Euiseok Jung

Kwak JI, et al. Korean Circ J. 2027 ;57:e47. https://doi.org/10.4070/kcj.2026.0106

Background: Ureaplasma spp. colonization/infection has been implicated in the inflammatory pathogenesis of bronchopulmonary dysplasia (BPD) in very low birth weight (VLBW) infants, but the benefit of targeted macrolide therapy remains uncertain. We evaluated respiratory outcomes associated with early Ureaplasma positivity in VLBW infants and assessed feasibility and preliminary efficacy of a standardized intravenous azithromycin regimen in a nested pilot randomized trial. Methods: This single-center study comprised (1) a retrospective cohort of inborn VLBW infants (< 1,500 g) born between July 2017 and December 2021 who underwent Ureaplasma screening within 24 h after birth, and (2) a prospective, double-blind, randomized, placebo-controlled pilot trial nested among Ureaplasma -positive infants requiring significant respiratory support. In the cohort, outcomes included moderate-to-severe and severe BPD at 36 weeks’ postmenstrual age and home oxygen therapy. Multivariable logistic regression adjusted for gestational age, sex, preterm premature rupture of membranes, histologic chorioamnionitis, antenatal steroid exposure, patent ductus arteriosus treatment, and sepsis. In the trial, infants were randomized 1:1 to intravenous azithromycin for 14 days (10 mg/kg/day for 7 days, then 5 mg/kg/day for 7 days) or placebo. Microbiologic response at 2 weeks and safety, including QTc, were assessed. Results: Among 536 VLBW infants, 34 (6.3%) were Ureaplasma positive. Ureaplasma -positive infants had higher rates of moderate-to-severe BPD (76.5% vs. 41.0%), severe BPD (67.6% vs. 36.0%), and home oxygen therapy (46.2% vs. 19.1%). After adjustment, Ureaplasma positivity remained associated with moderate-to-severe BPD (adjusted odds ratio [aOR] 3.86, 95% confidence interval [CI] 1.44–10.35) and severe BPD (aOR 2.93, CI 1.21–7.10). In the pilot trial ( n = 26; 13 per group), moderate-to-severe BPD occurred in 61.5% (8/13) with azithromycin versus 84.6% (11/13) with placebo, and severe BPD in 46.2% (6/13) versus 76.9% (10/13). Loss of detectable Ureaplasma by culture at 2 weeks occurred in 13/13 azithromycin-treated infants, while 5/13 placebo infants remained positive. No QTc prolongation or clinically significant safety concerns attributable to azithromycin were observed. Conclusion: Early Ureaplasma positivity in VLBW infants was associated with substantially worse respiratory outcomes. A two-week intravenous azithromycin regimen was feasible, microbiologically active, and showed directionally favorable estimates for BPD without an observed safety signal. Larger microbiology-guided trials are warranted. Trial registration: KCT0002373 (registered 7 July 2017).

To evaluate gestational age (GA)-specific associations between antenatal corticosteroid (ACS) exposure and early physiologic vulnerability and neonatal outcomes in preterm infants. This retrospective cohort study used Korean Neonatal Network data and included infants born 2013-2021 with birth weight <1500 g or GA < 32 weeks. ACS exposure was categorized as complete, incomplete, or none. Multivariable logistic regression estimated adjusted odds ratios, with GA-stratified analyses and a prespecified subgroup of infants born at <25 weeks. ACS exposure was associated with reduced need for advanced resuscitation at birth, reduced risk of severe intraventricular hemorrhage and decreased mortality, with the strongest associations before 32 weeks' gestation. In infants born at <25 weeks, any ACS exposure was associated with greater physiologic stability and improved survival versus no ACS exposure. ACS exposure was associated with improved physiologic stability and survival in preterm infants, with benefits greater at lower GAs.

To evaluate the feasibility and early physiologic effects of postoperative invasive neurally-adjusted ventilatory assist (NAVA) in neonates with severe congenital diaphragmatic hernia (CDH). Retrospective observational study of inborn neonates with CDH who received invasive NAVA during the post-repair ventilator weaning phase. Ventilator parameters, blood gas variables, respiratory indices, and diaphragm-based efficiency measures were evaluated serially within infants at 0, 12, 24, and 48 hours after NAVA initiation. Of 123 inborn infants with CDH, 19 with high disease severity received postoperative invasive NAVA. Oxygen requirements decreased over time, with favorable changes in gas exchange by 48 hours. The oxygenation index declined without increased ventilator pressures. Neuroventilatory and neuromechanical efficiency remained stable, including in infants with type D defects. All infants were successfully weaned from invasive mechanical ventilation. Postoperative invasive NAVA was feasible and well tolerated in neonates with severe CDH, including those with type D defects and prior extracorporeal membrane oxygenation support.

Objective Develop a birth anthropometry-based model to estimate initial endotracheal tube (ETT) insertion depth for infants with birth weight p < 0.001). A combined quadratic model showed the strongest fit (adjusted R² = 0.70), outperforming single parameter rules. Conclusion In neonates <500 g, a quadratic weight-length model improves the prediction of radiograph-defined midtracheal ETT depth and offers a practical bedside guide for initial placement.

Objective To evaluate gestational age (GA)-specific associations between antenatal corticosteroid (ACS) exposure and early physiologic vulnerability and neonatal outcomes in preterm infants. Study Design This retrospective cohort study used Korean Neonatal Network data and included infants born between 2013 and 2021 with birth weight < 1 500 g or GA < 32 weeks. ACS exposure was categorized as complete, incomplete, or none. Multivariable logistic regression estimated adjusted odds ratios, with GA-stratified analyses and a prespecified subgroup of infants born at < 25 weeks. Results ACS exposure was associated with lower delivery room resuscitation intensity, reduced risk of severe intraventricular hemorrhage, and decreased mortality, with strongest associations observed before 32 weeks. In infants born at < 25 weeks, any ACS exposure was associated with greater physiologic stability and improved survival compared with no ACS exposure. Conclusions ACS exposure was associated with improved physiologic stability and survival in preterm infants, with benefits greater at lower GAs.

Objective To quantify agreement between oscillometric non-invasive blood pressure (NIBP) and invasive arterial blood pressure (IBP) in infants <500 g during the first postnatal week. Study design Retrospective cohort of infants with a birth weight <500 g admitted to a tertiary NICU (2011–2023). Paired IBP–NIBP readings obtained within 1 min were analyzed. Bland–Altman plots quantified bias and 95% limits of agreement for systolic (SBP), diastolic (DBP) and mean arterial pressure (MAP). Results Thirty-six infants (median gestation of 26.2 weeks) contributed 337 paired measurements. Mean (±SD) IBP vs. NIBP were 47.3 ± 10.4 vs. 49.4 ± 9.3 mm Hg (SBP), 29.2 ± 7.0 vs. 28.3 ± 8.2 mm Hg (DBP) and 35.1 ± 7.7 vs. 35.2 ± 7.9 mm Hg (MAP). Mean bias was +2.1 ± 6.8 mm Hg (SBP), –0.9 ± 6.7 mm Hg (DBP) and +0.1 ± 5.4 mm Hg (MAP), satisfying AAMI/ESH/ISO criteria (≤5 mm Hg mean difference, ≤8 mm Hg SD). Bias remained <3 mm Hg without inotropes; MAP bias rose to +1.3 mm Hg with inotropic support. Conclusion Oscillometric NIBP compared to IBP provided acceptable agreement in hemodynamically stable neonates <500 g. Whereas, invasive arterial monitoring remains preferable in unstable neonates.