Randomized Controlled Trial of High-Flow Nasal Cannula in Preterm Infants After Extubation.

OBJECTIVES: Our aim is to compare the efficacy and safety of high-flow nasal cannula (HFNC) against those of nasal continuous positive airway pressure (NCPAP) or nasal intermittent positive-pressure ventilation (NIPPV) after extubation in preterm infants. METHODS: This prospective, randomized, noninferiority trial was conducted in 6 tertiary NICUs. Infants born at <34 weeks who needed noninvasive ventilation after extubation were enrolled. We randomly assigned infants to an HFNC group when HFNC was used or to an NCPAP/NIPPV group when NCPAP or NIPPV was used. The primary outcome was treatment failure within 7 days after extubation. We then examined clinical aspects of treatment failure with HFNC use. RESULTS: In total, 176 and 196 infants were assigned to the HFNC and NCPAP/NIPPV groups, respectively. The HFNC group showed a significantly higher rate of treatment failure than that of the NCPAP/NIPPV group, with treatment failure occurring in 54 infants (31%) compared with 31 infants (16%) in the NCPAP/NIPPV group (risk difference, 14.9 percentage points; 95% confidence interval, 6.2-23.2). Histologic chorioamnionitis (P = .02), treated patent ductus arteriosus (P = .001), and corrected gestational age at the start of treatment (P = .007) were factors independently related to treatment failure with HFNC use. CONCLUSIONS: We found HFNC revealed a significantly higher rate of treatment failure than NCPAP or NIPPV after extubation in preterm infants. The independent factors associated with treatment failure with HFNC use were histologic chorioamnionitis, treated patent ductus arteriosus, and a younger corrected gestational age at the start of treatment.

Heart-rate evaluation using fetal ultrasonic Doppler during neonatal resuscitation.

BACKGROUND: The objective of the present study was to verify the speed and accuracy of fetal ultrasonic Doppler (fetal Doppler) in measuring heart rate of newborns at rest, including preterm, low-birthweight infants, and its efficacy during neonatal resuscitation, including cases of neonatal asphyxia. METHODS: A three-lead electrocardiogram and fetal Doppler were used to measure resting heart rates in 100 newborns, including 48 preterm, low-birthweight infants, at 0 to 72 h after birth. Times to display heart rate were compared between electrocardiogram and fetal Doppler by the Bland-Altman analysis and Wilcoxon signed-rank test. The time required for the fetal Doppler to measure heart rate during neonatal resuscitation was also assessed. RESULTS: In 100 newborns, the mean error of the resting heart rate in 1,293 measurement points was 0.07 beats/min. To display the heart rate, the fetal Doppler required a median time of 5 s, and electrocardiogram required a median time of 10 s (P < 0.001). During neonatal resuscitation, the heart rate was measured within 10 s in 18 of 21 cases (86%) and displayed with a median time of 5 s; this was measured in all neonatal asphyxia cases (9/9, 100%). CONCLUSIONS: Fetal Doppler can measure heart rate in newborns accurately and rapidly and is useful for evaluating heart rate not only at rest but also during neonatal resuscitation, especially in asphyxia.

Intestinal Failure-Associated Liver Disease and Eicosapentaenoic Acid/Arachidonic Acid Ratio.

Intestinal failure-associated liver disease (IFALD) is a fatal complication of short bowel syndrome managed with parenteral nutrition. A clinical cohort study reported the usefulness of parenteral administration of fish-derived omega-3 fatty acids in improving IFALD; however, no biomarker has been developed as yet. The authors report the case of a preterm infant with IFALD complicated by extensive short bowel syndrome. Intravenous administration of omega-3 fatty acids were introduced using Omegaven®at the age of 4 mo for IFALD. The IFALD improved with an increase in Eicosapentaenoic acid (EPA)/ Arachidonic acid (AA) ratio (from 0.08 to 1.99) 7 d after the intravenous treatment. It is important to administer omega-3 fatty acids intravenously at an early stage for IFALD associated with extensive short bowel syndrome. A low EPA/AA ratio may be a serum marker of disease activity in IFALD.

Target value of oxygen saturation during the first 10 min after birth.

BACKGROUND: During neonatal resuscitation, careful oxygenation is needed. Pulse oximetry is recommended to evaluate the need for oxygenation, but it is not clear whether peripheral perfusion is adequate for the evaluation of arterial oxygen saturation (SpO2 ). Additionally, there has been no study on the changes in SpO2 immediately after birth in Japan, despite the indispensable need for definitive oxygenation criteria. METHODS: A prospective observational study was performed in neonates at gestational age 35-41 weeks. An SpO2 measurement probe was attached to the neonates immediately after birth at the right palm or wrist, and the perfusion index (PI), pulse rate, and SpO2 were measured until 10 min after birth. RESULTS: Sixty neonates were examined. Stable PI was obtained soon after birth, preceding SpO2 measurement. The median PI (%) was constant at approximately 1.3, and the median SpO2 at 2-10 min was 70%, 81%, 82%, 87%, 89%, 92%, 92%, 94%, and 95%, respectively. The current target value for SpO2 in the Neonatal Cardiopulmonary Resuscitation (NCPR) guideline in Japan is approximately the 25th percentile. CONCLUSION: PI is stable and sufficient in the early postnatal period, meaning that peripheral perfusion is adequate for the measurement of SpO2 . The current target SpO2 used in the NCPR guidelines is at approximately the 25th percentile and is thought to be sufficient for meeting oxygenation criteria.

Early postnatal alteration of body composition in preterm and small-for-gestational-age infants: implications of catch-up fat.

The concept of the developmental origins of health and disease is based on studies by Barker et al. They proposed a hypothesis that undernutrition in utero permanently changes the body's structure, function, and metabolism in ways that lead to atherosclerosis and insulin resistance in later life. In addition, profound effects on the extent of body fatness and insulin sensitivity are demonstrated, if there is a "mismatch" between prenatal and postnatal environments. In previous studies, undernutrition in utero has been evaluated simply by birth weight itself or birth weight for gestational age, and the degree of mismatch has been estimated by postnatal rapid weight gain. Recently, we investigated subcutaneous fat accumulation in small-for-gestational-age infants and found that a rapid catch-up in skinfold thickness developed prior to the body weight catch-up. Furthermore, insulin-like growth factor-I and lipoprotein lipase mass concentrations also demonstrate rapid increase during the neonatal period with fat accumulation. Investigating the precise mechanisms of developmental origins of health and disease including mediating metabolic and hormonal factors may provide a new approach to prevent atherosclerosis and insulin resistance. Better management of undernutrition during gestation and neonatal growth during the early postnatal period is an important theme for future health.

Residual blood volume in the umbilical cord of extremely premature infants.

BACKGROUND: The aim of this study was to investigate residual blood volume in the umbilical cord of extremely premature infants. METHODS: Twenty extremely premature infants were held at or below the placenta while the umbilical cord was clamped and cut at approximately 2-3 cm from the umbilicus within 30 s after birth. The umbilical cord was then clamped near the placenta to obtain a length of approximately 30 cm and cut. The residual blood volume in the segment of cord was drained and measured in milliliters. RESULTS: Mean birthweight was 846 ± 172 g (range, 587-1180 g). The average length of the clamped segment of umbilical cord was 29.8 ± 1.5 cm (range, 27-32 cm). Total residual blood volume and residual blood volume per cm were 15.5 ± 6.7 mL (range, 6-25 mL) and 0.5 ± 0.2 mL/cm (range, 0.2-0.8 mL/cm), respectively. The residual cord blood volume per kilogram of infant weight per 30 cm was 17.7 ± 5.5 mL/kg/30 cm (range, 8.9-29.0 mL/kg/30 cm). CONCLUSION: Infants could receive approximately 18 mL/kg of whole blood by one-time milking of 30 cm umbilical cord. With an average hematocrit of 40%, this volume is equivalent to approximately 13 mL of packed red blood cells (hematocrit 55%).

Gray matter volumetric MRI differences late-preterm and term infants.

Gray matter develops rapidly during the third trimester of pregnancy, which is a critical period for lipid deposition. We measured brain volume in term and late-preterm infants to determine if it is related to disabilities in late-preterm infants. In addition, we measured serum lipid concentrations to investigate the relationship between brain volume and lipid nutrition. Magnetic resonance imaging scans were obtained in 16 late-preterm and 13 term infants. We measured cerebrum, gray matter, and white matter volumes. We performed serum cholesterol, triglyceride (TG), and lipoprotein analyses in cord blood by high-performance liquid chromatography using gel permeation columns to assess lipid nutritional levels. The gray matter volume and percent cerebrum volume of gray matter were significantly smaller in late-preterm infants (p<0.001). Head circumference and cerebrum and white matter volume did not differ between the two groups. Gray matter volume correlated positively with gestational age (r=0.647, p<0.001), head circumference (r=0.688, p<0.001), and high-density lipoprotein (HDL)-TG levels (r=0.496, p=0.006). Late-preterm infants had a normal head circumference and a lower gray matter volume than term infants. Gestational age and head circumference were significantly associated with gray matter volume. Only HDL-TG levels were significantly associated with gray matter volume. HDL-TG might contribute to the transport of fatty acids and gray matter development during the postnatal period. Thus, delayed gray matter development may partly contribute to neurodevelopmental disabilities in late-preterm infants.

Treatment responses for disseminated intravascular coagulation in 25 children treated with recombinant thrombomodulin: a single institution experience.

INTRODUCTION: Recombinant thrombomodulin (rTM), which degrades factors Va and VIIIa by activating protein C, has been developed as a new drug for treating disseminated intravascular coagulation (DIC). MATERIALS AND METHODS: Since July 2009, we have treated 25 children with DIC using rTM (380 U/kg/day, or 130 U/kg/day for newborns) as a first-line therapy. Median duration of rTM administration was 5 consecutive days (range, 2-13 days). We employed DIC criteria of the Japan Welfare and Health Ministry. The first day on which rTM treatment was given was defined as day 1. RESULTS: Median patients age was 3 years. Underlying diseases were hematological disorders (n=13) and severe infection (n=12). Overall, 20 of the 25 patients had recovered from DIC by day 7 and 22 of the 25 patients remained alive at day 28. Median Pediatric Logistic Organ Dysfunction score improved from 11 on day 1 to 2 on day 7 (p=0.009). Laboratory data (median) on day 7 (prothrombin time (PT) ratio, 1.15; fibrin and fibrinogen degradation products (FDP), 9.6 mg/l; D-dimer, 1.6 mg/l FEU; antithrombin, 112%; protein C, 105%) were significantly improved compared to results on day 1 (PT ratio, 1.39; FDP, 21.6 mg/l; D-dimer, 6.4 mg/l FEU; antithrombin, 86%; protein C, 54%). Whereas, 5 patients failed to respond and serious bleeding events were observed in 2 newborns. CONCLUSION: The efficacy of rTM cannot be assessed from the present dataset, due to several limitations such as the small heterogenous patient cohort, and the lack of age- and disease-matched controls. Nevertheless, this case-series remains important in terms of enabling further prospective control studies to evaluate the efficacy of rTM in children.

Early postnatal changes of lipoprotein subclass profile in late preterm infants.

BACKGROUND: Late preterm infants (LPIs; 34-37 gestational weeks at birth) have higher risk for several morbidities than do term infants (TIs). It has been suggested that a cholesterol and fatty acid supply may improve their outcomes. We investigated the lipoprotein subclass profile in LPIs to evaluate their early postnatal lipid metabolism. METHODS: Eighty-one infants (25 LPIs, 56 TIs) were included. Cholesterol and triglyceride (TG) concentrations in 12 lipoprotein subclasses were measured at birth and at 1 month using HPLC. RESULTS: In LPIs, the cord blood exhibited higher cholesterol concentrations in medium and large subclasses of very low-density lipoprotein (VLDL), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) compared to the values in TIs. During the first month of life, LPIs had greater increases in cholesterol concentrations of medium and large subclasses of VLDL than TIs, whereas postnatal increases in cholesterol concentrations of medium and large subclasses of LDL and HDL were smaller. TG concentrations were not different in each VLDL subclass at birth and at 1 month. CONCLUSIONS: In LPIs, cord blood lipoprotein subclass profiles and the early postnatal change exhibited different, especially in cholesterol concentrations.

Incorporation of biaryl units into the 5' and 3' ends of sense and antisense strands of siRNA duplexes improves strand selectivity and nuclease resistance.

Small interfering RNA (siRNA) is a noncoding RNA with considerable potential as a new therapeutic drug for intractable diseases. siRNAs can be rationally designed and synthesized if the sequences of the disease-causing genes are known. In this paper, we describe the synthesis and properties of siRNAs modified with biaryl units. We found that incorporation of biaryl units into the 5' and 3' ends of sense and antisense strands of siRNA duplexes improved strand selectivity and nuclease resistance.

Synthesis of nuclease-resistant siRNAs possessing universal overhangs.

RNA interference (RNAi) induced by small interfering RNA (siRNA) has emerged as a powerful technique for the silencing of gene expression at the post-transcriptional level. It has been shown that in the RNAi machinery, the 3'-overhang region of a guide strand (an antisense strand) of siRNA is recognized by the PAZ domain in the Argonaute protein, and the 2-nucleotide (nt) 3'-overhang is accommodated into a binding pocket composed of hydrophobic amino acids in the PAZ domain. Based on this background information, we designed and synthesized siRNAs possessing aromatic compounds at their 3'-overhang regions. It was found that the modified siRNAs possessing aromatic compounds are more potent than the siRNAs without the 3'-overhang regions. Further, the silencing activities of the modified siRNAs are almost equal to those of normal siRNAs with natural nucleosides at their 3'-overhang regions. We also found that the siRNAs possessing the aromatic compounds at their 3'-overhang region could be used to inhibit hepatitis C virus (HCV) replication. Moreover, the RNAs with aromatic groups at their 3'-ends were more resistant to nucleolytic degradation by snake venom phosphodiesterase (SVPD) (a 3'-exonuclease) than natural RNAs. The aromatic compounds described in this report do not have functional groups capable of forming hydrogen bonds with nucleobases. Therefore, we expect that they can serve as the universal overhang units that can improve the nuclease resistance of siRNAs.

Effect of incorporation of alkyl linkers into siRNAs on RNA interference.

Unintended (off-target) transcript silencing is a critical problem associated with RNA interference (RNAi)-based therapeutic applications. This paper shows that the incorporation of appropriate alkyl linkers at the center of the sense strands can suppress the off-target effects induced by the sense strands without reducing the RNAi-inducing activity of the antisense strands.

Synthesis of nuclease-resistant siRNAs possessing benzene-phosphate backbones in their 3'-overhang regions.

We describe the synthesis and silencing activities of siRNA possessing N(1)-[3,5-bis(hydroxymethyl)phenyl]thymine (b(t)) in their 3'-overhang regions. We found that an siRNA possessing b(t) in the 3'-overhang region was more effective than an siRNA with natural nucleosides and the siRNA possessing 1,3-bis(hydroxymethyl)benzene (b) without a nucleobase at the 3'-overhang region in in vitro experiment using HeLa cells system. Furthermore, the RNA possessing b(t) at its 3'-end was more resistant to nucleolytic hydrolysis by snake venom phosphodiesterase (a 3'-exonuclease) than the RNA possessing the natural nucleoside 2'-deoxythymidine at the 3'-end. Thus, the compound b(t) will be a novel 3'-overhang moiety that can enhance the silencing activity and nuclease-resistant property of siRNAs.

Synthesis and silencing properties of siRNAs possessing lipophilic groups at their 3'-termini.

Short interfering RNAs (siRNAs) conjugated with lipophilic groups at their 3'-termini were synthesized. The silencing activities of these siRNAs were examined by a dual-luciferase assay. It was found that the '-end of the passenger strand (sense strand) was better than the guide strand (antisense strand) for connecting bulky lipophilic molecules, particularly a rigid molecule such as cholesterol.

Synthesis and silencing properties of siRNAs possessing lipophilic groups at their 3'-termini.

Short-interfering RNAs (siRNAs) conjugated with lipophilic groups at their 3'-termini were synthesized. The properties of the synthesized siRNAs were examined in detail, and it was found that at low concentrations, their silencing abilities were dependent on the positions of the modifications and the types of organic molecules attached. Although the modification of siRNAs with palmitic acid or oleic acid at the 3'-end slightly reduced their silencing activities, siRNAs had enough abilities to induce RNAi at 10 nM concentrations. On the other hand, the modification of siRNAs with cholesterol at the 3'-end of the passenger strand was tolerated; however, the modification at the guide strand significantly reduces its silencing activity. The siRNAs modified with the lipophilic groups did not possess ability to penetrate the plasma membranes of HT-1080 cells without the transfection reagent. However, the results described in this report will aid in designing novel siRNAs with cell membrane-permeable molecules.