart failure, and systemic hypertension may develop in untreated cases. Failure to thrive and delayed development are serious problems in younger children with OSAS. Diagnosis of pediatric OSAS should be based on snoring, relevant history of sleep disruption, findings of any narrow or collapsible portions of upper airway, and confirmed by polysomnography. Early diagnosis of pediatric OSAS is critical to prevent complications with appropriate interventions.

A Case of Seminal Vesicle Cyst Accompanied with Ipsilateral Renal Agenesis in an Infant

Seminal vesicle cysts have been rarely detected. Most of them are caused congenitally, and two- thirds of them are accompanied with ipsilateral renal agenesis or dysplasia. They are usually present with dysuria, urinary frequency, perineal pain, epididymitis, pain after ejaculation, scrotal pain or infertility in the second to fourth decade of patient's life. Occasionally cysts are palpable by digital rectal examination, but radiologic imaging study is necessary to diagnose. We report a case of an infant with seminal vesicle cyst accompanied with ipsilateral renal agenesis detected incidentally in postnatal sonogram. The infant's right side of kidney was diagnosed as antenatally multicystic dysplastic kidney.

The quality control and acceptability of spirometry in preschool children / 소아과

PURPOSE: We examined the ability of preschool aged children to meet the American Thoracic Society (ATS) and European Resiratory Society (ERS) goals for spirometry quality and tried to find out the major factor for improving the rate of success of spiromety test in this age group. METHODS: Spirometry was performed in 2-6 aged 155 children with chronic cough or suspicious asthma with the recording of maneuver quality measures of forced expiratory time, end-of-test volume, back-extrapolated volume (Vbe), and forced vital capacity (FVC), as well as flow-volume curve. The subjects were tested several times and the two best results in each subject were selected. All criteria for quality control were suggested by ATS/ERS guidelines. The criteria for starting of the test was Vbe <80 mL and Vbe/FVC <12.5%. The criteria for repeatability of the test was that second highest FVC and FEV1 are within 100 mL or 10% of the highest value, whichever is greater. For the criteria for termination of the test for preschool aged children, we evaluated the flow-volume curve RESULTS: As getting older, the success rate of spirometry increased and rapidly increased after 3 years old. Total success rate of the test was 59.4% (2 years old - 14.3%, 3 years old - 53.7%, 4 years old - 65.1%, 5 years old - 69.7%, 6 years old - 70.8%). The percentage of failure to meet the criteria for starting the test was 6.5%, repeatability of the test was 12.3% and end of the test was 31%. There was a significant difference only in age between success group and failure group. Evaluating the quality control criteria of previous studies, the success rate increased with age. CONCLUSION: About 60% of preschool aged children met ATS/ERS goals for spirometry test performance and the success rate was highly correlated with age. It is clearly needed that developing more feasible and suitable criteria for quality control of spirometry test in preschool aged children.

The quality control and acceptability of spirometry in preschool children / 소아과

PURPOSE: We examined the ability of preschool aged children to meet the American Thoracic Society (ATS) and European Resiratory Society (ERS) goals for spirometry quality and tried to find out the major factor for improving the rate of success of spiromety test in this age group. METHODS: Spirometry was performed in 2-6 aged 155 children with chronic cough or suspicious asthma with the recording of maneuver quality measures of forced expiratory time, end-of-test volume, back-extrapolated volume (Vbe), and forced vital capacity (FVC), as well as flow-volume curve. The subjects were tested several times and the two best results in each subject were selected. All criteria for quality control were suggested by ATS/ERS guidelines. The criteria for starting of the test was Vbe <80 mL and Vbe/FVC <12.5%. The criteria for repeatability of the test was that second highest FVC and FEV1 are within 100 mL or 10% of the highest value, whichever is greater. For the criteria for termination of the test for preschool aged children, we evaluated the flow-volume curve RESULTS: As getting older, the success rate of spirometry increased and rapidly increased after 3 years old. Total success rate of the test was 59.4% (2 years old - 14.3%, 3 years old - 53.7%, 4 years old - 65.1%, 5 years old - 69.7%, 6 years old - 70.8%). The percentage of failure to meet the criteria for starting the test was 6.5%, repeatability of the test was 12.3% and end of the test was 31%. There was a significant difference only in age between success group and failure group. Evaluating the quality control criteria of previous studies, the success rate increased with age. CONCLUSION: About 60% of preschool aged children met ATS/ERS goals for spirometry test performance and the success rate was highly correlated with age. It is clearly needed that developing more feasible and suitable criteria for quality control of spirometry test in preschool aged children.

Association between Ureaplasma urealyticum Colonization and Adverse Outcomes in Premature Infants

PURPOSE:Present evidences suggest that Ureaplasma urealyticum is a cause of pneumonia, septicemia, and bronchopulmonary dysplasia (BPD) in newborn infants, particularly those born prematurely. The purpose of this work was to examine the relationship between Ureaplasma urealyticum in the tracheal aspirates and adverse outcomes, such as BPD and early onset neonatal sepsis in premature infants. METHODS:A polymerase chain reaction (PCR) was performed on tracheal aspirates collected within 24 hour after birth in 176 premature infants less than 35 weeks of gestation and admitted to the neonatal intensive care unit of Bundang CHA Hospital. RESULTS:U. urealyticum was detected in 37 of 176 preterm infants (21.0%). Gestational age (29+5+/-2+5 wk vs. 30+6+/-2+5 wk, P=0.013) and birth weight (1.39+/-0.44 kg vs. 1.59+/-0.55 kg, P=0.037) were lower in the U. urealyticum-positive group compared to the control group. The incidence of early onset neonatal sepsis (16.2% vs. 6.5%, P=0.045) and BPD (45.9% vs. 29.5%, P=0.047) was higher in the U. urealyticum-positive group compared to the control group, but the severity of BPD was not different between two groups. However, multiple logistic regression analysis revealed that the presence of U. urealyticum was not independently related to the development of early onset neonatal sepsis and BPD. CONCLUSION:The results suggest that colonization of the lower respiratory tract by U. urealyticum might not be related to the development of neonatal sepsis and BPD directly in preterm infants.