Non-invasive versus invasive respiratory support in preterm infants

Respiratory insufficiency is almost ubiquitous in infants born preterm, with its incidence increasing with lower gestational age. A wide range of respiratory support management strategies are available for these infants, separable into non-invasive and invasive forms of respiratory support. Here we review the history and evolution of respiratory care for the preterm infant and then examine evidence that has emerged to support a non-invasive approach to respiratory management where able. Continuous positive airway pressure (CPAP) is the non-invasive respiratory support mode currently with the most evidence for benefit. CPAP can be delivered safely and effectively and can commence in the delivery room. Particularly in early life, time spent on non-invasive respiratory support, avoiding intubation and mechanical ventilation, affords benefit for the preterm infant by virtue of a lessening of lung injury and hence a reduction in incidence of bronchopulmonary dysplasia. In recent years, enthusiasm for application of non-invasive support has been further bolstered by new techniques for administration of exogenous surfactant. Methods of less invasive surfactant delivery, in particular with a thin catheter, have allowed neonatologists to administer surfactant without resort to endotracheal intubation. The benefits of this approach appear to be sustained, even in those infants subsequently requiring mechanical ventilation. This cements the notion that any reduction in exposure to mechanical ventilation leads to alleviation of injury to the vulnerable preterm lung, with a long-lasting effect. Despite the clear advantages of non-invasive respiratory support, there will continue to be a role for intubation and mechanical ventilation in some preterm infants, particularly for those born <25 weeks' gestation. It is currently unclear what role early non-invasive support has in this special population, with more studies required.

Noninvasive Ventilation

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

High-flow nasal cannula (HFNC) vs continuous positive airway pressure (CPAP) vs nasal intermittent positive pressure ventilation as primary respiratory support in infants of ≥ 32 weeks gestational age (GA): study protocol for a three-arm multi-center randomized controlled trial

BACKGROUND

Health problems in neonates with gestational age (GA) ≥ 32 weeks remain a major medical concern. Respiratory distress (RD) is one of the common reasons for admission of neonates with GA ≥ 32 weeks. Noninvasive ventilation (NIV) represents a crucial approach to treat RD, and currently, the most used NIV modes in neonatal intensive care unit include high-flow nasal cannula (HFNC), continuous positive airway pressure (CPAP), and nasal intermittent positive pressure ventilation. Although extensive evidence supports the use of NIPPV in neonates with a GA < 32 weeks, limited data exist regarding its effectiveness in neonates with GA ≥ 32 weeks. Therefore, the aim of this study is to compare the clinical efficacy of HFNC, CPAP, and NIPPV as primary NIV in neonates with GA ≥ 32 weeks who experience RD.

METHODS

This trial is designed as an assessor-blinded, three-arm, multi-center, parallel, randomized controlled trial, conducted in neonates ≥ 32 weeks' GA requiring primary NIV in the first 24 h of life. The neonates will be randomly assigned to one of three groups: HFNC, CPAP or NIPPV group. The effectiveness, safety and comfort of NIV will be evaluated. The primary outcome is the occurrence of treatment failure within 72 h after enrollment. Secondary outcomes include death before discharge, surfactant treatment within 72 h after randomization, duration of both noninvasive and invasive mechanical ventilation, duration of oxygen therapy, bronchopulmonary dysplasia, time to achieve full enteral nutrition, necrotizing enterocolitis, duration of admission, cost of admission, air leak syndrome, nasal trauma, and comfort score.

DISCUSSION

Currently, there is a paucity of data regarding the utilization of NIPPV in neonates with GA ≥ 32 weeks. This study will provide clinical evidence for the development of respiratory treatment strategies in neonates at GA ≥ 32 weeks with RD, with the aim of minimizing the incidence of tracheal intubation and reducing the complications associated with NIV.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR2300069192. Registered on March 9, 2023, https://www.chictr.org.cn/showproj.html?proj=171491 .

Fluctuations in Oxygen Saturation during Synchronized Nasal Intermittent Positive Pressure Ventilation and Nasal High-Frequency Oscillatory Ventilation in Very Low Birth Weight Infants: A Randomized Crossover Trial

BACKGROUND

Very low birth weight (VLBW) infants on noninvasive ventilation (NIV) experience frequent fluctuations in oxygen saturation (SpO2) that are associated with an increased risk for mortality and severe morbidities.

METHODS

In this randomized crossover trial, VLBW infants (n = 22) born 22+3 to 28+0 weeks on NIV with supplemental oxygen were allocated on two consecutive days in random order to synchronized nasal intermittent positive pressure ventilation (sNIPPV) and nasal high-frequency oscillatory ventilation (nHFOV) for 8 h. nHFOV and sNIPPV were set to equivalent mean airway pressure and transcutaneous pCO2. Primary outcome was the time spent within the SpO2 target (88-95%).

RESULTS

During sNIPPV, VLBW infants spent significantly more time within the SpO2 target (59.9%) than during nHFOV (54.6%). The proportion of time spent in hypoxemia (22.3% vs. 27.1%) and the mean fraction of supplemental oxygen (FiO2) (29.4% vs. 32.8%) were significantly reduced during sNIPPV, while the respiratory rate (50.1 vs. 42.6) was significantly higher. Mean SpO2, SpO2 above the target, number of prolonged (>1 min) and severe (SpO2 <80%) hypoxemic episodes, parameters of cerebral tissue oxygenation using NIRS, number of FiO2 adjustments, heart rate, number of bradycardias, abdominal distension and transcutaneous pCO2 did not differ between both interventions.

CONCLUSIONS

In VLBW infants with frequent fluctuations in SpO2, sNIPPV is more efficient than nHFOV to retain the SpO2 target and to reduce FiO2 exposure. These results demand more detailed investigations into cumulative oxygen toxicities during different modes of NIV over the weaning period, particularly with regard to consequences for long-term outcomes.

[Efficacy of noninvasive high-frequency oscillatory ventilation versus nasal intermittent positive pressure ventilation as post-extubation respiratory support in preterm infants: a Meta analysis]

OBJECTIVES

To systematically evaluate the efficacy and safety of noninvasive high-frequency oscillatory ventilation (NHFOV) versus nasal intermittent positive pressure ventilation (NIPPV) as post-extubation respiratory support in preterm infants.

METHODS

China National Knowledge Infrastructure, Wanfang Data, Chinese Journal Full-text Database, China Biology Medicine disc, PubMed, Web of Science, and the Cochrane Library were searched for articles on NHFOV and NIPPV as post-extubation respiratory support in preterm infants published up to August 31, 2022. RevMan 5.4 software and Stata 17.0 software were used for a Meta analysis to compare related indices between the NHFOV and NIPPV groups, including reintubation rate within 72 hours after extubation, partial pressure of carbon dioxide (PCO2) at 6-24 hours after switch to noninvasive assisted ventilation, and the incidence rates of bronchopulmonary dysplasia (BPD), air leak, nasal damage, periventricular leukomalacia (PVL), intraventricular hemorrhage (IVH), and retinopathy of prematurity (ROP).

RESULTS

A total of 9 randomized controlled trials were included. The Meta analysis showed that compared with the NIPPV group, the NHFOV group had significantly lower reintubation rate within 72 hours after extubation (RR=0.67, 95%CI: 0.52-0.88, P=0.003) and PCO2 at 6-24 hours after switch to noninvasive assisted ventilation (MD=-4.12, 95%CI: -6.12 to -2.13, P<0.001). There was no significant difference between the two groups in the incidence rates of complications such as BPD, air leak, nasal damage, PVL, IVH, and ROP (P>0.05).

CONCLUSIONS

Compared with NIPPV, NHFOV can effectively remove CO2 and reduce the risk of reintubation, without increasing the incidence of complications such as BPD, air leak, nasal damage, PVL, and IVH, and therefore, it can be used as a sequential respiratory support mode for preterm infants after extubation.

Efficacy and safety of nasal intermittent positive pressure ventilation and nasal continuous positive airway pressure ventilation in neonatal respiratory distress syndrome: a systematic review and meta-analysis

BACKGROUND

The efficacies of nasal continuous positive airway pressure (NCPAP) and nasal intermittent positive pressure ventilation (NIPPV) in neonatal respiratory distress syndrome (RDS) are controversial. The reasons for controversy may be the selection bias of research objects and the small sample size.

METHODS

Literature retrieval was performed in PubMed, EMBASE, Medline, Central, China National Knowledge Infrastructure (CNKI), Wanfang and China Science Digital Library (CSDL) databases. Inclusion criteria: (I) literatures involving subjects who were newborns with RDS; (II) studies that had established both experimental and control groups; (III) the intervention measures of the experimental and control groups were NIPPV and NCPAP, respectively; (IV) the results included the incidence of intubation, bronchopulmonary dysplasia (BPD), or mortality; and (V) randomized controlled trials (RCTs). The chi-square test was applied for heterogeneity test. Publication bias assessment was conducted by funnel plot and Egger's test. The revised Cochrane risk of bias tool for individually randomized, parallel group trials (RoB2.0) was used to evaluate the risk of bias of the included RCT research.

RESULTS

A total of 10 literatures were included for analysis, including 1,104 patients, 557 in the NIPPV group and 547 in the NCPAP group. Among the literatures, 2 literatures had low risk of bias, 2 literatures had high risk of bias, and the rest had uncertain risk of bias. Compared to NCPAP, NIPPV reduced the incidence of neonatal intubation in RDS [risk ratio (RR) =0.57, 95% confidence interval (CI): 0.46-0.71, Z=5.11, P<0.00001]. There was no statistically significant heterogeneity (P=0.13, I²=36%) or publication bias (P<0.05) among the studies. Compared with NCPAP, NIPPV reduced the incidence of BPD in RDS (RR =0.72, 95% CI: 0.57-0.91, Z=2.70, P=0.007). There was no statistically significant heterogeneity (P=0.10, I²=41%) or publication bias (P>0.05) among the studies. NIPPV reduced the neonatal mortality rate of RDS (RR =0.55, 95% CI: 0.31-0.97, Z=2.08, P=0.04). There was no statistically significant heterogeneity (P=0.20, I²=38%) or publication bias (P>0.05) among the studies.

DISCUSSION

Compared with NCPAP, NIPPV can reduce the incidence of intubation, BPD, and mortality. The conclusions need to be confirmed via high-quality RCTs.

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.

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

BACKGROUND

Bi-level noninvasive ventilation (NIV) has been used in respiratory distress syndrome (RDS) as primary treatment, post-extubation, and to treat apnea. This review summarizes studies on bi-level NIV in premature infants with RDS. Nonsynchronized nasal intermittent positive pressure ventilation (nsNIPPV) and synchronized NIPPV (SNIPPV) use pressure settings ≥ those used during mechanical ventilation (MV), and biphasic continuous positive airway pressure (BiPAP) use two nasal continuous positive airway pressure (NCPAP) levels ≤4 cm H2O apart.

METHODS

A systematic review (Medline OVID and Pubmed) and meta-analysis of randomized controlled trials. Primary outcomes were bronchopulmonary dysplasia (BPD) and mortality. Secondary outcomes included NIV failure (intubation) and extubation failure (re-intubation). Data were pooled using a fixed-effects model to calculate the relative risk (RR) with 95% confidence interval (CI) between NIV modes (RevMan v 5.3, Copenhagen, Denmark).

RESULTS

Twenty-four randomized controlled trials that largely did not correct for mean airway pressure (MAP) and used outdated ventilators were included. Compared with NCPAP, both nsNIPPV and SNIPPV resulted in less re-intubation (RR 0.88 with 95% CI (0.80, 0.97) and RR 0.20 (0.10, 0.38), respectively) and BPD (RR 0.69 (0.49, 0.97) and RR 0.51 (0.29, 0.88), respectively). nsNIPPV also resulted in less intubation (RR 0.57 (0.45, 0.73) versus NCPAP, with no difference in mortality. One study showed less intubation in BiPAP versus NCPAP.

CONCLUSIONS

Bi-level NIV versus NCPAP may reduce MV and BPD in premature infants with RDS. Studies comparing equivalent MAP utilizing currently available machines are needed.

Current insights in non-invasive ventilation for the treatment of neonatal respiratory disease

Deleterious consequences of the management of respiratory distress syndrome (RDS) with invasive ventilation have led to more in-depth investigation of non-invasive ventilation (NIV) modalities. NIV has significantly and positively altered the treatment outcomes and improved mortality rates of preterm infants with RDS. Among the different NIV modes, nasal intermittent positive pressure ventilation (NIPPV) has shown considerable benefits compared to nasal continuous positive airway pressure (NCPAP). Despite reports of heated humidified high-flow nasal cannula’s (HHHFNC) non-inferiority compared to NCPAP, some trials have been terminated due to high treatment failure rates with HHHFNC use. Moreover, RDS management with the combination of INSURE (INtubation SURfactant Extubation) technique and NIV ensures higher success rates. This review elaborates on the currently used various modes of NIV and novel techniques are also briefly discussed.

High-Frequency Ventilation as a Mode of Noninvasive Respiratory Support

High-frequency ventilation (HFV) as a mode of noninvasive respiratory support (NRS) in preterm neonates is gaining popularity. Benefits may accrue from combining the ventilatory efficiency of HFV delivered through a noninvasive interface, enhancing respiratory support while potentially limiting lung injury. Current evidence suggests that noninvasive HFV (NIHFV) may be superior to other NRS modes in eliminating carbon dioxide and preventing endotracheal ventilation after failure of other NRS modes. Animal data suggest NIHFV may promote improved alveolar development compared to endotracheal ventilation. However, adequately powered large-scale controlled trials are required to evaluate efficacy and safety prior to widespread use of NIHFV.