The fetal circulation, pathophysiology of hypoxemic respiratory failure and pulmonary hypertension in neonates, and the role of oxygen therapy

Response to Inhaled Nitric Oxide and Mortality Among Very Preterm Neonates With Pulmonary Hypertension

Importance

Clinical observations of immediate improvement in fraction of inspired oxygen (FiO2) in a proportion of cases is often cited as the rationale for using inhaled nitric oxide (iNO) in the management of acute pulmonary hypertension among very preterm neonates (gestational age, <32 weeks). However, the clinical effectiveness of such a response pattern remains underinvestigated.

Objective

To identify factors associated with predischarge mortality among very preterm neonates receiving iNO for acute pulmonary hypertension, with specific a priori emphasis on iNO responsiveness.

Design, Setting, and Participants

This prospective observational cohort study was conducted from January 1, 2018, to December 31, 2022, at 12 Canadian tertiary neonatal intensive care units. Consecutive very preterm neonates who received iNO for a diagnosis of acute pulmonary hypertension and pretreatment FiO2 of 0.50 or more were included. Neonates with congenital anomalies or those who were treated for chronic pulmonary hypertension with iNO were excluded. Early acute pulmonary hypertension (≤72 hours of age) and late acute pulmonary hypertension (>72 hours of age) cohorts were analyzed separately. Statistical analysis was performed from January 2023 to January 2024.

Exposure

Treatment with iNO for acute pulmonary hypertension.

Main Outcomes and Measures

The study cohorts were divided for comparison based on the primary outcome of predischarge mortality. Logistic regression analyses were used with predefined variables, including iNO responsiveness, to identify factors associated with mortality. A positive response to iNO was defined as a pre-iNO minus 4-hour post-iNO FiO2 of 0.20 or more.

Results

The early acute pulmonary hypertension group (mean [SD] birth gestational age, 26.3 [2.4] weeks; median treatment age, 1 day [IQR, 1-2 days]; 147 boys [56%]) included 262 neonates; 179 (68%) had a pre-iNO FiO2 of 1.0. The late acute pulmonary hypertension group (mean [SD] birth gestational age, 24.9 [1.7] weeks; median treatment age, 13 days [IQR, 9-20 days]; 72 boys [66%]) included 109 neonates; 51 (47%) had a pre-iNO FiO2 of 1.0. Neonates with early acute pulmonary hypertension more frequently had a positive iNO response (71% [186 of 262] vs 41% [45 of 109]) and lower mortality (34% [90 of 262] vs 49% [53 of 109]) than those with late acute pulmonary hypertension. Accounting for pretreatment illness factors, greater reduction in FiO2 with iNO remained associated with lower mortality for neonates with early acute pulmonary hypertension (adjusted odds ratio per FiO2 reduction of 0.10, 0.74 [95% CI, 0.65-0.84]). For those with late acute pulmonary hypertension, however, only pretreatment illness severity (lower pre-iNO FiO2 and higher pre-iNO pH), and not positive response to iNO (adjusted odds ratio, 0.47 [95% CI, 0.17-1.30]), was associated with mortality.

Conclusions and Relevance

In this cohort study of very preterm neonates with acute pulmonary hypertension treated with iNO, responsiveness to iNO was associated with improved outcomes during the first 72 hours of age. The prognostic role of iNO response in acute pulmonary hypertension presenting after 72 hours of age remains unclear. Future studies should investigate the distinct pathophysiological mechanisms associated with late acute pulmonary hypertension in this population.

Oxygen saturation targets in neonatal care: A narrative review

Optimal oxygenation requires the delivery of oxygen to meet tissue metabolic demands while minimizing hypoxic pulmonary vasoconstriction and oxygen toxicity. Oxygen saturation by pulse oximetry (SpO2) is a continuous, non-invasive method for monitoring oxygenation. The optimal SpO2 target varies during pregnancy and neonatal period. Maternal SpO2 should ideally be ≥95 % to ensure adequate fetal oxygenation. Term neonates can be resuscitated with an initial oxygen concentration of 21 %, while moderately preterm infants require 21-30 %. Extremely preterm infants may need higher FiO2, followed by titration to desired SpO2 targets. During the NICU course, extremely preterm infants managed with an 85-89 % SpO2 target compared to 90-94 % are associated with a reduced incidence of severe retinopathy of prematurity (ROP) requiring treatment, but with higher mortality. During the later stages of ROP progression, studies suggest that higher SpO2 targets may help limit progression. A target SpO2 of 90-95 % is generally reasonable for term infants with respiratory disease or pulmonary hypertension, with few exceptions such as severe acidosis, therapeutic hypothermia, and possibly dark skin pigmentation, where 93-98 % may be preferred. Infants with cyanotic heart disease and single-ventricle physiology have lower SpO2 targets to avoid pulmonary over-circulation. In low- and middle-income countries (LMICs), the scarcity of oxygen blenders and continuous monitoring may pose a challenge, increasing the risks of both hypoxia and hyperoxia, which can lead to mortality and ROP, respectively. Strategies to mitigate hyperoxia among preterm infants in LMICs are urgently needed to reduce the incidence of ROP.

Association of the distance travelled, and the call to hospital arrival time with early neonatal mortality in neonates born to mothers using emergency medical services at term gestation: a retrospective observational study

BACKGROUND

Most neonatal deaths in India occur due to a lack of timely and proper care just before and during delivery. Timely availability of an ambulance for institutional delivery has led to some decrease in this. However, the distance travelled and time taken may affect the outcome.

OBJECTIVE

The objective of this retrospective observational study was to determine if the distance travelled and the call to hospital arrival time are associated with deaths in the early neonatal period (0-7 days postnatal age), in neonates born to mothers who used a centralised emergency medical services (EMS) agency transportation at term gestation.

DESIGN

Retrospective observational study.

SETTING

This was a secondary analysis of a de-identified patient dataset from a previous cohort study on EMS usage by pregnant women, in five Indian states in 2014.

PARTICIPANTS

Neonates born to mothers using EMS at ≥37-42 weeks gestation were included as participants. The groups of pregnant individuals with low distance (≤10 km) and time (≤60 min) to hospital arrival vs longer distance or time to hospital arrival were then compared for neonatal death in the first 7 days of life or early neonatal death (ENND), which was the primary outcome. χ2 test and logistic regression were carried out. Additional analysis was also planned to test the higher cut-offs of distance and time, if the above cut-offs were not found to have a statistically significant association with ENND.

RESULTS

There were a total of 1180 neonates meeting the inclusion criteria. Of these, 272 (23%) were born to mothers who travelled ≤10 km (km) and took time ≤60 min to reach the hospital. There were a total of 57 (4.8%) ENNDs of which 14 occurred in the low distance and time group (≤10 km and ≤60 min). There was no statistically significant difference between the groups for ENND (p value=0.8). On additional univariate analysis for the different cut-offs of distance and time separately, it was found that there were lesser odds of ENND for a cut-off of distance ≤60 km (OR 0.28 (95% CI 0.08 to 0.98), p value=0.046) and for a cut-off time ≤120 min (OR 0.36 (95% CI 0.17 to 0.76), p value=0.007). When adjusted for other variables found to be significant on univariate analysis (caesarean section, <4 antenatal visits, maternal tachycardia and twin gestation) a cut-off distance ≤60 km had a trend towards lower odds of ENND (OR 0.31 (95% CI 0.084 to 1.12), p value=0.075) while a cut-off time of≤120 min had a significantly lower odds of ENND (OR 0.37 (95% CI 0.167 to 0.81), p value=0.013). When both of these cut-offs were combined and analysed in the multivariable logistic regression model, the association with ENND was still significant (OR 0.33 (95% CI 0.16 to 0.72), p value=0.005).

CONCLUSION

In neonates born to mothers using EMS at term gestation in India, those with distance travelled by the mother ≤60 km and time taken to reach health facility ≤120 min, had 67% lower odds of ENND compared with those with distance travelled >60 km or time taken >120 min. Further prospective observational studies are required to validate these cut-offs in a larger population.

Delivery room and early postnatal management of neonates with congenital heart disease

Advancements in prenatal detection have improved postnatal outcomes for patients with congenital heart disease (CHD). Detailed diagnosis during pregnancy allows for preparation for the delivery and immediate postnatal care for the newborns with CHD. Most CHDs do not result in hemodynamic instability at the time of birth and can be stabilized following the guidelines of the neonatal resuscitation program (NRP). Critical CHD that requires intervention immediately after birth is recommended to be delivered in facilities where immediate neonatal and cardiology care can be provided. Postnatal stabilization and resuscitation for these defects warrant deviation from the standardized NRP. For neonatal providers, knowing the diagnosis of fetal CHD allows for preparation for the anticipated instability in the delivery room. Prenatal detection fosters collaboration between fetal cardiology, cardiology specialists, obstetrics, and neonatology, improving outcomes for neonates with critical CHD.

Association of Fetal Lung Development Disorders with Adult Diseases: A Comprehensive Review

Fetal lung development is a crucial and complex process that lays the groundwork for postnatal respiratory health. However, disruptions in this delicate developmental journey can lead to fetal lung development disorders, impacting neonatal outcomes and potentially influencing health outcomes well into adulthood. Recent research has shed light on the intriguing association between fetal lung development disorders and the development of adult diseases. Understanding these links can provide valuable insights into the developmental origins of health and disease, paving the way for targeted preventive measures and clinical interventions. This review article aims to comprehensively explore the association of fetal lung development disorders with adult diseases. We delve into the stages of fetal lung development, examining key factors influencing fetal lung maturation. Subsequently, we investigate specific fetal lung development disorders, such as respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD), congenital diaphragmatic hernia (CDH), and other abnormalities. Furthermore, we explore the potential mechanisms underlying these associations, considering the role of epigenetic modifications, transgenerational effects, and intrauterine environmental factors. Additionally, we examine the epidemiological evidence and clinical findings linking fetal lung development disorders to adult respiratory diseases, including asthma, chronic obstructive pulmonary disease (COPD), and other respiratory ailments. This review provides valuable insights for healthcare professionals and researchers, guiding future investigations and shaping strategies for preventive interventions and long-term care.

Etiology, Diagnosis and Management of Persistent Pulmonary Hypertension of the Newborn in Resource-limited Settings

Persistent Pulmonary Hypertension of the Newborn (PPHN) is more common in Low and middle income countries (LMICs) due to high incidence of sepsis, perinatal asphyxia and meconium aspiration syndrome. Presence of hypoxic respiratory faillure and greater than 5% difference in preductal and post ductal saturation increases clinical sucipision for PPHN. The availability of Inhaled nitric oxide and extracorporaeal membrane oxygenation is limited but pulmonary vasodilators such as sildenafil are readily available in most LMICs.

Guidelines and Recommendations for Targeted Neonatal Echocardiography and Cardiac Point-of-Care Ultrasound in the Neonatal Intensive Care Unit: An Update from the American Society of Echocardiography

Targeted neonatal echocardiography (TNE) involves the use of comprehensive echocardiography to appraise cardiovascular physiology and neonatal hemodynamics to enhance diagnostic and therapeutic precision in the neonatal intensive care unit. Since the last publication of guidelines for TNE in 2011, the field has matured through the development of formalized neonatal hemodynamics fellowships, clinical programs, and the expansion of scientific knowledge to further enhance clinical care. The most common indications for TNE include adjudication of hemodynamic significance of a patent ductus arteriosus, evaluation of acute and chronic pulmonary hypertension, evaluation of right and left ventricular systolic and/or diastolic function, and screening for pericardial effusions and/or malpositioned central catheters. Neonatal cardiac point-of-care ultrasound (cPOCUS) is a limited cardiovascular evaluation which may include line tip evaluation, identification of pericardial effusion and differentiation of hypovolemia from severe impairment in myocardial contractility in the hemodynamically unstable neonate. This document is the product of an American Society of Echocardiography task force composed of representatives from neonatology-hemodynamics, pediatric cardiology, pediatric cardiac sonography, and neonatology-cPOCUS. This document provides (1) guidance on the purpose and rationale for both TNE and cPOCUS, (2) an overview of the components of a standard TNE and cPOCUS evaluation, (3) disease and/or clinical scenario-based indications for TNE, (4) training and competency-based evaluative requirements for both TNE and cPOCUS, and (5) components of quality assurance. The writing group would like to acknowledge the contributions of Dr. Regan Giesinger who sadly passed during the final revisions phase of these guidelines. Her contributions to the field of neonatal hemodynamics were immense.

Association between immediate oxygenation response and survival in preterm infants receiving rescue inhaled nitric oxide therapy for hypoxemia from pulmonary hypertension: A systematic review and meta-analysis

PURPOSE

To investigate whether immediate response to inhaled nitric oxide (iNO) therapy is associated with reduced mortality in preterm infants with hypoxemic respiratory failure (HRF) and pulmonary hypertension (PH).

METHODS

A systematic review and meta-analysis of observational studies was conducted to examine the association between immediate response (improved oxygenation ≤6 h) compared to non-response, and all-cause mortality among preterm infants <34 weeks gestational age without congenital anomalies or genetic disorders who received iNO treatment. Adjusted and unadjusted odds ratio, were pooled using a random effects meta-analysis Hartung-Knapp-Sidik-Jonkman approach. Subgroup analyses were planned for infants with preterm premature rupture of membranes (PPROM) and those treated within 72 h after birth.

RESULTS

The primary analysis included 5 eligible studies, a total of 400 infants (196 responders; 204 non-responders). The studies were rated as low to moderate risk of bias based on the Quality in Prognostic Studies tool. Immediate iNO responsiveness was associated with reduced odds of mortality [odds ratio (OR) 0.22, 95 % confidence interval (95 % CI) (0.10-0.49)]. Although there was insufficient data for a subgroup analysis of infants with PPROM, infants treated with iNO within 72 h demonstrated consistent findings of reduced mortality [OR 0.21 95 % CI (0.13-0.36)]. Based on the GRADE approach, considering the risk of bias of included studies, the overall strength of evidence was rated as moderate.

CONCLUSION

There is evidence to suggest that immediate improvement in oxygenation following iNO therapy is associated with reduced odds of mortality before discharge in preterm infants with HRF and clinically suspected or confirmed PH.

Assessment of normal pulmonary development using functional magnetic resonance imaging techniques

BACKGROUND

The mainstay of assessment of the fetal lungs in clinical practice is via evaluation of pulmonary size, primarily using 2D ultrasound and more recently with anatomical magnetic resonance imaging. The emergence of advanced magnetic resonance techniques such as T2* relaxometry in combination with the latest motion correction post-processing tools now facilitates assessment of the metabolic activity or perfusion of fetal pulmonary tissue in vivo.

OBJECTIVE

This study aimed to characterize normal pulmonary development using T2* relaxometry, accounting for fetal motion across gestation.

METHODS

Datasets from women with uncomplicated pregnancies that delivered at term, were analyzed. All subjects had undergone T2-weighted imaging and T2* relaxometry on a Phillips 3T magnetic resonance imaging system antenatally. T2* relaxometry of the fetal thorax was performed using a gradient echo single-shot echo planar imaging sequence. Following correction for fetal motion using slice-to-volume reconstruction, T2* maps were generated using in-house pipelines. Lungs were manually segmented and mean T2* values calculated for the right and left lungs individually, and for both lungs combined. Lung volumes were generated from the segmented images, and the right and left lungs, as well as both lungs combined were assessed.

RESULTS

Eighty-seven datasets were suitable for analysis. The mean gestation at scan was 29.9±4.3 weeks (range: 20.6-38.3) and mean gestation at delivery was 40±1.2 weeks (range: 37.1-42.4). Mean T2* values of the lungs increased over gestation for right and left lungs individually and for both lungs assessed together (P=.003; P=.04; P=.003, respectively). Right, left, and total lung volumes were also strongly correlated with increasing gestational age (P<.001 in all cases).

CONCLUSION

This large study assessed developing lungs using T2* imaging across a wide gestational age range. Mean T2* values increased with gestational age, which may reflect increasing perfusion and metabolic requirements and alterations in tissue composition as gestation advances. In the future, evaluation of findings in fetuses with conditions known to be associated with pulmonary morbidity may lead to enhanced prognostication antenatally, consequently improving counseling and perinatal care planning.

Torn between two worlds: parental experiences of neonatal follow-up for infants with hypoxic ischaemic encephalopathy in India-a qualitative study using interpretative phenomenological analysis

OBJECTIVE

This study aimed to understand the barriers and facilitators of a neonatal follow-up programme, as perceived by parents of infants born with hypoxic ischaemic encephalopathy (HIE).

DESIGN

This study applied a qualitative study design using interpretative phenomenological analysis. It included focus group discussions, face-to-face in-depth interviews and telephonic interviews. Data were analysed using thematic content analysis.

SETTING

Neonatal follow-up clinic of a tertiary hospital in South India. The study was conducted between March and December 2020.

PARTICIPANTS

Five fathers and eight mothers of infants with HIE.

RESULTS

Parents of children with HIE are torn between two worlds-an atmosphere of support and one of criticism. Three main themes were identified: (1) neonatal intensive care unit (NICU) stay: distressful versus reassuring experiences; (2) parenthood: supportive versus unsupportive environments; and (3) neonatal follow-up: adherence versus non-adherence.

CONCLUSION

Parents of children with HIE experience sociocultural barriers in the NICU, after discharge and during the follow-up period. These lead to a complex array of emotional and physical consequences that affect parenting and follow-up care.

[Early risk factors for death in neonates with persistent pulmonary hypertension of the newborn treated with inhaled nitric oxide]

OBJECTIVES

To evaluate the early risk factors for death in neonates with persistent pulmonary hypertension of the newborn (PPHN) treated with inhaled nitric oxide (iNO).

METHODS

A retrospective analysis was performed on 105 infants with PPHN (gestational age ≥34 weeks and age <7 days on admission) who received iNO treatment in the Department of Neonatology, Children's Hospital of Nanjing Medical University, from July 2017 to March 2021. Related general information and clinical data were collected. According to the clinical outcome at discharge, the infants were divided into a survival group with 79 infants and a death group with 26 infants. Univariate and multivariate Cox regression analyses were used to evaluate the risk factors for death in infants with PPHN treated with iNO. The receiver operating characteristic (ROC) curve was used to calculate the cut-off values of the factors in predicting the death risk.

RESULTS

A total of 105 infants with PPHN treated with iNO were included, among whom 26 died (26/105, 24.8%). The multivariate Cox regression analysis showed that no early response to iNO (HR=8.500, 95%CI: 3.024-23.887, P<0.001), 1-minute Apgar score ≤3 points (HR=10.094, 95%CI: 2.577-39.534, P=0.001), a low value of minimum PaO2/FiO2 within 12 hours after admission (HR=0.067, 95%CI: 0.009-0.481, P=0.007), and a low value of minimum pH within 12 hours after admission (HR=0.049, 95%CI: 0.004-0.545, P=0.014) were independent risk factors for death. The ROC curve analysis showed that the lowest PaO2/FiO2 value within 12 hours after admission had an area under the ROC curve of 0.783 in predicting death risk, with a sensitivity of 84.6% and a specificity of 73.4% at the cut-off value of 50, and the lowest pH value within 12 hours after admission had an area under the ROC curve of 0.746, with a sensitivity of 76.9% and a specificity of 65.8% at the cut-off value of 7.2.

CONCLUSIONS

Infants with PPHN requiring iNO treatment tend to have a high mortality rate. No early response to iNO, 1-minute Apgar score ≤3 points, the lowest PaO2/FiO2 value <50 within 12 hours after admission, and the lowest pH value <7.2 within 12 hours after admission are the early risk factors for death in such infants. Monitoring and evaluation of the above indicators will help to identify high-risk infants in the early stage.

Rotating nasal masks with nasal prongs reduces the incidence of moderate to severe nasal injury in preterm infants supported by noninvasive ventilation

OBJECTIVE

To investigate the association between noninvasive ventilation delivery devices and the incidence of nasal septum injury in preterm infants.

METHODS

This retrospective singlecenter cohort study included preterm infants supported by noninvasive ventilation. The incidence of nasal injury was compared among three groups according to the noninvasive ventilation delivery device (G1 - nasal mask; G2 - binasal prongs; and G3, rotation of nasal mask with prongs). Nasal injury was classified according to the National Pressure Ulcer Advisory Panel as stages 1 - 4. Multivariate regression analyses were performed to estimate relative risks to identify possible predictors associated with medical device-related injuries.

RESULTS

Among the 300 infants included in the study, the incidence of medical device-related injuries in the rotating group was significantly lower than that in the continuous mask or prong groups (n = 68; 40.48%; p value < 0.01).The basal prong group presented more stage 2 injuries (n = 15; 55.56%; p < 0.01). Staying ≥ 7 days in noninvasive ventilation was associated with a higher frequency of medical device-related injuries, regardless of device (63.81%; p < 0.01). Daily increments in noninvasive ventilation increased the risk for nasal injury by 4% (95%CI 1.02 - 1.06; p < 0.01). Higher birth weight indicated protection against medical device-related injuries. Each gained gram represented a decrease of 1% in the risk of developing nasal septum injury (RR: 0.99; 95%CI 0.99 - 0.99; p < 0.04).

CONCLUSION

Rotating nasal masks with nasal prongs reduces the incidence of moderate to severe nasal injury in comparison with single devices. The addition of days using noninvasive ventilation seems to contribute to medical device-related injuries, and higher birth weight is a protective factor.

Care of the critically ill neonate with hypoxemic respiratory failure and acute pulmonary hypertension: framework for practice based on consensus opinion of neonatal hemodynamics working group

Circulatory transition after birth presents a critical period whereby the pulmonary vascular bed and right ventricle must adapt to rapidly changing loading conditions. Failure of postnatal transition may present as hypoxemic respiratory failure, with disordered pulmonary and systemic blood flow. In this review, we present the biological and clinical contributors to pathophysiology and present a management framework.

Non-reassuring fetal status and anesthetic impact on cesarean section-delivered very-low-birthweight infants

BACKGROUND

There is limited evidence concerning the impact on neonatal outcomes of different types of anesthesia used for cesarean delivery due to non-reassuring fetal status (NRFS). We aimed to assess the impact of NRFS and general anesthesia (GA) on neonatal outcomes in very-low-birthweight (VLBW) infants delivered by cesarean section.

METHODS

Data were collected relating to VLBW infants admitted to our institution. Infants were grouped into no-NRFS and NRFS groups and further subcategorized into GA and regional anesthesia (RA) subgroups. Neonatal outcomes were evaluated based on the presence of NRFS and the type of anesthesia.

RESULTS

A total of 356 infants were included. The GA subgroup in the no-NRFS group had higher requirements for respiratory support. However, GA was not associated with adverse neonatal outcomes based on the multivariable logistic regression analysis except for 5 min Apgar score <5. On the other hand, NRFS was associated with an increased risk of 5 min Apgar score <5 [adjusted odds ratio (aOR) 2.062, 95% confidence interval (CI) 1.064-3.997], use of high-frequency ventilation (aOR: 2.891, 95% CI: 1.477-5.658), and pulmonary hypertension (aOR: 2.890, 95% CI: 1.436-5.819).

CONCLUSIONS

In our cohort of VLBW infants, NRFS was a significant risk factor for a low 5 min Apgar score, increased respiratory support requirement, and pulmonary hypertension. Accurate assessment of fetal well-being, timely delivery, and presence of a resuscitation team fully aware of perinatal conditions and anesthetic impact is important.

Renal biomarkers of acute kidney injury in response to increasing intermittent hypoxia episodes in the neonatal rat

BACKGROUND

We tested the hypotheses that: 1) early exposure to increasing episodes of clinically relevant intermittent hypoxia (IH) is detrimental to the developing kidneys; and 2) there is a critical number of daily IH episodes which will result in irreparable renal damage that may involve angiotensin (Ang) II and endothelin (ET)-1.

METHODS

At birth (P0), neonatal rat pups were exposed to brief IH episodes from the first day of life (P0) to P7 or from P0-P14. Pups were either euthanized immediately or placed in room air (RA) until P21. RA littermates served as controls. Kidneys were harvested at P7, P14, and P21 for histopathology; angiotensin converting enzyme (ACE), ACE-2, ET-1, big ET-1, and malondialdehyde (MDA) levels; immunoreactivity of ACE, ACE-2, ET-1, ET-2, ET receptors (ETAR, ETBR), and hypoxia inducible factor (HIF)1α; and apoptosis (TUNEL stain).

RESULTS

Histopathology showed increased renal damage with 8-12 IH episodes/day, and was associated with Ang II, ACE, HIF1α, and apoptosis. ACE-2 was not expressed at P7, and minimally increased at P14. However, a robust ACE-2 response was seen during recovery with maximum levels noted in the groups recovering from 8 IH episodes/day. ET-1, big ET-1, ETAR, ETBR, and MDA increased with increasing levels of neonatal IH.

CONCLUSIONS

Chronic neonatal IH causes severe damage to the developing kidney with associated elevations in vasoconstrictors, suggesting hypertension, particularly with 8 neonatal IH episodes. ACE-2 is not activated in early postnatal life, and this may contribute to IH-induced vasoconstriction. Therapeutic targeting of ACE and ET-1 may help decrease the risk for kidney injury in the developing neonate to prevent and/or treat neonatal acute kidney injury and/or chronic kidney disease.

Effectiveness of a short-structured training programme on knowledge of healthcare providers and programme managers involved in maternal and child health programmes in Odisha, India: a quality improvement study

OBJECTIVE

To evaluate the effectiveness of training programme on knowledge related to new interventions proposed under India Newborn Action Plan (INAP) and Integrated Action Plan against Pneumonia and Diarrhoea (IAPPD).

DESIGN

Quality improvement study with pre-evaluation and post evaluation.

SETTING

The study was conducted in 17 districts of Odisha, India.

PARTICIPANTS AND INTERVENTIONS

The participants were healthcare providers and programme managers involved in maternal and child health programmes. Intervention was a short-structured (8 hours) training delivered to 127 batches with expected participation of 30 trainees in each batch. Training was divided into four modules covering new interventions related to INAP and IAPPD like causes of neonatal death, kangaroo mother care (KMC), feeding of low birthweight (LBW) infants, use of injection gentamicin, identification of possible serious bacterial infection (PSBI), identification and management of pneumonia and diarrhoea and key interventions for maternal health. Various modalities of teaching-learning method were used.

OUTCOME MEASURES

Pretraining and post-training knowledge assessment was done with a pretested tool consisting of 15 items. Each item carried equal weightage in calculation of knowledge score thus maximum possible knowledge score was 15. Feedback assessment was also done after the training.

RESULTS

The mean (SD) knowledge score significantly improved to 10.24 (2.24) after training as compared with 4.73 (1.94) before training, p<0.001 (n=982). There was significant improvement in knowledge for majority of the components namely causes of neonatal death (61.9% vs 28.1%), KMC (68.0% vs 54.6%), feeding of LBW infants (77.7% vs 6.9%), use of injection gentamicin (69.7% vs 11.2%), identification of PSBI (69.5% vs 59.5%). The improvement in knowledge score was more when healthcare providers and programme managers had provided a favourable response on feedback.

CONCLUSION

Systematic pretest and post-test assessment coupled with feedback assessment can ensure the effectiveness of training programmes offered in programmatic settings.

Ensuring administration of first dose of antibiotics within the golden hour of management in neonates with sepsis

Administration of first dose of antibiotics within the golden hour in infants with sepsis is critical. Delays can increase mortality. During our observations as part of antibiotic stewardship programme in inborn neonatal unit, we found a significant delay in the administration of first dose of antibiotics from the decision time. We set up a quality improvement team to improve the proportion of neonates with sepsis, who received first dose of antibiotics within 1 hour of decision, from 0% to 80% over 2 months.We included inborn neonates requiring initiation or upgradation of antibiotics for a diagnosis of sepsis, from 1 May to 30 November 2018. We assessed the root causes behind delayed administration and found the lack of immediate availability of blood culture bottles, lack of awareness and busy clinical area as the major contributors to the delays in first dose. Various change ideas like ensuring prior availability of blood culture bottles, sensitising nursing staff and resident doctors, utilisation of hospital attendants and sharing responsibility of drawing culture between team members were tested through plan-do-study-act (PDSA) cycles.The proportion of neonates receiving first dose of antibiotics within 1 hour increased from 0% to 91% over the study period and was sustained at 92% after 6 months. There was a significant reduction in median (IQR) time interval between decision and first dose from 120 (100-290) to 45 (30-60) min (p<0.001) and after 6 months, it further decreased to 30 (30-45) min. We achieved significant improvement in administration of first dose of antibiotics within 1 hour of decision, by using system analysis and testing change ideas in sequential PDSA cycles.

Venovenous versus venoarterial extracorporeal membrane oxygenation among infants with hypoxic-ischemic encephalopathy: is there a difference in outcome?

OBJECTIVE

Our hypothesis was that among infants with hypoxic-ischemic encephalopathy (HIE), venoarterial (VA), compared to venovenous (VV), extracorporeal membrane oxygenation (ECMO) is associated with an increased risk of mortality or intracranial hemorrhage (ICH).

DESIGN/METHODS

Retrospective cohort analysis of infants in the Children's Hospitals Neonatal Database from 2010 to 2016 with moderate or severe HIE, gestational age ≥36 weeks, and ECMO initiation <7 days of age. The primary outcome was mortality or ICH.

RESULTS

Severe HIE was more common in the VA ECMO group (n = 57), compared to the VV ECMO group (n = 53) (47.4% vs. 26.4%, P = 0.02). VA ECMO was associated with a significantly higher risk of death or ICH [57.9% vs. 34.0%, aOR 2.39 (1.08-5.28)] and mortality [31.6% vs. 11.3%, aOR 3.06 (1.08-8.68)], after adjusting for HIE severity.

CONCLUSIONS

In HIE, VA ECMO was associated with a higher incidence of mortality or ICH. VV ECMO may be beneficial in this population.

Associations between community health workers' home visits and education-based inequalities in institutional delivery and perinatal mortality in rural Uttar Pradesh, India: a cross-sectional study

INTRODUCTION

India's National Health Mission has trained community health workers called Accredited Social Health Activists (ASHAs) to visit and counsel women before and after birth. Little is known about the extent to which exposure to ASHAs' home visits has reduced perinatal health inequalities as intended. This study aimed to examine whether ASHAs' third trimester home visits may have contributed to equitable improvements in institutional delivery and reductions in perinatal mortality rates (PMRs) between women with varying education levels in Uttar Pradesh (UP) state, India.

METHODS

Cross-sectional survey data were collected from a representative sample of 52 615 women who gave birth in the preceding 2 months in rural areas of 25 districts of UP in 2014-2015. We analysed the data using generalised linear modelling to examine the associations between exposure to home visits and education-based inequalities in institutional delivery and PMRs.

RESULTS

Third trimester home visits were associated with higher institutional delivery rates, in particular public facility delivery rates (adjusted risk ratio (aRR) 1.32, 95% CI 1.30 to 1.34), and to a lesser extent private facility delivery rates (aRR 1.09, 95% CI 1.04 to 1.13), after adjusting for confounders. Associations were stronger among women with lower education levels. Having no compared with any third trimester home visits was associated with higher perinatal mortality (aRR 1.18, 95% CI 1.09 to 1.28). Having any versus no visits was more highly associated with lower perinatal mortality among women with lower education levels than those with the most education, and most notably among public facility births.

CONCLUSIONS

The results suggest that ASHAs' home visits in the third trimester contributed to equitable improvements in institutional deliveries and lower PMRs, particularly within the public sector. Broader strategies must reinforce the role of ASHAs' home visits in reaching the sustainable development goals of improving maternal and newborn health and leaving no one behind.

Transport characteristics and predictors of mortality among neonates referred to a tertiary care centre in North India: a prospective observational study

OBJECTIVE

The paucity of specialised care in the peripheral areas of developing countries necessitates the referral of sick neonates to higher centres. Organised interhospital transport services provided by a skilled and well-equipped team can significantly improve the outcome. The present study evaluated the transport characteristics and predictors of mortality among neonates referred to a tertiary care centre in North India.

DESIGN

Prospective observational study.

SETTINGS

Tertiary care teaching hospital in North India.

PATIENTS

1013 neonates referred from peripheral health units.

MAIN OUTCOME MEASURES

Mortality among referred neonates on admission to our centre.

RESULTS

Of the 1013 enrolled neonates, 83% were transferred through national ambulance services, 13.7% through private hospital ambulances and 3.3% through personal vehicles. Major transfer indications were prematurity (35%), requirement for ventilation (32%), birth asphyxia (28%) and hyperbilirubinaemia (19%). Hypothermia (32.5%, 330 of 1013), shock (19%, 192 of 1013) and requirement for immediate cardiorespiratory support (ICRS) (10.4%, 106 of 1013) on arrival were the major complications observed during transfer. A total of 305 (30.1%, N=1013) deaths occurred. Of these, 52% (n=160) died within 24 hours of arrival. On multivariate logistic analysis, unsupervised pregnancy (<4 antenatal visits; p=0.037), antenatal complications (p<0.001), prematurity ≤30 weeks (p=0.005), shock (p=0.001), hypothermia (p<0.001), requirement for ICRS on arrival (p<0.001), birth asphyxia (p=0.004), travel time >2 hours (p=0.005) and absence of trained staff during transfer (p<0.001) were found to be significant predictors of mortality.

CONCLUSION

The present study depicts high mortality among infants referred to our centre. Adequate training of peripheral health personnel and availability of pre-referral stabilisation and dedicated interhospital transport teams for sick neonate transfers may prove valuable interventions for improved outcomes.

Development of a framework of intervention strategies for point of care quality improvement at different levels of healthcare delivery system in India: initial lessons

BACKGROUND

Inadequate quality of care has been identified as one of the most significant challenges to achieving universal health coverage in low-income and middle-income countries. To address this WHO-SEARO, the point of care quality improvement (POCQI) method has been developed. This paper describes developing a dynamic framework for the implementation of POCQI across India from 2015 to 2020.

METHODS

A total of 10 intervention strategies were designed as per the needs of the local health settings. These strategies were implemented across 10 states of India, using a modification of the 'translating research in practice' framework. Healthcare professionals and administrators were trained in POCQI using a combination of onsite and online training methods followed by coaching and mentoring support. The implementation strategy changed to a fully digital community of practice platform during the active phase of the COVID-19 pandemic. Dashboard process, outcome indicators and crude cost of implementation were collected and analysed across the implementation sites.

RESULTS

Three implementation frameworks were evolved over the study period. The combined population benefitting from these interventions was 103 million. A pool of QI teams from 131 facilities successfully undertook 165 QI projects supported by a pool of 240 mentors over the study period. A total of 21 QI resources and 6 publications in peer-reviewed journals were also developed. The average cost of implementing POCQI initiatives for a target population of one million was US$ 3219. A total of 100 online activities were conducted over 6 months by the digital community of practice. The framework has recently extended digitally across the South-East Asian region.

CONCLUSION

The development of an implementation framework for POCQI is an essential requirement for the initiative's successful country-wide scale. The implementation plan should be flexible to the healthcare system's needs, target population and the implementing agency's capacity and amenable to multiple iterative changes.

Effect of continuous positive airway pressure versus nasal cannula on late preterm and term infants with transient tachypnea of the newborn

OBJECTIVE

To compare continuous positive airway pressure (CPAP) with nasal cannula (NC) as primary noninvasive respiratory therapy in hypoxic infants for transient tachypnea of the newborn (TTN).

STUDY DESIGN

Retrospective cohort study of infants born at ≥34 weeks of gestation between January 1, 2015 and December 31, 2018.

RESULT

After adjusting for gestational age and birth weight, the maximum fractional inspired oxygen (FiO2) was significantly lower in the CPAP group with an incidence rate ratio (IRR) of 0.85 (95% CI: 0.76-0.96). Although nonsignificant, the CPAP group needed 32% fewer hours on oxygen with an IRR of 0.68 (95% CI: 0.38-1.22). The duration of respiratory support and the incidence of pneumothorax were similar between both groups.

CONCLUSION

Comparing CPAP with NC as initial noninvasive respiratory therapy for TTN, significantly lower maximum FiO2 was observed in the infants of CPAP group without increase in the incidence of pneumothorax.

[Contributing factors for the withdrawal from treatment in neonates with respiratory failure]

OBJECTIVE

To investigate the factors contributing to the withdrawal from treatment in neonates with respiratory failure.

METHODS

The medical data of 2 525 neonates with respiratory failure were retrospectively studied, who were reported in 30 hospitals of Jiangsu Province from January to December, 2019. According to whether a complete treatment was given, they were divided into a complete treatment group with 2 162 neonates and a withdrawal group with 363 neonates. A multivariate logistic regression analysis was used to investigate the factors contributing to the withdrawal from treatment in neonates with respiratory failure.

RESULTS

The multivariate logistic regression analysis showed that small-for-gestational-age birth, congenital abnormality, gestational age < 28 weeks, living in the rural area or county-level city, and maternal age < 25 years were risk factors for the withdrawal from treatment in neonates with respiratory failure (P < 0.05), while a higher 5-minute Apgar score and cesarean section were protective factors (P < 0.05). Furthermore, 176 answers were obtained from 160 parents of the neonates who were willing to tell the reason for the withdrawal from treatment, among which severe sequelae (44.9%, 79/176) had the highest frequency, followed by uncontrollable disease condition (24.4%, 43/176), family financial difficulties (18.2%, 32/176), and dependence on mechanical ventilation (12.5%, 22/176).

CONCLUSIONS

Small-for-gestational-age birth, congenital abnormality, gestational age, living area, maternal age, Apgar score at birth, and method of birth are contributing factors for the withdrawal from treatment in neonates with respiratory failure. A poor prognosis and a low quality of life in future might be major immediate causes of withdrawal from treatment in neonates with respiratory failure, which needs to be confirmed by further studies.

The impact of targeted oxygen reduction test in preterm infants on reducing the oxygen exposure

BACKGROUND

Caring for infants on respiratory support is a challenge in the middle-income countries, applying a protocol of targeted oxygen reduction test (tORT) guided by daily assessment of oxygen histograms is novel and practical approach.

OBJECTIVE

To study the impact of tORT guided by daily assessment of oxygen histograms as a quality improvement project aiming to decrease days on oxygen support, and duration of hospital admission in preterm infants.

STUDY DESIGN

A quality project conducted in neonatal intensive care units (NICU) of two hospitals, from 2017- 2018 (Epochs II). After a period of observation of a cohort of preterm Infants, 2016-2017 (Epoch I). The main aims were to reduce days on oxygen and hospital admission days. All infants in Epoch II underwent daily assessment of oxygen histograms and a trial of oxygen reduction if applicable as per a predefined protocol. Comparison was made between these two Epochs, and the primary outcome was the time to successful discontinuation of oxygen support.

RESULTS

Fifty-nine infants were included; 30 underwent the protocolized tORT (Epoch II) with a median (IQR) of 4 (2-6) tORC per infant. Postanal age at presentation (time of initial tORT assessment was performed at the postnatal age of 8 (5, 13) days. Days on oxygen and total numbers of hospital days were significantly less in Epoch II. Oxygen histograms significantly improved after tORT.

CONCLUSIONS

Applying tORT guided by oxygen histograms may have a significant impact on oxygen exposure and hospitalization days of patients admitted to the NICU.

Perioperative management of arteriovenous malformation guided by integrated evaluation of hemodynamics

We aimed to demonstrate the value of monitoring infants with arteriovenous malformation (AVM) during endovascular embolization with integrated evaluation of hemodynamics (IEH) and guiding decisions according to the underlying pathophysiology. This is a retrospective analysis of the perioperative hemodynamics data for 2 complex cases of AVM transferred to Khaula Hospital in Oman for interventional management. We described the value of novel physiological insights gained from comprehensive IEH and provided a systematic approach to the perioperative management. Postoperative targeted neonatal echo (TNE) was used to guide the weaning of the cardiovascular medications within 24 h. Both cases showed significant right ventricle (RV) volume overload before surgery. Narrowing of the pulse pressure (PP) during or after endovascular embolization was used as a marker of compromised systemic blood flow in real time followed by an assessment by TNE to guide the appropriate therapy.Conclusion: Integrated evaluation of hemodynamics is helpful to guide perioperative physiologic-based management of AVM. What is Known: • The preoperative management of hemodynamic compromise due to AVM has been described in many articles. • Perioperative management of AVM and related hemodynamics is a challenge to the intensive care team. What is New: • Integrated evaluation of hemodynamics is a comprehensive assessment and helpful in understanding the underlying physiologic changes during intervention with AVM. • This integrated evaluation can lead to physiologic-based medical recommendation with subsequent improvement.

Asphyxia and Neonatal Respiratory Distress Syndrome Are Independent Predictors of the Non-response to Inhaled Nitric Oxide in the Newborns With PPHN

Aim: Not all the neonates respond with improvement in oxygenation following inhaled nitric oxide treatment (iNO) treatment. The aim of this study was to assess the independent risk factors associated with non-response to iNO during the 2 weeks of postnatal treatment in neonates diagnosed with persistent pulmonary hypertension (PPHN). Materials and Methods: This retrospective cohort study included all newborns with PPHN who received iNO treatment for more than 24 h. Demographic, obstetric, perinatal data and clinical complications were extracted from the hospitalization records. Subjects were divided into two groups according to their response to iNO inspiration during the first 24 h of iNO treatment. No response was defined as an increase in SpO₂ < 5% or the inability to sustain saturation levels in the first 24 h of iNO treatment. For descriptive statistics, χ² and t-test analysis were used to compare categorical and continuous variables between the two groups. To evaluate independent risk factors of non-responsiveness to iNO treatment, binary logistic regression analysis were performed. Results: A total of 75 newborns were included in the study. Sixty-two cases were in the responders group, and 13 cases were in the non-responders group. Univariate analysis showed that asphyxia, neonatal respiratory distress syndrome (NRDS), pulmonary surfactant administration, meconium aspiration syndrome (MAS), the severity of pulmonary hypertension (PH), and high-frequency oscillatory ventilation (HFOV) therapy were the high-risk factors affecting the response to iNO treatment in the newborns with PPHN. The binary logistic regression analysis indicated that asphyxia and NRDS incidence were independent predictors of non-responsiveness to iNO treatment [asphyxia: OR 4.193, 95% CI 1.104-15.927, P = 0.035; NRDS: OR 0.154, 95% CI 0.036-0.647, P = 0.011]. The patients in the non-responders group had shorter iNO inspiration followed by MV duration, supplemental oxygen and hospital stay, and higher mortality. There were no significant differences in IVH, PVL, and BPD between two groups. Conclusion: In the newborns with PPHN, asphyxia and NRDS resulted as the independent risk factors of non-responsiveness to iNO therapy. Asphyxia in the newborns with PPHN is detrimental to the response to iNO treatment, while NRDS is beneficial.

Respiratory Severity Score with Regard to Birthweight during the Early Days of Life for Predicting Pulmonary Hypertension in Preterm Infants

OBJECTIVE

The respiratory severity score (RSS) has been demonstrated to be associated with the oxygenation index in intubated newborn infants. We aimed to evaluate the usefulness of RSS with regard to birthweight (BW) in preterm infants for predicting an association with future pulmonary hypertension (PH).

METHODS

Preterm infants with <30 weeks' gestation and <1250 g BW were reviewed and grouped into two (PH vs. no PH). Basic perinatal characteristics, comorbidities and parameters reflecting lung condition, including duration of invasive mechanical ventilator care, were compared. Respiratory support parameters (FiO2, RSS and RSS/kg) during the first 5 days of birth (0-120 h) were compared between the groups, and receiver operating characteristics curves were produced to evaluate the association with PH.

RESULTS

RSS/kg, of the three respiratory support parameters, demonstrated significantly higher values in the PH group in the early days of life. Particularly, RSS/kg at day 2 of life had the greatest area under the curve [0.762, 95% confidence interval (CI) 0.655-0.869, p < 0.001] and maintained statistical significance [odds ratio (OR) 1.352, 95% CI 1.055-1.732, p = 0.017] in the multivariable analysis for a potential association with PH, along with gestational age (OR 0.996, 95% CI 0.993-0.999, p = 0.015) and preterm premature rupture of membrane >18 h (OR 4.907, 95% CI 1.436-16.765, p = 0.011).

CONCLUSION

RSS/kg is a potential marker associated with the development of PH. Future studies could verify its usefulness as a reliable surrogate for predicting respiratory morbidity in clinical settings.

Pulmonary Hypertension with Prolonged Patency of the Ductus Arteriosus in Preterm Infants

There continues to be a reluctance to close the patent ductus arteriosus (PDA) in premature infants. The debate on whether the short-term outcomes translate to a difference in long-term benefits remains. This article intends to review the pulmonary vasculature changes that can occur with a chronic hemodynamically significant PDA in a preterm infant. It also explains the rationale and decision-making involved in a diagnostic cardiac catheterization and transcatheter PDA closure in these preterm infants.

Effect of basic public health service project on neonatal health services and neonatal mortality in China: a longitudinal time-series study

OBJECTIVE

To analyse the trend change and level change of neonatal health services and neonatal mortality before and after the introduction of the Basic Public Health Service (BPHS) project in 2009.

DESIGN AND SETTING

A national longitudinal study on neonatal mortality from 1991 to 2017 and neonatal health services from 2000 to 2017 was conducted based on data extracted from the National Neonatal Mortality Surveillance System and National Health Statistic Yearbook. The segmented linear regression model was used to assess the level changes and trend changes of the outcome variables before and after the introduction of BPHS project. Pearson correlation analysis as conducted to measure association between neonatal mortality rates (NMRs) and maternal health management rates (MMRs), neonatal visit rates, respectively.

PRIMARY AND SECONDARY OUTCOME MEASURES

The outcome variables were national NMR, the gap of NMR between urban and rural areas, maternal health management rate and neonatal visit rate.

RESULTS

The annual trend change coefficient of national NMR and the gap of NMR between urban and rural areas were -0.57 (p<0.01) and -0.49 (p<0.01) after the introduction of BPHS project, while the annual trend coefficient of the MMR and the neonatal visit rate were 1.21 (p<0.01) and 0.85 (p<0.01), respectively. The negative correlations were found between NMR and MMR (r=-0.79, p<0.01) and neonatal visit rate (r=-0.76, p<0.01).

CONCLUSION

The BPHS project was found to be associated with increased volume of neonatal health services and reduced NMR. The design and implementation of this project may provide references to other low-income and middle-income countries.

Transient Tachypnea of Newborns Is Associated With Maternal Spinal Hypotension During Elective Cesarean Delivery: A Retrospective Cohort Study

BACKGROUND

The risk for transient tachypnea of newborns, a common cause of respiratory distress in the neonatal period, is 2- to 6-fold higher during elective cesarean delivery compared to vaginal delivery. Here, we evaluated the association between transient tachypnea of newborns and the degree and duration of predelivery maternal hypotension during spinal anesthesia for elective cesarean delivery.

METHODS

Demographic data, details of anesthetic management, blood pressure measurements, and vasopressor requirement preceding delivery were compared between transient tachypnea newborns (n = 30) and healthy neonates (n = 151) with normal respiratory function born via elective cesarean delivery between July 2015 and February 2016. The degree and duration of hypotension were assessed using area under the curve for systolic blood pressure (SBP) ≤90 mm Hg and area under the curve for mean arterial pressure ≤65 mm Hg. After adjusting for confounders, multivariable logistic regression was used to evaluate the association between area under the curve for SBP and transient tachypnea of newborns.

RESULTS

The median area under the curve for SBP was higher in cases of transient tachypnea of newborns (0.94; interquartile range, 0-28.7 mm Hg*min) compared to healthy controls (0; interquartile range, 0-3.30 mm Hg*min; P = .001). Similarly, median area under the curve for mean arterial pressure was also higher in cases of transient tachypnea of newborns (0; interquartile range, 0-18.6 mm Hg*min) compared to controls (0; interquartile range, 0-1.1 mm Hg*min; P = .01). Mothers of transient tachypnea newborns received significantly higher amounts of phenylephrine and ephedrine compared to controls (P = .001 and 0.01, respectively). Hence, the total vasopressor dose given to mothers in the transient tachypnea of newborn group was much higher than for the control group (P = .001). In the multivariable logistic regression, area under the curve for SBP was significantly associated with transient tachypnea of newborns (odds ratio, 1.02; 95% CI, 1.01-1.04, P = .005) after adjusting for gravidity and the type of anesthetic (spinal versus combined spinal epidural).

CONCLUSIONS

Our results suggest that the degree and duration of maternal SBP <90 mm Hg after neuraxial anesthesia during elective cesarean delivery are associated with transient tachypnea of newborns. Future prospective studies should further explore the effects of maternal hypotension, its prevention, and treatment for transient tachypnea of newborns.

Inhaled nitric oxide as an adjunct to neonatal resuscitation in premature infants: a pilot, double blind, randomized controlled trial

BACKGROUND

Nitric oxide (NO) plays an important role in normal postnatal transition. Our aims were to determine whether adding inhaled NO (iNO) decreases supplemental oxygen exposure in preterm infants requiring positive pressure ventilation (PPV) during resuscitation and to study iNO effects on heart rate (HR), oxygen saturation (SpO₂), and need for intubation during the first 20 min of life.

METHODS

This was a pilot, double-blind, randomized, placebo-controlled trial. Infants 25 0/7-31 6/7 weeks' gestational age requiring PPV with supplemental oxygen during resuscitation were enrolled. PPV was initiated with either oxygen (FiO₂-0.30) + iNO at 20 ppm (iNO group) or oxygen (FiO₂-0.30) + nitrogen (placebo group). Oxygen was titrated targeting defined SpO₂ per current guidelines. After 10 min, iNO/nitrogen was weaned stepwise per protocol and terminated at 17 min.

RESULTS

Twenty-eight infants were studied (14 per group). The mean gestational age in both groups was similar. Cumulative FiO₂ and rate of exposure to high FiO₂ (>0.60) were significantly lower in the iNO group. There were no differences in HR, SpO₂, and need for intubation.

CONCLUSIONS

Administration of iNO as an adjunct during neonatal resuscitation is feasible without side effects. It diminishes exposure to high levels of supplemental oxygen.

Current strategies and opportunities to manufacture cells for modeling human lungs

Chronic lung diseases remain major healthcare burdens, for which the only curative treatment is lung transplantation. In vitro human models are promising platforms for identifying and testing novel compounds to potentially decrease this burden. Directed differentiation of pluripotent stem cells is an important strategy to generate lung cells to create such models. Current lung directed differentiation protocols are limited as they do not 1) recapitulate the diversity of respiratory epithelium, 2) generate consistent or sufficient cell numbers for drug discovery platforms, and 3) establish the histologic tissue-level organization critical for modeling lung function. In this review, we describe how lung development has formed the basis for directed differentiation protocols, and discuss the utility of available protocols for lung epithelial cell generation and drug development. We further highlight tissue engineering strategies for manipulating biophysical signals during directed differentiation such that future protocols can recapitulate both chemical and physical cues present during lung development.

Reactive oxygen species as mediators of oxygen signaling during fetal-to-neonatal circulatory transition

Reactive oxygen species (ROS) are frequently seen as pathological agents of oxidative stress. However, ROS are not always deleterious and can also act as cell signaling molecules. Vascular oxygen sensing and signaling during fetal-to-neonatal circulatory transition is a remarkable example of the physiological regulatory actions of ROS. The fetal relative hypoxic environment induces hypoxic pulmonary vasoconstriction (HPV) and ductus arteriosus (DA) relaxation favoring the presence of high pulmonary vascular resistance and right-to-left ductal shunt. At birth, the increase in oxygen tension causes relaxation of pulmonary arteries (PAs) and normoxic DA vasoconstriction (NDAV), thus diverting blood flow to the lungs. Although the response to changes in oxygen tension is diametrically opposite, the mechanisms responsible for HPV and NDAV appear to be the result of a similar interaction between triggering and modulating factors that lead to an increase in cytosolic Ca²⁺ concentration and Ca²⁺ sensitization of the contractile apparatus. Growing evidence points to an increase in ROS (mitochondria- and/or NADPH-derived superoxide and/or H₂O₂), leading to inhibition of voltage-gated K⁺ channels, membrane depolarization, and activation of voltage-gated L-type Ca²⁺ channels as critical events in the signaling pathway of both HPV and NDAV. Several groups of investigators have completed this pathway adding other elements such as neutral sphingomyelinase-derived ceramide, the sarcoplasmic/endoplasmic reticulum (through ryanodine and inositol 1,4,5-trisphosphate receptors), Rho kinase-mediated Ca²⁺ sensitization, or transient receptor potential channels. The present review focus on the role of ROS as mediators of the homeostatic oxygen sensing system during fetal and neonatal life not only in the PAs and DA but also in systemic arteries.

Antenatal melatonin modulates an enhanced antioxidant/pro-oxidant ratio in pulmonary hypertensive newborn sheep

Chronic hypobaric hypoxia during fetal and neonatal life induces neonatal pulmonary hypertension. Hypoxia and oxidative stress are driving this condition, which implies an increase generation of reactive oxygen species (ROS) and/or decreased antioxidant capacity. Melatonin has antioxidant properties that decrease oxidative stress and improves pulmonary vascular function when administered postnatally. However, the effects of an antenatal treatment with melatonin in the neonatal pulmonary function and oxidative status are unknown. Therefore, we hypothesized that an antenatal therapy with melatonin improves the pulmonary arterial pressure and antioxidant status in high altitude pulmonary hypertensive neonates. Twelve ewes were bred at high altitude (3600 m); 6 of them were used as a control group (vehicle 1.4% ethanol) and 6 as a melatonin treated group (10 mg d-1 melatonin in vehicle). Treatments were given once daily during the last third of gestation (100-150 days). Lambs were born and raised with their mothers until 12 days old, and neonatal pulmonary arterial pressure and resistance, plasma antioxidant capacity and the lung oxidative status were determined. Furthermore, we measured the pulmonary expression and activity for the antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase, and the oxidative stress markers 8-isoprostanes, 4HNE and nitrotyrosine. Finally, we assessed pulmonary pro-oxidant sources by the expression and function of NADPH oxidase, mitochondria and xanthine oxidase. Melatonin decreased the birth weight. However, melatonin enhanced the plasma antioxidant capacity and decreased the pulmonary antioxidant activity, associated with a diminished oxidative stress during postnatal life. Interestingly, melatonin also decreased ROS generation at the main pro-oxidant sources. Our findings suggest that antenatal administration of melatonin programs an enhanced antioxidant/pro-oxidant status, modulating ROS sources in the postnatal lung.

Socioeconomic and gender inequalities in neonatal, postneonatal and child mortality in India: a repeated cross-sectional study, 2005-2016

BACKGROUND

In India, excess female under-5 mortality is well documented. Under-5 mortality is also known to be patterned by socioeconomic factors. This study examines sex differentials and sex-specific wealth gradients in neonatal, postneonatal and child mortality in India.

METHODS

Repeated cross-sectional study of nationally representative samples of 298 955 children 0-60 months old from the National Family Health Surveys conducted in 2005-2006 and 2015-2016. The study used logistic regression models as well as Cox proportional hazards models.

RESULTS

Overall, boys had greater neonatal mortality than girls and the difference increased between 2005-2006 and 2015-2016. Girls had greater postneonatal and child mortality, but the difference decreased between the surveys and was not statistically significant for child mortality in 2015-2016. A negative wealth gradient was found for all mortality outcomes. Neonatal mortality was persistently greater for boys. Girls had higher child mortality than boys at low levels of wealth and greater postneonatal mortality over much of the wealth distribution. The wealth gradient in neonatal mortality increased between surveys. Females had a stronger wealth gradient than boys for child mortality.

CONCLUSION

Not distinguishing between neonatal, postneonatal and child mortality masks important gender-specific and wealth-specific disparities in under-5 mortality in India. Substantial gains towards the Sustainable Development Goals can be made by combating neonatal mortality, especially at low levels of wealth. Although impressive improvements have been made in reducing the female disadvantage in postneonatal and child mortality, concerted engagements are necessary to eliminate the gender gap-especially in poor households and in north India.

Evaluation of Oxygen Saturation Index Compared With Oxygenation Index in Neonates With Hypoxemic Respiratory Failure

IMPORTANCE

Oxygenation index (OI), an invasive measurement, is routinely used as a marker of severity of hypoxemic respiratory failure in neonates. Oxygen saturation index (OSI) is a noninvasive measurement and has been shown to be a reliable surrogate marker of OI in children and adults with respiratory failure.

OBJECTIVES

To evaluate the correlation of OI with OSI and to derive and validate predictive OI from noninvasive OSI measurements for clinically relevant OI values.

DESIGN, SETTING, AND PARTICIPANTS

For this retrospective cohort study, 220 neonates requiring invasive mechanical ventilation for hypoxic respiratory failure during the first 3 days of admission were recruited from a level III neonatal intensive care unit during a 6-year period, from January 1, 2012, to December 31, 2017. Data were analyzed from January 2017 to December 2017.

MAIN OUTCOMES AND MEASURES

The primary outcome was correlation of OI with OSI, analyzed using Pearson correlation coefficient. The secondary outcome was derivation and validation of OI from OSI. The data were split into derivative samples, from which a predictive equation for OI was derived using generalized linear model, and a validation sample was used to assess the predictive ability of the derived OI. Bland-Altman plot was used to assess agreement between derived OI and measured OI.

RESULTS

A total of 1442 paired OI and OSI measurements from 220 infants (190 preterm and 30 term; median [interquartile range] gestational age, 29 [26-33] weeks; mean [SD] birth weight, 1602 [1092] g) were recorded during the study. The median (interquartile range) number of samples was 5 (3-9) per patient. Overall, OI and OSI showed strong correlation (r = 0.89). The correlation was stronger in preterm infants (<28 weeks, r = 0.93; 28-33 weeks, r = 0.93) and within an oxygen saturation range of 85% to 95% (r = 0.94). The predictive derivative equation showed a strong linear association and good agreement in both derivation and validation data sets, with strong accuracy measures of derived OI for OI cutoffs of 5, 10, 15, 20, and 25.

CONCLUSIONS AND RELEVANCE

A strong correlation of OI with OSI was found. Derived OI from OSI was in good agreement and strongly predictive of clinically relevant OI cutoffs from 5 to 25. Oxygenation index derived from noninvasive sources may be useful to reliably assess severity of respiratory failure and response to therapy on a continuous basis.

The Perinatal Asphyxiated Lamb Model: A Model for Newborn Resuscitation

Birth asphyxia accounts for nearly one million deaths worldwide each year, and is one of the primary causes of early neonatal morbidity and mortality. Many aspects of the current neonatal resuscitation guidelines remain controversial given the difficulties in conducting randomized clinical trials owing to the infrequent and often unpredictable need for extensive resuscitation. Most studies on neonatal resuscitation stem from manikin models that fail to truly reflect physiologic changes or piglet models that have cleared their lung fluid and that have completed the transition from fetal to neonatal circulation. The present protocol provides a detailed step-by-step description on how to create a perinatal asphyxiated fetal lamb model. The proposed model has a transitioning circulation and fluid-filled lungs, which mimics human newborns following delivery, and is, therefore, an excellent animal model to study newborn physiology. An important limitation to lamb experiments is the higher associated cost.

Maternal anemia and underweight as determinants of pregnancy outcomes: cohort study in eastern rural Maharashtra, India

OBJECTIVES

To study the trend in the prevalence of anaemia and low BMI among pregnant women from Eastern Maharashtra and evaluate if low BMI and anaemia affect pregnancy outcomes.

DESIGN

Prospective observational cohort study.

SETTING

Catchment areas of 20 rural primary health centres in four eastern districts of Maharashtra State, India.

PARTICIPANTS

72 750 women from the Nagpur site of Maternal and Newborn Health Registry of NIH's Global Network, enrolled from 2009 to 2016.

MAIN OUTCOME MEASURES

Mode of delivery, pregnancy related complications at delivery, stillbirths, neonatal deaths and low birth weight (LBW) in babies.

RESULTS

Over 90% of the women included in the study were anaemic and over a third were underweight (BMI <18 kg/m2) and with both conditions. Mild anaemia at any time during delivery significantly increased the risk (Risk ratio; 95% confidence interval (RR;(95% CI)) of stillbirth (1.3 (1.1-1.6)), neonatal deaths (1.3 (1-1.6)) and LBW babies (1.1 (1-1.2)). The risks became even more significant and increased further with moderate/severe anaemia any time during pregnancy for stillbirth (1.4 (1.2-1.8)), neonatal deaths (1.7 (1.3-2.1)) and LBW babies (1.3 (1.2-1.4)).,. Underweight at anytime during pregnancy increased the risk of neonatal deaths (1.1 (1-1.3)) and LBW babies (1.2;(1.2-1.3)).The risk of having stillbirths (1.5;(1.2-1.8)), neonatal deaths (1.7;(1.3-2.3)) and LBW babies (1.5;(1.4-1.6)) was highest when - the anaemia and underweight co-existed in the included women. Obesity/overweight during pregnancy increased the risk of maternal complications at delivery (1.6;(1.5-1.7)) and of caesarean section (1.5;(1.4-1.6)) and reduced the risk of LBW babies 0.8 (0.8-0.9)).

CONCLUSION

Maternal anaemia is associated with enhanced risk of stillbirth, neonatal deaths and LBW. The risks increased if anaemia and underweight were present simultaneously.

TRIAL REGISTRATION NUMBER

NCT01073475.

Patent Ductus Arteriosus in Preterm Infants, Part 1: Understanding the Pathophysiologic Link Between the Patent Ductus Arteriosus and Clinical Complications

The clinical guidelines for treating patent ductus arteriosus (PDA) have significantly evolved over the last decades from treating any ductal shunt to more conservative management where only the hemodynamically significant patent ductus arteriosus (HSPDA) is treated. This shift has resulted largely from a lack of evidence from randomized controlled trials supporting a relationship between treating a PDA and improving long-term neonatal outcomes. However, there are many unresolved issues. There is no consensus on the precise definition of HSPDA requiring treatment or a clear understanding of when to treat HSPDA. Moreover, the current evidence shows worsening of the long-term neurodevelopmental outcome for infants undergoing surgical PDA ligation.<br/> The presence of physiologic variability among preterm infants, and the presence of different compensatory mechanisms may make it difficult to establish a link between pathophysiology and long-term outcomes. That is, the physiologic variability cannot be simply assessed by randomly assigning infants into two arms of a study. Relying on research from animal and human studies, this article explains the link between the pathophysiology of a PDA and neonatal outcomes.

Acute hypoxia-reoxygenation and vascular oxygen sensing in the chicken embryo

Fetal/perinatal hypoxia is one of the most common causes of perinatal morbidity and mortality and is frequently accompannied by vascular dysfunction. However, the mechanisms involved have not been fully delineated. We hypothesized that exposure to acute hypoxia‐reoxygenation induces alterations in vascular O₂ sensing/signaling as well as in endothelial function in the chicken embryo pulmonary artery (PA), mesenteric artery (MA), femoral artery (FA), and ductus arteriosus (DA). Noninternally pipped 19‐day embryos were exposed to 10% O₂ for 30 min followed by reoxygenation with 21% O₂ or 80% O₂. Another group was constantly maintained at 21% O₂ or at 21% O₂ for 30 min and then exposed to 80% O₂. Following treatment, responses of isolated blood vessels to hypoxia as well as endothelium‐dependent (acetylcholine) and ‐independent (sodium nitroprusside and forskolin) relaxation were investigated in a wire myograph. Hypoxia increased venous blood lactate from 2.03 ± 0.18 to 15.98 ± 0.73 mmol/L (P < 0.001) and reduced hatchability to 0%. However, ex vivo hypoxic contraction of PA and MA, hypoxic relaxation of FA, and normoxic contraction of DA were not significantly different in any of the experimental groups. Relaxations induced by acetylcholine, sodium nitroprusside, and forskolin in PA, MA, FA, and DA rings were also similar in the four groups. In conclusion, exposure to acute hypoxia‐reoxygenation did not affect vascular oxygen sensing or reactivity in the chicken embryo. This suggests that direct effects of acute hypoxia‐reoxygenation on vascular function does not play a role in the pathophysiology of hypoxic cardiovascular injury in the perinatal period.

Persistent Pulmonary Hypertension in the Newborn

Persistent pulmonary hypertension of the newborn (PPHN) is a syndrome of failed circulatory adaptation at birth due to delay or impairment in the normal fall in pulmonary vascular resistance (PVR) that occurs following birth. The fetus is in a state of physiological pulmonary hypertension. In utero, the fetus receives oxygenated blood from the placenta through the umbilical vein. At birth, following initiation of respiration, there is a sudden precipitous fall in the PVR and an increase of systemic vascular resistance (SVR) due to the removal of the placenta from circulation. There is dramatic increase in pulmonary blood flow with a decrease in, and later reversal of shunts at the foramen ovale and ductus arteriosus. The failure of this normal physiological pulmonary transition leads to the syndrome of PPHN. PPHN presents with varying degrees of hypoxemic respiratory failure. Survival of infants with PPHN has significantly improved with the use of gentle ventilation, surfactant and inhaled nitric oxide (iNO). PPHN is associated with significant mortality and morbidity among survivors. Newer agents that target different enzymatic pathways in the vascular smooth muscle are in different stages of development and testing. Further research using these agents is likely to further reduce morbidity and mortality associated with PPHN.

Pulmonary Vasodilators and Anesthesia Considerations

Pulmonary hypertension (PH) is a complex disease process of the pulmonary vasculature system characterized by elevated pulmonary arterial pressures. Patients with PH are at increased risk for morbidity and mortality, including intraoperatively and postoperatively. Appreciation by the clinical anesthesiologist of the pathophysiology of PH is warranted. Careful and meticulous strategy using appropriate anesthetic medications, pulmonary vasodilator and inotropic agents, and careful fluid management all increase the likelihood of the best possible outcome in this challenging patient population.