Sleep Patterns among South Korean Infants and Toddlers: Global Comparison

The purpose of this study was to examine sleep patterns in a large sample of infants and toddlers (ages birth to 36 months) in Korea, and to compare sleep patterns, sleep problems, sleep ecology, and parental behaviors to global sleep data on young children in both predominately Asian (P-A) and predominately Caucasian (P-C) countries/regions. We additionally examined parent and child demographic information, parental behaviors, and aspects of the sleep ecology as predictors of sleep patterns among infants and toddlers in Korea. Parents/caregivers of 1,036 Korean infants and toddlers completed an expanded, internet-based version of the brief infant sleep questionnaire. Consistent with other studies of sleep in early childhood, sleep/wake patterns became increasingly consolidated with older child age for the Korea sample. Compared to both P-A and P-C infants and toddlers, children in Korea had the latest bedtimes, shortest total sleep and daytime sleep durations, and the least frequent rates of napping. Even though half of parents perceive their children's sleep problematic, parental perceptions of severe child sleep problems were the lowest. Within Korea, breastfeeding and bottle-feeding at sleep resumption were associated with increased nocturnal awakenings. Evening television viewing was associated with later bedtimes, which may have implications for sleep hygiene recommendations in clinical practice. The current study provides important information about sleep/wake patterns, parental behaviors, and aspects of the sleep ecology for infants and toddlers for physicians to support healthy sleep in Korea.

Effect of Prophylactic Palivizumab on Admission Due to Respiratory Syncytial Virus Infection in Former Very Low Birth Weight Infants with Bronchopulmonary Dysplasia

The aim of this study was to observe the effects of prophylactic palivizumab on hospitalization secondary to respiratory syncytial virus (RSV) infection (RSVhospitalization) in former very low birth weight infants (VLBWI) with bronchopulmonary dysplasia (BPD). This study also sought to identify the risk factors of RSVhospitalizationin this particular infant population. A prospective observational study was conducted between September 2007 and April 2008 in seven Korean hospitals. Children with a history of very low birth weight, a diagnosis of BPD and who were <2 yr old at the onset of the RSV season were included in this study. Palivizumab injections were administered monthly for a maximum of five months during the RSV season. RSVhospitalization rates were reviewed, and RSVhospitalization rates between subgroups were categorized by gestational age, birth weight, and duration of ventilator care. A total of 90 subjects completed the follow-up interviews. The mean gestational age at birth was 26.1+/-1.7 weeks, and the mean birth weight was 889.4+/-222.2 g. The incidence of RSVhospitalization in the study population was 8.9% (8/90), and the mean hospital stay was 11.0+/-5.5 days, including one death. There were no statistically significant differences in the patients' demographic characteristics or risk factors for RSV hospitalization. When subgroup analyses were conducted, there were still no statistically significant differences. The administration of palivizumab prophylaxis during the entire RSV season is important in VLBWI with BPD, regardless of their gestational age and birth weight, or previous ventilator dependency.

Insensible Water Loss during the First Week of Life of Extremely Low Birth Weight Infants Less than 25 Gestational Weeks under High Humidification

PURPOSE: Extremely-low-birth-weight infants (ELBWIs), especially those or =26-GW (n=65) infants nursed in 60% humidity. RESULTS: Survival rate until discharge was 33%, 82%, 75% and 89.3% in 22-GW, 23-GW, 24-GW and > or =26-GW infants, respectively. Compared to > or =26-GW infants, fluid intake and IWL was higher in 22-GW and 23-WG, but not as different in 24-GW. At postnatal day (P) 3-5, urine output was significantly lower in > or =26-GW infants than in the other age groups. Serum sodium level was significantly higher in 22-, 23- and 24-GW (P1-2) than in > or =26-GW infants. Hypernatremia (>150 mEq/dl sodium) was more frequent in 22-GW (71%), 23-GW (41%) and 24-GW (21%) than in > or =26-GW infants (14%). CONCLUSION: High-humidity environments significantly decreased fluid intake and improved electrolyte imbalance in 24-GW, but not in 22- and 23-GW infants. Increased IWL in the latter might be related to more immature skin, implicating the need for additional nurturing conditions.

Two Cases of Tension Pneumopericardium in Mechanically Ventilated Preterm Infants

Pneumopericardium is a rare form of neonatal air leakage. Tension pneumopericardium is much more infrequent, but can cause a cardiovascular deterioration with high mortality up to 80% and neurodevelopmental morbidity in half of the cases. We report two cases of preterm infants who successfully recovered from tension pneumopericardium that developed during mechanical ventilator assistance. The patients displayed a sudden increase in oxygen demand and subsequent cardiovascular deterioration. Immediate needle aspiration of the pneumopericardium performed after checking X-ray images rescued each of patient. Since the clinical symptoms are non-specific, clinicians' suspicion is most important when patients show sudden refractory cardiovascular collapse, especially in ventilator-assisted neonates. This life threatening complication demands instant diagnosis and intervention.

Two Cases of Neonatal Persistent Pulmonary Hypertension Treated by Veno-venous Extracorporeal Membrane Oxygenation (V-V ECMO)

Persistent pulmonary hypertension in newborns (PPHN) is a disorder of the vascular transition from fetal to neonatal circulation. It results in cyanosis due to right-to-left shunting of the blood through the ductus arteriosus and/or foramen ovale manifesting as hypoxemic respiratory failure. We managed two cases of PPHN after meconium aspiration with high frequency oscillating ventilators and inhaled nitric oxide. They did not respond to conventional management. Veno-venous extracorporeal membrane oxygenation (ECMO) was provided, and ECMO weaning was possible resulting survivals in two cases. We report two PPHN cases, which were treated successfully with veno-venous ECMO for the first time in Korea.

Neonatal Resuscitation at Delivery Room in "gray zone" Extremely Low Birth-Weight Infants (gestational age < or =24 weeks) / 대한주산의학회잡지

OBJECTIVE: This study investigated the effects of modified neonatal resuscitation program (M-NRP) which intends to keep minimal handling, to stabilize initial vital signs in extremely low birth weight infants (ELBWI) in Samsung Medical Center, NICU. METHODS: Medical records of 128 ELBWI with gestational age (GA) < or =24 weeks who had been admitted to the NICU of SMC from January 2000 to December 2008 were reviewed retrospectively. The data of these patients with M-NRP (n=62) were compared with those with classic NRP (C-NRP) (n=66). RESULTS: These patients who received M-NRP had significantly higher in survived discharge rate (66% vs 47%, P=0.034), lower in mask ventilation (29% vs 97%, P<0.001), shorter incubator-in time (81+/-25min vs 138+/-50min, P<0.001), and higher 1'/5' APGAR score (1': 3.9+/-1.5 vs 2.6+/-1.3, P<0.001, 5': 6.6+/-1.7 vs 5.4+/-1.8, P<0.001) than those who received C-NRP. CONCLUSION: Improvement in survived discharge rate and 1'/5' APGAR score were noted in M-NRP group compared to C-NRP group in the management of GA < or =24 weeks ELBWI

Effect of Synagis(R) (palivizumab) prophylaxis on readmission due to respiratory syncytial virus in very low birth weight infants / 소아과

PURPOSE: The aim of this study was to determine the efficacy of Synagis(R) (palivizumab) in reducing the respiratory syncytial virus (RSV) readmission rate in very low birth weight infants (VLBWI ) and the subgroup that showed the most effective vaccination. METHODS: We enrolled 350 VLBWI who had been discharged alive from the neonatal intensive care unit of Samsung Medical Center from January 2005 to December 2007 and were followed up for at least one year. A retrospective study based on medical records was performed for a period of one year after discharge. RSV readmission rate was investigated according to BPD (bronchopulmonary dysplasia, requiring oxygen at postnatal day 28) and Synagis(R) prophylaxis. We categorized the subgroups by the severity of BPD gestational age, and birth weight and compared the RSV readmission rates between subgroups. RESULTS: Eleven VLBWI were readmitted. Synagis(R) prophylaxis resulted in a 86% reduction in the rate of readmission due to RSV infection (prophylaxis group, 0.7% and no prophylaxis group, 5.0%; P=0.02). Readmission rate in BPD patients was also reduced in the prophylaxis group (0.7% in the prophylaxis group vs. 5.2% in the no prophylaxis group, P=0.03). The readmission rate in patients without BPD was reduced in the prophylaxis group (0% in the prophylaxis group vs. 4.9% in the no prophylaxis group, P=1.00), but this was not statistically significant. CONCLUSION: Synagis(R) prophylaxis was effective at reducing RSV readmission in VLBWI. Its efficacy was verified irrespective of BPD, gestational age, or birth weight.

Rotavirus-associated neonatal necrotizing enterocolitis / 소아과

PURPOSE: This study aimed to test whether rotavirus-associated necrotizing enterocolitis (RV+NEC) produced diffe rent clinical findings or outcomes from those of non-rotavirus necrotizing enterocolitis (RV-NEC). METHODS: Eight patients from the RV+NEC group and 22 patients from the RV-NEC group diagnosed with modified Bell stage II or higher NEC were selected for this study. Fecal specimens from all infants were tested for rotavirus infection using a monoclonal antibody-based enzyme immunoassay (EIA). Clinical, radiographic, and clinical outcome data were analyzed retrospectively. RESULTS: RV+NEC infants had a significantly higher birth weight and were born at a significantly higher gestational age (33.5+/-3.3 weeks vs. 29.3+/-4.4 weeks; P=0.01). There were no differe nces in the occurrence of thrombocytopenia, mural gas, and pneumoperitoneum between the 2 groups. However, portal vein gas was more common in the RV+NEC group (88% vs. 9%; P<0.01). Neither the incidence of Bell stage III (or higher) NEC nor surgical inte rvention differed between the two groups. The number of complications and mortality rates were also similar. CONCLUSION: Rotavirus-associated NEC occurs in infants with a higher birth weight and those born at a greater gestational age. However, the severity of the condition and the resulting outcomes did not differ from those for infants affected by non-rotavirus NEC.

Gastrointestinal surgery in very low birth weight infants: Clinical characteristics / 소아과

PURPOSE: To report our experience of gastrointestinal (GI) operations (OP) performed in very low birth weight infants (VLBWI) and to evaluate their clinical characteristics. METHODS: Among the 1,117 VLBWI admitted to the SMC neonatal intensive care unit from November 1994 to February 2007, the medical records of 37 infants who underwent GI OP (except inguinal hernia OP) and 1,080 VLBWI without GI OP were retrospectively reviewed. RESULTS: The mean gestational age (27(+6)2(+3) vs. 28(+5)+/-2(+6)) and birth weight (979+/-241 g vs. 1,071+/-271 g) of the 37 VLBWI who underwent the GI OP was lower than the VLBWI without GI OP group (n=1,080). Mortality rates in the GI OP group were significantly higher than in the non GI OP group (28% vs. 15%, P<0.001). The incidence of cholestasis, retinopathy of prematurity and periventricular leukomalacia were higher in the GI OP group than in the non GI OP group, but the incidence of bronchopulmonary dysplasia was not significantly different between the GI OP group and the non GI OP group. For GI OP indications, focal intestinal perforation was most common and showed a more favorable outcome than necrotizing enterocolitis. Compared with an earlier 7-year period, 1994-2000, the incidence and survival rates increased in the subsequent 2001-2007 period. CONCLUSION: GI OP was associated with high mortality and morbidity in VLBWI. Further efforts to improve outcomes of GI OP in VLBWI should be investigated to improve the quality of care in VLBWI.

Periventricular leukomalacia induced by in utero clamping of pregnant rat aorta in fetal rats / 소아과

PURPOSE: This study was undertaken to develop an animal model of periventricular leukomalacia (PVL) induced by in utero clamping of pregnant rat aorta in fetal rats. METHODS: A timed pregnanct Sprague-Dawley rat on embryonic day 21 just prior to delivery was sedated and anesthetized, and a Harvard ventilator for small animals was applied. Following laparotomy, the maternal aorta was clamped reversibly for 40 minutes using a surgical clip. The fetal rats were then delivered by Cesarean section, resuscitated if necessary, and reared by a surrogate mother rat until postnatal day 21 to obtain the brain specimen. After systemic perfusion and fixation, 10 microm thick serial brain sections were obtained and stained for pathologic examination and assessment of ventriculomegaly. Ventriculomegaly was assessed by the measured ventricle to total brain volume ratio. RESULTS: Eight out of eleven fetal rats (73%) survived in the ischemia group after induction of in utero ischemia by clamping maternal rat aorta, and all ten survived in the control group. Body and brain weights measured at postnatal day 21 were significantly lower in the ischemia group compared to the control group. In pathologic findings, significant ventriculomagaly (3.67+/-1.21% vs. 0.23+/-0.06%) was observed in the ischemia group compared to the control group; although cystic lesion was not observed, mild (n=6) and moderate (n=2) rerefaction of the brain tissue was observed. CONCLUSION: A fetal rat model of PVL induced by in utero clamping of pregnant rat aorta was developed.

Discrimination between obstructive sleep apnea syndrome and primary snoring in children : comparison of clinical parameters and behavioral disturbance / 소아과

PURPOSE: To determine whether primary snoring could be distinguished from obstructive sleep apnea syndrome (OSAS) by clinical evaluation and symptom scores. METHODS: 56 snoring and 20 asymptomatic subjects were recruited and polysomnography was used to confirm that there were 39 OSAS, 17 primary snoring, and 20 control subjects. We evaluated the size of the childrens adenoids and tonsils. Parents completed sleep disordered breathing scale (SDBS) and obstructive sleep apnea 18 (OSA-18) questionnaires for use as symptom scores, as well as an attention deficit hyperactivity disorder rating scale-IV (ADHD RS-IV). RESULTS: There were no differences between primary snoring and OSAS in terms of tonsil and adenoid size, SDBS (9.4+/-4.6 vs 10.8+/-4.5), and OSA-18 score (61.1+/-25.1 vs 71.2+/-8.4). The patients with OSAS (15.8+/-7.9) and PS (22.2+/-9.4) had a higher ADHD RS-IV score than the control subjects (2.9+/-3.3). There was no difference in the ADHD RS-IV scores of patients with primary snoring and OSAS. CONCLUSION: We confirmed that clinical evaluation could not distinguish OSAS and primary snoring. In addition, our study suggests that primary snoring as well as OSAS is associated with attention deficit hyperactivity disorder.

A Case of Child with Obstructive Sleep Apnea Syndrome Recurred after Adenotonsillectomy / 수면정신생리

The most common cause of obstructive sleep apnea syndrome (OSAS) in childhood is adenotonsillar hypertrophy. Adenotonsillectomy improves the symptoms quite well in most cases. However, some patients could experience the OSAS again after adenotonsillectomy, who might have several risk factors such as incomplete operation, misdiagnosis, combined anatomical malformation, sinusitis or chronic allergic rhinitis, obesity, initial severe OSAS, and early onset OSAS. We report a case of 11-year-old obese boy who presented with snoring for several years. He was obese with body mass index (BMI) of 26.3 kg/m2 and also found to have fatty liver by ultrasonogram. Initial polysomnography (PSG) showed that he met the criteria of severe OSAS with the apnea-hypopnea index (AHI) of 70.5. He underwent adenotonsillectomy and symptoms improved immediately. Four months later symptoms were relieved with AHI of 0, but 1 year after the adenotonsillectomy he started to complain snoring again and the subsequent PSG results showed that OSAS has relapsed with AHI of 43. Paranasal sinus X-ray and physical examination showed sinusitis and re-growth of adenoid. Obesity was proved not to be a contributing factor because his BMI decreased to normal range (23.1 kg/m2) after diet control and regular exercise. Also, liver transaminase was normalized and fatty liver was disappeared on follow-up abdominal ultrasonogram. After treatment of sinusitis, symptoms were relieved with decreased AHI (8.5). This case suggests that simple adenotonsillectomy might not be the end of OSAS treatment in childhood. Patients who had adenotonsillectomy should be followed by subsequent PSG if symptoms recur. It is also important to be aware of risk factors in the recurrent OSAS for the proper intervention according to the cause.

The centrosomal localization of KM-HN-1 (MGC33607) depends on the leucine zipper motif and the C-terminal coiled-coil domain

KM-HN-1 is a C-terminal coiled-coil domain containing protein previously referred to as image clone MGC33607. This protein has been previously identified as a cancer/testis antigen and reported as nuclear and chromatin localizing protein. We raised polyclonal antisera with the GST fusion protein and identified them as a 105 kDa protein. Motif analysis showed that this protein harbors the leucine zipper motif in internal 1/3 region and the coiled-coil domain in the C-terminal region. Using the full length and various deletion mutants, we determined the motif that governs the subcellular localization of KM-HN-1. Immunofluorescence staining of the endogenous KM-HN-1 and various kinds of GFP-tagged KM-HN-1 revealed that KM-HN-1 localizes to the centrosomes as well as nucleus. The centrosomal localization-determining region of this protein is C-terminal coiled-coil domain in which the leucine zipper motif and the nuclear export signal (NES) harbor.

Two Cases of Solitary Liver Abscess in Preterm Infant Suspiciously Caused by Umbilical Venous Catheter

Solitary liver abscess in neonate is a rare disorder. It is different from multiple liver abscess in aspect of having more subacute course and relative lack of systemic symptoms. Solitary liver abscess is caused by direct bacterial invasion from contiguous infection or hepatic artery during bacterial hematogenous dissemination or by bacterial invasion of the biliary duct and the portal vein. We describe two cases of solitary liver abscess in preterm infant who had umbilical venous catheter for parenteral nutrition.