Objective: This study aimed to evaluate the association between electrical activity of the diaphragm (Edi) waveform patterns and peripheral oxygen saturation (SpO 2 ) in extremely preterm infants who are ventilated with neurally adjusted ventilatory assist (NAVA). Study Design:We conducted a retrospective cohort study at a level III neonatal intensive care unit. Extremely preterm infants born at our hospital between November 2019 and November 2020 and ventilated with NAVA were included. We collected Edi waveform data and classified them into four Edi waveform patterns, including the phasic pattern, central apnea pattern, irregular low-voltage pattern, and tonic burst pattern. We analyzed the Edi waveform pattern for the first 15 h of collectable data in each patient. To investigate the association between Edi waveform patterns and SpO 2 , we analyzed the dataset every 5 min as one data unit. We compared the proportion of each waveform pattern between the desaturation (Desat [+]) and non-desaturation (Desat [-]) groups.Results: We analyzed collected data for 105 h (1260 data units). The proportion of the phasic pattern in the Desat (+) group was significantly lower than that in the Desat (-) group (p < .001). However, the proportions of the central apnea, irregular low-voltage, and tonic burst patterns in the Desat (+) group were significantly higher than those in the Desat (-) group (all p < .05). Conclusion:Our results indicate that proportions of Edi waveform patterns have an effect on desaturation of SpO 2 in extremely preterm infants who are ventilated with NAVA.

Advances in perinatal care have improved the prognosis for preterm neonates. 1,2 Among them, the administration of antenatal corticosteroids (ANS) is one of the most effective. Since Liggins et al first reported that maternal ANS administration reduced the incidence of neonatal respiratory distress syndrome (RDS) in 1972, 3 its clinical efficacy has been verified in many studies. 4-6 The beneficial effects of ANS have been reported not only in reducing the incidence of RDS, but also in reducing the incidence of

Background Metabolic bone disease (MBD) is a common disorder in extremely low‐birth‐weight (ELBW) infants. However, no studies have investigated whether high‐dose calcium (Ca) and phosphorus (P) supplementation by parenteral nutrition (PN) prevents MBD in ELBW infants. This study aimed to identify the effect of PN on MBD in ELBW infants. Methods We retrospectively analyzed ELBW infants who were admitted between April 2011 and March 2017. ELBW infants were divided into the low‐P group (n = 22) and the high‐P group (n = 26) according to the dose of parenteral P supply. Biochemical and radiological markers of MBD and treatments were analyzed. Results Mean daily parenteral intake of Ca and P in the first week was significantly higher in the high‐P group than in the low‐P group (both P ≤ .001). Serum alkaline phosphatase (ALP) levels were significantly higher in the low‐P group than in the high‐P group in the first month. ELBW infants in the low‐P group received alfacalcidol much more frequently than those in the high‐P group. There was a trend of a higher rate of x‐ray changes in the low‐P group than in the high‐P group. No infants developed bone fractures. Conclusion Appropriate P intake by PN is required to ensure high Ca intake, reduce ALP levels in the first month, and prevent MBD from hyperparathyroidism and does not worsen x‐ray findings in ELBW infants.

Objective This study aimed to clarify the effect of antenatal glucocorticoids (AGs) on the incidence of refractory hypotension (RH) in very low birthweight (VLBW) infants after the first week of life. Study Design We included VLBW infants born at a gestational age of <30 weeks and divided them into three groups: the complete group (born within 7 days of completing a single course [two doses] of AGs), the incomplete group (born without complete course), and the late delivery group (born at ≥8 days after a single course). We compared the incidence and period of onset of RH among the three groups. Results A total of 115 infants were enrolled. The incidence of RH in the first week of life was significantly lower in the complete group than in the other groups. However, there was no significant difference in the incidence of RH after the first week of life among the groups. Conclusion AGs contribute to circulatory stabilization during the first week of life, but this effect does not last after 1 or 2 weeks of administration. In infants who receive AGs, physicians should consider that the risk of RH after the first week of life is not low.

Background Serum alkaline phosphatase (ALP) is a useful bone turnover marker to diagnose metabolic bone disease in preterm infants. In Japan, serum ALP levels were generally measured using the Japan Society of Clinical Chemistry (JSCC) method. It is problematic that ALP levels measured using the JSCC method tend to be higher in people with blood types B and O regardless of the disease. For international standardization, since 2020, the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) method has been used as a reference method for ALP measurement instead of the JSCC method. However, no report has investigated the correlation between these two methods in neonates. We therefore aimed to compare the JSCC and IFCC methods and demonstrate a conversion formula in neonates. Methods In this retrospective study, we used a total of 402 samples in 49 preterm and 38 term infants. Serum ALP levels were measured using the JSCC and IFCC methods. Results Alkaline phosphatase measured using the JSCC method strongly correlated with that measured using the IFCC method in all blood types in preterm and term infants (P < 0.01 for all). Conclusions We found that the serum ALP levels measured using the IFCC method could be calculated as 0.34 times the ALP levels measured using the JSCC method in preterm and term infants with any blood type: ALP levels (IFCC method) = 0.34 × ALP levels (JSCC method).