Does the use of higher versus lower oxygen concentration improve neurodevelopmental outcomes at 18-24 months in very low birthweight infants?

BACKGROUND: Immediately after birth, the oxygen saturation is between 30 and 50%, which then increases to 85-95% within the first 10 min. Over the last 10 years, recommendations regarding the ideal level of the initial fraction of inspired oxygen (FiO2) for resuscitation in preterm infants have changed from 1.0, to room air to low levels of oxygen (< 0.3), up to moderate concentrations (0.3-0.65). This leaves clinicians in a challenging position, and a large multi-center international trial of sufficient sample size that is powered to look at safety outcomes such as mortality and adverse neurodevelopmental outcomes is required to provide the necessary evidence to guide clinical practice with confidence. METHODS: An international cluster, cross-over randomized trial of initial FiO2 of 0.3 or 0.6 during neonatal resuscitation in preterm infants at birth to increase survival free of major neurodevelopmental outcomes at 18 and 24 months corrected age will be conducted. Preterm infants born between 230/7 and 286/7 weeks' gestation will be eligible. Each participating hospital will be randomized to either an initial FiO2 concentration of either 0.3 or 0.6 to recruit for up to 12 months' and then crossed over to the other concentration for up to 12 months. The intervention will be initial FiO2 of 0.6, and the comparator will be initial FiO2 of 0.3 during respiratory support in the delivery room. The sample size will be 1200 preterm infants. This will yield 80% power, assuming a type 1 error of 5% to detect a 25% reduction in relative risk of the primary outcome from 35 to 26.5%. The primary outcome will be a composite of all-cause mortality or the presence of a major neurodevelopmental outcome between 18 and 24 months corrected age. Secondary outcomes will include the components of the primary outcome (death, cerebral palsy, major developmental delay involving cognition, speech, visual, or hearing impairment) in addition to neonatal morbidities (severe brain injury, bronchopulmonary dysplasia; and severe retinopathy of prematurity). DISCUSSION: The use of supplementary oxygen may be crucial but also potentially detrimental to preterm infants at birth. The HiLo trial is powered for the primary outcome and will address gaps in the evidence due to its pragmatic and inclusive design, targeting all extremely preterm infants. Should 60% initial oxygen concertation increase survival free of major neurodevelopmental outcomes at 18-24 months corrected age, without severe adverse effects, this readily available intervention could be introduced immediately into clinical practice. TRIAL REGISTRATION: The trial was registered on January 31, 2019, at ClinicalTrials.gov with the Identifier: NCT03825835.

A Pilot Randomized Trial of Heart Rate Monitoring Using Conventional Versus a New Electrocardiogram Algorithm during Neonatal Resuscitation at Birth.

Current guidelines support the use of a cardiac monitor during neonatal resuscitation. Infants born preterm randomized to a novel electrocardiogram algorithm displayed a heart rate sooner than the conventional electrocardiogram algorithm. Although resuscitation outcomes were not different, the availability of an earlier heart rate may benefit neonatal providers during high-risk resuscitations. TRIAL REGISTRATION: ClinicalTrials.govNCT04587934.

Higher versus Lower Oxygen Concentration during Respiratory Support in the Delivery Room in Extremely Preterm Infants: A Pilot Feasibility Study.

BACKGROUND: Optimal starting oxygen concentration for delivery room resuscitation of extremely preterm infants (<29 weeks) remains unknown, with recommendations of 21-30% based on uncertain evidence. Individual patient randomized trials designed to answer this question have been hampered by poor enrolment. HYPOTHESIS: It is feasible to compare 30% vs. 60% starting oxygen for delivery room resuscitation of extremely preterm infants using a change in local hospital policy and deferred consent approach. STUDY DESIGN: Prospective, single-center, feasibility study, with each starting oxygen concentration used for two months for all eligible infants. POPULATION: Infants born at 23 + 0-28 + 6 weeks' gestation who received delivery room resuscitation. Study interventions: Initial oxygen at 30% or 60%, increasing by 10-20% every minute for heart rate < 100 bpm, or increase to 100% for chest compressions. PRIMARY OUTCOME: Feasibility, defined by (i) achieving difference in cumulative supplied oxygen concentration between groups, and (ii) post-intervention rate consent >50%. RESULTS: Thirty-four infants were born during a 4-month period; consent was obtained in 63%. Thirty (n = 12, 30% group; n = 18, 60% group) were analyzed, including limited data from eight who died or were transferred before parents could be approached. Median cumulative oxygen concentrations were significantly different between the two groups in the first 5 min. CONCLUSION: Randomized control trial of 30% or 60% oxygen at the initiation of resuscitation of extremely preterm neonates with deferred consent is feasible. TRIAL REGISTRATION: Clinicaltrials.gov NCT03706586.

Achieved oxygen saturations and retinopathy of prematurity in extreme preterms.

OBJECTIVE: To identify achieved oxygen saturations (SpO2) associated with increased risk of severe retinopathy of prematurity (ROP). DESIGN: This is a secondary analysis of the Surfactant Positive Airway Pressure and Pulse Oximetry Trial (SUPPORT)randomised controlled trial. SpO2 was recorded up to 36 weeks' postmenstrual age. Saturations through 9 postnatal weeks were explored graphically, and logistic regression models were created to predict severe ROP. SETTING: 20 centres of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. PATIENTS: 984 surviving infants of 24-27 weeks' gestational age born in 2005-2009. INTERVENTIONS: SUPPORT targeted SpO2 to a lower (85%-89%) or higher (91%-95%) range through 36 weeks' postmenstrual age or off respiratory support. MAIN OUTCOME MEASURES: Severe ROP defined as threshold ROP, ophthalmological surgery or bevacizumab treatment. RESULTS: There were statistically significant interactions between duration of oxygen supplementation and percentage of time in certain achieved saturation ranges. Specifically, for infants who spent at least 2 weeks on oxygen in postnatal weeks 1-5, a higher percentage of time at 91%-96% SpO2 was associated with increased odds of severe ROP. For infants who spent at least 3 weeks on oxygen in postnatal weeks 6-9, a higher percentage of time at 97%-100% SpO2 was associated with increased odds of severe ROP. Other significant risk factors were lower gestational age and birth weight, non-Hispanic white versus black race, prospectively defined severe illness, late-onset sepsis or meningitis, and clinical centre. CONCLUSIONS: Among extremely preterm survivors to discharge, the association between SpO2 and severe ROP depended on the timing and duration of oxygen supplementation.

Haemodynamic effects of premedication for neonatal intubation: an observational study.

OBJECTIVE: To examine changes in blood pressure (BP), cardiac output (CO) and cerebral regional oxygen saturation (rScO2) with administration of premedication for neonatal intubation. DESIGN: Pilot, prospective, observational study. Oxygen saturation, heart rate, CO, rScO2 and BP data were collected. Monitoring began 5 min prior to premedication and continued until spontaneous movement. SETTING: Single-centre, level 3 neonatal intensive care unit PATIENTS: 35 infants, all gestational ages. 81 eligible infants: 66 consented, 15 refused. INTERVENTIONS: Intravenous atropine, fentanyl or morphine, ±cisatracurium MAIN OUTCOME MEASURES: BP, CO, rScO2 RESULTS: n=37 intubations. Mean gestational age and median birth weight were 31 4/7 weeks and 1511 g. After premedication, 10 episodes resulted in a BP increase from baseline and 27 in a BP decrease. Of those whose BP decreased, 17 had <20% decrease and 10 had ≥20% decrease. Those with <20% BP decrease took an average of 2.5 min to return to baseline while those with a ≥20% BP decline took an average of 15.2 min. Three did not return to baseline by 35 min. Following intubation, further declines in BP (21%-51%) were observed in eight additional cases. One infant required a bolus for persistently low BPs. CO and rScO2 changes were statistically similar between the two groups. CONCLUSION: About 30% of infants dropped their BP by ≥20% after premedication for elective intubation. These BP changes were not associated with any significant change in rScO2 or CO. More data are needed to better characterise the immediate haemodynamic changes and clinical outcomes associated with premedication.

Prospective observational study of early respiratory management in preterm neonates less than 35 weeks of gestation.

BACKGROUND: Current guidelines for management of respiratory distress syndrome (RDS) recommend continuous positive airway pressure (CPAP) as the primary mode of respiratory support even in the most premature neonates, reserving endotracheal intubation (ETI) for rescue surfactant or respiratory failure. The incidence and timing of ETI in practice is poorly documented. METHODS: In 27 Level III NICUs in the US (n = 19), Canada (n = 3) and Poland (n = 5), demographics and baseline characteristics, respiratory support modalities including timing of ETI, administration of surfactant and caffeine/other methylxanthines, and neonatal morbidities were prospectively recorded in consecutive preterm neonates following written parental consent. Infants were divided into three groups according to gestational age (GA) at birth, namely 26-28, 29-32 and 33-34 weeks. Statistical comparisons between groups were done using Chi-Square tests. RESULTS: Of 2093 neonates (US = 1507, 254 Canada, 332 Poland), 378 (18%) were 26-28 weeks gestational age (GA), 835 (40%) were 29-32 weeks, and 880 (42%) were 33-34 weeks. Antenatal steroid use was 81% overall, and approximately 89% in neonates ≤32 weeks. RDS incidence and use of ventilatory or supplemental oxygen support were similar across all sites. CPAP was initiated in 43% of all infants, being highest in the 29-32-week group, with a lower proportion in other GA categories (p < 0.001). The overall rate of ETI was 74% for neonates 26-28 weeks (42% within 15 min of birth, 49% within 60 min, and 57% within 3 h), 33% for 29-32 weeks (13 16 and 21%, respectively), and 16% for 33-34 weeks (5, 6 and 8%, respectively). Overall intubation rates and timing were similar between countries in all GAs. Rates within each country varied widely, however. Across US sites, overall ETI rates in 26-28-week neonates were 30-60%, and ETI within 15 min varied from 0 to 83%. Similar within 15-min variability was seen at Polish sites (22-67%) in this GA, and within all countries for 29-32 and 33-34-week neonates. CONCLUSION: Despite published guidelines for management of RDS, rate and timing of ETI varies widely, apparently unrelated to severity of illness. The impact of this variability on outcome is unknown but provides opportunities for further approaches which can avoid the need for ETI.

Preterm Neuroimaging and School-Age Cognitive Outcomes.

BACKGROUND AND OBJECTIVES: Children born extremely preterm are at risk for cognitive difficulties and disability. The relative prognostic value of neonatal brain MRI and cranial ultrasound (CUS) for school-age outcomes remains unclear. Our objectives were to relate near-term conventional brain MRI and early and late CUS to cognitive impairment and disability at 6 to 7 years among children born extremely preterm and assess prognostic value. METHODS: A prospective study of adverse early and late CUS and near-term conventional MRI findings to predict outcomes at 6 to 7 years including a full-scale IQ (FSIQ) <70 and disability (FSIQ <70, moderate-to-severe cerebral palsy, or severe vision or hearing impairment) in a subgroup of Surfactant Positive Airway Pressure and Pulse Oximetry Randomized Trial enrollees. Stepwise logistic regression evaluated associations of neuroimaging with outcomes, adjusting for perinatal-neonatal factors. RESULTS: A total of 386 children had follow-up. In unadjusted analyses, severity of white matter abnormality and cerebellar lesions on MRI and adverse CUS findings were associated with outcomes. In full regression models, both adverse late CUS findings (odds ratio [OR] 27.9; 95% confidence interval [CI] 6.0-129) and significant cerebellar lesions on MRI (OR 2.71; 95% CI 1.1-6.7) remained associated with disability, but only adverse late CUS findings (OR 20.1; 95% CI 3.6-111) were associated with FSIQ <70. Predictive accuracy of stepwise models was not substantially improved with the addition of neuroimaging. CONCLUSIONS: Severe but rare adverse late CUS findings were most strongly associated with cognitive impairment and disability at school age, and significant cerebellar lesions on MRI were associated with disability. Near-term conventional MRI did not substantively enhance prediction of severe early school-age outcomes.

Outcomes of oxygen saturation targeting during delivery room stabilisation of preterm infants.

OBJECTIVE: To determine the association between SpO2 at 5 min and preterm infant outcomes. DESIGN: Data from 768 infants <32 weeks gestation from 8 randomised controlled trials (RCTs) of lower (≤0.3) versus higher (≥0.6) initial inspiratory fractions of oxygen (FiO2) for resuscitation, were examined. SETTING: Individual patient analysis of 8 RCTs INTERVENTIONS: Lower (≤0.3) versus higher (≥0.6) oxygen resuscitation strategies targeted to specific predefined SpO2 before 10 min of age. PATIENTS: Infants <32 weeks gestation. MAIN OUTCOME MEASURES: Relationship between SpO2 at 5 min, death and intraventricular haemorrhage (IVH) >grade 3. RESULTS: 5 min SpO2 data were obtained from 706 (92%) infants. Only 159 (23%) infants met SpO2 study targets and 323 (46%) did not reach SpO280%. Pooled data showed decreased likelihood of reaching SpO280% if resuscitation was initiated with FiO2 <0.3 (OR 2.63, 95% CI 1.21 to 5.74, p<0.05). SpO2 <80% was associated with lower heart rates (mean difference -8.37, 95% CI -15.73 to -1.01, *p<0.05) and after accounting for confounders, with IVH (OR 2.04, 95% CI 1.01 to 4.11, p<0.05). Bradycardia (heart rate <100 bpm) at 5 min increased risk of death (OR 4.57, 95% CI 1.62 to 13.98, p<0.05). Taking into account confounders including gestation, birth weight and 5 min bradycardia, risk of death was significantly increased with time taken to reach SpO280%. CONCLUSION: Not reaching SpO280% at 5 min is associated with adverse outcomes, including IVH. Whether this is because of infant illness or the amount of oxygen that is administered during stabilisation is uncertain and needs to be examined in randomised trials.

Laryngeal Mask Airway for Surfactant Administration in Neonates: A Randomized, Controlled Trial.

OBJECTIVE: To determine if preterm infants with moderate respiratory distress syndrome on continuous positive airway pressure (CPAP) who received surfactant via a laryngeal mask airway (LMA) would have a decreased rate of intubation and mechanical ventilation compared with those on CPAP who did not receive surfactant. STUDY DESIGN: In this prospective, multicenter, randomized controlled trial, 103 premature infants 280/7-356/7 weeks gestation, ≥1250 g and ≤36 hours old on CPAP requiring fraction of inspired oxygen 0.30-0.40 were assigned to receive surfactant administered through an LMA then placed back on CPAP (LMA group) or maintained on CPAP with no surfactant administered (control group). The primary outcome was treatment failure necessitating intubation and mechanical ventilation in the first 7 days of life. RESULTS: Surfactant administration through an LMA (n = 50) significantly decreased the rate of intubation and mechanical ventilation compared with controls (n = 53): 38% vs 64%, respectively, OR 0.30 (95% CI 0.13, 0.70), P = .006, number needed to treat: 4). There were no serious adverse events associated with placement of the LMA or surfactant administration. CONCLUSIONS: In premature neonates with moderate respiratory distress syndrome, surfactant administered through an LMA decreased the rate of intubation and mechanical ventilation. This intervention may have significant impact on clinical care in both high and low resource settings. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01116921.

Delayed Cord Clamping in Newborns Born at Term at Risk for Resuscitation: A Feasibility Randomized Clinical Trial.

Infants may benefit if resuscitation could be provided with an intact umbilical cord. Infants identified at risk for resuscitation were randomized to 1- or 5-minute cord clamping. The 5-minute group had greater cerebral oxygenation and blood pressure. Studies are needed to determine whether this translates into improved outcomes. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02827409.

Umbilical Cord Milking Versus Delayed Cord Clamping in Preterm Infants.

BACKGROUND AND OBJECTIVE: Delayed cord clamping (DCC) is recommended for premature infants to improve blood volume. Most preterm infants are born by cesarean delivery (CD), and placental transfusion may be less effective than in vaginal delivery (VD). We sought to determine whether infants <32 weeks born by CD who undergo umbilical cord milking (UCM) have higher measures of systemic blood flow than infants who undergo DCC. METHODS: This was a 2-center trial. Infants delivered by CD were randomly assigned to undergo UCM or DCC. Infants delivered by VD were also randomly assigned separately. UCM (4 strippings) or DCC (45-60 seconds) were performed. Continuous hemodynamic measurements and echocardiography were done at site 1. RESULTS: A total of 197 infants were enrolled (mean gestational age 28 ± 2 weeks). Of the 154 infants delivered by CD, 75 were assigned to UCM and 79 to DCC. Of the infants delivered by CD, neonates randomly assigned to UCM had higher superior vena cava flow and right ventricular output in the first 12 hours of life. Neonates undergoing UCM also had higher hemoglobin, delivery room temperature, blood pressure over the first 15 hours, and urine output in the first 24 hours of life. There were no differences for the 43 infants delivered by VD. CONCLUSIONS: This is the first randomized controlled trial demonstrating higher systemic blood flow with UCM in preterm neonates compared with DCC. UCM may be a more efficient technique to improve blood volume in premature infants delivered by CD.

Neuroimaging and neurodevelopmental outcome in extremely preterm infants.

BACKGROUND: Extremely preterm infants are at risk for neurodevelopmental impairment (NDI). Early cranial ultrasound (CUS) is usual practice, but near-term brain MRI has been reported to better predict outcomes. We prospectively evaluated MRI white matter abnormality (WMA) and cerebellar lesions, and serial CUS adverse findings as predictors of outcomes at 18 to 22 months' corrected age. METHODS: Early and late CUS, and brain MRI were read by masked central readers, in a large cohort (n = 480) of infants <28 weeks' gestation surviving to near term in the Neonatal Research Network. Outcomes included NDI or death after neuroimaging, and significant gross motor impairment or death, with NDI defined as cognitive composite score <70, significant gross motor impairment, and severe hearing or visual impairment. Multivariable models evaluated the relative predictive value of neuroimaging while controlling for other factors. RESULTS: Of 480 infants, 15 died and 20 were lost. Increasing severity of WMA and significant cerebellar lesions on MRI were associated with adverse outcomes. Cerebellar lesions were rarely identified by CUS. In full multivariable models, both late CUS and MRI, but not early CUS, remained independently associated with NDI or death (MRI cerebellar lesions: odds ratio, 3.0 [95% confidence interval: 1.3-6.8]; late CUS: odds ratio, 9.8 [95% confidence interval: 2.8-35]), and significant gross motor impairment or death. In models that did not include late CUS, MRI moderate-severe WMA was independently associated with adverse outcomes. CONCLUSIONS: Both late CUS and near-term MRI abnormalities were associated with outcomes, independent of early CUS and other factors, underscoring the relative prognostic value of near-term neuroimaging.

A Pilot Randomized Controlled Trial of Early versus Routine Caffeine in Extremely Premature Infants.

OBJECTIVE: This study aims to compare the effects of early and late (routine) initiation of caffeine in nonintubated preterm neonates. STUDY DESIGN: A total of 21 neonates < 29 weeks gestational age were randomized to receive intravenous caffeine citrate (20 mg/kg) or placebo either before 2 hours of age (early) or at 12 hours of age (routine). This was an observational trial to determine the power needed to reduce the need for endotracheal intubation by 12 hours of age. Other outcomes included comparisons of cerebral oxygenation, systemic and pulmonary blood flow, hemodynamics, hypotension treatment, oxygen requirement, and head ultrasound findings. RESULTS: There was no difference in the need for intubation (p = 0.08), or vasopressors (p = 0.21) by 12 hours of age. Early caffeine was associated with improved blood pressure (p = 0.03) and systemic blood flow (superior vena cava flow, p = 0.04 and right ventricular output, p = 0.03). Heart rate, left ventricular output, and stroke volume were not significantly affected. Cerebral oxygenation transiently decreased 1 hour after caffeine administration. There were no differences in other outcomes. CONCLUSION: This pilot study demonstrated the feasibility of conducting such a trial in extremely preterm neonates. We found that early caffeine administration was associated with improved hemodynamics. Larger studies are needed to determine whether early caffeine reduces intubation, intraventricular hemorrhage, and related long-term outcomes.

Measuring cardiac changes using electrical impedance during delayed cord clamping: a feasibility trial.

BACKGROUND: To date no study has attempted to continuously evaluate changes in hemodynamics during delayed cord clamping in humans. We aimed to demonstrate 1. the feasibility of measurements of hemodynamics during delayed cord clamping and 2. to describe the changes that occur over each minute. RESULTS: After vaginal delivery, term infants (37(0)-41(6) weeks) were placed on a Life Start® bed 10-20 cm below the placenta. Transcutaneous sensors were placed on the neck and chest to determine heart rate, stroke volume and cardiac output at each beat. Once a signal was obtained, first 5 values (taken every beat) were averaged and the percent change for each subject from baseline was calculated. 20 infants were enrolled and all had a reliable signal obtained from transcutaneous sensors and had a delay in cord clamping for about 5 minutes. Cardiac output increased from 2 to 5 minutes of life (p = 0.008). For every minute of life the cord was kept unclamped, the stroke volume increased 13.1% ± 12.3 (p = 0.0001) and cardiac output increased 12.6% ± 6.3 from baseline (p < 0.0001). While the majority of infants continued to have an increase in cardiac output at 5 minutes of life, 7/20 infants reached their peak cardiac output at 188 ± 41 seconds of life. CONCLUSIONS: This study demonstrates that hemodynamic measures could be successfully obtained during the first five minutes of birth and while a newborn was receiving delayed cord clamping. This study also provides reference values for changes in cardiac output and stroke volume in well term infants during delayed cord clamping. TRIAL REGISTRATION: Clinical Trials.gov NCT02195037 Registered 17 July 2014.

Implementation methods for delivery room management: a quality improvement comparison study.

BACKGROUND: There is little evidence to compare the effectiveness of large collaborative quality improvement versus individual local projects. METHODS: This was a prospective pre-post intervention study of neonatal resuscitation practice, comparing 3 groups of nonrandomized hospitals in the California Perinatal Quality Care Collaborative: (1) collaborative, hospitals working together through face-to-face meetings, webcasts, electronic mailing list, and data sharing; (2) individual, hospitals working independently; and (3) nonparticipant hospitals. The collaborative and individual arms participated in improvement activities, focusing on reducing hypothermia and invasive ventilatory support. RESULTS: There were 20 collaborative, 31 individual, and 44 nonparticipant hospitals caring for 12,528 eligible infants. Each group had reduced hypothermia from baseline to postintervention. The collaborative group had the most significant decrease in hypothermia, from 39% to 21%, compared with individual hospital efforts of 38% to 33%, and nonparticipants of 42% to 34%. After risk adjustment, the collaborative group had twice the magnitude of decrease in rates of newborns with hypothermia compared with the other groups. Collaborative improvement also led to greater decreases in delivery room intubation (53% to 40%) and surfactant administration (37% to 20%). CONCLUSIONS: Collaborative efforts resulted in larger improvements in delivery room outcomes and processes than individual efforts or nonparticipation. These findings have implications for planning quality improvement projects for implementation of evidence-based practices.

Noninvasive inhaled nitric oxide does not prevent bronchopulmonary dysplasia in premature newborns.

OBJECTIVE: To assess the efficacy and safety of early, noninvasive inhaled nitric oxide (iNO) therapy in premature newborns who do not require mechanical ventilation. STUDY DESIGN: We performed a multicenter randomized trial including 124 premature newborns who required noninvasive supplemental oxygen within the first 72 hours after birth. Newborns were stratified into 3 different groups by birth weight (500-749, 750-999, 1000-1250 g) prior to randomization to iNO (10 ppm) or placebo gas (controls) until 30 weeks postmenstrual age. The primary outcome was a composite of death or bronchopulmonary dysplasia (BPD) at 36 weeks postmenstrual age. Secondary outcomes included the need for and duration of mechanical ventilation, severity of BPD, and safety outcomes. RESULTS: There was no difference in the incidence of death or BPD in the iNO and placebo groups (42% vs 40%, P = .86, relative risk = 1.06, 0.7-1.6). BPD severity was not different between the treatment groups. There were no differences between the groups in the need for mechanical ventilation (22% vs 23%; P = .89), duration of mechanical ventilation (9.7 vs 8.4 days; P = .27), or safety outcomes including severe intracranial hemorrhage (3.4% vs 6.2%, P = .68). CONCLUSIONS: We found that iNO delivered noninvasively to premature infants who have not progressed to early respiratory failure is a safe treatment, but does not decrease the incidence or severity of BPD, reduce the need for mechanical ventilation, or alter the clinical course.