Bi-Level Noninvasive Ventilation in Neonatal Respiratory Distress Syndrome. A Systematic Review and Meta-Analysis

Optimal respiratory support for extremely low birth weight infants - do we have the answers?

Survival rates for extremely low birth weight (ELBW) infants have improved over the recent years, yet morbidity remains high. This review explores respiratory management strategies for this unique cohort and how it may impact their long-term outcomes. Although there is a preference towards non-invasive respiratory support in less immature infants, ELBW infants often require invasive ventilation. This comes with an increased risk of bronchopulmonary dysplasia, adverse neurodevelopmental outcomes and lifelong respiratory impairment. There are a range of options available to reduce volutrauma and minimise lung injury, including volume targeted ventilation and high-frequency ventilation. In the absence of high-quality evidence focussing on ELBW infants, much of current practice is inferred from studies involving infants with a broader range of gestational ages and experiences at high-volume centres. This highlights the need for further research targeted to this specific population with a focus on long-term respiratory health.

Blinding Assessments in Neonatal Ventilation Meta-Analyses: A Systematic Meta-Epidemiological Review

INTRODUCTION

Randomization and blinding are generally important in randomized trials. In neonatology, blinding of ventilation strategies is unfeasible if not impossible and we hypothesized that its importance has been overestimated, while the peculiarities of the neonatal patient and the specific outcomes have not been considered.

METHODS

For this meta-epidemiological review, we searched PubMed and Scopus databases in November 2023. We included all meta-analyses focusing on ventilation, published in past 5 years, and reporting either mortality or bronchopulmonary dysplasia (BPD) as an outcome. We extracted the information about how the authors had analyzed risk of bias and evidence certainty.

RESULTS

We screened 494 abstracts and included 40 meta-analyses. Overall, 13 of the 40 reviews assessed blinding properly. Australian and European authors were most likely to perform correct assessment of the blinding (p = 0.03) and the use of RoB 2.0 tool was also associated with proper assessment (p < 0.001). In multivariate regression, the use of RoB 2.0 was the only factor associated with a proper assessment (Beta 0.57 [95% confidence interval: 0.29-0.99]). GRADE ratings were performed in 25 reviews, and the authors downgraded the evidence certainty due to risk of bias in 19 of these and none of these reviews performed the blinding assessment correctly.

CONCLUSION

In past neonatal evidence syntheses, the role of blinding has been mostly overestimated, which has led to downgrading of evidence certainty. Objective outcomes (such as mortality and BPD) do not need to be downgraded due to lack of blinding, as the knowledge of the received intervention does not influence the outcome assessment.

Ultrasound evaluation of diaphragm kinetics after minimally invasive surfactant administration

PURPOSE

Concerns remain on different alveolar deposition of surfactant between LISA and INSURE methods. Ultrasound evaluation of diaphragm kinetics may provide clinical evidence on this issue, as indirect representation of the respiratory system compliance.

METHODS

This was a prospective-observational pilot study. The inclusion criterion was CPAP-supported infants ≤ 32 weeks with RDS receiving surfactant via minimally invasive technique. 52 patients randomized for surfactant administration via LISA or INSURE methods were enrolled. Right diaphragm (RD) global mean peak velocity (MPV) by Pulsed-Wave Tissue Doppler Imaging (PTDI) was recorded before and two hours after surfactant administration with simultaneous measurements of oxygen saturation (SpO2)/fraction of inspired oxygen (FiO2) (SF ratio). Mechanical ventilation ≤ 72 h from birth represented treatment failure.

RESULTS

LISA infants had significantly higher gestational age (p = 0.029) and birth weight (p = 0.030) with lower CRIB-II scores (p = 0.030) than INSURE infants. LISA infants showed higher median MPV at baseline RD-PTDI US assessment (p = 0.024), but post-surfactant median MPV and other the investigated variables were similar at the adjusted analysis for gestational age and sedation. 8/52 (15%) infants who failed treatment had a significantly lower SF ratio (p = 0.002) and higher median MPV at RD-PTDI US (p = 0.004) after surfactant administration, despite the higher CPAP support level before (p = 0.007) and after (p = 0.001) surfactant administration. A full course of antenatal steroids was protective against mechanical ventilation (p = 0.038).

CONCLUSIONS

Different minimally invasive surfactant administration techniques do not appear to influence diaphragm kinetics evaluated by RD-PTDI US.

Invasive and non-invasive ventilatory strategies for early and evolving bronchopulmonary dysplasia

In the age of surfactant and antenatal steroids, neonatal care has improved outcomes of preterm infants dramatically. Since the early 2000's neonatologists have strived to decrease bronchopulmonary dysplasia (BPD) by decreasing ventilator-associated lung injury and utilizing many novel modes of non-invasive respiratory support. After the initial success with nasal continuous positive airway pressure, it was established that discontinuing invasive ventilation early in favor of non-invasive respiratory support is the most effective way to reduce the incidence of BPD. In this review, we discuss the management of the preterm lung from the time of delivery, through the phases of respiratory distress syndrome (early BPD) and then evolving BPD. The goal remains to optimize respiratory support of the preterm lung while minimizing ventilator-associated lung injury and oxygen toxicity. A multidisciplinary approach involving the medical team and family is quintessential in reaching this goal and involves adequate respiratory support, optimizing nutrition and fluid balance as well as preventing infections.

Nasal intermittent positive pressure ventilation (NIPPV) versus nasal continuous positive airway pressure (NCPAP) for preterm neonates after extubation

BACKGROUND

Nasal continuous positive airway pressure (NCPAP) is a useful method for providing respiratory support after extubation. Nasal intermittent positive pressure ventilation (NIPPV) can augment NCPAP by delivering ventilator breaths via nasal prongs.

OBJECTIVES

Primary objective To determine the effects of management with NIPPV versus NCPAP on the need for additional ventilatory support in preterm infants whose endotracheal tube was removed after a period of intermittent positive pressure ventilation. Secondary objectives To compare rates of abdominal distension, gastrointestinal perforation, necrotising enterocolitis, chronic lung disease, pulmonary air leak, mortality, duration of hospitalisation, rates of apnoea and neurodevelopmental status at 18 to 24 months for NIPPV and NCPAP. To compare the effect of NIPPV versus NCPAP delivered via ventilators versus bilevel devices, and assess the effects of the synchronisation of ventilation, and the strength of interventions in different economic settings.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was January 2023.

SELECTION CRITERIA

We included randomised and quasi-randomised trials of ventilated preterm infants (less than 37 weeks' gestational age (GA)) ready for extubation to non-invasive respiratory support. Interventions were NIPPV and NCPAP.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcome was 1. respiratory failure. Our secondary outcomes were 2. endotracheal reintubation, 3. abdominal distension, 4. gastrointestinal perforation, 5. necrotising enterocolitis (NEC), 6. chronic lung disease, 7. pulmonary air leak, 8. mortality, 9. hospitalisation, 10. apnoea and bradycardia, and 11. neurodevelopmental status. We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included 19 trials (2738 infants). Compared to NCPAP, NIPPV likely reduces the risk of respiratory failure postextubation (risk ratio (RR) 0.75, 95% confidence interval (CI) 0.67 to 0.84; number needed to treat for an additional beneficial outcome (NNTB) 11, 95% CI 8 to 17; 19 trials, 2738 infants; moderate-certainty evidence) and endotracheal reintubation (RR 0.78, 95% CI 0.70 to 0.87; NNTB 12, 95% CI 9 to 25; 17 trials, 2608 infants, moderate-certainty evidence), and may reduce pulmonary air leaks (RR 0.57, 95% CI 0.37 to 0.87; NNTB 50, 95% CI 33 to infinite; 13 trials, 2404 infants; low-certainty evidence). NIPPV likely results in little to no difference in gastrointestinal perforation (RR 0.89, 95% CI 0.58 to 1.38; 8 trials, 1478 infants, low-certainty evidence), NEC (RR 0.86, 95% CI 0.65 to 1.15; 10 trials, 2069 infants; moderate-certainty evidence), chronic lung disease defined as oxygen requirement at 36 weeks (RR 0.93, 95% CI 0.84 to 1.05; 9 trials, 2001 infants; moderate-certainty evidence) and mortality prior to discharge (RR 0.81, 95% CI 0.61 to 1.07; 11 trials, 2258 infants; low-certainty evidence). When considering subgroup analysis, ventilator-generated NIPPV likely reduces respiratory failure postextubation (RR 0.49, 95% CI 0.40 to 0.62; 1057 infants; I2 = 47%; moderate-certainty evidence), while bilevel devices (RR 0.95, 95% CI 0.77 to 1.17; 716 infants) or a mix of both ventilator-generated and bilevel devices likely results in little to no difference (RR 0.87, 95% CI 0.73 to 1.02; 965 infants).

AUTHORS' CONCLUSIONS

NIPPV likely reduces the incidence of extubation failure and the need for reintubation within 48 hours to one-week postextubation more effectively than NCPAP in very preterm infants (GA 28 weeks and above). There is a paucity of data for infants less than 28 weeks' gestation. Pulmonary air leaks were also potentially reduced in the NIPPV group. However, it has no effect on other clinically relevant outcomes such as gastrointestinal perforation, NEC, chronic lung disease or mortality. Ventilator-generated NIPPV appears superior to bilevel devices in reducing the incidence of respiratory failure postextubation failure and need for reintubation. Synchronisation used to deliver NIPPV may be important; however, data are insufficient to support strong conclusions. Future trials should enrol a sufficient number of infants, particularly those less than 28 weeks' GA, to detect differences in death or chronic lung disease and should compare different categories of devices, establish the impact of synchronisation of NIPPV on safety and efficacy of the technique as well as the best combination of settings for NIPPV (rate, peak pressure and positive end-expiratory). Trials should strive to match the mean airway pressure between the intervention groups to allow a better comparison. Neurally adjusted ventilatory assist needs further assessment with properly powered randomised trials.

Early nasal intermittent positive pressure ventilation (NIPPV) versus early nasal continuous positive airway pressure (NCPAP) for preterm infants

BACKGROUND

Nasal continuous positive airway pressure (NCPAP) is a strategy to maintain positive airway pressure throughout the respiratory cycle through the application of a bias flow of respiratory gas to an apparatus attached to the nose. Early treatment with NCPAP is associated with decreased risk of mechanical ventilation exposure and might reduce chronic lung disease. Nasal intermittent positive pressure ventilation (NIPPV) is a form of noninvasive ventilation delivered through the same nasal interface during which patients are exposed to short inflations, along with background end-expiratory pressure.

OBJECTIVES

To examine the risks and benefits of early (within the first six hours after birth) NIPPV versus early NCPAP for preterm infants at risk of or with respiratory distress syndrome (RDS). Primary endpoints are respiratory failure and the need for intubated ventilatory support during the first week of life. Secondary endpoints include the incidence of mortality, chronic lung disease (CLD) (oxygen therapy at 36 weeks' postmenstrual age), pneumothorax, duration of respiratory support, duration of oxygen therapy, and intraventricular hemorrhage (IVH).

SEARCH METHODS

Searches were conducted in January 2023 in CENTRAL, MEDLINE, Embase, Web of Science, and Dissertation Abstracts. The reference lists of related systematic reviews and of studies selected for inclusion were also searched.

SELECTION CRITERIA

We considered all randomized and quasi-randomized controlled trials. Eligible studies compared NIPPV versus NCPAP treatment, starting within six hours after birth in preterm infants (< 37 weeks' gestational age (GA)).

DATA COLLECTION AND ANALYSIS

We collected and analyzed data using the recommendations of the Cochrane Neonatal Review Group.

MAIN RESULTS

We included 17 trials, enrolling 1958 infants in this review. NIPPV likely reduces the rate of respiratory failure (risk ratio (RR) 0.65, 95% confidence interval (CI) 0.54 to 0.78; risk difference (RD) -0.08, 95% CI -0.12 to -0.05; 17 RCTs, 1958 infants; moderate-certainty evidence) and needing endotracheal tube ventilation (RR 0.67, 95% CI 0.56 to 0.81; RD -0.07, 95% CI -0.11 to -0.04; 16 RCTs; 1848 infants; moderate-certainty evidence) amongst infants treated with early NIPPV compared with early NCPAP. The meta-analysis demonstrated that NIPPV may reduce the risk of developing CLD compared to CPAP (RR 0.70, 95% CI 0.52 to 0.92; 12 RCTs, 1284 infants; low-certainty evidence) slightly. NIPPV may result in little to no difference in mortality (RR 0.82, 95% CI 0.62 to 1.10; 17 RCTs; 1958 infants; I2 of 0%; low-certainty evidence), the incidence of pneumothorax (RR 0.92, 95% CI 0.60 to 1.41; 16 RCTs; 1674 infants; I2 of 0%; low-certainty evidence), and rates of severe IVH (RR 0.98, 95% CI 0.53 to 1.79; 8 RCTs; 977 infants; I2 of 0%; low-certainty evidence).

AUTHORS' CONCLUSIONS

When applied within six hours after birth, NIPPV likely reduces the risk of respiratory failure and the need for intubation and endotracheal tube ventilation in very preterm infants (GA 28 weeks and above) with respiratory distress syndrome or at risk for RDS. It may also decrease the rate of CLD slightly. However, most trials enrolled infants with a gestational age of approximately 28 to 32 weeks with an overall mean gestational age of around 30 weeks. As such, the results of this review may not apply to extremely preterm infants that are most at risk of needing mechanical ventilation or developing CLD. Additional studies are needed to confirm these results and to assess the safety of NIPPV compared with NCPAP alone in a larger patient population.

The clinical effects of two non-invasive ventilation modes on premature infants with respiratory distress syndrome: A randomized controlled trial

BACKGROUND

To compare the safety and effectiveness of nasal noninvasive high- frequency oscillatory ventilation (NHFOV) and duo positive airway pressure (DuoPAP) applications in preterm babies with respiratory distress syndrome (RDS).

METHODS

This was a randomized controlled trial. Forty-three premature infants with RDS treated in the neonatal intensive care unit of Huaibei Maternal and Child Health Hospital from January 2020 to November 2021 were selected as the research participants. They were randomly divided into the NHFOV group (n = 22) and DuoPAP group (n = 21). General conditions, including the arterial oxygen partial pressure (PaO2), carbon dioxide partial pressure (PaCO2), oxygenation index (OI), the incidence of apnea at 72 hours, duration of noninvasive respiratory support, maternal high-risk factors, total oxygen consumption time, total gastrointestinal feeding time, and the frequency of intraventricular hemorrhage (IVH), neonatal necrotizing enterocolitis (NEC), and bronchopulmonary dysplasia (BPD) and apnea were compared between the NHFOV group and DuoPAP group at 12 and 24 hours after noninvasive respiratory support.

RESULTS

There was no noteworthy difference between the 2 groups with respect to PaO2, PaCO2, OI, IVH, and NEC and BPD at different nodes (all P > .05).

CONCLUSION

The endpoints of PaO2, PaCO2 and OI and complications of IVH, NEC, BPD and Apnea, and did not reveal any statistical differences between NHFOV and DuoPAP during the respiratory support in preterm babies with RDS.

Recent research on the mechanism of mesenchymal stem cells in the treatment of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a chronic lung disease due to impaired pulmonary development and is one of the main causes of respiratory failure in preterm infants. Preterm infants with BPD have significantly higher complication and mortality rates than those without BPD. At present, comprehensive management is the main intervention method for BPD, including reasonable respiratory and circulatory support, appropriate enteral nutrition and parenteral nutrition, application of caffeine/glucocorticoids/surfactants, and out-of-hospital management after discharge. The continuous advances in stem cell medicine in recent years provide new ideas for the treatment of BPD. Various pre-clinical trials have confirmed that stem cell therapy can effectively prevent lung injury and promote lung growth and damage repair. This article performs a comprehensive analysis of the mechanism of mesenchymal stem cells in the treatment of BPD, so as to provide a basis for clinical applications.

The Intertemporal Role of Respiratory Support in Improving Neonatal Outcomes: A Narrative Review

Defining improvements in healthcare can be challenging due to the need to assess multiple outcomes and measures. In neonates, although progress in respiratory support has been a key factor in improving survival, the same degree of improvement has not been documented in certain outcomes, such as bronchopulmonary dysplasia. By exploring the evolution of neonatal respiratory care over the last 60 years, this review highlights not only the scientific advances that occurred with the application of invasive mechanical ventilation but also the weakness of the existing knowledge. The contributing role of non-invasive ventilation and less-invasive surfactant administration methods as well as of certain pharmacological therapies is also discussed. Moreover, we analyze the cost-benefit of neonatal care-respiratory support and present future challenges and perspectives.

Reintubation rates after extubation to different non-invasive ventilation modes in preterm infants

INTRODUCTION

Respiratory Distress Syndrome (RDS) is a common cause of neonatal morbidity and mortality in premature newborns. In this study, we aim to compare the reintubation rate in preterm babies with RDS who were extubated to Nasal Continuous Positive Airway Pressure (NCPAP) versus those extubated to Nasal Intermittent Positive Pressure Ventilation (NIPPV).

METHODS

This is a retrospective study conducted in the Neonatal Intensive Care Unit (NICU) of Women's Wellness and Research Center (WWRC), Doha, Qatar. The medical files (n = 220) of ventilated preterm infants with gestational age ranging between 28 weeks 0 days and 36 weeks + 6 days gestation and extubated to non-invasive respiratory support (whether NCPAP, NIPPV, or Nasal Cannula) during the period from January 2016 to December 2017 were reviewed.

RESULTS

From the study group of 220 babies, n = 97 (44%) babies were extubated to CPAP, n = 77 (35%) were extubated to NIPPV, and n = 46 (21%) babies were extubated to Nasal Cannula (NC). Out of the n = 220 babies, 18 (8.2%) were reintubated within 1 week after extubation. 14 of the 18 (77.8%) were reintubated within 48 h of extubation. Eleven babies needed reintubation after being extubated to NCPAP (11.2%) and seven were reintubated after extubation to NIPPV (9.2%), none of those who were extubated to NC required reintubation (P = 0.203). The reintubation rate was not affected by extubation to any form of non-invasive ventilation (P = 0.625). The mode of ventilation before extubation does not affect the reintubation rate (P = 0.877). The presence of PDA and NEC was strongly associated with reintubation which increased by two and four-folds respectively in those morbidities. There is an increased risk of reintubation with babies suffering from NEC and BPD and this was associated with an increased risk of hospital stay with a P-value ranging (from 0.02-0.003). Using multivariate logistic regression, NEC the NEC (OR = 5.52, 95% CI 1.26, 24.11, P = 0.023) and the vaginal delivery (OR = 0.23, 95% CI 0.07, 0.78, P = 0.018) remained significantly associated with reintubation.

CONCLUSION

Reintubation rates were less with NIPPV when compared with NCPAP, however, this difference was not statistically significant. This study highlights the need for further research studies with a larger number of neonates in different gestational ages birth weight categories. Ascertaining this information will provide valuable data for the factors that contribute to re-intubation rates and influence the decision-making and management of RDS patients in the future.