Incidence, Risk Factors, Short-term Outcomes, and Microbiome of Ventilator-associated Pneumonia in Very-low-birth-weight Infants: Experience at a Single Level III Neonatal Intensive Care Unit

BACKGROUND

Ventilator-associated pneumonia (VAP) is a common hospital-acquired infection in neonates on invasive mechanical ventilation, resulting in high morbidity and mortality. The objective of this study is to determine the incidence, risk factors, short-term outcomes and microbiome associated with VAP in very-low-birth-weight (VLBW) infants born at <32 weeks of gestational age (GA).

METHODS

Retrospective study of intubated VLBW infants born at <32 weeks of GA admitted to the Los Angeles General Medical Center neonatal intensive care unit from July 2015 to July 2021 who had routine tracheal aspirate cultures obtained. Neonates were retrospectively classified into 3 groups, confirmed VAP, suspected VAP and no VAP, for comparison of risk factors, outcomes and airway microbial colonization.

RESULTS

Eighty-seven infants met inclusion criteria with a mean GA of 26.1 ± 1 weeks and mean birth weight of 812 ± 281 g. The incidence of VAP was 7.8 per 1000 ventilator days, and the most common causative organisms were Gram-positive organisms (39%), predominantly coagulase-negative Staphylococcus. Duration of postnatal dexamethasone exposure predicted VAP compared to no VAP (coefficient, 0.31; 95% CI 0.03-0.59; P = 0.03) after adjusting for duration of intubation, surfactant use and antenatal steroid exposure. Infants with VAP had higher rate of grade 2/3 bronchopulmonary dysplasia (P = 0.03) and longer hospital stay (P = 0.04).

CONCLUSIONS

VAP occurs at a high rate in VLBW infants who are exposed to prolonged dexamethasone use. It is predominantly caused by Gram-positive organisms.

Hemodynamic assessment by neonatologist using echocardiography: Primary provider versus consultation model

Hemodynamic instability is very common in sick neonates and the currently used traditional hemodynamic monitoring tools lack sensitivity and specificity. Hemodynamic evaluation on echocardiography can provide direct information regarding the pathophysiology causing the hemodynamic instability and help the bedside clinician in making a personalized treatment approach based upon the deranged pathophysiology. Assessment of cardiac function and hemodynamics is essential in the management of neonates with cardiorespiratory failure, and hence neonatologist-performed echocardiography is becoming an essential tool in modern neonatal care. Depending on the level and size of the NICU, there is a daily need for echocardiography, and for a subset of sick infants, serial echocardiographic assessments are warranted. Comprehensive guidelines for neonatologists performing echocardiography and targeted neonatal echocardiography have been published providing a framework for training and quality assurance. There has been a significant interest among the providers to learn echocardiography skills. This manuscript explores the various needs of neonatal care providers around echocardiography, the current challenges neonatologists face in learning echocardiography, and how they, especially neonatal fellows, can learn these important skills during their training.

Milrinone in persistent pulmonary hypertension of newborn: a scoping review

Persistent pulmonary hypertension of the newborn (PPHN) is a common neonatal condition in newborns admitted to the neonatal intensive care units (NICUs). PPHN has still a high mortality and morbidity. Inhaled nitric oxide (iNO) is the first line vasodilator therapy for PPHN in high income countries. In low-to-middle income countries (LMICs), availability of iNO remains scarce and expensive. The purpose of this scoping review was to evaluate the current existing literature for milrinone therapy in PPHN and to identify the knowledge gaps in milrinone use in infants with PPHN. The available evidence for milrinone remains limited both as monotherapy and as an adjuvant to iNO. The studies were heterogeneous, conducted in different settings, with different populations and more importantly the endpoints of these trials were short-term outcomes such as changes in oxygenation and blood pressure. Large prospective studies investigating long-term outcomes, mortality, and the need for Extracorporeal membrane oxygenation (ECMO) are warranted. Randomized controlled trials with milrinone as monotherapy are needed in LMICs where iNO availability remains limited. IMPACT: Milrinone has a potential role in the management of PPHN both as an adjuvant to iNO as well as a monotherapy. This scoping review identified the problems existing in the published literature on milrinone and the barriers to generalization of these results. Multi-centre randomized controlled trials on milrinone, especially involving centers from low- and middle-income countries are needed, where it can be evaluated as first-line pulmonary vasodilator therapy.

Effectiveness of Simulation Training in Acquiring Echocardiography Skills among Neonatology Care Providers

OBJECTIVES

 The objective of this study was to test the hypothesis that simulation training improves echocardiography skills.

STUDY DESIGN

 In this prospective study, 43 participants (16 neonatologists, 26 neonatology fellows, and 1 nurse practitioner) were tested on the simulator after 4 hours of didactic sessions on topographical cardiac anatomy and standard echocardiographic views. Participants were given 20 minutes to obtain and save the standard views. After the simulation hands-on training for 8 hours over 3 days, they were tested again. Each image was scored from 0 to 3 based on the image quality. Pre- and postsimulator training data were compared using both automated and visual scoring methods.

RESULTS

 After the hands-on simulator training, the automated median (interquartile) score for the quality of acquired images increased from 36 (22, 43) to 55 (48, 58), p < 0.0001. The increase was similar using visual scoring. The number of views with acceptable or good image quality (scores of 2 or 3) increased from 11 (6, 16) to 20 (17, 21), p < 0.0001. The neonatology fellows and faculty, as well as those with or without prior echocardiography experience, demonstrated significant improvement.

CONCLUSIONS

 Echocardiography simulation is an effective tool in improving echocardiography skills among neonatology care providers.

KEY POINTS

· Simulation is effective in acquiring echocardiography skills among neonatology care providers.. · Simulation improves image acquisition in those with and without prior echocardiography experience.. · Effectiveness of simulation in retaining the acquired echocardiography skill should be investigated..

Effect of Maternal Preeclampsia on Cardiac Structure and Function in Very Low Birth Weight Infants

OBJECTIVE

 We aimed to determine whether exposure to severe maternal preeclampsia (PE) in very low birth weight (VLBW) infants is associated with hypertrophic cardiac changes and altered hemodynamics.

STUDY DESIGN

 Case-control study of VLBW infants born at Los Angeles General Medical Center from May 2015 to August 2023, who had an echocardiogram within the first 7 days of life. Cases were infants exposed to maternal PE and controls were infants not exposed to maternal PE matched by birth weight (BW) 1:1. Laboratory, placental pathology results, hemodynamic data and clinical outcomes were collected and compared between cases and control infants.

RESULTS

 A total of 43 cases matched by BW with control infants were studied. There were no significant anatomical cardiac changes by echocardiography between cases and control infants. Cases had significantly higher blood pressure within the first 72 hours of life and lower ejection fraction (EF), fractional shortening, and peak systolic flow velocity through their patent ductus arteriosus (PDA) within the first week of life. Cases were more likely to be smaller despite being born at a later gestational age (GA), as well as small for GA with placental weight less than 10th percentile compared to control infants.

CONCLUSION

 Our findings indicate that infants born to mothers with PE have higher systemic vascular resistance as evidenced by elevated blood pressure, and lower EF and shortening fraction and higher pulmonary vascular resistance as evidenced by lower peak flow velocity through the PDA. We did not observe hypertrophic cardiac changes in exposed infants. These findings should be considered in clinical decision-making during management of these infants.

KEY POINTS

· VLBW infants exposed to severe PE have higher rate of Small for gestational age and smaller placentas.. · VLBW infants exposed to severe PE have higher systemic vascular resistance during transitional period and lower EF and fractional shortening.. · VLBW infants exposed to severe PE have higher pulmonary vascular resistance..

Transient Hypoglycemia and Biochemical Differences in Infants Less Than 1,250 G at Birth Fed Human Milk with Human Milk-Derived Fortifier versus Cow Milk-Derived Fortifier

OBJECTIVE

 Fortification of human milk (HM) with either human milk-derived fortifier (HMDF) or cow milk-derived fortifier (CMDF) is important in preterm infants. The objective is to compare the incidence of hypoglycemia, and biochemical values in infants less than 1,250 g at birth fed HMDF versus CMDF.

STUDY DESIGN

 It is a retrospective cohort study on infants less than 1,250 g at birth who were fed with HMDF or CMDF. Hypoglycemia was defined as blood glucose (BG) level equal to or less than 60 mg/dL within 72 hours of full enteral feeds when off total parenteral nutrition and intravenous fluids.

RESULTS

 Ninety infants were enrolled (HMDF = 61, CMDF = 29). HMDF group had a higher rate of hypoglycemia (46 vs. 24%; p = 0.048) after achievement of full enteral feeding. The median minimum BG was lower (61 vs. 71; p ≤ 0.01), while blood urea nitrogen (12 vs. 6; p ≤ 0.01) and albumin (3.1 vs. 2.7; p ≤ 0.01) were higher in HMDF group compared with CMDF.

CONCLUSION

 At full enteral feedings in infants less than 1,250 g at birth, an HMDF diet may predispose to hypoglycemia needing intervention. Close monitoring of BG levels once off parenteral nutrition is recommended.

KEY POINTS

· Exclusive human milk (EHM) feeding results in better nutritional indices.. · EHM feeding at higher calorie/ounce improves growth.. · Blood glucose needs to be monitored when off TPN during EHM feeding..

Noninvasive Ventilation

Systematic Reviews and Randomized clinical trials have shown that the use of noninvasive ventilation (NIV) compared to invasive mechanical ventilation reduces the risk of bronchopulmonary dysplasia and or mortality. Most commonly used NIV modes include nasal continuous positive airway pressure, bi-phasic modes, such as, bi-level positive airway pressure, nasal intermittent positive pressure ventilation, high flow nasal cannula, noninvasive neurally adjusted ventilatory assist, and nasal high frequency ventilation are discussed in this review.

Economic and Clinical Impact of Using Human Milk-Derived Fortifier in Very Low Birth Weight Infants

Background: Implementation of exclusive human milk (EHM) feeding defined as mother's own milk or donor human milk fortified with human milk-derived fortifiers can place an economic burden on institutions. Methods: Retrospective study of very low birth weight (VLBW) infants before and after the implementation of EHM feedings. Neonatal demographics and clinical outcomes including necrotizing enterocolitis, severe retinopathy of prematurity, bronchopulmonary dysplasia, late-onset sepsis, days on parenteral nutrition (PN), and length-of-stay were collected. The net cost to the institution was estimated using published data. Results: Sixty-four infants in the pre-EHM period and 57 infants in the post-EHM period were enrolled. Net product acquisition cost in 2020 and 2021 was $884,823. The EHM feeding guideline led to a reduction in the mean length of stay and mean days of PN use by 6.3 and 6.8 days per infant, respectively. This led to a cost saving of $1,813,444 ($31,815 per infant). No significant difference in incidence of short-term morbidities was observed. Combining the cost avoidance from clinical outcomes, the estimated financial impact over 2 years excluding insurance reimbursement was an estimated $ 913,840 ($16,032 per infant). Conclusion: Implementation of EHM-based feeding in VLBW infants is a cost-effective option for neonatal intensive care units that can result in reduced length of stay and days on PN without adversely impacting short-term morbidities.

Evaluation of the Puritan Bennett™ 980 Ventilator System Safety and Performance in the Real-World Setting

Purpose

Mechanical ventilation is a life-supporting intervention but is associated with known risks and complications. To improve the efficacy and safety profile of mechanical ventilation, manufacturers have developed advanced ventilator settings, modes, and alarm strategies to optimize ventilation for patient needs while avoiding complications. However, there is little real-world data published on the deployment of ventilator technology. The main objective of this study was to assess the clinical safety and performance of the Puritan Bennett™ 980 Ventilator System (PB980) using real-world clinical data collected from a diverse, global patient population.

Methods

This was a multi-center, post-market registry study that included nine sites: four in the United States of America, one in Europe, and four in China. Patients were enrolled into the registry if they were intended to be treated with a PB980. Data collection began at the start of ventilation and continued until extubation off the ventilator or up to seven days of ventilation, whichever occurred first. Subjects were divided by age into three categories: infants (0-365 days), pediatric (1-17 years), and adult (18 years and older). The primary outcome was device-related complication rate.

Results

Two-hundred-and-eleven subjects were enrolled (41 infants, 48 pediatric, and 122 adults). Sixteen deaths, unrelated to device deficiency, occurred during the data collection timeframe (relative frequency: 7.58, 95% CI: 4.40, 12.0). Only one device-related adverse event was reported (relative frequency: 0.47% 95% CI: 0.01%, 2.61%).

Conclusion

Ventilation by the PB980 was delivered safely in this multi-center observational study, which included a diverse sample of patients with broad ventilatory needs.

Common Clinical Scenarios of Systemic Hypertension in the NICU

Hypertension affects ∼1% to 3% of newborns in the NICU. However, the identification and management of hypertension can be challenging because of the lack of data-driven diagnostic criteria and management guidelines. In this review, we summarize the most recent approaches to diagnosis, evaluation, and treatment of hypertension in neonates and infants. We also identify common clinical conditions in neonates in whom hypertension occurs, such as renal vascular and parenchymal disease, bronchopulmonary dysplasia, and cardiac conditions, and address specific considerations for the evaluation and treatment of hypertension in those conditions. Finally, we discuss the importance of ongoing monitoring and long-term follow-up of infants diagnosed with hypertension.

Umbilical Cord Milking Versus Delayed Cord Clamping in Infants 28 to 32 Weeks: A Randomized Trial

OBJECTIVES

To determine whether rate of severe intraventricular hemorrhage (IVH) or death among preterm infants receiving placental transfusion with UCM is noninferior to delayed cord clamping (DCC).

METHODS

Noninferiority randomized controlled trial comparing UCM versus DCC in preterm infants born 28 to 32 weeks recruited between June 2017 through September 2022 from 19 university and private medical centers in 4 countries. The primary outcome was Grade III/IV IVH or death evaluated at a 1% noninferiority margin.

RESULTS

Among 1019 infants (UCM n = 511 and DCC n = 508), all completed the trial from birth through initial hospitalization (mean gestational age 31 weeks, 44% female). For the primary outcome, 7 of 511 (1.4%) infants randomized to UCM developed severe IVH or died compared to 7 of 508 (1.4%) infants randomized to DCC (rate difference 0.01%, 95% confidence interval: (-1.4% to 1.4%), P = .99).

CONCLUSIONS

In this randomized controlled trial of UCM versus DCC among preterm infants born between 28 and 32 weeks' gestation, there was no difference in the rates of severe IVH or death. UCM may be a safe alternative to DCC in premature infants born at 28 to 32 weeks who require resuscitation.

Effect of assessing velocity time integral at different locations across ventricular outflow tracts when calculating cardiac output in neonates

This study aims to evaluate the effect of assessing velocity time integral at different locations across ventricular outflow tracts for calculating cardiac output (CO) in neonates. Velocity time integral (VTI) and CO were measured at 3 different locations across right and left ventricular outflow tracts using transthoracic echocardiography in healthy term neonates without any major congenital heart disease. ANOVA with Bonferroni correction was used to determine the differences between the VTI and CO sampled at these three locations. Forty-one neonates met inclusion criteria with mean gestational age of 38.6 ± 1 weeks and mean birth weight of 3155 ± 463 g. The median hours after birth when echocardiography was obtained was 23 h (range 11-68 h after birth). Left CO were 121 ± 30 mL/kg/min, 155 ± 38 mL/kg/min, and 176 ± 36 mL/kg/min measured below the valve, hinges of the valve, and tip of the valve, respectively. Right CO were 197 ± 73 mL/kg/min, 270 ± 83 mL/kg/min, and 329 ± 104 mL/kg/min measured below the valve, hinges of the valve, and tip of the valve, respectively. A statistically significant difference (P < 0.001) was found in the VTI and CO measured at the 3 different locations across both left and right ventricular outflow tracts.     Conclusions: There is a significant difference in measurements of VTI and CO depending on the location of Doppler gate sampling across the ventricular outflow tracts. Consistency and precision in Doppler gate location are essential for measuring VTI and calculating CO while assessing changes in hemodynamic status in critically ill infants. What is Known: • Targeted Neonatal Echocardiography is increasingly applied to measure cardiac output in critically ill neonates and serial assessments are performed to assess the trend in changes in cardiac output. • Noninvasive measurement using velocity time integral to calculate cardiac output is commonly performed. However, location of Doppler sample gate to measure ventricular outflow tract velocity time integral is not consistent. What is New: • Statistically significant changes in measured velocity time integral and cardiac output are noted based on the location of Doppler gate sampling. • To monitor the cardiac output for trending, it is important to be consistent with regards to the location of the Doppler sample gate to assess changes in cardiac output in critically ill newborns.

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.

Outcomes of patent foramen ovale greater than 3 mm at birth in extremely low birthweight infants

BACKGROUND

Foramen ovale (FO) is an obligate fetal shunt that typically resolves after birth, although patency throughout life is not uncommon. The natural history of patent FO (PFO) is known in term infants, but less is known about its course in extremely preterm infants. We describe the echocardiographic changes in FO size from birth to discharge in extremely low birth weight (ELBW) infants in this retrospective study.

METHODS

Cohort was divided based on size of FO at birth. Size of FO at discharge was measured and evaluated relative to postnatal weight gain. Demographics and clinical outcomes were compared between the two groups.

RESULTS

Of the 54 ELBW infants, 50 were born with FO less than 3 mm in diameter (small), and 4 were born with FO greater than 3 mm (large). Of small defects, the majority (44/50, 88%) did not increase in size with weight gain, and minority (6/50, 12%) increased in size, and three of these 6 patients, FO grew to be slightly larger than 3 mm. In contrast, all large defects (4 of 4, 100%) nearly doubled in size with postnatal growth. These 4 ELBW infants with enlargement of FO had a flap valve evident on echocardiogram obtained prior to discharge, and subsequently closed on outpatient follow-up echocardiograms, although time to resolution was variable (6 months - 3 years). One infant had presumptive resolution because of the presence of flap valve.

CONCLUSION

No maternal or neonatal demographic characteristics were predictive of FO enlargement, although, demonstrable flap valve on discharge echocardiogram correlated with resolution of FO on outpatient follow-up echocardiogram. Therefore, based on our data, we recommend that ELBW infants born with large FO should have echocardiographic re-evaluation of the atrial septal opening prior to discharge, to specify the presence of a flap valve or lack thereof, which is an important detail that can help a neonatologist determine the need for outpatient cardiac follow-up.

Transcutaneous bilirubin levels in extremely preterm infants less than 30 weeks gestation

OBJECTIVE

The primary objective of this study was to determine the relationship between transcutaneous bilirubin (TcB) levels and total serum bilirubin (TSB) levels in extremely preterm infants.

STUDY DESIGN

We conducted a prospective multicenter study of extremely preterm infants less than 30 weeks gestation in California. Difference between paired TcB and TSB values were compared based on gestational age, birth weight, maternal race/ethnicity, chronological age as well as during and after phototherapy.

RESULTS

TSB values ranged from 0 to 12.6 mg/dl and the TcB values ranged from 0 to 14.2 mg/dl. TSB was predicted with a high degree of accuracy at TSB = 2.37 + 0.54 (TcB) with r = 0.786. There was good correlation across gestational age, birth weight, race/ethnic, chronological age subgroups as well as during and after phototherapy.

CONCLUSION

Our study supports the use of TcB as a screening tool for monitoring jaundice in extremely preterm infants.

Twin Premature Infants With Riboflavin and Biotin Deficiency Presenting With Refractory Lactic Acidosis, Rash, and Multiorgan Failure During Prolonged Parenteral Nutrition

We are reporting monochorionic, diamniotic twin premature infants born at 25 weeks and 6 days gestation with riboflavin (vitamin B2) and biotin (vitamin B7) deficiency, while on prolonged total parenteral nutrition (TPN) during vitamin shortage. They presented initially with skin rash, lactic acidosis, and thrombocytopenia. Both twins progressed to severe respiratory failure, severe lactic acidosis, with refractory vasodilatory shock, pancytopenia, ischemic bowel injury, acute kidney injury, liver injury, and capillary leak syndrome leading to death of twin A. The surviving twin B was diagnosed with riboflavin and biotin deficiency that presented with abnormal metabolic work up suggestive of maple syrup urine disease, glutaric acidemia type 2, and X-linked adrenoleukodystrophy. Twin B was started on riboflavin and biotin supplementation at 41 days of life, with rapid improvement in clinical findings and laboratory abnormalities within days of starting biotin and riboflavin supplementation. He was discharged home in stable condition at 49 weeks of postmenstrual age.

A Review of User-Centred Design Methods for Designing a Portable Oil Spill Skimmer

Boom and skimmer are mechanical techniques in Oil Spill Response and Recovery (OSRR) that collect oil from the water surface. However, there are several drawbacks of using boom and skimmer, such as the oil could pass over the boom during strong wind and high tides. Moreover, the currently available oil skimmer designed by the engineers is heavy-duty; in consequence, it is ineffective in shallow water. Thus, there is a need to develop a portable oil spill skimmer to complement the current drawbacks. Several journals on the fabrication of the oil spill skimmer were reviewed. Findings from literature shows that the development of oil spill skimmer lacks user requirements when designing a portable oil spill skimmer. This article provides a systematic review of Kansei Engineering and the Analytical Hierarchy Process in the product development process. Therefore, Kansei Engineering and Analytical Hierarchy Process (AHP) can be incorporated in the early stage of designing a portable oil spill skimmer. This paper also includes the application of Kansei Engineering and AHP in design research articles. Findings from observed articles indicate a lack of design and development technologies relating to products for environmental protection; the AHP and Kansei Engineering application is somewhat lacking. Moreover, the fabrication of an oil spill skimmer focuses more on technical specifications and includes fewer user requirements. As a result, the characteristics such as ease of use, robustness, and safety cannot be evaluated. The AHP and Kansei Engineering methodology can be extended to the design and manufacture of products for environmental protection.

Evaluation of Correlation and Agreement between SpO2/FiO2 ratio and PaO2/FiO2 ratio in Neonates

Objectives This article evaluates correlation and agreement between oxygen saturation (SpO2)/fraction of inspired oxygen (FiO2) (SF) ratio and partial pressure of oxygen (PaO2)/FiO2 (PF) ratio. It also derives and validates predictive PF ratio from noninvasive SF ratio measurements for clinically relevant PF ratios and derives SF ratio equivalent of PF ratio cutoffs used to define acute lung injury (ALI, PF < 300) and acute respiratory distress syndrome (ARDS, PF < 200).

Methods Retrospective cohort study including neonates with respiratory failure over a 6-year study period. Correlation and agreement between PF ratio with SF ratio was analyzed by Pearson's correlation coefficient and Bland–Altman analysis. Generalized estimating equation was used to derive PF ratio from measured PF ratio and derive corresponding SF ratio for PF ratio cutoffs for ALI and ARDS.

Results A total of 1,019 paired measurements from 196 neonates with mean 28 (± 4.7) weeks' gestational age and 925 (± 1111) g birth weight were analyzed. Strong correlation was noted between SF ratio and PF ratio (r = 0.90). Derived PF ratios from regression (1/PF = –0.0004304 + 2.0897987/SF) showed strong accuracy measures for PF ratio cutoffs < 200 (area under the curve [AUC]: 0.85) and < 100 (AUC: 0.92) with good agreement. Equivalent SF ratio to define ALI was < 450, moderate ARDS was < 355, and severe ARDS was < 220 with strong accuracy measures (AUC > 0.81, 0.84, and 0.93, respectively).

Conclusion SF ratio correlated strongly with PF ratio with good agreement between derived PF ratio from noninvasive SpO2 source and measure PF ratio. Derived PF ratio may be useful to reliably assess severity of respiratory failure in neonates. Further studies are needed to validate SF ratio with clinical illness severity and outcomes.

The effect of cooking duration on radical scavenging properties of Hypsizygus tessellatus and Pleurotus ostreatus

Mushrooms are a popular ingredient in the human diet due to their flavour, nutritional values and functional properties, in particular, their antioxidant potential. Most mushrooms are consumed after cooking and the impact of cooking methods and durations on the antioxidant properties of various edible mushrooms have been reported. However, the reports on the effect of cooking on the antioxidant properties of Hypsizygus tessellatus (shimeji), a widely consumed mushroom in East Asia, are limited. Therefore, this study aimed to investigate the effect of cooking duration on the radical scavenging properties of H. tessellatus. Pleurotus ostreatus was included for comparison purposes. Mushroom samples were prepared raw, boiled in distilled water for 1 min, 3 mins and 5 mins, then blended and centrifuged to obtain mushroom extracts. The mushroom extracts were evaluated for their radical scavenging properties using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Results showed that 1-min cooked H. tessellatus extract exhibited the highest radical scavenging activity (76.6±2.14% DPPH scavenging activity) while extract boiled for 5 mins had the lowest radical scavenging activity (62.9±6.08% DPPH scavenging activity). Thus, cooking time has a significant effect on the radical scavenging activity of H. tessellatus extract. In conclusion, the effect of cooking on H. tessellatus and P. ostreatus can be both beneficial and disadvantageous depending on the duration.

Bisindolylmaleimide Ligands Stabilize c-MYC G-Quadruplex DNA Structure and Downregulate Gene Expression

G-Quadruplex (G4) structures play a pivotal role in diverse biological functions, including essential processes, such as telomere maintenance and gene regulation. G4 structures formed in functional regions of genomes are actively pursued toward therapeutics and are targeted by small-molecule ligands that alter their structure and/or stability. Herein, we report the synthesis of bisindolylmaleimide-based (BIM) ligands, which preferentially stabilize parallel G4 structures of c-MYC and c-KIT oncogenes over the telomeric h-RAS1 G4 and duplex DNAs. The preferential stabilization of parallel G4s with BIM ligands is further validated by the DNA polymerase stop assay, where stop products were only observed for templates containing the c-MYC G4 sequence. Nuclear magnetic resonance (NMR) titration studies indicate that the lead ligand BIM-Pr1 forms a 2:1 complex with c-MYC G4 DNA with a K_D of 38 ± 5 μM. The BIM ligand stacks at the 5' and 3' quartets, with molecular modeling and dynamics studies supporting the proposed binding mode. The ligand is cytotoxic to HeLa cells and downregulates c-MYC gene expression. Collectively, the results present bisindolylmaleimide scaffolds as novel and powerful G4 targeting agents.

Late Preterm Infant With Postnatal Diagnosis of Renal Tubular Dysgenesis

A male infant born at 34 weeks' gestation presented with acute cardiorespiratory decompensation soon after birth followed by renal failure. Initial clinical course was complicated by ventilator requirement, bilateral pneumothoraces, and hypotension managed with multiple inotropes. Persistent renal failure with oliguria and renal ultrasound showing noncystic medical renal disease prompted further investigation. Whole-exome sequencing showed 2 pathologic mutations in the angiotensin-converting enzyme (ACE) gene, suggesting a diagnosis of renal tubular dysgenesis (RTD). Renal tubular dysgenesis is usually a fatal condition affecting the renin-angiotensin system with possible autosomal recessive inheritance. Acquired cases have been described in the setting of in utero exposure to medications such as nonsteroidal anti-inflammatory medications (NSAIDs) and ACE inhibitors. Renal tubular dysgenesis should be suspected in any neonate presenting with renal failure, refractory hypotension, ventilator requirement, hypoplastic lungs, renal ultrasound showing normal-sized echogenic noncystic kidneys with poor corticomedullary differentiation, and antenatal history significant for oligohydramnios. The overall prognosis of patients with RTD continues to improve with better ventilatory management and renal replacement therapies.

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.

Association between blood carboxyhemoglobin level and bronchopulmonary dysplasia in extremely low birthweight infants

Carboxyhemoglobin (CO-Hb) can be endogenously formed in the presence of oxidative stress and may be elevated in inflammatory lung disease. There is lack of evidence of its relationship with the development of bronchopulmonary dysplasia (BPD) in extremely low birthweight (ELBW) infants. The objective of the study is to evaluate the relationship between blood CO-Hb levels in the first 14 days of life (DOL) in ELBW infants and the development of BPD at 36 weeks postmenstrual age (PMA). This is a retrospective cohort study of 58 ELBW infants born at LAC-USC Medical Center between June 2015 and and June 2019 who survived to 36 weeks PMA. CO-Hb values were collected daily from DOL 1 to DOL 14. BPD definition using the recent 2019 NICHD criteria was used. Multivariate logistic regression was performed to determine the association between blood CO-Hb levels and BPD. Receiver operator curve was used to evaluate the ability of the median fraction of inspired oxygen (FiO₂) level used at DOL 11-14 in discriminating absent to mild BPD versus moderate to severe BPD. 58 ELBW infants were included in the study. 24 (41%) were diagnosed with moderate to severe BPD, while 34 (59%) were diagnosed with no to mild BPD. Severity of BPD was fairly discriminated by FiO₂ at DOL 11-14, but not with CO-Hb levels at any point within the first 14 DOL. The role and mechanism of CO-Hb production in this population need to be further studied.