Mi Lim Chung

Effect of Furosemide on Ductal Closure and Renal Function in Indomethacin-Treated Preterm Infants during the Early Neonatal Period

Background: Furosemide is known to increase renal prostaglandin synthesis. However, its influence on ductal closure and renal toxicities of indomethacin in preterm infants has not been conclusive, especially during the early neonatal period. Objectives: To identify the effects of furosemide after indomethacin administration on the rate of patent ductus arteriosus (PDA) closure and renal function in preterm infants. Methods: 68 infants (gestational age <34 weeks and birth weight <2,000 g) receiving indomethacin therapy (one course: 0.2–0.1–0.1 mg/kg q 12 h, mostly started <48 h after birth) were randomly assigned to the furosemide (n = 35) or control (n = 33) group. Each indomethacin dose was followed by furosemide (1.0 mg/kg) or placebo. The primary (PDA closure) and secondary (acute renal failure (ARF) and others) outcomes were assessed. Renal parameters before and 0–12 and 24–36 h after the first course of indomethacin were also investigated. Results: In an intention-to-treat analysis, there were no differences in the PDA closure rate between the furosemide (29/34) and the control (27/29) group (p = 0.437). The incidence of ARF (serum creatinine >1.6 mg/dl) was greater in the furosemide group (20/34) than in the control group (3/29) (p < 0.001). Compared with the control group, serum creatinine and cystatin C levels and fractional excretion of sodium were significantly increased in the furosemide group for 24–36 h after indomethacin therapy (p < 0.01). There were no between-group differences in mortality and other neonatal morbidity rates. Conclusions: Use of furosemide in combination with indomethacin increased the incidence of ARF but did not affect the PDA closure rate in preterm infants.

Impact of fetal echocardiography on trends in disease patterns and outcomes of congenital heart disease in a neonatal intensive care unit.

Background: Congenital heart disease (CHD) is the most common developmental malformation and the leading cause of neonatal mortality and morbidity. The introduction of fetal echocardiography has made prenatal diagnosis of CHD possible. Objective: This study was conducted to investigate the impact of fetal echocardiography on the changing disease patterns and outcomes of CHD. Methods: A retrospective analysis of data from infants with CHD admitted to the neonatal intensive care unit (NICU) of the Asan Medical Center during the time periods was performed. Period I (1994–1996) was considered representative of a period before the introduction of fetal echocardiography, while period II (2004–2006) represented a period of more extensive application of fetal echocardiography. Results: A total of 164 patients were admitted to the NICU during period I and 320 during period II. The number of infants prenatally diagnosed with CHD was 5 of 164 (3.0%) in period I and 219 of 320 (68.4%) in period II (p < 0.05). The overall accuracy of fetal diagnosis was approximately 92%. Of the 3 CHD categories, there was a greater proportion of infants with ‘significant’ heart disease in period II than I (47 vs. 32%; p < 0.05). In contrast, there was a smaller proportion of infants with ‘simple’ heart defects in period II than I (22 vs. 40%; p < 0.05). The proportion of infants with ‘complex’ heart disease was similar in both periods (28% in period I and 31% in period II). The 1-year survival rate of patients with CHD has improved remarkably with time (70.1% in period I to 88.8% in period II). Multivariate analysis showed prenatal diagnosis and planned delivery in a tertiary NICU are factors affecting CHD outcomes, especially when defects are ‘complex’ (p < 0.01). Conclusion: Fetal echocardiography has resulted in an increased frequency of prenatal CHD diagnosis, has altered the disease patterns observed in the NICU, and has resulted in better 1-year outcomes.

Thyroid dysfunctions of prematurity and their impacts on neurodevelopmental outcome1)

Abstract Background: Thyroid dysfunction is very common and is associated with neurodevelopmental impairments in preterm infants. Objectives: This study was conducted to determine the incidence and natural course of various thyroid dysfunctions and their impacts on neurodevelopmental outcomes among premature infants. Methods: A total of 177 infants were enrolled who were born at <34 weeks or whose birth weight was <1500 g and who underwent repeat thyroid function tests. We analyzed how various thyroid dysfunctions affected neurodevelopmental outcomes at 18 months of corrected age. Results: Thyroid dysfunction was noted in 88 infants. Hypothyroxinemia was observed in 23 infants, and their thyroid function was influenced by variable clinical factors. Free T4 levels were all normalized without thyroxine medication, and neurodevelopmental outcomes were not affected. In contrast, hyperthyrotropinemia was not associated with other clinical factors. Among 58 subjects who had hyperthyrotropinemia, only 31 infants showed normal thyroid-stimulating hormone (TSH) levels at follow-up tests. The remaining 27 infants had persistently high TSH levels, which significantly and poorly influenced the neurodevelopmental outcomes. Conclusions: Thyroid dysfunction is common among preterm infants. With the exception of persistent hyperthyrotropinemia, it generally does not affect neurodevelopmental outcomes. However, the beneficial effects of thyroid hormone therapy in patients with persistent hyperthyrotropinemia merits further study.

Risk factor analysis of parenteral nutrition‐associated cholestasis in extremely low birth weight infants

Parenteral nutrition (PN) provides an alternative nutrition source for preterm infants who are intolerant of enteral nutrition. However, prolonged PN increases the risk of PN‐associated cholestasis (PNAC). We conducted this study to determine the incidence and risk factors of PNAC in extremely low birth weight (ELBW) infants.

Clinical description of a neonate carrying the largest reported deletion involving the 10p15.3p13 region

Chromosome 10p deletion is a rare disorder. This is the largest deletion in chromosome 10p reported to date and the first to be diagnosed in the early neonatal period because of severe clinical manifestations. This rare case might help to understand the genotype‐phenotype spectrum in infants with 10p deletion.

Feasibility of an Early Discontinuation of Thyroid Hormone Treatment in Very-Low-Birth-Weight Infants at Risk for Transient or Permanent Congenital Hypothyroidism.

Background/Aims: This prospective study was conducted to investigate the feasibility of an early discontinuation of thyroid hormone treatment in very-low-birth-weight (VLBW) infants with congenital hypothyroidism (CH). Methods: We enrolled VLBW infants between January 2011 and December 2012. The infants were divided into the hypothyroid and normal thyroid function groups according to the results of a thyroid function test. We performed an early off-therapy trial at 24 months of age. Results: Of the 182 VLBW infants enrolled, 15 were lost to follow-up and 167 were finally enrolled. In total, 24 infants (14.4%) were assigned to the hypothyroid function group and were treated with thyroid hormone. Younger gestational age and a lower birth weight were associated with hypothyroid function. In the hypothyroid function group, hypothyroidism (HT) and hyperthyrotropinemia (HTT) were observed in 13 and 11 infants, respectively. There were no differences in the clinical characteristics between the HT and HTT groups. Overall, 24 infants discontinued thyroxine medication at 24 months of age after normal results had been confirmed by radiologic work-ups, including thyroid ultrasonography and technetium-99m scans. All infants were successfully weaned off thyroxine and maintained euthyroid function. Conclusion: Early discontinuation of thyroid hormone replacement therapy is possible in the majority of VLBW infants with CH.

Neonatal Hemoperitoneum Secondary to Hemorrhage from Omental Venous Malformation

Hemoperitoneum in the neonate is uncommon. We report our experience with a neonate who suddenly developed hemoperitoneum in late gestation. Ascites with right pleural effusion initially suggested fetal hydrops. However, a decrease in hemoglobin with bloody ascites from the paracentesis gave the impression of hemoperitoneum. Ultrasonography and computed tomography showed no abnormality in the solid organs. Using 3-mm laparoscopic exploration, we found the omental mass and excised it. It was histologically confirmed as a venous malformation. Venous malformation of the omentum with significant bleeding requiring exploration is a very rare condition in the neonate, but it should be considered as a cause of neonatal hemoperitoneum.

Establishing a reference range for triiodothyronine levels in preterm infants.

OBJECTIVES Thyroid dysfunction affects clinical complications in preterm infants and older children. However, thyroid hormone replacement in preterm infants has no proven benefits, possibly owing to the lack of an appropriate reference range for thyroid hormone levels. We aimed to establish a reference range for triiodothyronine (T3) levels at 1-month postnatal age (PNA) in preterm infants. METHODS This retrospective study included preterm infants born at a tertiary referral neonatal center at gestational age (GA)<35 weeks with no apparent thyroid dysfunction, for 6 consecutive years, with follow-up from PNA 2 weeks to 16 weeks. Using thyroid function tests (TFT), the relationships between T3 levels and thyrotropin (TSH) and free thyroxine (fT4) levels, birth weight, GA, postmenstrual age (PMA), and PNA were examined. The conversion trend for fT4 to T3 was analyzed using the T3/fT4 ratio. RESULTS Overall, 464 TFTs from 266 infants were analyzed, after excluding 65 infants with thyroid dysfunction. T3 levels increased with fT4 levels, birth weight, GA, PMA, and PNA but not with TSH levels. The T3/fT4 ratio also increased with GA, PNA, and PMA. The average T3 level at 1 month PNA was 72.56 ± 27.83 ng/dL, with significant stratifications by GA. CONCLUSIONS Relatively low T3 and fT4 levels in preterm infants were considered normal, with T3 levels and conversion trends increasing with GA, PMA, and PNA. Further studies are required to confirm the role of the present reference range in thyroid hormone replacement therapy.