In vitro comparison of nasal continuous positive airway pressure devices for neonates

Non-invasive high-frequency oscillatory ventilation (NHFOV) versus nasal continuous positive airway pressure (NCPAP) for preterm infants: a systematic review and meta-analysis

OBJECTIVE

To compare the efficacy and safety of non-invasive high-frequency oscillatory ventilation (NHFOV) and nasal continuous positive airway pressure (NCPAP) in preterm infants.

DESIGN

The study conducted a comprehensive analysis across three databases, namely EMBASE, MEDLINE and Cochrane Central, to identify randomised controlled trials comparing NHFOV and NCPAP. Statistical analysis was performed using Review Manager V.5.3 software.

MAIN OUTCOMES MEASURES

The primary outcomes of the study were the intubation or reintubation rate in the NHFOV and NCPAP groups. Additionally, secondary outcomes included the partial pressure of carbon dioxide levels and major complications associated with non-invasive respiratory support ventilation.

RESULTS

Ten randomised controlled studies, involving 2031 preterm infants, were included in this meta-analysis. When compared with NCPAP, NHFOV demonstrated a significant reduction in the intubation or reintubation rate (p<0.01, relative risk=0.45, 95% CI 0.37 to 0.55), and there was no statistical difference in related complications.

CONCLUSION

In preterm infants, NHFOV appears to be an effective intervention for decreasing the intubation or reintubation rate compared with NCPAP, with no increase in associated complications.

TRIAL REGISTRATION NUMBER

CRD42023403968.

State of the art on neonatal noninvasive respiratory support: How physiological and technological principles explain the clinical outcomes

Noninvasive respiratory support has gained significant popularity in neonatal units because of its potential to reduce lung injury associated with invasive mechanical ventilation. To minimize lung injury, clinicians aim to apply for noninvasive respiratory support as early as possible. However, the physiological background and the technology behind such support modes are not always clear, and many open questions remain regarding the indications of use and clinical outcomes. This narrative review discusses the currently available evidence for various noninvasive respiratory support modes applied in Neonatal Medicine in terms of physiological effects and indications. Reviewed modes include nasal continuous positive airway pressure, nasal high-flow therapy, noninvasive high-frequency oscillatory ventilation, nasal intermittent positive pressure ventilation (NIPPV), synchronized NIPPV and noninvasive neurally adjusted ventilatory assist. To enhance clinicians' awareness of each support mode's strengths and limitations, we summarize technical features related to the functioning mechanisms of devices and the physical properties of the interfaces commonly used for providing noninvasive respiratory support to neonates. We finally address areas of current controversy and suggest possible areas of research for implementing noninvasive respiratory support in neonatal intensive care units.

A Three-Arm Randomized, Controlled Trial of Different Nasal Interfaces on the Safety and Efficacy of Nasal Intermittent Positive-Pressure Ventilation in Preterm Newborns

OBJECTIVES

To compare the safety and efficacy of different nasal interfaces for delivering non invasive positive pressure ventilation (NIPPV) in preterm neonates.

METHODS

In this three-arm parallel group stratified nonblinded randomized trial involving 210 preterm neonates the participants were randomly allocated to 'nasal mask', 'nasal prongs' and '4 hourly rotation of masks and prongs' groups in a 1:1:1 ratio. The groups were further stratified by gestational age (26-31^6/7 wk versus 32-36^6/7 wk) and indication of NIPPV (primary versus post extubation). Primary outcome was incidence of NIPPV failure within 72 h of initiation. Secondary outcomes were moderate/severe nasal injury, requirement of surfactant post randomization, total duration of respiratory support, duration of NICU stay, common neonatal morbidities and mortality.

RESULTS

Primary analysis revealed that mask group was superior to prongs and rotation groups in terms of reduction in NIPPV failure within 72 h (8.6%, 24.3%, 22.8%, p = 0.033), decreased incidence of moderate/severe nasal injury (8.6%, 22.8%, 11.4% p = 0.038), decreased requirement of surfactant (20%, 38.6%, 42.8%, p = 0.01) and reduction in total duration of respiratory support [median (interquartile range)-6 (3, 10) d, 7.7 (4.9, 19.2) d, 7 (5.5, 18.5) d, p = 0.005]. Post hoc analysis confirmed that nasal mask was superior to prongs with respect to primary outcome (p = 0.012) and also reduced surfactant requirement compared to both prongs (p = 0.015) and rotation (p = 0.003) groups. Other pairwise comparisons were not statistically significant.

CONCLUSIONS

Administering NIPPV by nasal mask significantly decreases the incidence of NIPPV failure within first 72 h compared to nasal prongs and also reduces the requirement of surfactant compared to both prongs and rotation groups.

Masks versus prongs as interfaces for nasal continuous positive airway pressure in preterm infants

BACKGROUND

Nasal masks and nasal prongs are used as interfaces for providing continuous positive airway pressure (CPAP) for preterm infants with or at risk of respiratory distress, either as primary support after birth or as ongoing support after endotracheal extubation from mechanical ventilation. It is unclear which type of interface is associated with lower rates of CPAP treatment failure, nasal trauma, or mortality and other morbidity.

OBJECTIVES

To assess the benefits and harms of nasal masks versus nasal prongs for reducing CPAP treatment failure, nasal trauma, or mortality and other morbidity in newborn preterm infants with or at risk of respiratory distress.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was October 2021.

SELECTION CRITERIA

We included randomised controlled trials comparing masks versus prongs as interfaces for delivery of nasal CPAP in newborn preterm infants (less than 37 weeks' gestation) with or at risk of respiratory distress.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. treatment failure, 2. all-cause mortality, and 3. neurodevelopmental impairment. Our secondary outcomes were 4. pneumothorax, 5. moderate-severe nasal trauma, 6. bronchopulmonary dysplasia, 7. duration of CPAP use, 8. duration of oxygen supplementation, 9. duration of hospitalisation, 10. patent ductus arteriosus receiving medical or surgical treatment, 11. necrotising enterocolitis, 12. severe intraventricular haemorrhage, and 13. severe retinopathy of prematurity. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

We included 12 trials with 1604 infants. All trials were small (median number of participants 118). The trials occurred after 2001 in care facilities internationally, predominantly in India (eight trials). Most participants were preterm infants of 26 to 34 weeks' gestation who received nasal CPAP as the primary form of respiratory support after birth. The studied interfaces included commonly used commercially available masks and prongs. Lack of measures to blind caregivers or investigators was a potential source of performance and detection bias in all the trials. Meta-analyses suggested that use of masks compared with prongs may reduce CPAP treatment failure (risk ratio (RR) 0.72, 95% confidence interval (CI) 0.58 to 0.90; 8 trials, 919 infants; low certainty). The type of interface may not affect mortality prior to hospital discharge (RR 0.83, 95% CI 0.56 to 1.22; 7 trials, 814 infants; low certainty). There are no data on neurodevelopmental impairment. Meta-analyses suggest that the choice of interface may result in little or no difference in the risk of pneumothorax (RR 0.93, 95% CI 0.45 to 1.93; 5 trials, 625 infants; low certainty). Use of masks rather than prongs may reduce the risk of moderate-severe nasal injury (RR 0.55, 95% CI 0.44 to 0.71; 10 trials, 1058 infants; low certainty). The evidence is very uncertain about the effect on bronchopulmonary dysplasia (RR 0.69, 95% CI 0.46 to 1.03; 7 trials, 843 infants; very low certainty).

AUTHORS' CONCLUSIONS

The available trial data provide low-certainty evidence that use of masks compared with prongs as the nasal CPAP interface may reduce treatment failure and nasal injury, and may have little or no effect on mortality or the risk of pneumothorax in newborn preterm infants with or at risk of respiratory distress. The effect on bronchopulmonary dysplasia is very uncertain. Large, high-quality trials would be needed to provide evidence of sufficient validity and applicability to inform policy and practice.

Interface leakage during neonatal CPAP treatment: a randomised, cross-over trial

OBJECTIVE

To determine leakage for two neonatal continuous positive airway pressure (CPAP) interfaces and evaluate leak-corrective manoeuvres.

DESIGN

The ToNIL (Trial of NCPAP Interface Leakage) study was a randomised, clinical, cross-over trial with data collection between August 2018 and October 2019. The primary outcome was blinded to the treating staff.

SETTING

One secondary, 8-bed neonatal intensive care unit (NICU) and three larger (>15 beds), academic NICU referral centres.

PATIENTS

Newborn infants with CPAP were screened (n=73), and those with stable spontaneous breathing, low oxygen requirement, postmenstrual age (PMA) over 28 weeks and no comorbidities were eligible. In total, 50 infants were included (median PMA 33 completed weeks).

INTERVENTIONS

Leakage was measured for both prongs and nasal mask, before and after leak-corrective manoeuvres. Interface application was performed in a randomised order by a nurse, blinded to the measured leakage.

MAIN OUTCOME MEASURES

30 s average leakage, measured in litres per minute (LPM).

RESULTS

Analyses showed a significantly lower leakage (mean difference 0.86 LPM, 95% CI 0.07 to 1.65) with prongs (median 2.01 LPM, IQR 1.00-2.80) than nasal mask (median 2.45 LPM, IQR 0.99-5.11). Leak-corrective manoeuvres reduced leakage significantly for both prongs (median 1.22 LPM, IQR 0.54-1.87) and nasal mask (median 2.35 LPM, IQR 0.76-4.75).

CONCLUSIONS

Large leakages were common for both interfaces, less with prongs. Simple care manoeuvres reduced leakage for both interfaces. This is the first report of absolute leakage for nasal interfaces and should encourage further studies on leakage during CPAP treatment.

Comparison of Respiratory Support After Delivery in Infants Born Before 28 Weeks' Gestational Age: The CORSAD Randomized Clinical Trial

IMPORTANCE

Establishing stable breathing is a key event for preterm infants after birth. Delivery of pressure-stable continuous positive airway pressure and avoiding face mask use could be of importance in the delivery room.

OBJECTIVE

To determine whether using a new respiratory support system with low imposed work of breathing and short binasal prongs decreases delivery room intubations or death compared with a standard T-piece system with a face mask.

DESIGN, SETTING, AND PARTICIPANTS

In this unblinded randomized clinical trial, mothers threatening preterm delivery before week 28 of gestation were screened. A total of 365 mothers were enrolled, and 250 infants were randomized before birth and 246 liveborn infants were treated. The trial was conducted in 7 neonatal intensive care units in 5 European countries from March 2016 to May 2020. The follow-up period was 72 hours after intervention.

INTERVENTIONS

Infants were randomized to either the new respiratory support system with short binasal prongs (n = 124 infants) or the standard T-piece system with face mask (n = 122 infants). The intervention was providing continuous positive airway pressure for 10 to 30 minutes and positive pressure ventilation, if needed, with the randomized system.

MAIN OUTCOMES AND MEASURES

The primary outcome was delivery room intubation or death within 30 minutes of birth. Secondary outcomes included respiratory and safety variables.

RESULTS

Of 246 liveborn infants treated, the mean (SD) gestational age was 25.9 (1.3) weeks, and 127 (51.6%) were female. A total of 41 infants (33.1%) receiving the new respiratory support system were intubated or died in the delivery room compared with 55 infants (45.1%) receiving standard care. The adjusted odds ratio was statistically significant after adjusting for stratification variables (adjusted odds ratio, 0.53; 95% CI, 0.30-0.94; P = .03). No significant differences were seen in secondary outcomes or safety variables.

CONCLUSIONS AND RELEVANCE

In this study, using the new respiratory support system reduced delivery room intubation in extremely preterm infants. Stabilizing preterm infants with a system that has low imposed work of breathing and binasal prongs as interface is safe and feasible.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02563717.

Role of ventilator and nasal interface in pressure transmission during neonatal intermittent positive pressure ventilation: A bench study

We aimed at evaluating pressure transmission and stability during non-synchronized neonatal nasal intermittent positive pressure ventilation (NIPPV) delivered using five mechanical ventilators and three nasal interfaces. An artificial nose-throat model was connected to a mechanical analog of the infant respiratory system and a breath generator. Ventilation was administrated via a nasal mask (NM), short bi-nasal prongs (SBN), or RAM® cannula. We applied positive end-expiratory pressures (PEEP) of 5 and 10 cmH₂ O, inspiratory pressures (PIP) of 15 and 30 cmH₂ O, inspiratory times of 0.23, 0.42, and 0.57 s. Measurements were performed with leaks of 0, 1.5, and 4 L/min. The pressure was measured at the airways opening (P_AW ) and the glottis (P_GL ). The difference between set and delivered pressures (P_AW ) was less than ±1 cmH₂ O for all ventilators. We documented a significant difference between P_AW and P_GL in the presence of leaks. With 4 L/min leaks, PEEP dropped by 43%, 49%, and 63% with NM, SBP, and RAM® cannula, respectively; PIP dropped by 58%, 64%, and 74%. On average, the SD of PEEP fluctuations was ±0.60 and ±2.50 cmH₂ O for P_AW and P_GL ; the breath-by-breath SD of PIP was ±0.77 and ±2.06 cmH₂ O. During NIPPV, the PIP and PEEP transmission to the glottis is markedly lower than the set values and highly variable. The impact of leaks and nasal interface is much more significant than the differences in ventilators' performance on the efficacy of pressure transmission and stability of non-synchronized ventilator-generated NIPPV.

Aerosol drug delivery to spontaneously-breathing preterm neonates: lessons learned

Delivery of medications to preterm neonates receiving non-invasive ventilation (NIV) represents one of the most challenging scenarios for aerosol medicine. This challenge is highlighted by the undersized anatomy and the complex (patho)physiological characteristics of the lungs in such infants. Key physiological restraints include low lung volumes, low compliance, and irregular respiratory rates, which significantly reduce lung deposition. Such factors are inherent to premature birth and thus can be regarded to as the intrinsic factors that affect lung deposition. However, there are a number of extrinsic factors that also impact lung deposition: such factors include the choice of aerosol generator and its configuration within the ventilation circuit, the drug formulation, the aerosol particle size distribution, the choice of NIV type, and the patient interface between the delivery system and the patient. Together, these extrinsic factors provide an opportunity to optimize the lung deposition of therapeutic aerosols and, ultimately, the efficacy of the therapy.

In this review, we first provide a comprehensive characterization of both the intrinsic and extrinsic factors affecting lung deposition in premature infants, followed by a revision of the clinical attempts to deliver therapeutic aerosols to premature neonates during NIV, which are almost exclusively related to the non-invasive delivery of surfactant aerosols. In this review, we provide clues to the interpretation of existing experimental and clinical data on neonatal aerosol delivery and we also describe a frame of measurable variables and available tools, including in vitro and in vivo models, that should be considered when developing a drug for inhalation in this important but under-served patient population.

Nasal mask vs binasal prongs for nasal continuous positive airway pressure in preterm infants: A systematic review and meta-analysis

OBJECTIVE

To investigate the effect of nasal continuous positive airway pressure (NCPAP) given with nasal masks (NM) compared with binasal prongs (BNP) on the incidence of intubation within 72 hours in preterm infants (primary outcome) via meta-analysis of clinical studies.

DATA SOURCES

We searched for randomized clinical trials (RCTs) or quasi-RCTs in Medline, PubMed, and Web of Science from inception through 4 December 2019.

DATA EXTRACTION/SYNTHESIS

Two independent co-authors extracting data performed the meta-analysis using a fixed-effect model to yield pooled relative risk (RR) and its 95% confidence interval (CI) for each outcome. We used Cochrane GRADE to evaluate the evidence quality.

RESULTS

Eleven RCTs met the inclusion criteria. The meta-analysis showed NCPAP provided via NM significantly reduced the rate of intubation within 72 hours (RR, 0.72; 95% CI, 0.58-0.90; nine studies; GRADE-moderate) and nasal trauma (RR, 0.64; 95% CI, 0.55-0.74; GRADE-low) compared with NCPAP provided via BNP. Also, NCPAP via NM significantly reduced surfactant treatment (RR, 0.85; 95% CI, 0.74-0.97; GRADE-very low) and bronchopulmonary dysplasia (RR, 0.47; 95% CI, 0.23-0.95; GRADE-low) compared with BNP in a setting where NCPAP was used as the primary support in respiratory distress syndrome. No statistically significant differences were noted between groups in secondary outcomes except increased NCPAP duration when NCPAP given with NM compared with BNP (mean difference [days], 1.78; 95% CI, 1.67-1.89; GRADE-low).

CONCLUSION

Among premature infants, NCPAP provided with NM is more effective in preventing intubation and mechanical ventilation within 72 hours of initiating the support compared with NCPAP provided with BNP.

Noninvasive Ventilation in the Delivery Room for the Preterm Infant

A decade ago, preterm infants were prophylactically intubated and mechanically ventilated starting in the delivery room; however, now the shift is toward maintaining even the smallest of neonates on noninvasive respiratory support. The resuscitation of very low gestational age neonates continues to push the boundaries of neonatal care, as the events that transpire during the golden minutes right after birth prove ever more important for determining long-term neurodevelopmental outcomes. Continuous positive airway pressure (CPAP) remains the most important mode of noninvasive respiratory support for the preterm infant to establish and maintain functional residual capacity and decrease ventilation/perfusion mismatch. However, the majority of extremely low gestational age infants require face mask positive pressure ventilation during initial stabilization before receiving CPAP. Effectiveness of face mask positive pressure ventilation depends on the ability to detect and overcome mask leak and airway obstruction. In this review, the current evidence on devices and techniques of noninvasive ventilation in the delivery room are discussed.

Comparison of delivered distending pressures in the oropharynx in preterm infant on bubble CPAP and on three different nasal interfaces

OBJECTIVE

To compare the level of continuous positive airway pressure (CPAP) delivered by three different CPAP delivery interfaces (RAM cannula system, Hudson prongs, and nasal mask) in preterm neonates with respiratory distress.

METHODS

Preterm neonates with gestation between 28 weeks and 34 weeks and birth weight more than or equal to 1000 g and requiring nasal CPAP for respiratory distress were eligible for the study. During the study period, consecutive infants requiring CPAP were started on Hudson prongs or RAM cannula or nasal mask in that order. We measured the mean oropharyngeal pressure, which approximates the applied CPAP level. Oropharyngeal pressures in the recruited neonates were measured between 24 and 48 hours of postnatal age, when stable and in sleep or quiet awake state. Comparison of the delivered oropharyngeal pressures when on three different nasal interfaces at the same set flow rate and at set CPAP of 5 cm or 6 cm of H₂ O was the primary outcome.

RESULTS

Data was analyzed from 30 neonates in each group. We found that measured oropharyngeal pressures were less than set CPAP level in all three studied interfaces. Maximum drop in oropharyngeal pressure was observed with use of RAM cannula with measured oropharyngeal pressures being 1.1 and 1.2 cm H₂ O less than set CPAP of 5 and 6 cm H₂ O respectively. Pharyngeal pressure best correlated to set CPAP level with the use of nasal mask.

CONCLUSION

None of the nasal interfaces delivered oropharyngeal pressure equivalent to the set CPAP. However, nasal mask delivered oropharyngeal pressure best matched to the set CPAP.

Extended Pharmacopeial Characterization of Surfactant Aerosols Generated by a Customized eFlow Neos Nebulizer Delivered through Neonatal Nasal Prongs

The delivery of nebulized medications to preterm infants during Non-Invasive Ventilation (NIV) remains an unmet clinical need. In this regard, the effective delivery of nebulized surfactant has been particularly investigated in preclinical and clinical studies. In this work, we investigated the feasibility of delivering nebulized surfactant through various commercially available nasal prong types. We first performed a compendial characterization of surfactant aerosols generated by the eFlow Neos nebulizer, customized to be used in neonates, determining the amount of surfactant delivered by the device as well as the aerodynamic characteristics of surfactant aerosols. Additionally, we extended the compendial characterization by testing the effect of different nasal prong types on the estimated lung dose using a realistic Continuous Positive Airway Pressure (CPAP) circuit that included a cast of the upper airways of a preterm neonate. The compendial characterization of surfactant aerosols delivered through different nasal prongs achieved relatively high delivered surfactant doses (in the range 63-74% of the nominal dose), with aerodynamic characteristics displaying mass median aerodynamic diameters ranging between 2.52 and 2.81 µm. Nevertheless, when using a representative in vitro setup mimicking NIV in a clinical setting, significant differences were observed in terms of the estimated lung dose accounting for up to two-fold differences (from 10% to 20% estimated lung deposition of the nominal dose) depending on the chosen nasal prong type. Considering that surfactant lung deposition rates are correlated with therapeutic efficacy, this study points out the relevance of choosing the appropriate NIV interface to maximize the lung dose of nebulized medications.

Non-invasive high flow oscillatory ventilation in comparison with nasal continuous positive pressure ventilation for respiratory distress syndrome, a literature review

BACKGROUND

Noninvasive high-frequency oscillatory ventilation (NHFOV) keeps the lung open with add-on effective rhythmic oscillations in addition to allowing spontaneous breathing. This review aims at reconstructing the different pieces of available research articles and evidence into a more solid collective evidence for NHFOV in preterm infants with respiratory distress syndrome (RDS).

METHODS

A thorough systemic search was conducted in Medline, Embase, Web of Science, Google Scholar, CINAHL, and Cochrane. Randomized controlled trials (RCTs) on preterm infants with RDS comparing NHFOV with nasal continuous positive airway pressure (NCPAP) in terms of PCO₂ change, need for ventilation, duration of respiratory support, mortality air leak, or BPD were included. Data quality assessment and meta-analyses were carried out.

RESULTS

Five RCTs involving 270 preterm infants included in the review. PCO₂ relatively decreased on NHFOV (MD = 3.84, confidence interval (CI) 7.32-0.35, p = .03). On the other hand, relative risk (RR) of intubation was unquestionably decreased with NHFOV in comparison with NCPAP (RR  =  0.43, CI 0.25-0.75, p = .003) without statistical heterogeneity I² = 0%. Although the risk of mortality was less in NHFOV, the difference was statistically insignificant (RR = 0.72, CI 0.24-2.18, p = .56). Other outcomes reported in single studies only. Duration of respiratory support was significantly shorter in NHFOV compared with NCPAP (37.35 ± 8.96 versus 49.77 ± 10.33, p = .009), whereas air leak and BPD were reported in very few cases without a significant difference between the two interventions.

CONCLUSIONS

NHFOV improved the PCO₂ elimination and decreased the risk of intubation without a significant change in mortality compared with NCPAP.

Assessment of resistance of nasal continuous positive airway pressure interfaces

OBJECTIVE

To compare the resistance of interfaces used for the delivery of nasal continuous positive airway pressure (CPAP) in neonates, as measured by the generated system pressure at fixed gas flows, in an in vitro setting.

DESIGN

Gas flows of 6, 8 and 10 L/min were passed through three sizes of each of a selection of available neonatal nasal CPAP interfaces (Hudson prong, RAM Cannula, Fisher & Paykel prong, Infant Flow prong, Fisher & Paykel mask, Infant Flow mask). The expiratory limb was occluded and pressure differential measured using a calibrated pressure transducer.

RESULTS

Variation in resistance, assessed by mean pressure differential, was seen between CPAP interfaces. Binasal prong interfaces typically had greater resistance at the smallest assessed sizes, and with higher gas flows. However, Infant Flow prongs produced low pressures (<1.5 cmH₂O) at all sizes and gas flows. RAM Cannula had a high resistance, producing a pressure >4.5 cmH₂O at all sizes and gas flows. Both nasal mask interfaces had low resistance at all assessed sizes and gas flows, with recorded pressure <1 cmH₂O in all cases.

CONCLUSIONS

There is considerable variation in measured resistance of available CPAP interfaces at gas flows commonly applied in clinical neonatal care. Use of interfaces with high resistance may result in a greater drop in delivered airway pressure in comparison to set circuit pressure, which may have implications for clinical efficacy. Device manufacturers and clinicians should consider CPAP interface resistance prior to introduction into routine clinical care.

To compare nasal mask with binasal prongs in delivering continuous positive airway pressure for reducing need of invasive ventilation: randomized controlled trial

AIMS

To compare nasal mask with binasal prongs in delivering bubble continuous positive airway pressure (CPAP) for reducing need of invasive ventilation in VLBW infants: randomized controlled trial.

METHODS

In this randomized control trial 178 infants were enrolled, 90 were randomized to nasal mask group and 88 to nasal prong group for delivering bubble CPAP. Preterm neonates between 26 and 32 weeks of gestational age requiring CPAP for respiratory distress within 6 h of life were assessed for eligibility and were included if neonates had spontaneous respiratory efforts with respiratory distress in the form of tachypnea (respiratory rate >60/min), intercostal/subcostal retractions, grunting (audible with/without stethoscope), Silverman Anderson score ≥3, increased respiratory efforts or cyanosis. Infants received either nasal mask or binasal prongs for delivery of bubble CPAP. The primary outcome was the need for mechanical ventilation in first 72 h of life.

RESULTS

Baseline characteristics were comparable between the two groups. There was significant reduction in incidence of CPAP failure [15 (16.6%) versus 26 (29.5%); RR 0.47 (95% CI 0.23-0.97), p = .04]; nasal trauma (any grade) [14 (15.9%) versus 38 (43.2%); RR 0.26 (95% CI 0.12-0.52), p = .0002]; nasal trauma grade I [12 (13.3%) versus 23 (26.1%); RR 0.43 (95% CI 0.20-0.94), p = .03]; nasal trauma grade II [1 (1.1%) versus 10 (11.3%); RR 0.08 (95% CI 0.01-0.70), p = .02]; nasal trauma severe grade (II and III) [2 (2.2%) versus 15 (17.0%);RR 0.11 (95% CI 0.02-0.49), p = .004] and bronchopulmonary dysplasia [4 (4.4%) versus 12 (13.6%); RR 0.30 (95% CI 0.10-0.95), p = .04] in nasal mask group when compared to nasal prong group.

CONCLUSION

Nasal mask leads to significant reduction in need for mechanical ventilation in initial 72 h.

A randomized trial comparing the short binasal prong to the RAM cannula for noninvasive ventilation support of preterm infants with respiratory distress syndrome

PURPOSE

In this study, we compared the efficacy of the RAM cannula and the short binasal prong (SBP) as noninvasive ventilation (NIV) interfaces in preterm infants with respiratory distress syndrome (RDS).

MATERIALS AND METHODS

Premature infants with RDS who required NIV were randomized in the RAM cannula and SBP groups within the first half hour. The groups were compared in terms of their need for invasive ventilation, their surfactant use, and their morbidities.

RESULTS

We assessed 126 patients (62 SBPs and 64 RAM cannulas). Clinical and demographic features of the groups were similar. Within the first 72 hours, the RAM cannula group showed a higher need for invasive ventilation (32.8 and 9.6%, p = .002, respectively), surfactant (42.1 and 19.3%, p = .007, respectively), and rate of pulmonary hemorrhage was also higher. There were no differences between the groups in terms of other morbidities.

CONCLUSIONS

In preterm infants with RDS, RAM cannula use as an interface for NIV results in increased invasive ventilation and surfactant use.

Noninvasive high-frequency oscillatory ventilation as respiratory support in preterm infants: a meta-analysis of randomized controlled trials

BACKGROUND

Noninvasive high-frequency oscillatory ventilation (nHFOV), a relatively new modality, is gaining popularity despite scarce evidence. This meta-analysis was designed to evaluate the efficacy and safety of nHFOV as respiratory support in premature infants.

METHODS

We searched MEDLINE, EMBASE, CINAHL, and Cochrane CENTRAL from inception of the database to January 2019. All published randomized controlled trials (RCTs) evaluating the effect of nHFOV therapy with nasal continuous positive airway pressure (nCPAP) or biphasic nCPAP (BP-CPAP) in newborns for respiratory support were included. All meta-analyses were performed using Review Manager 5.3.

RESULTS

A total of 8 RCTs involving 463 patients were included. The meta-analysis estimated a lower risk of intubation (relative risk = 0.50, 95% confidence interval of 0.36 to 0.70) and more effective clearance of carbon dioxide (weighted mean difference = - 4.61, 95% confidence interval of - 7.94 to - 1.28) in the nHFOV group than in the nCPAP/BP-CPAP group.

CONCLUSIONS

Our meta-analysis of RCTs suggests that nHFOV, as respiratory support in preterm infants, significantly remove carbon dioxide and reduce the risk of intubation compared with nCPAP/BP-CPAP. The appropriate parameter settings for different types of noninvasive high-frequency ventilators, the effect of nHFOV in extremely preterm infants, and the long-term safety of nHFOV need to be assessed in large trials.

Risk and benefits of Bubble Continuous Positive Airway Pressure for neonatal and childhood respiratory diseases in Low- and Middle-Income countries

Over 80% of the global burden of childhood deaths occur in Low- and Middle-Income Countries (LMIC). Of the leading causes of death, respiratory failure is common to the top three. Bubble Continuous Positive Airway Pressure (bCPAP) is a standard therapy considered safe and cost effective in high resource settings. Although high-quality trials from LMIC are few, pooled available trial data considered alongside studies from high-income countries suggest that bCPAP: (i) reduces mortality; (ii) reduces the need for mechanical ventilation; and (iii) prevents extubation failure. Wider availability and optimal use at all levels of the health care system in LMIC are important steps to improve childhood survival. Studies aimed at effectively implementing, and sustaining safe use of bCPAP in the resource limited setting of LMIC are required.

Effectiveness and safety of nasal mask versus binasal prongs for providing continuous positive airway pressure in preterm infants-A systematic review and meta-analysis

Continuous positive airway pressure (CPAP) delivered via binasal prongs has been the cornerstone of respiratory management in preterm infants. Though effective, the use of binasal prongs is associated with nasal trauma, and CPAP failure. To overcome these issues, nasal masks are increasingly used to deliver CPAP in preterm infants. The aim was to conduct a systematic review of randomized controlled trials (RCTs) comparing nasal mask versus binasal prongs to deliver CPAP in preterm infants. Medline, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index of Nursing, and Allied Health Literature, and E-abstracts from the Pediatric Academic Society meetings were searched in May 2017. All RCTs comparing nasal mask versus binasal prongs for delivering CPAP in preterm infants were included. Primary outcome was CPAP failure (need for mechanical ventilation within 72 h of initiating CPAP). Secondary outcomes included duration of CPAP, moderate to severe nasal trauma, any nasal trauma, pneumothorax, severe IVH, bronchopulmonary dysplasia at 36 weeks postmenstrual age, and mortality. Five RCTs with low risk of bias were included. Nasal mask significantly decreased the risk of CPAP failure (4 RCTs [N = 459]; relative risk [RR]: 0.63; 95% confidence interval [CI]: 0.45-0.88; P=.007; I2 = 0%, NNT: 9), and the incidence of moderate to severe nasal trauma (3 RCTs [N = 275], RR: 0.41; 95%CI, 0.24-0.72; P = 0.002; I2 = 74%, NNT: 6). Other outcomes did not differ significantly between the groups. Compared to binasal prongs, nasal mask may provide a safe and effective alternative by minimizing the risk of CPAP failure in preterm infants needing CPAP support.

Continuous positive airway pressure delivery during less invasive surfactant administration: a physiologic study

OBJECTIVE

We sought to investigate the pressure delivery during less invasive surfactant administration, as we hypothesize that it might be reduced.

STUDY DESIGN

Physiologic in vitro study in a ventilation lab, using different pressure generators, levels, and leaks in a model of neonatal airways/lung mimicking mechanical characteristics of respiratory distress syndrome. Pressure was measured at the lung and verified in vivo measuring pharyngeal pressure in 19 neonates under same conditions. Data were analyzed using repeated measures-analysis of variance.

RESULTS

Pressure delivery in vitro is significantly and variably reduced during minimally invasive surfactant administration: pressure loss is ≈99% and ≈10-97%, during mouth opening and closure, respectively. Pressure loss seems independent from the type of CPAP and interface. In vivo measurements showed similar pressure drops.

CONCLUSIONS

Pressure transmission during minimally invasive surfactant administration is significantly reduced or totally absent. Pressure drop occurs despite the increased airway resistances and the airflow limitation due to the tracheal catheterization, but is independent from the type of pressure generator and interface.

Effect of nasal continuous positive airway pressure on the pharyngeal swallow in neonates

OBJECTIVE

Feeding neonates orally while on nasal continuous positive airway pressure (nCPAP) is a common practice. We hypothesize that pressurized airflow provided by nCPAP will alter the swallowing mechanism in neonates, increasing the risk of aspiration during oral feeding.

STUDY DESIGN

Infants receiving nCPAP with a RAM cannula and tolerating at least 50% of their feeding orally were included in the study (one term; six preterm infants). Each participant underwent a videofluoroscopic swallow study while on nCPAP and off nCPAP. A non-parametric signed-rank test was used for paired data.

RESULT

The incidence of deep penetration (P=0.03) and aspiration (P=0.01) decreased significantly off-nCPAP compared with on-nCPAP. However, the incidence of mild penetration (P=0.65) and nasopharyngeal reflux (P=0.87) remained the same under both conditions.

CONCLUSION

Oral feeding while on-nCPAP significantly increases the risk of laryngeal penetration and tracheal aspiration events. We recommend caution when initiating oral feedings on nCPAP.

Nasal masks or binasal prongs for delivering continuous positive airway pressure in preterm neonates-a randomised trial

The objective of this study was to compare the efficacy and safety of continuous positive airway pressure (CPAP) delivered using nasal masks with binasal prongs. We randomly allocated 72 neonates between 26 and 32 weeks gestation to receive bubble CPAP by either nasal mask (n = 37) or short binasal prongs (n = 35). Primary outcome was mean FiO₂ requirement at 6, 12 and 24 h of CPAP initiation and the area under curve (AUC) of FiO₂ against time during the first 24 h (FiO₂ AUC_0-24). Secondary outcomes were the incidence of CPAP failure and nasal trauma. FiO₂ requirement at 6, 12 and 24 h (mean (SD); 25 (5.8) vs. 27.9 (8); 23.8 (4.5) vs. 25.4 (6.8) and 22.6 (6.8) vs. 22.7 (3.3)) as well as FiO₂ AUC_0-24 (584.0 (117.8) vs. 610.6 (123.6)) were similar between the groups. There was no difference in the incidence of CPAP failure (14 vs. 20%; relative risk 0.67; 95% confidence interval 0.24-1.93). Incidence of severe nasal trauma was lower with the use of nasal masks (0 vs. 31%; p < .001).

CONCLUSIONS

Nasal masks appear to be as efficacious as binasal prongs in providing CPAP. Masks are associated with lower risk of severe nasal trauma.

TRIAL REGISTRATION

CTRI2012/08/002868 What is Known? • Binasal prongs are better than single nasal and nasopharyngeal prongs for delivering continuous positive airway pressure (CPAP) in preventing need for re-intubation. • It is unclear if they are superior to newer generation nasal masks in preterm neonates requiring CPAP. What is New? • Oxygen requirement during the first 24 h of CPAP delivery is comparable with use of nasal masks and binasal prongs. • Use of nasal masks is, however, associated with significantly lower risk of severe grades of nasal injury.

Non-invasive high-frequency oscillatory ventilation in neonates: review of physiology, biology and clinical data

Non-invasive high-frequency oscillatory ventilation (NHFOV) consists of the application of a bias flow generating a continuous distending positive pressure with superimposed oscillations, which have constant frequency and active expiratory phase. NHFOV matches together the advantages of high-frequency ventilation (no need for synchronisation, high efficacy in removing CO₂) and nasal continuous positive airway pressure (CPAP) (non-invasive interface, increase in functional residual capacity allowing oxygenation to improve). There is enough clinical expertise demonstrating that NHFOV may be tried in some selected cases, in whom CPAP or conventional non-invasive ventilation have failed. Nonetheless, there are no clear data about its clinical usefulness and there is a need for randomised controlled studies. Our purpose is to review the physiology and biological effects of NHFOV, to present the current clinical evidence on its use, to provide some guiding principles to clinicians and suggest directions for further research.

Continuous positive airway pressure: Physiology and comparison of devices

Nasal continuous positive airway pressure (CPAP) is increasingly used for respiratory support in preterm babies at birth and after extubation from mechanical ventilation. Various CPAP devices are available for use that can be broadly grouped into continuous flow and variable flow. There are potential physiologic differences between these CPAP systems and the choice of a CPAP device is too often guided by individual expertise and experience rather than by evidence. When interpreting the evidence clinicians should take into account the pressure generation sources, nasal interface, and the factors affecting the delivery of pressure, such as mouth position and respiratory drive. With increasing use of these devices, better monitoring techniques are required to assess the efficacy and early recognition of babies who are failing and in need of escalated support.

Physiology of non-invasive respiratory support

Non-invasive ventilation (NIV) is used in neonates to treat extrathoracic and intrathoracic airway obstruction, parenchymal lung disease and disorders of control of breathing. Avoidance of airway intubation is associated with a reduction in the incidence of chronic lung disease among preterm infants with respiratory distress syndrome. Use of nasal continuous positive airway pressure (nCPAP) may help establish and maintain functional residual capacity (FRC), decrease respiratory work, and improve gas exchange. Other modes of non-invasive ventilation, which include heated humidified high-flow nasal cannula therapy (HHHFNC), nasal intermittent mandatory ventilation (NIMV), non-invasive pressure support ventilation (NI-PSV), and bi-level CPAP (SiPAP™), have also been shown to provide additional benefit in improving breathing patterns, reducing work of breathing, and increasing gas exchange when compared with nCPAP. Newer modes, such as neurally adjusted ventilatory assist (NAVA), hold the promise of improving patient-ventilator synchrony and so might ultimately improve outcomes for preterm infants with respiratory distress.

Strategies for the prevention of continuous positive airway pressure failure

Progress in neonatal intensive care is closely linked to improvements in the management of respiratory failure in preterm infants. Current modalities of respiratory support range from the more benign continuous positive airway pressure (CPAP) to various modes of mechanical ventilation. Data from recent randomized control trials suggest that the use of nasal (n)CPAP as the initial mode of respiratory support in critically ill very low birth weight infants is associated with a lower incidence of chronic lung disease. The practice of early initiation of nasal-prong CPAP in all spontaneously breathing infants at Columbia University has resulted in very low rates of chronic lung disease for decades. Many institutions have attempted to replicate the practices and results at Columbia University. However, success rates with nCPAP are highly variable, which may in part be attributable to how well it is utilized. With recent renewed interest in non-invasive respiratory support, particularly bubble nCPAP, it is essential to evaluate strategies for the prevention of CPAP failure. This review discusses strategies that address these issues and shares the practical aspects for replicating success with bubble nCPAP. In addition, it reviews desirable features, major components, and physiological consequences of various bubble CPAP systems along with clinical experience of CPAP use.

Impact of interprofessional education on noninvasive ventilation in a tertiary neonatal intensive care unit

OBJECTIVE

To evaluate the impact and effectiveness of an experiential interprofessional education workshop on noninvasive ventilation (NIV) in the setting of a neonatal intensive care unit.

METHODS

In the present cross-sectional study, a full-day workshop, consisting of didactic and hands-on components, was developed to assess knowledge and perceptions, and to disseminate the latest evidence and practical aspects of NIV use. All health care professionals (HCPs) were asked to participate. Pre- and post-participation questionnaires and knowledge tests were used to assess the effectiveness of knowledge transfer, and to seek participants' reflections on the utility of the workshop.

RESULTS

Among 214 participants, 206 (96%) and 195 (91%) completed the pre- and post-participation questionnaires, respectively. The majority agreed (14%) or strongly agreed (75%) that NIV education was important for their role. Participants scored their perceived comfort with NIV following the workshop highly (median 5 [interquartile range (IQR) 1]) on a five-point Likert scale and 96% would recommend it to a colleague. Median knowledge scores on NIV, assessed as percent correct responses, increased from 74% (IQR 16) to 86% (IQR 11) (P<0.05).

CONCLUSIONS

A focused, context-specific workshop helped improve understanding and comfort among HCPs while reducing misconceptions about NIV. Further research to assess optimal delivery of NIV education and impact on patient outcomes is required.

Neonatal nasal intermittent positive pressure ventilation efficacy and lung pressure transmission

OBJECTIVE

The objective of this study was to evaluate carbon dioxide (CO2) clearance, delivered pressures and tidal volume (VT) during neonatal nasal intermittent positive pressure ventilation (NIPPV) with two commonly used interfaces.

STUDY DESIGN

A neonatal lung model, with either short binasal prongs (SBP) or a small caliber nasal cannula (RAM) interface, was tested over a range of clinically relevant settings. A fixed amount of CO2 was infused and the fraction remaining in the lung 100 s postinfusion was measured. Pressure transmission to the lung and VT was measured at the level of the trachea.

RESULT

CO2 elimination was directly proportional to the inspiratory pressure during NIPPV. At peak pressures of 22 to 34 cm H2O, CO2 clearance was greater (P<0.001) with SBP as compared with RAM. Relative to the set ventilator parameters, a substantial pressure dampening effect was documented at the lung level, which was significantly lower with RAM when compared with SBP (2.8% (0.2) versus 11.9% (1.5), P<0.0001). CO2 elimination was dependent on VT and effective despite only a small fraction of physiological VT (maximum delivered VT%: SBP 15.5 (0.7) versus RAM 6.1 (1.4), P<0.0001).

CONCLUSION

NIPPV promotes CO2 elimination even at low transmitted airway pressures, but less effective with RAM as compared with SBP. CO2 elimination despite small VT suggests that NIPPV may depend on a non-conventional gas-exchange mechanism.

Nasal high-frequency oscillation ventilation in neonates: a survey in five European countries

Nasal high-frequency oscillation ventilation (nHFOV) is a non-invasive ventilation mode that applies an oscillatory pressure waveform to the airways using a nasal interface. nHFOV has been shown to facilitate carbon dioxide expiration, but little is known about its use in neonates. In a questionnaire-based survey, we assessed nHFOV use in neonatal intensive care units (NICUs) in Austria, Switzerland, Germany, the Netherlands, and Sweden. Questions included indications for nHFOV, equipment used, ventilator settings, and observed side effects. Of the clinical directors of 186 NICUs contacted, 172 (92 %) participated. Among those responding, 30/172 (17 %) used nHFOV, most frequently in premature infants <1500 g (27/30) for the indication nasal continuous positive airway pressure (nCPAP) failure (27/30). Binasal prongs (22/30) were the most common interfaces. The median (range) mean airway pressure when starting nHFOV was 8 (6-12) cm H2O, and the maximum mean airway pressure was 10 (7-18) cm H2O. The nHFOV frequency was 10 (6-13) Hz. Abdominal distension (11/30), upper airway obstruction due to secretions (8/30), and highly viscous secretions (7/30) were the most common nHFOV side effects.

CONCLUSION

In a number of European NICUs, clinicians use nHFOV. The present survey identified differences in nHFOV equipment, indications, and settings. Controlled clinical trials are needed to investigate the efficacy and side effects of nHFOV in neonates.

Acute Neonatal Respiratory Failure

Acute respiratory failure requiring assisted ventilation is one of the most common reasons for admission to the neonatal intensive care unit. Respiratory failure is the inability to maintain either normal delivery of oxygen to the tissues or normal removal of carbon dioxide from the tissues. It occurs when there is an imbalance between the respiratory workload and ventilatory strength and endurance. Definitions are somewhat arbitrary but suggested laboratory criteria for respiratory failure include two or more of the following: PaCO₂ > 60 mmHg, PaO₂ < 50 mmHg or O₂ saturation <80 % with an FiO₂ of 1.0 and pH < 7.25 (Wen et al. 2004).

Tidal breathing in preterm infants receiving and weaning from continuous positive airway pressure

OBJECTIVE

To compare tidal breathing on different continuous positive airway pressure (CPAP) devices and pressures and to serially measure tidal breathing during weaning off CPAP using electromagnetic inductive plethysmography.

STUDY DESIGN

Using electromagnetic inductive plethysmography, tidal breathing was measured in 29 preterm infants receiving CPAP, gestational age 28 ± 2 weeks. Variable-flow nasal CPAP (nCPAP), bubble CPAP (bCPAP) at pressures of 5, 7, and 9 cmH2O, nasal bi-level positive airway pressure (nBiPAP) system at pressures of 5, 7/5, and 9/5 cmH2O, and unsupported breathing were studied. Twenty-one infants had weekly tidal breathing measurements on and off nCPAP.

RESULTS

Minute volume (MV/kg) was similar between all devices (0.30-0.33 L/kg/min). On bCPAP, weight corrected tidal volume (VT/kg) was the least, changing little with increasing pressures. On nCPAP and nBiPAP, VT/kg increased with increasing pressure and the respiratory rate (fR) decreased. The delivered pressure varied slightly from the set pressure being most dissimilar on nBiPAP and similar on bCPAP. Compared with unsupported breathing, all devices decreased VT/kg, MV/kg, and phase angle, but did not alter fR. Serial tidal breathing measurements showed decreasing difference for VT/kg over time on and off nCPAP.

CONCLUSIONS

At different pressure settings, on all CPAP devices the measured MV/kg was similar either through increasing VT/kg and decreasing fR (nCPAP and nBiPAP) or maintaining both (bCPAP). Serial tidal breathing measurements may aid weaning from CPAP.

Influence of nose and mouth leaks on peripheral oxygen saturation during continuous positive airway pressure in neonates

BACKGROUND

Nose and mouth leaks impair effective pressure transmission during neonatal continuous positive airway pressure (CPAP), but little is known about how these leaks affect physiological parameters. This study investigated the influence of nose leaks and spontaneous mouth opening on peripheral oxygen saturation (SpO₂) and respiratory rate (RR) using nasopharyngeal CPAP.

METHODS

In 32 neonates with a gestational age of 30 (24-38) weeks and a birth weight of 1435 (710-2730) g, SpO₂ and RR measurements were taken with and without occlusion of the contralateral nostril in a randomized cross-over trial in 1-minute intervals over a 10-minute period during each condition. Mouth opening and newborn activity were documented.

RESULTS

SpO₂ with open nostril was comparable to that with occluded nostril [93 (78.5-99.5)% vs. 94 (80-100)%, P=0.20]. RR decreased from 51 (26-82)/min to 48 (32-85)/min (P=0.027). In infants with an SpO₂ ≤ 93% during open nostril (n=17), SpO₂ increased after nostril occlusion [91 (80-96)% vs. 89.5 (78.5-93)%, P=0.036]. The mouth was open in 78.5% of measurements with open nostril, and in 87.4% of measurements after nostril occlusion (P=0.005). No significant influence of mouth opening or closure on SpO₂ or RR was detected.

CONCLUSIONS

In neonates on unilateral nasopharyngeal CPAP with an SpO₂ ≤ 93%, occlusion of the contralateral nostril significantly increased SpO₂ and reduced RR. The beneficial physiological effects further support using binasal prongs to minimize nose leaks in this population. Future studies should investigate the beneficial effects of reducing mouth leaks when applying CPAP to these infants.

Randomized trial of prongs or mask for nasal continuous positive airway pressure in preterm infants

OBJECTIVE

To determine whether nasal continuous positive airway pressure (NCPAP) given with nasal prongs compared with nasal mask reduces the rate of intubation and mechanical ventilation in preterm infants within 72 hours of starting therapy.

METHODS

Infants <31 weeks' gestation treated with NCPAP were randomly assigned to receive it via either prongs or mask. Randomization was stratified by gestational age (<28 weeks, 28-30 weeks) and according to whether NCPAP was started as a primary treatment for respiratory distress or postextubation. Infants were intubated and ventilated if they fulfilled 2 or more of 5 failure criteria (worsening signs of respiratory distress; recurrent apnea treated with mask positive pressure ventilation; fraction of inspired oxygen >0.4 to keep oxygen saturation >88% sustained for 30 minutes; pH <7.2 on 2 blood gases ≥ 30 minutes apart; Pco(2) >9 kPa [68 mm Hg] on 2 blood gases ≥ 30 minutes apart) within 72 hours of starting therapy. The groups were treated the same in all other respects. We recorded relevant secondary outcomes and analyzed data by using the intention-to-treat principle.

RESULTS

We enrolled 120 infants. Thirty-two of 62 (52%) infants randomly assigned to prongs were intubated within 72 hours, compared with 16/58 (28%) of those randomly assigned to mask (P = .007). There were no statistically significant differences between the groups in any secondary outcomes.

CONCLUSIONS

In premature infants, NCPAP was more effective at preventing intubation and ventilation within 72 hours of starting therapy when given via nasal masks compared with nasal prongs.

Nasal continuous positive airway pressure for respiratory distress in non-tertiary care centres: what is needed and where to from here?

Respiratory distress is one of the commonest reasons for admission to a special care nursery (SCN) affecting between 2.5 and 5.0% of all babies born per year. While most recover with supplemental oxygen, some require transfer to a neonatal intensive care leading to significant family disruption, and financial cost. Does nasal continuous positive airway pressure (nCPAP) improve outcomes in babies with respiratory distress? What are the risks of its use? Should it be used in SCNs, and, if so, what is required in order to undertake nCPAP safely? There is strong evidence to support the use of nCPAP in the treatment of babies with respiratory distress. The risk benefit ratio of providing nCPAP in SCNs depends upon many factors including the ability to maintain the skills required and the distance/time to the nearest tertiary centre. Appropriate nurseries should be identified with the aim of supporting them in the provision of nCPAP in a safe manner.

Which continuous positive airway pressure system is best for the preterm infant with respiratory distress syndrome?

Various commercial and home-made continuous positive airway pressure (CPAP) systems are described in this article. CPAP may be delivered via a range of device-patient interfaces; nasal CPAP is most common, and short binasal prongs impose the least extrinsic load impedance on the infant. The source of pressure generation is categorized as either constant pressure or constant flow. The efficacy of different systems may vary according to whether lung volume recruitment, airway patency, minimization of work of breathing, or central nervous system stimulation are the primary goal of the clinical decision to use CPAP therapy.

A simple and cheap alternative approach to administering continuous positive airway pressure in resource limited settings

Continuous positive airway pressure (CPAP) is a valuable tool in managing infants requiring respiratory support. This article highlights a simple and economical alternative model to administer nasal CPAP using an infant feeding tube.

Comparison of seven infant continuous positive airway pressure systems using simulated neonatal breathing

OBJECTIVE

Continuous positive airway pressure is an established treatment for respiratory distress in neonates. Continuous positive airway pressure has been applied to infants using an array of devices. The aim of this experimental study was to investigate the characteristics of seven continuous positive airway pressure systems using simulated breath profiles from newborns.

DESIGN

Experimental in vitro study.

SETTING

Research laboratory in Sweden.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

In vitro simulation of spontaneous neonatal breathing was achieved with a mechanical lung model. Simulation included two breath profiles, three levels of continuous positive airway pressure with and without short binasal prongs and different levels of constant leak. Pressure stability and imposed work of breathing were determined. Seven continuous positive airway pressure systems were tested. There were large differences in pressure stability and imposed work of breathing between tested continuous positive airway pressure systems. Neopuff and Medijet had the highest pressure instability and imposed work of breathing. Benveniste, Hamilton Universal (Arabella), and Bubble continuous positive airway pressure showed intermediate results. AirLife and Infant Flow had the lowest pressure instability and imposed work of breathing. AirLife and Infant Flow showed the least decrease in delivered pressure when challenged with constant leak.

CONCLUSION

The seven tested continuous positive airway pressure systems showed large variations in pressure stability and imposed work of breathing. They also showed large differences in how well they maintain continuous positive airway pressure when exposed to leak. For most systems, imposed work of breathing increased with increasing continuous positive airway pressure level. The clinical importance of the difference in pressure stability is uncertain. Our results may facilitate the design of clinical studies examining the effect of pressure stability on outcome.

Noninvasive high frequency oscillatory ventilation through nasal prongs: bench evaluation of efficacy and mechanics

BACKGROUND

Noninvasive high frequency oscillatory ventilation through nasal prongs (nHFOV) has been proposed as a new respiratory support in neonatology. We studied the effect of ventilation parameters and nasal prongs on nHFOV efficacy and mechanics.

METHODS

Customized sealed circuits connecting a SM3100A oscillator to a neonatal lung model were developed to evaluate the effect of applying HFOV via two different sized nasal prongs on delivered tidal volume and pressure. Measurements were made across a range of frequencies and pressures; amplitude was set to obtain visible lung oscillation.

RESULTS

Volume delivered by peak-to-peak oscillation, ventilation, and pressure significantly differed among the interfaces, being higher for large cannulae and the control circuit (p < 0.0001). The interposition of a large or small nasal prong reduced volume to 56 and 26%, ventilation to 32 and 9%, and mean pressure to 83 and 79%, respectively, of the values measured for the direct connection of the oscillator to the test lung. Volume and ventilation were inversely related to frequency, which was particularly evident with larger diameter circuits due to higher delivered tidal volume (R (2) > 0.9). Increasing ventilation was associated with larger tidal volume and nasal prong diameter (adjusted R (2) = 0.97).

CONCLUSIONS

nHFOV using common nasal prongs is technically possible. Efficiency of tidal volume delivery is significantly affected by prong diameter.

Noninvasive respiratory support of juvenile rabbits by high-amplitude bubble continuous positive airway pressure

Bubble continuous positive airway pressure (B-CPAP) applies small-amplitude, high-frequency oscillations in airway pressure (DeltaPaw) that may improve gas exchange in infants with respiratory disease. We developed a device, high-amplitude B-CPAP (HAB-CPAP), which provides greater DeltaPaw than B-CPAP provides. We studied the effects of different operational parameters on DeltaPaw and volumes of gas delivered to a mechanical infant lung model. In vivo studies tested the hypothesis that HAB-CPAP provides noninvasive respiratory support greater than that provided by B-CPAP. Lavaged juvenile rabbits were stabilized on ventilator nasal CPAP. The animals were then supported at the same mean airway pressure, bias flow, and fraction of inspired oxygen (FiO2) required for stabilization, whereas the bubbler angle was varied in a randomized crossover design at exit angles, relative to vertical, of 0 (HAB-CPAP0; equivalent to conventional B-CPAP), 90 (HAB-CPAP90), and 135 degrees (HAB-CPAP135). Arterial blood gases and pressure-rate product (PRP) were measured after 15 min at each bubbler angle. Pao2 levels were higher (p<0.007) with HAB-CPAP135 than with conventional B-CPAP. PaCO2 levels did not differ (p=0.073) among the three bubbler configurations. PRP with HAB-CPAP135 were half of the PRP with HAB-CPAP0 or HAB-CPAP90 (p=0.001). These results indicate that HAB-CPAP135 provides greater respiratory support than conventional B-CPAP does.

Non-invasive respiratory support of preterm neonates with respiratory distress: continuous positive airway pressure and nasal intermittent positive pressure ventilation

Non-invasive techniques of respiratory support were developed in order to reduce the adverse effects associated with ventilation via an endotracheal tube. Short bi-nasal prongs provide the most effective nasal interface for delivery of nasal continuous positive airway pressure (nCPAP). Devices used to generate CPAP include conventional ventilators, the 'bubbly bottle' system and the infant flow driver. NCPAP improves the rate of successful extubation. It is useful for preterm infants with respiratory distress syndrome, reducing time spent on an endotracheal tube and oxygen requirement at 28d. However, nCPAP is associated with an increased rate of pneumothorax. Nasal intermittent positive pressure ventilation (NIPPV) is useful for augmenting the effectiveness of nCPAP. It further improves rates of successful extubation and shows promise as an initial method of respiratory support. Further research is required to determine the optimal settings for both nCPAP and NIPPV.

Humidified high-flow nasal cannula: is it the new and improved CPAP?

Humidified high-flow nasal cannula (HHFNC) therapy for neonates has become increasingly popular in recent years. It is frequently used in circumstances when continuous positive airway pressure (CPAP) might otherwise have been used. Limited evidence is available to support the specific role, efficacy, and safety of HHFNC in newborns. This evidence suggests that HHFNC provides inconsistent and relatively unpredictable positive airway pressure, but may be effective in the treatment of some neonatal respiratory conditions while being more user-friendly for caregivers than conventional CPAP. Concerns regarding infection risks have resulted in one major HHFNC device being withdrawn from the market before being recently reintroduced. Caution should be exercised in the use of HHFNC in neonates (eg, by limiting its use to relatively lower flows and to relatively larger neonates, while collecting and closely monitoring safety and efficacy data) until further evidence is available to clearly delineate its role, as well as to support its safety and efficacy.

Nursing Care Guidelines for prevention of nasal breakdown in neonates receiving nasal CPAP

Use of nasal continuous positive airway pressure (CPAP) is increasing as a means of respiratory support for respiratory distress syndrome in many premature neonates across the United States. Nasal CPAP is less invasive and may be as effective as mechanical ventilation in premature infants, and has been shown to cause less lung damage in premature neonates. Because of the increased use of nasal CPAP in neonates, especially younger and more fragile neonates, the presence of nare and nasal septum breakdown may be seen as a complication. Currently, all nasal CPAP systems use a hat and prong or mask type of delivery system. This appears to be effective for many neonates, but for some, it is difficult to appropriately fit the hat and prongs. The result of an inappropriately fitted device can be mild to severe nare and nasal septum damage. This article will discuss the need for nasal CPAP and the mechanics of nasal CPAP, but more importantly, serve to guide caregivers in the appropriate physical assessment and care of a neonate on nasal CPAP with the goal of preventing skin breakdown and nasal damage.

Devices and pressure sources for administration of nasal continuous positive airway pressure (NCPAP) in preterm neonates

BACKGROUND

Nasal continuous positive airway pressure (NCPAP) is used to support preterm infants recently extubated, those experiencing significant apnoea of prematurity and those with respiratory distress soon after birth as an alternative to intubation and ventilation. This review focuses exclusively on identifying the most effective pressure source and interface for NCPAP delivery in preterm infants.

OBJECTIVES

To determine which technique of pressure generation and which type of nasal interface for NCPAP delivery most effectively reduces the need for additional respiratory support in preterm infants extubated to NCPAP following intermittent positive pressure ventilation (IPPV) for respiratory distress syndrome (RDS) or in those treated with NCPAP soon after birth.

SEARCH STRATEGY

The strategy included searches of MEDLINE (1966 - 2006), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2006) CINAHL, abstracts from conference proceedings, cross-referencing of previous reviews and the use of expert informants.

SELECTION CRITERIA

Randomised or quasi-randomised trials comparing different techniques of NCPAP pressure generation and/or nasal interfaces in preterm infants extubated to NCPAP following IPPV for RDS or treated with NCPAP soon after birth.

DATA COLLECTION AND ANALYSIS

Data was extracted and analysed by the first three authors. Dichotomous results were analysed using the relative risk (RR), risk difference (RD) and number needed to treat (NNT).

MAIN RESULTS

1. Preterm infants being extubated to NCPAP following a period of IPPV for RDS:Meta-analysis of the results from Davis 2001 and Roukema 1999a demonstrated that short binasal prongs are more effective at preventing re-intubation than single nasal or nasopharyngeal prongs [typical RR 0.59 (CI: 0.41, 0.85), typical RD -0.21 (CI: -0.35, -0.07), NNT 5 (CI: 3, 14)]. In one study comparing short binasal prong devices (Sun 1999), the re-intubation rate was significantly lower with the Infant Flow Driver than with the Medicorp prong [RR 0.33 (CI: 0.17, 0.67), RD -0.32 (CI: -0.49, -0.15), NNT 3 (CI: 2, 7)]. The other study comparing short binasal prong devices (Infant Flow Driver versus INCA prongs, Stefanescu 2003) demonstrated no significant difference in the re-intubation rate but did show a significant reduction in the total days in hospital in the Infant Flow Driver group [MD -12.60 (95% CI: -22.81, -2.39) days].2. Preterm infants primarily treated with NCPAP soon after birth:In the one trial identified, Mazzella 2001 found a significantly lower oxygen requirement and respiratory rate in those randomised to short binasal prongs when compared with CPAP delivered via nasopharyngeal prong. The requirement for intubation beyond 48 hours from randomisation was not assessed.3. Studies randomising preterm infants to different NCPAP systems using broad inclusion criteriaThe studies of Rego 2002 and Buettiker 2004 did not examine the primary outcomes of this review. Of the secondary outcomes, Rego 2002 demonstrated a significantly higher incidence of nasal hyperaemia with the use of the Argyle prong compared with Hudson prongs [RR 2.39 (95% CI: 1.27, 4.50), RD 0.28 (95% CI: 0.10, 0.46)]. One study comparing different techniques of pressure generation is awaiting further assessment as it is currently available in abstract form only.

AUTHORS' CONCLUSIONS

Short binasal prong devices are more effective than single prongs in reducing the rate of re-intubation. Although the Infant Flow Driver appears more effective than Medicorp prongs the most effective short binasal prong device remains to be determined. The improvement in respiratory parameters with short binasal prongs suggests they are more effective than nasopharyngeal CPAP in the treatment of early RDS. Further studies incorporating longer-term outcomes are required. Studies are also needed to determine the optimal pressure source for the delivery of NCPAP.

Continuous positive airway pressure and noninvasive ventilation

Continuous positive airway pressure (CPAP) and noninvasive ventilation (NIV) hold much promise as means to protect the lungs of newborn infants who have respiratory distress from many causes. A wide variety of options are available to the clinician, including CPAP, bilevel CPAP, and both synchronized and unsynchronized noninvasive mechanical breaths. Limited data are available regarding the best ways to use CPAP and NIV in today's NICU environment. This article reviews current information on these modalities, including available options, possible risks, and unanswered questions.