Factors Associated with Clinical Response to Low-Dose Dexamethasone Therapy for Bronchopulmonary Dysplasia in Very Low Birth Weight Infants

Purpose@#To identify factors associated with the clinical response to low-dose dexamethasone therapy (LDDT) in preterm infants for bronchopulmonary dysplasia (BPD). @*Methods@#We used a retrospective medical record review to evaluate preterm infants who were born before 32 weeks of gestation or with a birth weight less than 1,500 g. All infants were admitted to the neonatal intensive care unit at a tertiary academic hospital between January 2010 and June 2019, and received LDDT for BPD. The preterm infants’ respiratory severity scores (RSS) were calculated from the first day of LDDT to the day of extubation, or the last day of LDDT. A good response was defined as a decreasing RSS with a slope greater than 0.181. A poor response was defined as a non-decreasing RSS, or a decreasing RSS with a slope less than 0.181 during LDDT. A total dose of 1.1 mg/kg was administered for 10 days for each single course of LDDT. @*Results@#A total of 51 preterm infants were included in the final analysis. Thirty preterm infants (58.8 %) were in the good response group, and 21 preterm infants (41.2%) were in the poor response group. There were no significant differences in gestational age, birth weight, and sex between the good response group and poor response group. Preterm premature rupture of membrane and histologic chorioamnionitis were significantly associated with a poor response to LDDT. Higher RSS on the first day of the LDDT was associated with a good response to LDDT. @*Conclusion@#Antenatal infection and/or inflammation may be associated with an unfavorable response to postnatal LDDT for BPD. Preterm infants with more severe respiratory failure seem to benefit more from LDDT for BPD.

Clinical Features of Late-Onset Circulatory Collapse in Preterm Infants

PURPOSE: This study aimed to investigate the incidence and clinical features of late-onset circulatory collapse (LCC) in preterm infants. METHODS: Medical records of 327 preterm infants (born before 32 gestational weeks) admitted to the neonatal intensive care unit of Seoul National University Bundang Hospital between January 2014 and December 2017 were reviewed. LCC was defined as sudden onset of refractory hypotension occurring after 7 days of life without obvious causes, which responded to glucocorticoid administration. Clinical characteristics and outcomes in infants with LCC were compared with those in infants with hypotension associated with identifiable causes, which developed after 7 days of life. RESULTS: Among 327 preterm infants who enrolled in this study, 65 infants developed hypotension with oliguria after 7 days of life. Among these 65 infants, 35 (53.8%) met the criteria for LCC and 30 (46.2%) were diagnosed with hypotension associated with other identifiable causes. No statistically significant differences were observed in the baseline pre- and perinatal characteristics between infants with LCC and those with hypotension associated with other causes. Infants with hypotension associated with other causes showed a higher mortality rate than those with LCC (33.3% vs. 5.7%, P=0.004). The mean gestational age and birth weight of infants with LCC were 27+5±2+1 weeks and 963±245 g, respectively. LCC occurred at a mean postnatal age of 18 days. The median body weight at the time of diagnosis of LCC was 1,200 g. No association was observed between LCC and gestational age. CONCLUSION: Among preterm infants born before 32 gestastional weeks who developed hypotension after 7 days of life, nearly 50% were diagnosed with LCC without apparent identifiable causes. Infants with LCC showed a lower mortality rate than those with hypotension associated with other causes.

Decreased Incidence of Necrotizing Enterocolitis after Introduction of Exclusive Breast Milk Feeding in a Single Neonatal Intensive Care Center

PURPOSE: To evaluate the effects of exclusive breast milk feeding (BMF) on the incidence of necrotizing enterocolitis (NEC) in preterm infants. METHODS: All newborn infants, born at <32 weeks of gestation and weighing <1,500 g, admitted to the neonatal intensive care center at Seoul National University Bundang Hospital during the study period, were included. The study was divided into period I: pre-exclusive BMF (January 2010–March 2014) and period II: exclusive BMF (April 2014–December 2016). RESULTS: A total of 374 infants were enrolled in this study, with 174 in period I and 174 in period II. The incidence of NEC was 11.5% in period I and 3.4% in period II. As the mean gestational age and birth weight were significantly greater in infants in period II, the difference in the incidence of NEC between the two periods was adjusted by gestational age. After adjustment, the incidence of NEC in period II was significantly lower than in period I (P=0.024). CONCLUSION: Exclusive BMF significantly reduced the incidence of NEC in a single neonatal intensive care center.

Comparison on the profiles of a modified Borg scale and the pediatric dyspnea scale during an induced bronchoconstriction in children with clinical asthma

PURPOSE: Dyspnea is the cardinal symptom of asthma, but it is difficult to quantify clinically. Although modified Borg (mBorg) scale has been successfully used in adult, but there has been some difficulties to apply in children. Recently, Pediatric Dyspnea Scale (PDS) was adequately designed and has been widely used. The aim of this study is to compare 2 evaluating scales of dyspnea provoked by induced-bronchoconstriction in childhood asthma. METHODS: Seventy-three clinically suspected children with asthma were enrolled in this study. Each ‘fractional exhaled nitric oxide (FeNO)’ was documented. Forced expiratory volume in 1 second (FEV₁), mBorg score and PDS score were recorded during methacholine provocation test. RESULTS: Mapping using canonical plot demonstrated global similarity between 2 scales with some distinctive features. Whereas mBorg score showed more diverse categories in low level of dyspnea, PDS score did in medium level of it. A distribution of dyspnea perception score at a 20% decrease in FEV₁ relative to baseline (PS₂₀), a perception score of dyspnea at 20% fall in FEV1 of 2 scales represented similar wide, biphasic feature. Statistical relevance was verified with spearman correlation (R(s)=0.903, P<0.001) and Bland-Altman analysis. PS₂₀ of both scores and FeNO had no statistical relationship. While relationship between PS20 by mBorg score and the concentration of methacholine at 20% fall in FEV₁ (PC₂₀) was not significant (R(s)=0.224, P=0.154), that between PS₂₀ by PDS and PC₂₀ was weak positive (R(s)=0.29, P=0.063). CONCLUSION: PDS had similar pattern to assess the dyspnea with the mBorg scale suggesting adequacy of PDS in evaluating pediatric clinical asthma. We expect these scales to help clinical practice in complementary ways.