Oxygen Saturation Targets in Preterm Infants and Outcomes at 18-24 Months: A Systematic Review

Heart Rate and Pulse Oximetry Dynamics in the First Week after Birth in Neonatal Intensive Care Unit Patients and the Risk of Cerebral Palsy

OBJECTIVE

 Infants in the neonatal intensive care unit (NICU) are at high risk of adverse neuromotor outcomes. Atypical patterns of heart rate (HR) and pulse oximetry (SpO2) may serve as biomarkers for risk assessment for cerebral palsy (CP). The purpose of this study was to determine whether atypical HR and SpO2 patterns in NICU patients add to clinical variables predicting later diagnosis of CP.

STUDY DESIGN

 This was a retrospective study including patients admitted to a level IV NICU from 2009 to 2017 with archived cardiorespiratory data in the first 7 days from birth to follow-up at >2 years of age. The mean, standard deviation (SD), skewness, kurtosis and cross-correlation of HR and SpO2 were calculated. Three predictive models were developed using least absolute shrinkage and selection operator regression (clinical, cardiorespiratory and combined model), and their performance for predicting CP was evaluated.

RESULTS

 Seventy infants with CP and 1,733 controls met inclusion criteria for a 3.8% population prevalence. Area under the receiver operating characteristic curve for CP prediction was 0.7524 for the clinical model, 0.7419 for the vital sign model, and 0.7725 for the combined model. Variables included in the combined model were lower maternal age, outborn delivery, lower 5-minute Apgar's score, lower SD of HR, and more negative skewness of HR.

CONCLUSION

 In this study including NICU patients of all gestational ages, HR but not SpO2 patterns added to clinical variables to predict the eventual diagnosis of CP. Identification of risk of CP within the first few days of life could result in improved therapy resource allocation and risk stratification in clinical trials of new therapeutics.

KEY POINTS

· SD and skewness of HR have some added predictive value of later diagnosis of CP.. · SpO2 measures do not add to CP prediction.. · Combining clinical variables with early HR measures may improve the prediction of later CP..

Oxygen in the neonatal ICU: a complicated history and where are we now?

Despite major advances in neonatal care, oxygen remains the most commonly used medication in the neonatal intensive care unit (NICU). Supplemental oxygen can be life-saving for term and preterm neonates in the resuscitation period and beyond, however use of oxygen in the neonatal period must be judicious as there can be toxic effects. Newborns experience substantial hemodynamic changes at birth, rapid energy consumption, and decreased antioxidant capacity, which requires a delicate balance of sufficient oxygen while mitigating reactive oxygen species causing oxidative stress. In this review, we will discuss the physiology of neonates in relation to hypoxia and hyperoxic injury, the history of supplemental oxygen in the delivery room and beyond, supporting clinical research guiding trends for oxygen therapy in neonatal care, current practices, and future directions.

Oxygen Targets in Neonatal Pulmonary Hypertension: Individualized, "Precision-Medicine" Approach

Oxygen is a specific pulmonary vasodilator. Hypoxemia causes pulmonary vasoconstriction, and normoxia leads to pulmonary vasodilation. However, hyperoxia does not enhance pulmonary vasodilation but causes oxidative stress. There are no clinical trials evaluating optimal oxygen saturation or Pao2 in pulmonary hypertension. Data from translational studies and case series suggest that oxygen saturation of 90% to 97% or Pao2 between 50 and 80 mm Hg is associated with the lowest pulmonary vascular resistance.

Prolonged use of closed-loop inspired oxygen support in preterm infants: a randomised controlled trial

OBJECTIVE

This randomised study in preterm infants on non-invasive respiratory support investigated the effectiveness of automated oxygen control (A-FiO2) in keeping the oxygen saturation (SpO2) within a target range (TR) during a 28-day period compared with manual titration (M-FiO2).

DESIGN

A single-centre randomised control trial.

SETTING

A level III neonatal intensive care unit.

PATIENTS

Preterm infants (<28 weeks' gestation) on non-invasive respiratory support.

INTERVENTIONS

A-FiO2 versus M-FiO2 control.

METHODS

Main outcomes were the proportion of time spent and median area of episodes in the TR, hyperoxaemia, hypoxaemia and the trend over 28 days using a linear random intercept model.

RESULTS

23 preterm infants (median gestation 25.7 weeks; birth weight 820 g) were randomised. Compared with M-FiO2, the time spent within TR was higher in the A-FiO2 group (68.7% vs 48.0%, p<0.001). Infants in the A-FiO2 group spent less time in hyperoxaemia (13.8% vs 37.7%, p<0.001), but no difference was found in hypoxaemia. The time-based analyses showed that the A-FiO2 efficacy may differ over time, especially for hypoxaemia. Compared with the M-FiO2 group, the A-FiO2 group had a larger intercept but with an inversed slope for the daily median area below the TR (intercept 70.1 vs 36.3; estimate/day -0.70 vs 0.69, p<0.001).

CONCLUSION

A-FiO2 control was superior to manual control in keeping preterm infants on non-invasive respiratory support in a prespecified TR over a period of 28 days. This improvement may come at the expense of increased time below the TR in the first days after initiating A-FiO2 control.

TRIAL REGISTRATION NUMBER

NTR6731.

Similar adverse outcome rates with high or low oxygen saturation targets in an area with low background mortality

Background

Randomized controlled trials have indicated reduced mortality rates in very preterm infants assigned to high compared to low oxygen saturation (SpO2) target levels, accompanied by higher rates of retinopathy of prematurity and bronchopulmonary dysplasia. However, the benefit-to-harm ratio may depend on the local background mortality risk. We therefore aimed to quantify the risk-benefit ratios of different SpO2 target ranges in 10 tertiary newborn intensive care units (NICUs) in East Germany.

Methods

In a retrospective multicenter study, 1,399 infants born between 2008 and 2012 at a gestational age between 24 0/7 and 27 6/7 weeks and with a birthweight below 1,250 g were grouped according to the hospital's target SpO2 range [high oxygen saturation group (HOSG) above 90%], low oxygen saturation group (LOSG) below 90%] and the compliance of units with their target SpO2 range. The association between neonatal morbidities, neurodevelopmental outcomes, selected treatment strategies, and target SpO2 ranges was calculated using chi-squared and Mann Whitney U tests.

Results

Nine of the ten participating NICUs met their SpO2 target ranges. Five units were considered as HOSG, and five units were considered as LOSG. Necrotizing enterocolitis and intraventricular hemorrhage grade ≥ 2 occurred significantly more frequently in the HOSG than in the LOSG (8.4% vs. 5.1%, p = 0.02; and 26.6% vs. 17.7%, p < 0.001). No significant differences in the mortality rate and the rate of retinopathy of prematurity were found.

Conclusion

In our patient population, a lower SpO2 target range was not associated with increased safety risks in extremely preterm infants. We cannot be sure that our outcome differences are associated with differences in oxygen saturations due to the retrospective study design and the differences in site practices.

Pathophysiology of Retinopathy of Prematurity

Retinopathy of prematurity (ROP) is a complex disease involving development of the neural retina, ocular circulations, and other organ systems of the premature infant. The external stresses of the ex utero environment also influence the pathophysiology of ROP through interactions among retinal neural, vascular, and glial cells. There is variability among individual infants and presentations of the disease throughout the world, making ROP challenging to study. The methods used include representative animal models, cell culture, and clinical studies. This article describes the impact of maternal-fetal interactions; stresses that the preterm infant experiences; and biologic pathways of interest, including growth factor effects and cell-cell interactions, on the complex pathophysiology of ROP phenotypes in developed and emerging countries.

Retinopathy of Prematurity: The Role of Nutrition

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness. ROP occurs in infants who are born very preterm. In ROP, retinal blood vessel development, which is prematurely arrested in preterm infants, is altered by perinatal exposures like oxygen and inflammation. Optimizing nutritional practices for preterm infants may mitigate the risk of ROP. In this article, we review the evidence that postnatal growth, hyperglycemia, polyunsaturated fatty acids, and breast milk provision may affect ROP risk. We also outline the current management strategies for ROP and describe the vision outcomes of children affected by ROP. [Pediatr Ann. 2023;52(8):e303-e308.].

Effects of semi-upright swings on vital signs in NICU infants

BACKGROUND

The aim of this study was to compare the impact of a semi-upright swing with a standard crib on vital signs in infants in the neonatal intensive care unit (NICU).

METHODS

We performed a within-subjects' comparison of vital signs of NICU infants corrected to ≥34 weeks of gestation and placed in the supine position versus the semi-upright position in a swing. The primary outcome was the mean oxygen saturation, and the secondary outcomes were the mean heart rate, the proportion of time with oxygen saturation (SpO₂) <90%, and respiratory rate.

RESULTS

Of the 65 infants, 34 (57%) were male and 32 (50%) were black. The mean ± SD gestational age at birth was 32.4 ± 5.1 weeks. In all, 40% were on noninvasive respiratory support. There were no significant differences in oxygen saturation, heart rate, time with oxygen desaturation defined by SpO₂ < 90%, or respiratory rate between the supine and semi-upright positions. A higher risk of desaturations was observed in infants without respiratory support (RR, 1.24, 95% CI, 1.15-1.33) and low-birth-weight infants (RR, 1.55, 95% CI, 1.42-1.69).

CONCLUSIONS

The placement of infants in a semi-upright swing resulted in no discernible differences in averaged vital signs compared to the supine position in NICU infants.

IMPACT

We identified no significant differences in averaged oxygen saturation, heart rate, or respiratory rate among NICU infants placed in a semi-upright swing compared to the supine position. Desaturation events occurred at a higher frequency in low-birth-weight infants and those on room air when placed in the swing, although none required oxygen supplementation. The results from the current study support that it is probably safe to use semi-upright swings in the NICU environment, although additional studies are necessary for generalization to the unmonitored home environment.

Updates in Neonatal Extracorporeal Membrane Oxygenation and the Artificial Placenta

Extracorporeal life support, initially performed in neonates, is now commonly used for both pediatric and adult patients requiring pulmonary and/or cardiac support. Data suggests the clinical feasibility of Extracorporeal Membrane Oxygenation for premature infants (29-33 weeks estimated gestational age [EGA]). For extremely premature infants less than 28 weeks EGA, an artificial placenta has been developed to recreate the fetal environment. This approach is investigational but clinical translation is promising. In this article, we discuss the current state and advances in neonatal and "preemie Extracorporeal Membrane Oxygenation" and the development of an artificial placenta and its potential use in extremely premature infants.

Frequent hypoxemia found in infants with bronchopulmonary dysplasia after weaning home oxygen

OBJECTIVE

Parental reports and brief clinical examinations are the primary information used to assist clinicians in weaning home supplemental oxygen in infants with bronchopulmonary dysplasia (BPD). Recorded nocturnal oximetry provides an objective assessment of hypoxemia; however, it is unknown if it identifies clinically undetected hypoxemia in the home setting. Our objective was to determine if nocturnal oximetry can identify unreported hypoxemia in infants with BPD who appear ready to wean from supplemental oxygen.

STUDY DESIGN

We conducted a retrospective chart review of infants born <32 weeks gestation with BPD who were discharged to home receiving supplemental oxygen and completed recorded nocturnal oximetry in room air during an 18-month period. Abnormal oximetry was defined as >5 min with SpO₂  < 90% and/or an oxyhemoglobin desaturation index (ODI4) >5. Comparative analysis of patients with normal and abnormal overnight oximetry was performed using Fisher Exact and Wilcoxon signed-rank test.

RESULTS

Thirty-five former premature infants completed nocturnal oximetry at 5.8 (3.4-8.3) months corrected age. Nocturnal oximetry was abnormal as defined in 67% of the cohort (n = 21). Five percent of patients were hypoxemic, 52% had frequent desaturation events, and 43% had both. No significant differences existed in neonatal characteristics between patients with normal and abnormal studies.

CONCLUSIONS

Nocturnal oximetry was abnormal in the majority of infants with BPD who were otherwise clinically ready to wean from oxygen support, suggesting that recorded home oximetry could be a feasible and useful tool to evaluate for otherwise clinically unapparent nocturnal hypoxemia in patients with BPD.

Neonatal Vital Sign Trajectories and Risk Factors During Transport Within a Regional Care Network

OBJECTIVE

The aim of this study was to characterize vital sign abnormalities, trajectories, and related risk factors during neonatal transport.

METHODS

We performed a retrospective analysis of neonates transported within a US regional care network in 2020 to 2021. Demographic and clinical data were collected from electronic records. Group-based trajectory modeling was applied to identify groups of neonates who followed distinct vital sign trajectories during transport. Patients with conditions likely to impact the assessed vital were excluded. Risk factors for trajectories were examined using modified Poisson regression models.

RESULTS

Of the 620 neonates in the study, 92% had one abnormal systolic blood pressure (SBP) measure, approximately half had an abnormal heart rate (47%) or temperature (56%), and 28% had an abnormal oxygen saturation measure during transport. Over half (53%) were in a low and decreasing SBP trajectory, and 36% were in a high and increasing heart rate trajectory. Most infants ≤ 28 weeks postmenstrual age had 2 or more concerning vital sign trajectories during transport.

CONCLUSION

Abnormal vital signs were common during neonatal transport, and potentially negative trajectories in heart rate and SBP were more common than temperature or oxygen saturation. Transport teams should be trained and equipped to detect concerning trends and respond appropriately while en route.

Endotypes of Prematurity and Phenotypes of Bronchopulmonary Dysplasia: Toward Personalized Neonatology

Bronchopulmonary dysplasia (BPD), the chronic lung disease of prematurity, is increasingly recognized as the consequence of a pathological reparative response of the developing lung to both antenatal and postnatal injury. According to this view, the pathogenesis of BPD is multifactorial and heterogeneous with different patterns of antenatal stress (endotypes) that combine with varying postnatal insults and might distinctively damage the development of airways, lung parenchyma, interstitium, lymphatic system, and pulmonary vasculature. This results in different clinical phenotypes of BPD. There is no clear consensus on which are the endotypes of prematurity but the combination of clinical information with placental and bacteriological data enables the identification of two main pathways leading to birth before 32 weeks of gestation: (1) infection/inflammation and (2) dysfunctional placentation. Regarding BPD phenotypes, the following have been proposed: parenchymal, peripheral airway, central airway, interstitial, congestive, vascular, and mixed phenotype. In line with the approach of personalized medicine, endotyping prematurity and phenotyping BPD will facilitate the design of more targeted therapeutic and prognostic approaches.

Factors to Consider to Study Preductal Oxygen Saturation Targets in Neonatal Pulmonary Hypertension

There are potential benefits and risks to the infant with higher and lower oxygen saturation (SpO₂) targets, and the ideal range for infants with pulmonary hypertension (PH) remains unknown. Targeting high SpO₂ can promote pulmonary vasodilation but cause oxygen toxicity. Targeting lower SpO₂ may increase pulmonary vascular resistance, especially in the presence of acidosis and hypothermia. We will conduct a randomized pilot trial to compare two ranges of target preductal SpO₂ in late-preterm and term infants with hypoxic respiratory failure (HRF) and acute pulmonary hypertension (aPH) of the newborn. We will assess the reliability of a newly created HRF/PH score that could be used in larger trials. We will assess trial feasibility and obtain preliminary estimates of outcomes. Our primary hypothesis is that in neonates with PH and HRF, targeting preductal SpO₂ of 95-99% (intervention) will result in lower pulmonary vascular resistance and pulmonary arterial pressures, and lower the need for pulmonary vasodilators (inhaled nitric oxide-iNO, milrinone and sildenafil) compared to targeting SpO₂ at 91-95% (standard). We also speculate that a higher SpO₂ target can potentially induce oxidative stress and decrease response to iNO (oxygenation and pulmonary vasodilation) for those patients that still require iNO in this range. We present considerations in planning this trial as well as some of the details of the protocol design (Clinicaltrials.gov (NCT04938167)).

Decoupling Oxygen Tension From Retinal Vascularization as a New Perspective for Management of Retinopathy of Prematurity. New Opportunities From β-adrenoceptors

Retinopathy of prematurity (ROP) is an evolutive and potentially blinding eye disease that affects preterm newborns. Unfortunately, until now no conservative therapy of active ROP with proven efficacy is available. Although ROP is a multifactorial disease, premature exposition to oxygen concentrations higher than those intrauterine, represents the initial pathogenetic trigger. The increase of oxygenation in a retina still incompletely vascularized promotes the downregulation of proangiogenic factors and finally the interruption of vascularization (ischemic phase). However, the increasing metabolic requirement of the ischemic retina induces, over the following weeks, a progressive hypoxia that specularly increases the levels of proangiogenic factors finally leading to proliferative retinopathy (proliferative phase). Considering non-modifiable the coupling between oxygen levels and vascularization, so far, neonatologists and ophthalmologists have “played defense”, meticulously searching the minimum necessary concentration of oxygen for individual newborns, refining their diagnostic ability, adopting a careful monitoring policy, ready to decisively intervene only in a very advanced stage of disease progression. However, recent advances have demonstrated the possibility to pharmacologically modulate the relationship between oxygen and vascularization, opening thus the perspective for new therapeutic or preventive opportunities. The perspective of a shift from a defensive towards an attack strategy is now at hand.

The status of chronic lung disease diagnosis in Japan: Secondary publication

BACKGROUND

In Japan, the definition and classification of neonatal chronic lung disease (CLD) used for its diagnosis are a combination of those used in Japan and abroad.

METHODS

To clarify the current state of CLD diagnosis, a questionnaire survey was conducted.

RESULTS

Half of the patients of the medical centers included in the study were diagnosed with CLD in real time, while the other half were diagnosed after discharge. In addition, in approximately 70% of the facilities, diagnosis was made after discussions various among medical teams. In approximately 80% of the centers, the chest radiography used for CLD diagnosis were evaluated by multiple doctors. Furthermore, some centers used chest X-rays that were taken at approximately 28 days of age for CLD diagnosis, whereas at other facilities, diagnosis was made regardless of time at which the chest radiography were obtained. Only a small number of centers have established criteria for determining the necessity of oxygen at the corrected age of 36 weeks, and the target saturation of peripheral oxygen levels also tend to vary for each facility. Whether the conditions wherein the patient receives respiratory support for apnea or respiratory tract diseases should be considered as CLD also differed among the facilities.

CONCLUSIONS

It is necessary to reassess the definition and classification of CLD in Japan to accurately evaluate and improve the quality of respiratory management based on the long-term prognosis.

Automated Oxygen Delivery in Neonatal Intensive Care

Oxygen is the most common drug used in the neonatal intensive care. It has a narrow therapeutic range in preterm infants. Too high (hyperoxemia) or low oxygen (hypoxemia) is associated with adverse neonatal outcomes. It is not only prudent to maintain oxygen saturations in the target range, but also to avoid extremes of oxygen saturations. In routine practice when done manually by the staff, it is challenging to maintain oxygen saturations within the target range. Automatic control of oxygen delivery is now feasible and has shown to improve the time spent with in the target range of oxygen saturations. In addition, it also helps to avoid extremes of oxygen saturation. However, there are no studies that evaluated the clinical outcomes with automatic control of oxygen delivery. In this narrative review article, we aim to present the current evidence on automatic oxygen control and the future directions.

Supplemental Oxygen in the Newborn: Historical Perspective and Current Trends

Oxygen is the final electron acceptor in aerobic respiration, and a lack of oxygen can result in bioenergetic failure and cell death. Thus, administration of supplemental concentrations of oxygen to overcome barriers to tissue oxygen delivery (e.g., heart failure, lung disease, ischemia), can rescue dying cells where cellular oxygen content is low. However, the balance of oxygen delivery and oxygen consumption relies on tightly controlled oxygen gradients and compartmentalized redox potential. While therapeutic oxygen delivery can be life-saving, it can disrupt growth and development, impair bioenergetic function, and induce inflammation. Newborns, and premature newborns especially, have features that confer particular susceptibility to hyperoxic injury due to oxidative stress. In this review, we will describe the unique features of newborn redox physiology and antioxidant defenses, the history of therapeutic oxygen use in this population and its role in disease, and clinical trends in the use of therapeutic oxygen and mitigation of neonatal oxidative injury.

Cerebral and splanchnic oxygenation during automated control of inspired oxygen (FiO2 ) in preterm infants

OBJECTIVES

Our aim in this study was to assess the effect of the Predictive Intelligent Control of Oxygenation (PRICO^® ) system on cerebral (rSO₂ C) and splanchnic (rSO₂ S) oxygenation in a cohort of preterm infants with frequent desaturations.

METHODS

Twenty infants with gestational age <32 weeks (n = 20) were assigned in random sequence to 12 h of automated or manual adjustment of FiO₂ . Over this period, they were studied continuously by near-infrared spectroscopy (NIRS).

RESULTS

We found that rSO₂ C [68.0% (60.5%-74.7%) vs. 68.5% (62%-72%); p = .824] and rSO₂ S [27.0% (17.3%-45.7%) vs. 27.0% (15%-53%); p = .878] were similar during automatic and manual control of FiO₂ . Time spent with SpO₂ 90%-95% was higher during the automatic than manual control of FiO₂ , while time spent with SpO₂ <80% or >95% was lower.

CONCLUSIONS

Automated control of FiO₂ with PRICO^® system did not improve brain and splanchnic oxygenation in comparison with manual control in a cohort of preterm infants, but it significantly decreased SpO₂ fluctuations and limited the duration of both hypoxemia and hyperoxemia.

Development of an artificial placenta for support of premature infants: narrative review of the history, recent milestones, and future innovation

Over 50 years ago, visionary researchers began work on an extracorporeal artificial placenta to support premature infants. Despite rudimentary technology and incomplete understanding of fetal physiology, these pioneering scientists laid the foundation for future work. The research was episodic, as medical advances improved outcomes of premature infants and extracorporeal life support (ECLS) was introduced for the treatment of term and near-term infants with respiratory or cardiac failure. Despite ongoing medical advances, extremely premature infants continue to suffer a disproportionate burden of mortality and morbidity due to organ immaturity and unintended iatrogenic consequences of medical treatment. With advancing technology and innovative approaches, there has been a resurgence of interest in developing an artificial placenta to further diminish the mortality and morbidity of prematurity. Two related but distinct platforms have emerged to support premature infants by recreating fetal physiology: a system based on arteriovenous (AV) ECLS and one based on veno-venous (VV) ECLS. The AV-ECLS approach utilizes only the umbilical vessels for cannulation. It requires immediate transition of the infant at the time of birth to a fluid-filled artificial womb to prevent umbilical vessel spasm and avoid gas ventilation. In contradistinction, the VV-ECLS approach utilizes the umbilical vein and the internal jugular vein. It would be applied after birth to infants failing maximal medical therapy or preemptively if risk stratified for high mortality and morbidity. Animal studies are promising, demonstrating prolonged support and ongoing organ development in both systems. The milestones for clinical translation are currently being evaluated.

Automated control of fraction of inspired oxygen: is it time for widespread adoption?

PURPOSE OF REVIEW

Over the past two decades, numerous algorithms for automated control of the fraction of inspired oxygen (FiO2) have been developed and incorporated into contemporary neonatal ventilators and high-flow devices in an attempt to optimize supplemental oxygen therapy in preterm infants. This review explores whether current evidence is sufficient to recommend widespread adoption of automated oxygen control in neonatal care.

RECENT FINDINGS

To date, 15 studies have compared automated versus manual control of FiO2 in preterm infants on respiratory support. This includes four new randomized cross-over trials published in the last 2 years. Available evidence consistently demonstrates a significant improvement in time spent within the target saturation range with automated FiO2 control. There are fewer episodes of severe hypoxemia and fewer manual FiO2 adjustments with automated oxygen control. Nursing workload may be reduced. However, no currently completed studies report on clinical outcomes, such as chronic lung disease or retinopathy of prematurity.

SUMMARY

Automated oxygen control appears to be a reasonable option for FiO2 titration in preterm infants on respiratory support, if resources are available, and might substantially reduce nursing workload. Further randomized clinical trials to explore its effects on clinical outcomes are required.

Comparative cohorts of retinopathy of prematurity outcomes of differing oxygen saturation: real-world outcomes

Objective

An ongoing third epidemic of retinopathy of prematurity (ROP) is contributed largely by developing nations. We describe a cohort of infants in a single neonatal unit where two limits of oxygen saturation were administered, to show real-world outcomes from trend in neonatology for higher oxygen to improve survival.

Methods and analysis

This retrospective, comparative study of prospectively collected data in an ROP screening programme included infants indicated by gestational age ≤32 weeks, birth weight <1501 g, ventilation for 7 days or requiring oxygen >1 month, who underwent dilated fundoscopic examination from age 4 weeks, every 2 weeks until full retinal vascularisation. Infants with ROP were examined weekly and treated where indicated. Data were divided into two epochs. Epoch 1 oxygen saturation targets were [88–92%], epoch 2 targets [90–95% (99%)] with allowance of increase to 20% for several hours after procedures. Outcome measures included development of ROP, treatment, mortality, sepsis and intraventricular haemorrhage.

Results

A total of 651 infants underwent examination between 2003 and 2016. The incidence of ROP in epoch 1 was 29.1% and epoch 2 was 29.3% (p=0.24). ROP progression doubled in epoch 2 (5 vs 11%, p=0.006), proportion of cases treated halved (14% vs 6%, p=0.0005), sepsis was halved (78.5% vs 41.2%, p<0.0001) and intraventricular haemorrhage doubled (20.2% vs 43.8%, p=0.0001) in epoch 2. Mortality was 4% and 0% in epochs 1 and 2, respectively.

Conclusion

Incidence of ROP did not differ, although ROP cases that worsened doubled with higher oxygen targets. ROP cases requiring treatment decreased, as did sepsis and mortality. Intraventricular haemorrhage cases doubled.

Early Chronic Intermittent Maternal Hyperoxygenation Impairs Cortical Development by Inhibition of Pax6-Positive Apical Progenitor Cell Proliferation

Maternal hyperoxygenation is a feasible, noninvasive method to treat fetal diseases, such as heart hypoplasia, but effects of maternal hyperoxygenation on the developing brain remain poorly understood. Previous studies showed that short-term maternal hyperoxygenation during midneurogenic phase (E14-E16) but not in earlier development (E10-E12) increases oxygen tension and enhances neurogenesis in the developing mouse cortex. We investigated effects of early chronic maternal hyperoxygenation (CMH) as a potential clinical treatment. Pregnant C57BL/6J mice were housed in a chamber at 75% atmospheric oxygen and the brains of E16 fetuses were analyzed using immunohistochemistry. The mitosis marker phH3 showed a significant reduction of proliferation in the dorsolateral cortices of CMH-treated E16 fetuses. Numbers of Tbr2-positive intermediate progenitor cells were unaffected whereas numbers of Pax6-positive apical progenitor cells were significantly reduced in CMH-treated mice. This resulted in altered cortical plate development with fewer Satb2-positive upper layer neurons but more Tbr1-positive neurons corresponding to the deeper layer 6. Thus, maternal hyperoxygenation affects the developing cortex depending on timing and length of applied oxygen. Early CMH causes a severe reduction of neuroprogenitor proliferation likely affecting cortical development. Further studies are needed to investigate the mechanisms underlying these findings and to assess the clinical and neurodevelopmental outcomes of the pups.

Non-invasive carbon dioxide monitoring in neonates: methods, benefits, and pitfalls

Wide fluctuations in partial pressure of carbon dioxide (PaCO₂) can potentially be associated with neurological and lung injury in neonates. Blood gas measurement is the gold standard for assessing gas exchange but is intermittent, invasive, and contributes to iatrogenic blood loss. Non-invasive carbon dioxide (CO₂) monitoring has become ubiquitous in anesthesia and critical care and is being increasingly used in neonates. Two common methods of non-invasive CO₂ monitoring are end-tidal and transcutaneous. A colorimetric CO₂ detector (a modified end-tidal CO₂ detector) is recommended by the International Liaison Committee on Resuscitation (ILCOR) and the American Academy of Pediatrics to confirm endotracheal tube placement. Continuous CO₂ monitoring is helpful in trending PaCO₂ in critically ill neonates on respiratory support and can potentially lead to early detection and minimization of fluctuations in PaCO₂. This review includes a description of the various types of CO₂ monitoring and their applications, benefits, and limitations in neonates.

Bronchopulmonary dysplasia requiring tracheostomy: A review of management and outcomes

Bronchopulmonary Dysplasia (BPD) is a pulmonary disease affecting newborns, commonly those with prematurity or low birth weight. Its pathogenesis involves underdevelopment of lung tissue with subsequent limitations in ventilation and oxygenation, resulting in impaired postnatal alveolarization. Despite advances in care with improved survival, BPD remains a prevalent comorbidity of prematurity. In severe cases, management may involve mechanical ventilation via tracheostomy. BPD's demand for multidisciplinary care compounds the challenges in management of this condition. Here, we review existing literature: the history of disease, criteria for diagnosis, pathogenesis, and modes of treatment with a focus on the severe subtype: that which is associated with pulmonary hypertension (PAH) for which tracheostomy is often required to facilitate long-term mechanical ventilation. We review the current recommendations for tracheostomy and decannulation.

Oxygen metabolism and oxygenation of the newborn

The premature infant is to some extent protected from hypoxia, however defense against hyperoxia is poorly developed. The optimal assessment of oxygenation is to measure oxygen delivery and extraction. At the bedside PaO₂ and SpO₂ are approximations of oxygenation at the tissue level. After birth asphyxia it is crucial to know whether or not to give oxygen supplementation, when, how much, and for how long. Oxygen saturation targets in the delivery room have been studied, but the optimal targets might still be unknown because factors like gender and delayed cord clamping influence saturation levels. However, SpO₂ > 80% at 5 min of age is associated with favorable long term outcome in preterm babies. Immature infants most often need oxygen supplementation beyond the delivery room. Predefined saturation levels, and narrow alarm limits together with the total oxygen exposure may impact on development of oxygen related diseases like ROP and BPD. Hyperoxia is a strong trigger for genetic and epigenetic changes, contributing to the development of these conditions and perhaps lifelong changes.

Oxygen saturation target ranges and alarm settings in the NICU: What have we learnt from the neonatal oxygenation prospective meta-analysis (NeOProM)?

The Neonatal Oxygenation Prospective Meta-analysis combined the individual participant data of 4965 extremely preterm infants. They had been randomly assigned in 5 trials to arterial oxygen saturations of 85%-89% or 91%-95% using modified oximeters to mask the treatment allocation. The primary outcome of death or disability did not differ significantly between the groups. Assignment to the higher target range reduced the risks of death and severe necrotizing enterocolitis but increased the risk of treated retinopathy. Trade-offs between the benefits and risks of higher or lower saturation targets should be informed by the local patient risks and institutional rates for outcomes that may be affected by a policy change. Features of the oximeter masking algorithm introduced unanticipated artifacts into the saturation display that are not seen in routine care. NeOProM provides little guidance on where to set the oximeter alarms and how to respond to them.

Current Recommendations and Practice of Oxygen Therapy in Preterm Infants

This narrative review identified 23 publications in 2011 to 2019 discussing randomized trials of oxygen saturation targets of 85% to 89% versus 91% to 95% in infants below 28 weeks' gestation. Of 18 commentaries or consensus statements, 17 recommended saturation targets above 89%. Five systematic reviews reported that the 85% to 89% target increased mortality but not the composite of death or disability. The evidence for increased mortality was assessed as of "high", "moderate," or "low," quality, reflecting substantial differences in interpreting the GRADE guidelines. Systematic reviews and guidelines without biostatisticians or epidemiologists as co-authors should be considered potentially problematic.

Intermittent Hypoxemia in Preterm Infants

Intermittent hypoxemia (IH) events are common during early postnatal life, particularly in preterm infants. These events have been associated with multiple morbidities, including retinopathy of prematurity, sleep disordered breathing, neurodevelopmental impairment, and mortality. The relationship between IH and poor outcomes may depend on the patterns (frequency, duration, and timing) of the IH events. Current treatment modalities used in the clinical setting have been only partially successful in reducing the incidence of apnea and accompanying IH, but the risks and benefits of more aggressive interventions should include knowledge of the relationship between IH and morbidity.

Optimal oxygen saturation in extremely premature neonates

So far, great efforts have been made to understand the demands of extremely premature neonates (EPNs´; born before the 28(th) week of gestation) on postnatal care, including optimal oxygen saturation, that will allow them to survive without disability. A major yet unresolved problem is to find an "optimal range" of their oxygen saturation and to maintain it without drops or increases, i.e., without hypoxia or hyperoxia. The individual sections of this paper deal with the changes of SpO(2) (an estimate of SaO(2) measured by pulse oximetry) that occur before, during, and after premature labor, postnatal factors affecting SpO(2), and especially how to find an acceptable compromise in choosing the most effective and minimally harmful range of SpO(2) for EPNs' with the careful FiO(2) adjustment and continually monitored SpO(2). At present, the two SpO(2) ranges, narrow (90-94%) vs. wider (88-94%), are most discussed. However, the question of how much oxygen is too much or little remains unanswered. There is even a view that there is no uniform optimal SpO(2) range for EPNs, and that each newborn has its own, individually specific range that changes due to its intrinsic and/or extrinsic factors.

Experimental Evidence Behind Clinical Trial Outcomes in Retinopathy of Prematurity

Treatment of severe retinopathy of prematurity (ROP) has evolved over the last decade. This article reviews recent clinical trials and experimental evidence that supports clinical outcomes and observations, including the efficacy of anti-vascular endothelial growth factor (VEGF) agents in reducing the vascular activity of severe ROP, and the mechanisms behind recurrent stage 3 ROP and plus disease in some infants treated with anti-VEGF agents. Also discussed will be current imaging modalities that link experimental models of ROP with longitudinal human studies and which provide exciting future opportunities to enhance the understanding of pathophysiology of ROP and improve treatments. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:228-234.].

Automated control of inspired oxygen (FiO2 ) in preterm infants: Literature review

The vast majority (95%) of very preterm infants receive oxygen-therapy monitored by oxygen pulse saturation (SpO₂ ). However, they spend a significant percentage of time out of the SpO₂ target with a high risk of severe complications such as bronchopulmonary dysplasia (BPD) and retinopathy of prematurity (ROP). Recently, systems allowing the automated control of inspired oxygen (FiO₂ ) for patient delivery to maintain target SpO₂ has been become commercially available. We reviewed literature and individuated sixteen studies on the effectiveness of automated control of FiO₂ in preterm infants. These studies demonstrate that automated devices are significantly more effective than manual control in maintaining target SpO₂ and in preventing hyperoxia, while they seem to be less effective in preventing hypoxia. The studies were very heterogeneous for design, population size, duration, and device used, and this precludes firm conclusions regarding effectiveness and best setting of these systems. Moreover, none of the studies investigated if automated control of FiO₂ can actually improve outcome in preterm infants. We conclude that further large-scale studies are warranted to assess the actual clinical relevance of these devices and to decide if they should become the standard of care.

Oxygen therapy of the newborn from molecular understanding to clinical practice

Oxygen is one of the most critical components of life. Nature has taken billions of years to develop optimal atmospheric oxygen concentrations for human life, evolving from very low, peaking at 30% before reaching 20.95%. There is now increased understanding of the potential toxicity of both too much and too little oxygen, especially for preterm and asphyxiated infants and of the potential and lifelong impact of oxygen exposure, even for a few minutes after birth. In this review, we discuss the contribution of knowledge gleaned from basic science studies and their implication in the care and outcomes of the human infant within the first few minutes of life and afterwards. We emphasize current knowledge gaps and research that is needed to answer a problem that has taken Nature a considerably longer time to resolve.

Neuroinflammation in preterm babies and autism spectrum disorders

Genetic anomalies have a role in autism spectrum disorders (ASD). Each genetic factor is responsible for a small fraction of cases. Environment factors, like preterm delivery, have an important role in ASD. Preterm infants have a 10-fold higher risk of developing ASD. Preterm birth is often associated with maternal/fetal inflammation, leading to a fetal/neonatal inflammatory syndrome. There are demonstrated experimental links between fetal inflammation and the later development of behavioral symptoms consistent with ASD. Preterm infants have deficits in connectivity. Most ASD genes encode synaptic proteins, suggesting that ASD are connectivity pathologies. Microglia are essential for normal synaptogenesis. Microglia are diverted from homeostatic functions towards inflammatory phenotypes during perinatal inflammation, impairing synaptogenesis. Preterm infants with ASD have a different phenotype from term born peers. Our original hypothesis is that exposure to inflammation in preterm infants, combined with at risk genetic background, deregulates brain development leading to ASD.

Preterm Neonates with Respiratory Distress Syndrome: Ventilator-Induced Lung Injury and Oxidative Stress

Ventilator-induced lung injury is well recognized, and appropriate arterial saturation target is unknown, so gentle modes of ventilation and minimizing oxidative stress have been well studied. Our objective was to analyze any association between the oxygen levels at blood sampling and plasma levels of the interleukins IL-6, IL-1β, IL-10, and IL-8 and TNF-α in preterm newborns under mechanical ventilation (MV) in their first two days. Methods. Prospective cohort including neonates with severe respiratory distress. Blood samples were collected right before and 2 hours after invasive MV. For analysis purposes, newborns were separated according to oxygen requirement: low oxygen (≤30%) and high oxygen (>30%) groups. Interleukins were measured using a commercially available kit. Results. 20 neonates (gestational age 32.2 ± 3 weeks) were evaluated. Median O₂ saturation levels pre-MV were not different in both oxygen groups. In the high oxygen group, IL-6, IL-8, and TNF-α plasma levels increased significantly after two hours under MV. Conclusions. Despite the small sample studied, data showed that there is a relationship between VILI, proinflammatory cytokines, and oxygen-induced lung injury, but a study considering oxidative marker measurements is needed. It seems that less oxygen may keep safer saturation targets playing a less harmful role.

Automated versus manual control of inspired oxygen to target oxygen saturation in preterm infants: a systematic review and meta-analysis

OBJECTIVES

To conduct a systematic review of clinical trials comparing automated versus manual fraction of inspired oxygen (FiO₂) control to target oxygen saturation (SpO₂) in preterm infants.

DESIGN

The authors searched MEDLINE, Embase, CENTRAL, and CINAHL from inception upto December 2016, reviewed conference proceedings and sought results of unpublished trials. Studies were included if automated FiO₂ control was compared to manual control in preterm infants on positive pressure respiratory support. The primary outcome was percentage of time spent within the target SpO₂ range. Summary mean differences (MD) were computed using random effects model.

RESULTS

Out of 276 identified studies 10 met the inclusion criteria. Automated FiO₂ control significantly improved time being spent within the target SpO₂ range [MD: 12.8%; 95% CI: 6.5-19.2%; I² = 90%]. Periods of hyperoxia (MD:-8.8%; 95% CI: -15 to -2.7%), severe hypoxia(SpO₂ < 80%)(MD: -0.9%;95%CI: -1.5 to -0.4%) and hypoxic events (MD: -5.6%; 95% CI: -9.1 to -2.1%) were significantly reduced with automated control.

CONCLUSION

Automated FiO₂ adjustment provides significant improvement of time in target saturations, reduces periods of hyperoxia, and severe hypoxia in preterm infants on positive pressure respiratory support.

A Translational Model of Incomplete Catch-Up Growth: Early-Life Hypoxia and the Effect of Physical Activity

Advances in therapies have led to prolonged survival from many previously lethal health threats in children, notably among prematurely born babies and those with congenital heart disease. Evidence for catch‐up growth is common in these children, but in many cases the adult phenotype is never achieved. A translational animal model is required in which specific tissues can be studied over a reasonable time interval. We investigated the impact of postnatal hypoxia (HY) (12%O₂ (HY12) or 10% O₂ (HY10)) on growth in rats relative to animals raised in room air. Subgroups had access to running wheels following the HY period. Growth was fully compensated in adult HY12 rats but not HY10 rats. The results of this study indicate that neonatal hypoxia can be a useful model for the elucidation of mechanisms that mediate successful catch‐up growth following neonatal insults and identify the critical factors that prevent successful catch‐up growth.

Association of unit-wide oxygen saturation target on incidence of pulmonary hypertension in very low birthweight premature infants

OBJECTIVE

Assess the effect of increasing pulse oximetry targets on incidence of pulmonary hypertension in very low birthweight premature infants.

STUDY DESIGN

Retrospective cohort study comparing pulmonary hypertension incidence among three cohorts of premature infants exposed to varying oxygen saturation targets (Cohort 1: n=459, 1 May 2009 to 30 April 2011, 85-94%; Cohort 2: n=474, 1 May 2011 to 31 May 2013, 88-94%; Cohort 3: n=387, 1 June 2013 to 31 May 2015, 90-95%). Subjects had birth weight <1500 g and gestational age 23-32 weeks. Chi-square, Kruskall-Wallis and Anderson-Darling tests were used, as well as multivariable logistic regression.

RESULTS

Incidence of pulmonary hypertension declined with higher oxygen saturation targets (19.0% Cohort 1, 7.9% Cohort 2, 9.6% Cohort 3, P<0.001). Other parameters were largely not different between cohorts though rates of chorioamnionitis and prenatal steroids increased and oxygen use, inhaled nitric oxide use, necrotizing enterocolitis and patent ductus arteriosus ligation decreased over time.

CONCLUSION

Higher oxygen saturation targets for very low-birthweight premature infants were associated with reduced rates of pulmonary hypertension in this retrospective cohort study.

Oxygenation of the Immature Infant: A Commentary and Recommendations for Oxygen Saturation Targets and Alarm Limits

BACKGROUND

For 70 years, there has been a search for the optimal oxygenation of premature infants. In spite of the lack of evidence, guidelines have successively reduced oxygenation targets during these years.

OBJECTIVES

(1) To present a summary of previously published meta-analyses of 5 randomized studies (NeOProM) which tested a low (85-89%) versus a high (91-95%) oxygen saturation target the first weeks after birth on outcome of immature newborn infants. (2) To present international recommendations for oxygenation the first weeks after birth.

METHODS

Data were retrieved from meta-analyses and reviews of these studies.

RESULTS

Mortality and necrotizing enterocolitis (NEC) are significantly higher in patients with a low saturation target (relative risk, RR 1.16 and 1.24, respectively), while severe retinopathy of prematurity (ROP) is reduced (RR 0.74), fortunately without a change in the rate of blindness. Severe intraventricular hemorrhage, patent ductus arteriosus, and bronchopulmonary dysplasia (defined physiologically) were not significantly affected by the oxygen targets in the range of these studies. Based on these data, it is recommended that SpO2 targets from birth to 36 weeks postconceptional age for infants < 28 weeks gestational age (GA) should be between 90 and 94% (with alarm limits of 89 and 95%), respectively. It is recommended to keep infants small for GA well oxygenated within the suggested targets avoiding fluctuations.

CONCLUSIONS

The ideal oxygen saturation targets for infants < 28 weeks GA are not known. Mortality, ROP, and NEC seem to be particularly oxygen-sensitive outcome variables. The optimal oxygen saturation for premature infants > 28 weeks GA has not been carefully studied.

Pulse Oximetry Targets in Extremely Premature Infants and Associated Mortality: One-Size May Not Fit All

Oxygen saturation targets in premature infants have been investigated in multiple international randomized controlled trials. Some trials have shown increased mortality with targeting lower (85% to 89%) compared to higher (91% to 95%) oxygen saturation ranges, while others have not. We will review the mortality outcomes of the largest multi-centered trials and a post hoc study that observed increased mortality at lower target ranges among small for gestational age infants. The planned Neonatal Oxygen Prospective Meta-analysis (NeOProM) collaborative will hopefully provide further insight into patient-specific risks, which include growth status.

How to decrease bronchopulmonary dysplasia in your neonatal intensive care unit today and "tomorrow"

Bronchopulmonary dysplasia, or BPD, is the most common chronic lung disease in infants. Genetic predisposition and developmental vulnerability secondary to antenatal and postnatal infections, compounded with exposure to hyperoxia and invasive mechanical ventilation to an immature lung, result in persistent inflammation, culminating in the characteristic pulmonary phenotype of BPD of impaired alveolarization and dysregulated vascularization. In this article, we highlight specific areas in current management, and speculate on therapeutic strategies that are on the horizon, that we believe will make an impact in decreasing the incidence of BPD in your neonatal intensive care units.

Effects of targeting lower versus higher arterial oxygen saturations on death or disability in preterm infants

BACKGROUND

The use of supplemental oxygen in the care of extremely preterm infants has been common practice since the 1940s. Despite this, there is little agreement regarding which oxygen saturation (SpO₂) ranges to target to maximise short- or long-term growth and development, while minimising harms. There are two opposing concerns. Lower oxygen levels (targeting SpO₂ at 90% or less) may impair neurodevelopment or result in death. Higher oxygen levels (targeting SpO₂ greater than 90%) may increase severe retinopathy of prematurity or chronic lung disease.The use of pulse oximetry to non-invasively assess neonatal SpO₂ levels has been widespread since the 1990s. Until recently there were no randomised controlled trials (RCTs) that had assessed whether it is better to target higher or lower oxygen saturation levels in extremely preterm infants, from birth or soon thereafter. As a result, there is significant international practice variation and uncertainty remains as to the most appropriate range to target oxygen saturation levels in preterm and low birth weight infants.

OBJECTIVES

1. What are the effects of targeting lower versus higher oxygen saturation ranges on death or major neonatal and infant morbidities, or both, in extremely preterm infants?2. Do these effects differ in different types of infants, including those born at a very early gestational age, or in those who are outborn, without antenatal corticosteroid coverage, of male sex, small for gestational age or of multiple birth, or by mode of delivery?

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 4), MEDLINE via PubMed (1966 to 11 April 2016), Embase (1980 to 11 April 2016) and CINAHL (1982 to 11 April 2016). We also searched clinical trials databases, conference proceedings and the reference lists of retrieved articles for randomised controlled trials.

SELECTION CRITERIA

Randomised controlled trials that enrolled babies born at less than 28 weeks' gestation, at birth or soon thereafter, and targeted SpO₂ ranges of either 90% or below or above 90% via pulse oximetry, with the intention of maintaining such targets for at least the first two weeks of life.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane Neonatal to extract data from the published reports of the included studies. We sought some additional aggregate data from the original investigators in order to align the definitions of two key outcomes. We conducted the meta-analyses with Review Manager 5 software, using the Mantel-Haenszel method for estimates of typical risk ratio (RR) and risk difference (RD) and a fixed-effect model. We assessed the included studies using the Cochrane 'Risk of bias' and GRADE criteria in order to establish the quality of the evidence. We investigated heterogeneity of effects via pre-specified subgroup and sensitivity analyses.

MAIN RESULTS

Five trials, which together enrolled 4965 infants, were eligible for inclusion. The investigators of these five trials had prospectively planned to combine their data as part of the NeOProM (Neonatal Oxygen Prospective Meta-analysis) Collaboration. We graded the quality of evidence as high for the key outcomes of death, major disability, the composite of death or major disability, and necrotising enterocolitis; and as moderate for blindness and retinopathy of prematurity requiring treatment.When an aligned definition of major disability was used, there was no significant difference in the composite primary outcome of death or major disability in extremely preterm infants when targeting a lower (SpO₂ 85% to 89%) versus a higher (SpO₂ 91% to 95%) oxygen saturation range (typical RR 1.04, 95% confidence interval (CI) 0.98 to 1.10; typical RD 0.02, 95% CI -0.01 to 0.05; 5 trials, 4754 infants) (high-quality evidence). Compared with a higher target range, a lower target range significantly increased the incidence of death at 18 to 24 months corrected age (typical RR 1.16, 95% CI 1.03 to 1.31; typical RD 0.03, 95% CI 0.01 to 0.05; 5 trials, 4873 infants) (high-quality evidence) and necrotising enterocolitis (typical RR 1.24, 95% 1.05 to 1.47; typical RD 0.02, 95% CI 0.01 to 0.04; 5 trials, 4929 infants; I² = 0%) (high-quality evidence). Targeting the lower range significantly decreased the incidence of retinopathy of prematurity requiring treatment (typical RR 0.72, 95% CI 0.61 to 0.85; typical RD -0.04, 95% CI -0.06 to -0.02; 5 trials, 4089 infants; I² = 69%) (moderate-quality evidence). There were no significant differences between the two treatment groups for major disability including blindness, severe hearing loss, cerebral palsy, or other important neonatal morbidities.A subgroup analysis of major outcomes by type of oximeter calibration software (original versus revised) found a significant difference in the treatment effect between the two software types for death (interaction P = 0.03), with a significantly larger treatment effect seen for those infants using the revised algorithm (typical RR 1.38, 95% CI 1.13 to 1.68; typical RD 0.06, 95% CI 0.01 to 0.10; 3 trials, 1716 infants). There were no other important differences in treatment effect shown by the subgroup analyses using the currently available data.

AUTHORS' CONCLUSIONS

In extremely preterm infants, targeting lower (85% to 89%) SpO₂ compared to higher (91% to 95%) SpO₂ had no significant effect on the composite outcome of death or major disability or on major disability alone, including blindness, but increased the average risk of mortality by 28 per 1000 infants treated. The trade-offs between the benefits and harms of the different oxygen saturation target ranges may need to be assessed within local settings (e.g. alarm limit settings, staffing, baseline outcome risks) when deciding on oxygen saturation targeting policies.

Oxygen saturation targeting by pulse oximetry in the extremely low gestational age neonate: a quixotic quest

PURPOSE OF REVIEW

A collaboration of comparative effectiveness research trials of pulse oximeter saturation (SpO2) targeting in extremely low-gestational-age neonates have begun to report their aggregate results. We examine the results of those trials, collectively referred to as the Neonatal Oxygenation Prospective Meta-analysis or NeOProM. We also discuss the uncertainties that remain and the clinical challenges that lie ahead.

RECENT FINDINGS

The primary outcome from NeOProM was a composite of death or disability at 18-24 months corrected age. In 2016 the last of these reports was published. Although there were no differences in the primary outcome overall, analyses of secondary outcomes and data subsets following a pulse oximeter revision show significant treatment differences between targeting a lower compared with a higher SpO2.

SUMMARY

NeOProM represents the largest collaborative clinical research study of SpO2 targets in extremely low-gestational-age neonates. Although aggregate results give us some insight into the feasibility and efficacy of SpO2 targeting in this population, many questions remain. A patient-level analysis, tracking individual outcomes based on actual SpO2 experienced, may shed some light on these questions. However, finding a single optimal SpO2 range seems unlikely.