Transcutaneous CO2 Monitoring in Extremely Low Birth Weight Premature Infants.

Extremely low birth weight (ELBW) premature infants are particularly susceptible to hypocarbia and hypercarbia, which are associated with brain and lung morbidities. Transcutaneous CO2 (TcCO2) monitoring allows for continuous non-invasive CO2 monitoring during invasive and non-invasive ventilation and is becoming more popular in the NICU. We aimed to evaluate the correlation and agreement between CO2 levels measured by a TcCO2 monitor and blood gas CO2 (bgCO2) among ELBW infants. This was a prospective observational multicenter study. All infants < 1000 g admitted to the participating NICUs during the study period were monitored by a TcCO2 monitor, if available. For each bgCO2 measured, a simultaneous TcCO2 measurement was documented. In total, 1828 pairs of TcCO2-bgCO2 values of 94 infants were collected, with a median (IQR) gestational age of 26.4 (26.0, 28.3) weeks and birth weight of 800 (702, 900) g. A moderate correlation (Pearson: r = 0.64) and good agreement (bias (95% limits of agreement)):(2.9 [-11.8, 17.6] mmHg) were found between the TcCO2 and bgCO2 values in the 25-70 mmHg TcCO2 range. The correlation between the TcCO2 and bgCO2 trends was moderate. CO2 measurements by TcCO2 are in good agreement (bias < 5 mmHg) with bgCO2 among premature infants < 1000 g during the first week of life, regardless of day of life, ventilation mode (invasive/non-invasive), and sampling method (arterial/capillary/venous). However, wide limits of agreement and moderate correlation dictate the use of TcCO2 as a complementary tool to blood gas sampling, to assess CO2 levels and trends in individual patients.

Two-Year Outcomes After Minimally Invasive Surfactant Therapy in Preterm Infants: Follow-Up of the OPTIMIST-A Randomized Clinical Trial.

Importance: The long-term effects of surfactant administration via a thin catheter (minimally invasive surfactant therapy [MIST]) in preterm infants with respiratory distress syndrome remain to be definitively clarified. Objective: To examine the effect of MIST on death or neurodevelopmental disability (NDD) at 2 years' corrected age. Design, Setting, and Participants: Follow-up study of a randomized clinical trial with blinding of clinicians and outcome assessors conducted in 33 tertiary-level neonatal intensive care units in 11 countries. The trial included 486 infants with a gestational age of 25 to 28 weeks supported with continuous positive airway pressure (CPAP). Collection of follow-up data at 2 years' corrected age was completed on December 9, 2022. Interventions: Infants assigned to MIST (n = 242) received exogenous surfactant (200 mg/kg poractant alfa) via a thin catheter; those assigned to the control group (n = 244) received sham treatment. Main Outcomes and Measures: The key secondary outcome of death or moderate to severe NDD was assessed at 2 years' corrected age. Other secondary outcomes included components of this composite outcome, as well as hospitalizations for respiratory illness and parent-reported wheezing or breathing difficulty in the first 2 years. Results: Among the 486 infants randomized, 453 had follow-up data available (median gestation, 27.3 weeks; 228 females [50.3%]); data on the key secondary outcome were available in 434 infants. Death or NDD occurred in 78 infants (36.3%) in the MIST group and 79 (36.1%) in the control group (risk difference, 0% [95% CI, -7.6% to 7.7%]; relative risk [RR], 1.0 [95% CI, 0.81-1.24]); components of this outcome did not differ significantly between groups. Secondary respiratory outcomes favored the MIST group. Hospitalization with respiratory illness occurred in 49 infants (25.1%) in the MIST group vs 78 (38.2%) in the control group (RR, 0.66 [95% CI, 0.54-0.81]) and parent-reported wheezing or breathing difficulty in 73 (40.6%) vs 104 (53.6%), respectively (RR, 0.76 [95% CI, 0.63-0.90]). Conclusions and Relevance: In this follow-up study of a randomized clinical trial of preterm infants with respiratory distress syndrome supported with CPAP, MIST compared with sham treatment did not reduce the incidence of death or NDD by 2 years of age. However, infants who received MIST had lower rates of adverse respiratory outcomes during their first 2 years of life. Trial Registration: anzctr.org.au Identifier: ACTRN12611000916943.

Oxygenation Instability during Bolus versus Continuous Feeding among Very Low Birth Weight Premature Infants, Supported by Noninvasive Ventilation: A Randomized Prospective Study.

OBJECTIVE: This study aimed to compare oxygenation instability, as documented by the oxygen saturation (SpO2) histograms, during bolus (over 30 minutes) versus continuous (over 2 hours) feeding among very low birth weight (VLBW) premature infants, supported with noninvasive ventilation (NIV). STUDY DESIGN: This was a randomized prospective study. VLBW infants supported with NIV received three consecutive feeds in a random order of bolus-continuous-bolus or continuous-bolus-continuous. During each feed, 30 minutes and 2 hours histograms were documented. RESULTS: Twenty-four infants (birth weight [mean ± standard deviation, SD] 820 ± 168 g, gestational age [mean ± SD] 27.0 ± 1.6 weeks) were included in our study (12 infants started with bolus feeding and 12 with continuous feeding) and 72 histograms were obtained (36 during bolus feeding and 36 during continuous feeding). No differences in mean fraction of inspired oxygen (FiO2), and number of apnea events were observed between the two feeding modes. Oxygenation instability as assessed by time spent in different SpO2 ranges and histogram types (stable or unstable) was comparable during bolus and continuous feedings. Changing feeding mode from bolus to continuous or vice versa did not significantly change the oxygenation instability of the group, though individual infants did show a consistence response to feeding length changes. CONCLUSION: Among VLBW infants supported with NIV, oxygenation instability, as documented by SpO2 histograms, was comparable between bolus and continuous feedings. Individual infants may benefit from specific feeding length, and this can be easily demonstrated by the SpO2 histograms. KEY POINTS: · Feeding length did not affect oxygenation instability of preterm infants on noninvasive respiratory Support.. · Oxygen saturation histograms allow objective quantification of oxygenation instability at the bedside.. · Individual infants benefit from specific feeding length, as demonstrated by SpO2 histograms..

The effect of changing respiratory rate settings on CO2 levels during nasal intermittent positive pressure ventilation (NIPPV) in premature infants.

OBJECTIVE: To examine the change in CO2, when applying NIPPV with either a low or a high rate in stable premature infants. STUDY DESIGN: Prospective, controlled, crossover study. Preterm infants on NIPPV were monitored by tcCO2 during two rate changes switching every hour between high (30 bpm) and low (10 bpm) set rates. RESULTS: Fifty premature infants (mean ± SD: 28.3 ± 2.4 weeks' gestation) were enrolled. Each infant had two rate changes; therefore, a hundred rate changes were studied. The mean change in tcCO2, i.e., ΔtcCO2 (95% confidence-interval), was -1.1 (-2.3 to 0.1) mmHg for increasing rate from low to high, and 0.46 (-0.49 to 1.41) mmHg for decreasing rate from high to low. CONCLUSION: Multiplying or dividing the rate settings by three did not significantly change the tcCO2 readings an hour after the change. These findings could affect the management of ventilation settings of NIPPV in premature infants. CLINICAL TRIAL REGISTRY: ClinicalTrials.gov ID: NCT04836689 , The name of the trial registry: "Influence of Respiratory Rate Settings on CO2 Levels During Nasal Intermittent Positive Pressure Ventilation (NIPPV)."

Oxygenation in the NICU: there is more to it than meets the eye.

IMPACT: Dormishian and colleagues in their study address an issue that care teams in the NICU encounter on a daily basis, regarding motion artifacts during oxygenation monitoring. In our commentary, we discuss the available tools that allow continuous noninvasive monitoring of oxygenation in the NICU, and modalities that increase the time premature infants spend in the desired SpO2 range and impact their clinical outcomes.

Oxygen saturation histogram classification system to evaluate response to doxapram treatment in preterm infants.

BACKGROUND: An oxygen saturation (SpO2) histogram classification system has been shown to enable quantification of SpO2 instability into five types, based on histogram distribution and time spent at SpO2 ≤ 80%. We aimed to investigate this classification system as a tool to describe response to doxapram treatment in infants with severe apnea of prematurity. METHODS: This retrospective study included 61 very-low-birth-weight infants who received doxapram. SpO2 histograms were generated over the 24-h before and after doxapram start. Therapy response was defined as a decrease of ≥1 histogram types after therapy start. RESULTS: The median (IQR) histogram type decreased from 4 (3-4) before to 3 (2-3) after therapy start (p < 0.001). The median (IQR) FiO2 remained constant before (27% [24-35%]) and after (26% [22-35%]) therapy. Thirty-six infants (59%) responded to therapy within 24 h. In 34/36 (94%) of the responders, invasive mechanical ventilation (IMV) was not required during the first 72 h of therapy, compared to 15/25 (60%) of non-responders (p = 0.002). Positive and negative predictive values of the 24-h response for no IMV requirement within 72 h were 0.46 and 0.94, respectively. CONCLUSIONS: Classification of SpO2 histograms provides an objective bedside measure to assess response to doxapram therapy and can serve as a tool to detect changes in oxygenation status around respiratory interventions. IMPACT: The SpO2 histogram classification system provides a tool for quantifying response to doxapram therapy. The classification system allowed estimation of the probability of invasive mechanical ventilation requirement, already within a few hours of treatment. The SpO2 histogram classification system allows an objective bedside assessment of the oxygenation status of the preterm infant, making it possible to assess the changes in oxygenation status in response to respiratory interventions.

Cardiopulmonary Exercise Testing in Childhood in Late Preterms: Comparison to Early Preterms and Term-Born Controls.

Background: Late preterm (340−366 weeks gestational age [GA]) infants may have abnormal pulmonary development and possible exercise physiology parameters. We aim to assess the effect of late prematurity on exercise capacity in childhood and to compare it to early preterm (EP) (born < 300 GA), and to term healthy control (TC) (>370 week GA). Methods: Late preterm and early preterm (7−10 years) completed a cardiopulmonary exercise test (CPET) and spirometry and were compared to EP and to TC. Results: Eighty-four children (age 9.6 ± 1.0 years, 48% girls) participated. Twenty-one former LP were compared to 38 EP (15 with Bronchopulmonary dysplasia (BPD) [EP+], 23 without BPD [EP−]) and to 25 TC children. Peak oxygen uptake (peakV̇O2) was statistically lower than in the TC, but within the normal range, and without difference from the EP (LP 90.2 ± 15.1%, TC 112.4 ± 16.9%, p < 0.001; EP+ 97.3 ± 25.5%, EP− 85.4 ± 20.8%, p = 0.016 and p < 0.001, respectively, when compared with TC). Lung function (FEV1) was lower than normal only in the EP+ (75.6 ± 14.9% predicted, compared with 12.5 ± 87.8 in EP−, 87.5 ± 16.9 in LP and 91.0 ± 11.7 in TC). Respiratory and cardiac limitations were similar between all four study groups. Conclusions: This study demonstrated lower exercise capacity (peakV̇O2) in former LP children compared with healthy term children. Exercise capacity in LP was comparable to that of EP, with and without BPD. However, the exercise test parameters, specifically peakV̇O2, were within the normal range, and no significant physiological exercise limitations were found.

Continuous versus Bolus Gastric Tube Feeding in Very Low Birth Weight Infants Supported with Noninvasive Respiratory Support: A Randomized, Pilot Study.

OBJECTIVES: This study aimed to compare time to full feeding (TFF) between continuous gastric feeding (CGF) and bolus feeding (BF) in very low birth weight (VLBW) infants supported with noninvasive ventilation (NIV) and to evaluate feasibility and identify methodological pitfalls for future large-scale studies. STUDY DESIGN: This study is a randomized controlled, prospective, pilot study. VLBW premature infants, supported with NIV, were randomized while still on trophic feeding <20 mL/kg/day to receive feeding over 2 hours of CGF or over 15- to 30-minute BF. The primary outcome was TFF. Analysis was done by intention to treat. RESULTS: Overall, 32 infants were included in this analysis, 17 in the CGF group and 15 in the BF group. Infants in the CGF group were significantly younger than the BF group (mean ± standard deviation [SD] gestational age [GA] 26.9 ± 1.2 vs. 28.9 ± 1.5 weeks, respectively). TFF was comparable with median (interquartile range [IQR]) for the two groups, 10.0 (10.0, 19.0) days in the BF group versus 12.0 (9.0, 13.0) days in the CGF group (p = 0.59). Feeding length was not found to significantly affect TFF in multivariate analysis correcting for GA. Groups were comparable in weight gain, gastrointestinal complications, length of NIV, bronchopulmonary dysplasia incidence, and age at discharge. Most infants from both groups (60% of BF and 70% of CGF) required changes in feeding length. CONCLUSION: In this pilot study, among VLBW infants supported with NIV, TFF was comparable between the BF and CGF groups. These results should be interpreted with caution due to the small sample size and despite the multivariate analysis correcting for the different GA. Interestingly, most infants required changes in feeding length regardless of their allocation. This feasibility study emphasizes the need for careful attention to randomization and strict feeding protocols including criteria for switching allocation in future large-scale studies aimed at determining the preferred feeding length during NIV in VLBW infants. KEY POINTS: · Among infants supported with NIV, length of feeding affects gastric venting.. · BF might increase gastrointestinal reflux, while continuous feeding hinders gastric decompression.. · Among infants supported by NIV, feeding tolerance was comparable between bolus and continuous groups..

Same baby, different care: variations in practice between neonatologists and pediatric intensivists.

The aim of the study was to identify and explore areas in neonatal care in which significant differences in clinical care exist, among neonatal intensive care (NICU) and pediatric intensive care (PICU) physicians. A questionnaire presenting three common scenarios in neonatal critical care-severe pneumonia, post-cardiac-surgery care, and congenital diaphragmatic hernia (CDH) was electronically sent to all PICU and NICU physicians in Israel. The survey was completed by 110 physicians. Significant differences were noted between NICU and PICU physicians' treatment choices. A non-cuffed endotracheal tube, initial high-frequency ventilation, and lower tidal volumes when applying synchronized-intermittent-mechanical-ventilation were selected more often by NICU physicians. For sedation/analgesia, NICU physicians treated as needed or by continuous infusion of a single agent, while PICU physicians more often chose to continuously infuse ≥ 2 medications. Fentanyl, midazolam, and muscle relaxants were chosen more often by PICU physicians. Morphine administration was similar for both groups. Treating CDH with pulmonary hypertension and systemic hypotension, NICU physicians more often began treatment with high dose dopamine and/or dobutamine, while PICU physicians chose low-dose adrenalin and/or milrinone. For vascular access NICU physicians chose umbilical lines most often, while PICU physicians preferred other central sites. CONCLUSION: Our study identified major differences in respiratory and hemodynamic care, sedation and analgesia, and vascular access between NICU and PICU physicians, resulting from field-specific consensus guidelines and practice traditions. We suggest to establish joint committees from both professions, aimed at finding the optimal treatment for this vulnerable population - be it in the NICU or in the PICU. WHAT IS KNOWN: • Variability in neonatal care between the neonatal and the pediatric intensive care units has been previously described. WHAT IS NEW: • This scenario-based survey study identified major differences in respiratory and hemodynamic care, sedation and analgesia, and vascular access between neonatologists and pediatric intensivists, resulting from lack of evidence-based literature to guide neonatal care, field-specific consensus guidelines, and practice traditions. • These findings indicate a need for joint committees, combining the unique skills and literature from both professions, to conduct clinical trials focusing on these specific areas of care, aimed at finding the optimal treatment for this vulnerable population - be it in the neonatal or the pediatric intensive care unit.

Effect of Minimally Invasive Surfactant Therapy vs Sham Treatment on Death or Bronchopulmonary Dysplasia in Preterm Infants With Respiratory Distress Syndrome: The OPTIMIST-A Randomized Clinical Trial.

Importance: The benefits of surfactant administration via a thin catheter (minimally invasive surfactant therapy [MIST]) in preterm infants with respiratory distress syndrome are uncertain. Objective: To examine the effect of selective application of MIST at a low fraction of inspired oxygen threshold on survival without bronchopulmonary dysplasia (BPD). Design, Setting, and Participants: Randomized clinical trial including 485 preterm infants with a gestational age of 25 to 28 weeks who were supported with continuous positive airway pressure (CPAP) and required a fraction of inspired oxygen of 0.30 or greater within 6 hours of birth. The trial was conducted at 33 tertiary-level neonatal intensive care units around the world, with blinding of the clinicians and outcome assessors. Enrollment took place between December 16, 2011, and March 26, 2020; follow-up was completed on December 2, 2020. Interventions: Infants were randomized to the MIST group (n = 241) and received exogenous surfactant (200 mg/kg of poractant alfa) via a thin catheter or to the control group (n = 244) and received a sham (control) treatment; CPAP was continued thereafter in both groups unless specified intubation criteria were met. Main Outcomes and Measures: The primary outcome was the composite of death or physiological BPD assessed at 36 weeks' postmenstrual age. The components of the primary outcome (death prior to 36 weeks' postmenstrual age and BPD at 36 weeks' postmenstrual age) also were considered separately. Results: Among the 485 infants randomized (median gestational age, 27.3 weeks; 241 [49.7%] female), all completed follow-up. Death or BPD occurred in 105 infants (43.6%) in the MIST group and 121 (49.6%) in the control group (risk difference [RD], -6.3% [95% CI, -14.2% to 1.6%]; relative risk [RR], 0.87 [95% CI, 0.74 to 1.03]; P = .10). Incidence of death before 36 weeks' postmenstrual age did not differ significantly between groups (24 [10.0%] in MIST vs 19 [7.8%] in control; RD, 2.1% [95% CI, -3.6% to 7.8%]; RR, 1.27 [95% CI, 0.63 to 2.57]; P = .51), but incidence of BPD in survivors to 36 weeks' postmenstrual age was lower in the MIST group (81/217 [37.3%] vs 102/225 [45.3%] in the control group; RD, -7.8% [95% CI, -14.9% to -0.7%]; RR, 0.83 [95% CI, 0.70 to 0.98]; P = .03). Serious adverse events occurred in 10.3% of infants in the MIST group and 11.1% in the control group. Conclusions and Relevance: Among preterm infants with respiratory distress syndrome supported with CPAP, minimally invasive surfactant therapy compared with sham (control) treatment did not significantly reduce the incidence of the composite outcome of death or bronchopulmonary dysplasia at 36 weeks' postmenstrual age. However, given the statistical uncertainty reflected in the 95% CI, a clinically important effect cannot be excluded. Trial Registration: anzctr.org.au Identifier: ACTRN12611000916943.

Rapid methicillin resistance diversification in Staphylococcus epidermidis colonizing human neonates.

Early in life, infants are colonized with multiple bacterial strains whose differences in gene content can have important health consequences. Metagenomics-based approaches have revealed gene content differences between different strains co-colonizing newborns, but less is known about the rate, mechanism, and phenotypic consequences of gene content diversification within strains. Here, focusing on Staphylococcus epidermidis, we whole-genome sequence and phenotype more than 600 isolates from newborns. Within days of birth, infants are co-colonized with a highly personalized repertoire of S. epidermidis strains, which are spread across the newborn body. Comparing the genomes of multiple isolates of each strain, we find very little evidence of adaptive evolution via single-nucleotide polymorphisms. By contrast, we observe gene content differences even between otherwise genetically identical cells, including variation of the clinically important methicillin resistance gene, mecA, suggesting rapid gene gain and loss events at rates higher than point mutations. Mapping the genomic architecture of structural variants by long-read Nanopore sequencing, we find that deleted regions were always flanked by direct repeats, consistent with site-specific recombination. However, we find that even within a single genetic background, recombination occurs at multiple, often non-canonical repeats, leading to the rapid evolution of patient-specific diverse structural variants in the SCCmec island and to differences in antibiotic resistance.

Respiratory morbidity in very low birth weight infants through childhood and adolescence.

OBJECTIVE: To describe the long-term (up to 18 years of age) respiratory outcomes of children and adolescents born at very low birth weight (VLBW; ≤1500 g) in comparison with that of children born >1500 g. METHODS: An observational, longitudinal, retrospective study comparing VLBW infants with matched controls, registered at a large health maintenance organization in Israel. Pulmonary outcomes collected anonymously from the electronic medical files included respiratory illness diagnoses, purchased medications for respiratory problems, office visits with either a pediatric pulmonologist or cardiologist and composite respiratory morbidity combining all these parameters. RESULTS: Our study included 5793 VLBW infants and 11,590 matched controls born between 1998 and 2012. The majority (99%) of VLBW infants were premature (born < 37 weeks' gestation), while 93% of controls were born at term. The composite respiratory morbidity was significantly higher in VLBW infants compared with controls in all age groups (relative risk [95% confidence interval]: 1 year: 1.22 [1.19-1.26], <2 years: 1.30 [1.27-1.34], 2-6 years: 1.29 [1.27-1.32], 6-12 years: 1.53 [1.47-1.59], 12-18 years: 1.46 [1.35-1.56]; respectively). Both VLBW infants and controls demonstrated a steady decline in the composite respiratory morbidity with aging. In VLBW infants, lower gestational age was associated with higher respiratory morbidity only until 2 years of age and the morbidity declined in each gestational age group until adolescence. CONCLUSION: Our study confirmed a strong association between VLBW and pulmonary morbidity. The higher prevalence of respiratory composite morbidity in VLBW infants persists over the years until adolescence. The respiratory morbidity is most evident in the first year of life and declines afterward.

Evaluation of audio-voice guided application for neonatal resuscitation: a prospective, randomized, pilot study.

OBJECTIVES: To examine whether audio-voice guidance application improves adherence to resuscitation sequence and recommended time frames during neonatal resuscitation. METHODS: A prospective, randomized, pilot study examining the use of an audio-voice application for guiding resuscitation on newborn mannequins, based on the Neonatal Resuscitation Program (NRP) algorithm. Two different scenarios, with and without voice guidance, were presented to 20 medical personnel (2 midwives, 8 nurses, and 10 physicians) in random order, and their performance videotaped. RESULTS: Audio-voice guided resuscitation compared with non-guided resuscitation, resulted in significantly better compliance with NRP order sequence (p<0.01), correct use of oxygen supplementation (p<0.01) and performance of MR SOPA (Mask, reposition, suction, open mouth, pressure, airway) (p<0.01), and shortened the time to "positive pressure ventilation" (p<0.01). CONCLUSIONS: In this pilot study, audio-voice guidance application for newborn resuscitation simulation on mannequins, based on the NRP algorithm, improved adherence and performance of NRP guidelines.

Cannula With Long and Narrow Tubing vs Short Binasal Prongs for Noninvasive Ventilation in Preterm Infants: Noninferiority Randomized Clinical Trial.

Importance: Use of cannulas with long and narrow tubing (CLNT) has gained increasing popularity for applying noninvasive respiratory support for newborn infants thanks to ease of use, perceived patient comfort, and reduced nasal trauma. However, there is concern that this interface delivers reduced and suboptimal support. Objective: To determine whether CLNT is noninferior to short binasal prongs and masks (SPM) when providing nasal intermittent positive pressure ventilation (NIPPV) in preterm infants. Design, Setting, and Participants: This randomized controlled, unblinded, prospective noninferiority trial was conducted between December 2017 and December 2019 at 2 tertiary neonatal intensive care units. Preterm infants born between 24 weeks' and 33 weeks and 6 days' gestation were eligible if presented with respiratory distress syndrome with the need for noninvasive ventilatory support either as initial treatment after birth or after first extubation. Analysis was performed by intention to treat. Interventions: Randomization to NIPPV with either CLNT or SPM interface. Main Outcomes and Measures: The primary outcome was the need for intubation within 72 hours after NIPPV treatment began. Noninferiority margin was defined as 15% or less absolute difference. Results: Overall, 166 infants were included in this analysis, and infant characteristics and clinical condition (including fraction of inspired oxygen, Pco2, and pH level) were comparable at recruitment in the CLNT group (n = 83) and SPM group (n = 83). The mean (SD) gestational age was 29.3 (2.2) weeks vs 29.2 (2.5) weeks, and the mean (SD) birth weight was 1237 (414) g vs 1254 (448) g in the CLNT and SPM groups, respectively. Intubation within 72 hours occurred in 12 of 83 infants (14%) in the CLNT group and in 15 of 83 infants (18%) in the SPM group (risk difference, -3.6%; 95% CI, -14.8 to 7.6 [within the noninferiority margin], χ2 P = .53). Moderate to severe nasal trauma was significantly less common in the CLNT group compared with the SPM group (4 [5%] vs 14 [17%]; P = .01). There were no differences in other adverse events or in the course during hospitalization. Conclusions and Relevance: In this study, CLNT was noninferior to SPM in providing NIPPV for preterm infants, while causing significantly less nasal trauma. Trial Registration: ClinicalTrials.gov Identifier: NCT03081611.

Antenatal betamethasone and the risk of neonatal hypoglycemia: it's all about timing.

INTRODUCTION: Our objective was to evaluate whether there is a relationship between the "time during the day" of maternal betamethasone administration between 24 and 34 weeks' gestation and the risk for neonatal hypoglycemia. MATERIAL AND METHODS: A retrospective study included cases between 2008 and 2018. Eligible cases were pregnant women with singleton pregnancies who received a single course of betamethasone between 24 and 34 weeks' gestation. Each woman was allocated into one of four pre-defined groups based on the time when intramuscular betamethasone was administered. Group 1 (23:00-04:59) represents the lowest daily natural corticosteroids' activity, group 2 (05:00-10:59) represents the peak daily natural corticosteroids' activity, whereas group 3 (11:00-16:59) and group 4 (17:00-22:59) present an intermediate natural state of steady corticosteroids' secretion and activity. The primary outcome of the study was the incidence of neonatal hypoglycemia (glucose level of less than 40 mg/dL). RESULTS: We have identified 868 women who received a single complete course of betamethasone, of which 353 women (40.7%) had a steroid treatment latency to delivery up to 14 days. The incidence of neonatal hypoglycemia was significantly higher in group 2 (39.5%, 30/76, p = 0.0063), compared to group 1, who had the lowest incidence of neonatal hypoglycemia (16.9%, 12/71), and to group 3 and group 4. CONCLUSIONS: The "time during the day" when betamethasone administered is important when considering the risk for neonatal hypoglycemia. The risk was significantly higher when betamethasone was administered during the peak time and significantly lower when administered at the nadir time of maternal endogenous corticosteroid activity.

[ALTERATIONS IN SENSITIVE MEASURES OF CARDIAC FUNCTION IN HEALTHY NEONATES DURING PHOTOTHERAPY].

OBJECTIVES: Phototherapy has been reported to reduce coronary blood flow in neonates but without affecting gross measures of cardiac function. The aim of our current study was to evaluate earlier, more sensitive changes in cardiac function during phototherapy. METHODS: Nineteen neonates with jaundice treated with phototherapy had Doppler echocardiographic evaluation, before, during and after phototherapy and were compared to 25 matched controls. Sensitive measures for cardiac performance in this study included left ventricular dimension, ventricular Doppler parameters and regional function assessment. RESULTS: Phototherapy was associated with a significant increase in heart rate. In addition, atrioventricular valve closure to opening interval decreased significantly during phototherapy while ventricular ejection times tended to decrease. However, left and right ventricular filling parameters and outflow velocity parameters, longitudinal tissue-Doppler annular velocities and myocardial performance indices were not affected by phototherapy and were similar to those in controls. Coronary blood velocities and integrals decreased significantly during phototherapy. CONCLUSIONS: Our study found no differences in early and sensitive measures of cardiac performance including the diastolic and systolic function, despite modestly lower flow in coronary arteries among healthy neonates during phototherapy.