A randomized controlled trial of post-extubation bubble continuous positive airway pressure versus Infant Flow Driver continuous positive airway pressure in preterm infants with respiratory distress syndrome

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.

Bubble devices versus other pressure sources for nasal continuous positive airway pressure in preterm infants

BACKGROUND

Several types of pressure sources, including underwater bubble devices, mechanical ventilators, and the Infant Flow Driver, are used for providing continuous positive airway pressure (CPAP) to preterm infants with respiratory distress. It is unclear whether the use of bubble CPAP versus other pressure sources is associated with lower rates of CPAP treatment failure, or mortality and other morbidity.  OBJECTIVES: To assess the benefits and harms of bubble CPAP versus other pressure sources (mechanical ventilators or Infant Flow Driver) for reducing treatment failure and associated morbidity and mortality in newborn preterm infants with or at risk of respiratory distress.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2023, Issue 1); MEDLINE (1946 to 6 January 2023), Embase (1974 to 6 January 2023), Maternity & Infant Care Database (1971 to 6 January 2023), and the Cumulative Index to Nursing and Allied Health Literature (1982 to 6 January 2023). We searched clinical trials databases and the reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised controlled trials comparing bubble CPAP with other pressure sources (mechanical ventilators or Infant Flow Driver) for the delivery of nasal CPAP to preterm infants.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Two review authors separately evaluated trial quality, extracted data, and synthesised effect estimates using risk ratio (RR), risk difference (RD), and mean difference. We used the GRADE approach to assess the certainty of the evidence for effects on treatment failure, all-cause mortality, neurodevelopmental impairment, pneumothorax, moderate-severe nasal trauma, and bronchopulmonary dysplasia.

MAIN RESULTS

We included 15 trials involving a total of 1437 infants. All trials were small (median number of participants 88). The methods used to generate the randomisation sequence and ensure allocation concealment were unclear in about half of the trial reports. Lack of measures to blind caregivers or investigators was a potential source of bias in all of the included trials. The trials took place during the past 25 years in care facilities internationally, predominantly in India (five trials) and Iran (four trials). The studied pressure sources were commercially available bubble CPAP devices versus a variety of mechanical ventilator (11 trials) or Infant Flow Driver (4 trials) devices.  Meta-analyses suggest that the use of bubble CPAP compared with mechanical ventilator or Infant Flow Driver CPAP may reduce the rate of treatment failure (RR 0.76, 95% confidence interval (CI) 0.60 to 0.95; (I² = 31%); RD -0.05, 95% CI -0.10 to -0.01; number needed to treat for an additional beneficial outcome 20, 95% CI 10 to 100; 13 trials, 1230 infants; low certainty evidence). The type of pressure source may not affect mortality prior to hospital discharge (RR 0.93, 95% CI 0.64 to 1.36 (I² = 0%); RD -0.01, 95% CI -0.04 to 0.02; 10 trials, 1189 infants; low certainty evidence). No data were available on neurodevelopmental impairment. Meta-analysis suggests that the pressure source may not affect the risk of pneumothorax (RR 0.73, 95% CI 0.40 to 1.34 (I² = 0%); RD -0.01, 95% CI -0.03 to 0.01; 14 trials, 1340 infants; low certainty evidence). Bubble CPAP likely increases the risk of moderate-severe nasal injury (RR 2.29, 95% CI 1.37 to 3.82 (I² = 17%); RD 0.07, 95% CI 0.03 to 0.11; number needed to treat for an additional harmful outcome 14, 95% CI 9 to 33; 8 trials, 753 infants; moderate certainty evidence). The pressure source may not affect the risk of bronchopulmonary dysplasia (RR 0.76, 95% CI 0.53 to 1.10 (I² = 0%); RD -0.04, 95% CI -0.09 to 0.01; 7 trials, 603 infants; low certainty evidence).  AUTHORS' CONCLUSIONS: Given the low level of certainty about the effects of bubble CPAP versus other pressure sources on the risk of treatment failure and most associated morbidity and mortality for preterm infants, further large, high-quality trials are needed to provide evidence of sufficient validity and applicability to inform context- and setting-relevant policy and practice.

Systematic rotation versus continuous application of 'nasal prongs' or 'nasal mask' in preterm infants on nCPAP: a randomized controlled trial

To compare whether alternate rotation of nasal mask with nasal prongs every 8 h as compared to continuous use of either interface alone decreases the incidence of nasal injury in preterm infants receiving nasal Continuous Positive Airway Pressure (nCPAP). This was an open-label, three-arm, stratified randomized controlled trial where infants < 35 weeks receiving nCPAP were randomized into three groups using two different nasal interfaces (continuous prongs group, continuous mask group, and rotation group). All infants were assessed for nasal injury six hours post-removal of nCPAP using grading suggested by Fischer et al. The nursing care was uniform across all three groups. Intention-to-treat analysis was done. Fifty-seven infants were enrolled, with nineteen in each group. The incidence of nasal injury was 42.1% vs. 47.4% vs. 68.4% in the rotation group, continuous mask, and continuous prongs groups, respectively (P = 0.228). On adjusted analysis (gestational age, birth weight, and duration of nCPAP therapy), the incidence of nasal injury was significantly less in the rotation group as compared to continuous prongs group (Adjusted Odds Ratio [AOR], 95% confidence interval [CI]; 0.10 [0.01-0.69], P = 0.02) and a trend towards lesser nasal injury as compared to continuous mask group (AOR, 95% CI; 0.15 [0.02-1.08], P = 0.06). However, there was no significant difference in incidence of nasal injuries between continuous prongs versus continuous mask group (P = 0.60). The need for surfactant, nCPAP failure rate, duration of nCPAP, and common neonatal co-morbidities were similar across all three groups.   Conclusion: Systematic rotation of nasal mask with nasal prongs significantly reduced nasal injury among preterm infants on nCPAP as compared to continuous use of nasal prongs alone without affecting nCPAP failure rate.   Trial registration: CTRI/2019/01/017320, registered on 31/01/2019. What is Known: • Use of nasal mask as an interface for nasal Continuous Positive Airway Pressure decreases nasal injury as compared to nasal prongs. What is New: • Rotation of nasal prongs and nasal mask interfaces alternately every 8 h may reduce the nasal injury even further as compared to either interface alone.

Nasal continuous positive airway pressure practices in preterm infants: A survey of neonatal providers

BACKGROUND

The standard of care for respiratory support of preterm infants is nasal continuous positive airway pressure (CPAP), yet practices are not standardized. Our aim was to survey CPAP practices in infants < 32 weeks gestation among the American Academy of Pediatrics Neonatal-Perinatal section.

METHODS

A US, web-based survey inquired about the initiation, management, and discontinuation of CPAP, and chinstrap use and oral feedings on CPAP.

RESULTS

857 providers consented. Regarding criteria to discontinue/wean CPAP: 69% use specific respiratory stability criteria; 22% a specific post-menstrual age; 8% responded other. 64% did not have guidelines for CPAP discontinuation; 54% did not have guidelines for CPAP initiation. 66% believe chinstraps improve CPAP efficacy; however, 11% routinely apply a chinstrap. 22% allow oral feeds on CPAP in certain circumstances.

CONCLUSION

There are meaningful variabilities in CPAP practices among neonatal providers across the US. Given the potential long-term implications this can have on the growth and development of the preterm lung, further evidence-based research is needed in relation to respiratory outcomes to optimize and standardize CPAP strategies.

Vitamin D supplementation among Bangladeshi children under-five years of age hospitalised for severe pneumonia: A randomised placebo controlled trial

INTRODUCTION

Vitamin D is important for its immunomodulatory role and there is an independent association between vitamin D deficiency and pneumonia. We assessed the effect of vitamin D supplementation on the outcome in children hospitalized for severe pneumonia.

METHODS

This was a randomised, double blinded, placebo-controlled clinical trial in children aged >2-59 months with severe pneumonia attending Dhaka Hospital, icddr,b. Children received age-specific megadose of vitamin D3 (20,000IU: <6 months, 50,000 IU: 6-12 months, 100,000 IU:13-59 months) or placebo on first day and 10,000 IU as maintenance dose for next 4 days or until discharge (if discharged earlier) along with standard therapy. This trial is registered at ClinicalTrials.gov, number NCT02185196.

FINDINGS

We enrolled 100 children in placebo group and 97 in vitamin D group. On admission, 50 (52%) and 49 (49%) of children in vitamin D and placebo groups, respectively were vitamin D deficient. Among children with a sufficient serum vitamin D level on admission, a lower trend for duration of resolution of severe pneumonia in hours [72(IQR:44-96)vs. 88(IQR:48-132);p = 0.07] and duration of hospital stay in days [4(IQR:3-5)vs.5(IQR:4-7);P = 0.09] was observed in vitamin D group compared to placebo. No beneficial effect was observed in vitamin D deficient group or irrespective of vitamin D status.

CONCLUSION

Age-specific mega dose of vitamin D followed by a maintenance dose shown to have no statistical difference between the two intervention groups, however there was a trend of reduction of time to recovery from pneumonia and overall duration of hospital stay in under-five children with a sufficient serum vitamin D level on hospital admission.

Non-Invasive Ventilatory Strategies to Decrease Bronchopulmonary Dysplasia-Where Are We in 2021?

Recent advances in neonatology have led to the increased survival of extremely low-birth weight infants. However, the incidence of bronchopulmonary dysplasia (BPD) has not improved proportionally, partly due to increased survival of extremely premature infants born at the late-canalicular stage of lung development. Due to minimal surfactant production at this stage, these infants are at risk for severe respiratory distress syndrome, needing prolonged ventilation. While the etiology of BPD is multifactorial with antenatal, postnatal, and genetic factors playing a role, ventilator-induced lung injury is a major, potentially modifiable, risk factor implicated in its causation. Infants with BPD are at a higher risk of developing complications including sepsis, pulmonary arterial hypertension, respiratory failure, and death. Long-term problems include increased risk of hospital readmissions, respiratory infections, and asthma-like symptoms during infancy and childhood. Survivors who have BPD are also at increased risk of poor neurodevelopmental outcomes. While the ultimate solution for avoiding BPD lies in the prevention of preterm births, strategies to decrease its incidence are the need of the hour. It is time to focus on gentler modes of ventilation and the use of less invasive surfactant administration techniques to mitigate lung injury, thereby potentially decreasing the burden of BPD. In this article, we discuss the use of non-invasive ventilation in premature infants, with an emphasis on studies showing an effect on BPD with different modes of non-invasive ventilation. Practical considerations in the use of nasal intermittent positive pressure ventilation are also discussed, considering the significant heterogeneity in clinical practices and management strategies in its use.

Efficacy of noninvasive respiratory support modes as postextubation respiratory support in preterm neonates: A systematic review and network meta-analysis

BACKGROUND

Multiple noninvasive respiratory support (NRS) modalities are used for postextubation support in preterm neonates. Seven NRS modalities were compared-constant flow continuous positive airway pressure (CPAP) (CF-CPAP) (bubble CPAP; ventilator CPAP), variable flow CPAP (VF-CPAP), high flow nasal cannula (HFNC), synchronized noninvasive positive pressure ventilation (S-NIPPV), nonsynchronized NIPPV (NS-NIPPV), bilevel CPAP (BiPAP), noninvasive high-frequency oscillation ventilation (nHFOV).

DESIGN

Systematic review and network meta-analysis (NMA) using the Bayesian random-effects approach. MEDLINE, EMBASE, CENTRAL, WHO-ICTRP were searched.

MAIN OUTCOME MEASURE

Requirement of invasive mechanical ventilation within 7 days of extubation.

RESULTS

A total of 33 studies with 4080 preterm neonates were included. S-NIPPV, NS-NIPPV, nHFOV, and VF-CPAP were more efficacious in preventing reintubation than CF-CPAP (risk ratio [RR] [95% credible intervals {CrI}]: 0.22 [0.12, 0.35]; 0.44 [0.27, 0.67]; 0.42 [0.18, 0.81]; 0.73 [0.52, 0.99]). Surface under the cumulative ranking curve (SUCRA) value ranked S-NIPPV to be the best postextubation intervention (SUCRA: 0.98). S-NIPPV was more effective than NS-NIPPV, BiPAP, VF-CPAP, and HFNC (RR [95% CrI]: 0.52 [0.24, 0.97]; 0.32 [0.14, 0.64]; 0.30 [0.16, 0.50]; 0.24 [0.12, 0.41]). NS-NIPPV resulted in lesser reintubation compared to VF-CPAP and HFNC (RR [95% CrI]: 0.61 [0.36, 0.97]; 0.49 [0.27, 0.80]). BiPAP, VF-CPAP, and HFNC had comparable efficacies. The overall quality of evidence was very low to moderate.

CONCLUSION

Results of this NMA indicate that S-NIPPV might be the most effective and CF-CPAP the least effective NRS modality for preventing extubation failure.

Bubble versus other continuous positive airway pressure forms: a systematic review and meta-analysis

BACKGROUND

Use of bubble continuous positive airway pressure (CPAP) has generated considerable interest in neonatal care, but its comparative effectiveness compared with other forms of CPAP, especially in developed countries, remains unclear.

OBJECTIVE

To systematically review and meta-analyse short-term clinical outcomes among preterm infants treated with bubble CPAP vs all other forms of CPAP.

METHODS

Prospective experimental studies published from 1995 onward until October 2018 comparing bubble versus other CPAP forms in preterm neonates <37 weeks' gestational age were included after a systematic review of multiple databases using pre-specified search criteria.

RESULTS

A total of 978 articles were identified, of which 19 articles were included in meta-analyses. Of these, 5 had a high risk of bias, 8 had unclear risk and 6 had low risk. The risk of the primary outcome (CPAP failure within 7 days) was lower with bubble CPAP (0.75; 95% CI 0.57 to 0.98; 12 studies, 1194 subjects, I²=21%). Among secondary outcomes, only nasal injury was higher with use of bubble CPAP (risk ratio (RR) 2.04, 95% CI 1.33 to 3.14; 9 studies, 983 subjects; I²=42%) whereas no differences in mortality (RR 0.82, 95% CI 0.47 to 1.92; 9 studies, 1212 subjects, I²=20%) or bronchopulmonary dysplasia (BPD) (RR 0.8, 95% CI 0.53 to 1.21; 8 studies, 816 subjects, I²=0%) were noted.

CONCLUSION

Bubble CPAP may lead to lower incidence of CPAP failure compared with other CPAP forms. However, it does not appear to translate to improvement in mortality or BPD and potential for nasal injury warrants close monitoring during clinical application.

TRIAL REGISTRATION NUMBER

CRD42019120411.

Non-invasive Respiratory Support of the Premature Neonate: From Physics to Bench to Practice

Premature births continue to rise globally with a corresponding increase in various morbidities among this population. Rates of respiratory distress syndrome and the consequent development of Bronchopulmonary Dysplasia (BPD) are highest among the extremely preterm infants. The majority of extremely low birth weight premature neonates need some form of respiratory support during their early days of life. Invasive modes of respiratory assistance have been popular amongst care providers for many years. However, the practice of prolonged invasive mechanical ventilation is associated with an increased likelihood of developing BPD along with other comorbidities. Due to the improved understanding of the pathophysiology of BPD, and technological advances, non-invasive respiratory support is gaining popularity; whether as an initial mode of support, or for post-extubation of extremely preterm infants with respiratory insufficiency. Due to availability of a wide range of modalities, wide variations in practice exist among care providers. This review article aims to address the physical and biological basis for providing non-invasive respiratory support, the current clinical evidence, and the most recent developments in this field of Neonatology.

Non-invasive respiratory support for preterm infants following extubation from mechanical ventilation. A narrative review and guideline suggestion

The recent introduction of different non-invasive ventilation modes for preterm has decreased the need for intubation, invasive ventilation and sedation. However, specific guidelines for each non-invasive mode are still lacking. This paper reviews available evidence for each of the commonly used noninvasive mode. Electronic search was carried out as a step forward towards a more comprehensive and detailed neonatal noninvasive ventilation guideline.

Decreasing Chronic Lung Disease Associated with Bubble CPAP Technology: Experience at Five Years

Introduction:

Bubble continuous positive airway pressure (bCPAP) is associated with a decreased risk for chronic lung disease (CLD) in preterm neonates. This report examined the effectiveness of adopting bCPAP to reduce respiratory complications and medication usage in a community hospital NICU.

Methods:

The efficacy of bCPAP was assessed by retrospective examination and comparison of 45 neonates who received bCPAP and 87 neonates who received conventional ventilation only. Data on medication usage were also collected and analyzed.

Results:

After introduction of the bCPAP protocol, the median number of days on oxygen decreased in the bCPAP group compared with the conventional ventilation only group (median = 33 days, IQR = 7.5–66 vs median = 0, IQR = 0–0; P < 0.001). The exposure to conventional ventilation decreased in the bCPAP group compared with the conventional ventilation only group (median = 18 days, IQR = 5–42.5 vs median = 0, IQR = 0–7; P < 0.001). Postimplementation of bCPAP revealed decreases in CLD from 26 (30%) in the conventional ventilation only group to 2 (4%) in the bCPAP group (P = 0.002); there was also a significant decrease in the use of sedative medications in the bCPAP group compared with the conventional ventilation only group (mean = 5.20 doses, SD = 31.97 vs mean = 1.43, SD = 9.98; P < 0.001).

Conclusion:

The use of bCPAP results in significant decreases in the use of conventional ventilation, the risk for CLD, and the need for sedative medication.

Electrostatic Filters to Reduce COVID-19 Spread in Bubble CPAP: An in vitro Study of Safety and Efficacy

BACKGROUND

Bubble CPAP may be used in infants with suspected or confirmed COVID-19. Electrostatic filters may reduce cross infection. This study aims to determine if including a filter in the bubble CPAP circuit impacts stability of pressure delivery.

METHODS

A new electrostatic filter was placed before (pre) or after (post) the bubble CPAP generator, or with no filter (control) in an in vitro study. Pressure was recorded at the nasal interface for 18 h (6 L/min; 7 cm H2O) on 3 occasions for each configuration. Filter failure was defined as pressure >9 cm H2O for 60 continuous minutes. The filter was weighed before and after each experiment.

RESULTS

Mean (SD) time to reach the fail point was 257 (116) min and 525 (566) min for filter placement pre- and post-CPAP generator, respectively. Mean pressure was higher throughout in the pre-generator position compared to control. The filter weight was heavier at end study in the pre- compared to the post-generator position.

CONCLUSIONS

Placement of the filter at the pre-generator position in a bubble CPAP circuit should be avoided due to unstable mean pressure. Filters are likely to become saturated with water over time. The post-generator position may accommodate a filter, but regular pressure monitoring and early replacement are required.

A Review on Non-invasive Respiratory Support for Management of Respiratory Distress in Extremely Preterm Infants

Majority of extremely preterm infants require positive pressure ventilatory support at the time of delivery or during the transitional period. Most of these infants present with respiratory distress (RD) and continue to require significant respiratory support in the neonatal intensive care unit (NICU). Bronchopulmonary dysplasia (BPD) remains as one of the major morbidities among survivors of the extremely preterm infants. BPD is associated with long-term adverse pulmonary and neurological outcomes. Invasive mechanical ventilation (IMV) and supplemental oxygen are two major risk factors for the development of BPD. Non-invasive ventilation (NIV) has been shown to decrease the need for IMV and reduce the risk of BPD when compared to IMV. This article reviews respiratory management with current NIV support strategies in extremely preterm infants both in delivery room as well as in the NICU and discusses the evidence to support commonly used NIV modes including nasal continuous positive airway pressure (NCPAP), nasal intermittent positive pressure ventilation (NIPPV), bi-level positive pressure (BI-PAP), high flow nasal cannula (HFNC), and newer NIV strategies currently being studied including, nasal high frequency ventilation (NHFV) and non-invasive neutrally adjusted ventilatory assist (NIV-NAVA). Randomized, clinical trials have shown that early NIPPV is superior to NCPAP to decrease the need for intubation and IMV in preterm infants with RD. It is also important to understand that selection of the device used to deliver NIPPV has a significant impact on its success. Ventilator generated NIPPV results in significantly lower rates of extubation failures when compared to Bi-PAP. Future studies should address synchronized NIPPV including NIV-NAVA and early rescue use of NHFV in the respiratory management of extremely preterm infants.

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.

High amplitude bubble continuous positive airway pressure decreases lung injury in rats with ventilator-induced lung injury

BACKGROUND

Bubble continuous positive airway pressure (BCPAP) has been used in neonates with respiratory distress for decades; however, the optimal setting for BCPAP circuits remains unknown. This study compared the gas exchange efficiency and lung protection efficacy between conventional and high-amplitude BCPAP devices.

METHODS

We compared gas exchange, lung volume, and pulmonary inflammation severity among rats with ventilator-induced lung injury (VILI) that were treated with conventional BCPAP (BCPAP with an expiratory limb at 0°), high-amplitude BCPAP (BCPAP with an expiratory limb at 135°), or spontaneous breathing (SB). After mechanical ventilation for 90 minutes, the rats were randomly divided into four groups: a control group (euthanized immediately; n = 3), an SB group (n = 8), and two BCPAP groups that received BCPAP with the expiratory limb at either 0° (n = 8) or 135° (n = 7) for 90 minutes.

RESULTS

The high-amplitude BCPAP group exhibited significantly lower alveolar protein, lung volume, and Interleukin-6 (IL-6) levels than did the SB group. The high-amplitude BCPAP group exhibited significantly lower IL-6 levels than did the conventional BCPAP group. The two BCPAP groups demonstrated no difference in gas exchange efficiency.

CONCLUSION

High-amplitude BCPAP reduced lung inflammation and alveolar overdistension in rats with VILI after mechanical ventilation was ceased. Thus high-amplitude BCPAP may offer a superior lung protective effect than conventional BCPAP.

Nasal Intermittent Mandatory Ventilation Versus Nasal Continuous Positive Airway Pressure Before and After Invasive Ventilatory Support

Continuous positive airway pressure (CPAP), noninvasive intermittent positive pressure ventilation (NIPPV), and heated humidified high-flow nasal cannula (HHFNC) are modes of noninvasive respiratory support used in neonatal practice. These modes of noninvasive respiratory support may obviate mechanical ventilation, prevent extubation failure, and reduce the risk of developing bronchopulmonary dysplasia. Although the physiologic bases of CPAP and HHFNC are well delineated, and their modes and practical application consistent, those of NIPPV are unproven and varied. Available evidence suggests that NIPPV is superior to CPAP as a primary and postextubation respiratory support in preterm infants.

Predictors of extubation readiness in preterm infants: a systematic review and meta-analysis

CONTEXT

A variety of extubation readiness tests have already been incorporated into clinical practice in preterm infants.

OBJECTIVE

To identify predictor tests of successful extubation and determine their accuracy compared with clinical judgement alone.

METHODS

MEDLINE, Embase, PubMed, Cochrane Library and Web of Science were searched between 1984 and June 2016. Studies evaluating predictors of extubation success during a period free of mechanical inflations in infants less than 37 weeks' gestation were included. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. After identifying and describing all predictor tests, pooled sensitivity and specificity estimates for the different test categories were generated using a bivariate random-effects model.

RESULTS

Thirty-five studies were included, showing wide heterogeneities in population characteristics, methodologies and definitions of extubation success. Assessments ranged from a few seconds to 24 hours, provided 0-6 cmH₂O positive end-expiratory pressure and measured several clinical and/or physiological parameters. Thirty-one predictor tests were identified, showing good sensitivities but low and variable specificities. Given the high variation in test definitions across studies, pooling could only be performed on a subset. The commonly performed spontaneous breathing trials had pooled sensitivity of 95% (95% CI 87% to 99%) and specificity of 62% (95% CI 38% to 82%), while composite tests offered the best performance characteristics.

CONCLUSIONS

There is a lack of strong evidence to support the use of extubation readiness tests in preterm infants. Although spontaneous breathing trials are attractive assessment tools, higher quality studies are needed for determining the optimal strategies for improving their accuracy.

Comparison of Bubble CPAP Devices Using RAM Cannula for Extubation Failure in Very Low Birth Weight Infants: Randomized and Cohort Studies

INTRODUCTION

Bubble continuous positive airway pressure (bCPAP) generates a variable pressure due to bubble size and frequency, and these pressure oscillations may contribute to lung recruitment and gas exchange. Single-outlet bCPAP devices generate larger pressure fluctuation than bCPAP devices with diffusers, but clinical efficacy is unclear. Our hypothesis was that a single-outlet bCPAP device (B&amp;B Bubbler©) would decrease extubation failure and improve oxygenation compared with a bCPAP device with a diffuser (BabiPlus©).

METHODS

Bench testing of bCPAP devices with the RAM© cannula determined pressure averages, fluctuations, and CPAP transmission at prongs. The B&amp;B Bubbler© and the BabiPlus© devices were compared for oxygenation and bCPAP failure within 72 h of extubation in a randomized trial in infants less than 1,250 g (n = 43). Additionally, a cohort study with infants extubated to BabiPlus© (n = 128), B&amp;B Bubbler© (n = 119), and noninvasive positive pressure ventilation (NIPPV) (n = 107) were compared.

RESULTS

Small differences in pressure fluctuations between bCPAP devices are attenuated by the RAM© cannula. Pressures at RAM© prongs are 62% of set pressure. The bCPAP extubation failure rate (35%) and oxygenation were similar between the bCPAP devices. bCPAP success was associated with lower FiO2 at extubation and decreased need for additional FiO2 in both groups. In the setting of the RAM© cannula, there were no differences in extubation failure rate for infants extubated to bCPAP or NIPPV.

CONCLUSIONS

There were no clinical differences at extubation between the B&amp;B Bubbler© and BabiPlus© devices. Oxygenation may predict bCPAP failure. The use of the RAM© cannula as a bCPAP interface should be more closely examined.

Care of the Neonate on Nasal Continuous Positive Airway Pressure: A Bedside Guide

Respiratory distress continues to be a major cause of neonatal morbidity. Current neonatal practice recommends the use of nasal continuous positive airway pressure (nCPAP) in the immediate resuscitation and continued support of neonates of all gestations with clinical manifestations of respiratory distress. Despite the many short- and long-term benefits of nCPAP, many neonatal care units have met resistance in its routine use. Although there have been numerous recent publications investigating the use and outcomes of various modes of nCPAP delivery, surfactant administration, mechanical ventilation, and other forms of noninvasive respiratory support (high-flow nasal cannula, nasal intermittent positive pressure ventilation), there has been a relative lack of publications addressing the practical bedside care of infants managed on nCPAP. Effective use of nCPAP requires a coordinated interprofessional team approach, ongoing assessment of the neonate, troubleshooting the nCPAP circuit, and parent education.

Evidence Regarding the Use of Bubble Continuous Positive Airway Pressure in the Extremely Low Birth-Weight Infant: Benefits, Challenges, and Implications for Nursing Practice

BACKGROUND

Gentle ventilation with optimal oxygenation is integral to prevention of chronic lung disease in the extremely low birth-weight (ELBW) infant. Various types of noninvasive ventilation are used in neonatal intensive care units worldwide. Bubble continuous positive airway pressure (BCPAP) has been in use in newborn intensive care since 1975.

PURPOSE

To synthesize the current evidence on the use of BCPAP in the ELBW infant and its relationship to outcomes, particularly morbidity and mortality.

METHODS/SEARCH STRATEGIES

A literature review was completed using PubMed, EMBASE, CINAHL, and Cochrane with a focus on BCPAP use in the ELBW population.

FINDINGS/RESULTS

No study found was exclusive to the ELBW population. All studies ranged from ELBW to full-term neonates. Studies supported the use of BCPAP in the ELBW, demonstrating decreased incidence of chronic lung disease and barotrauma through the use of oscillation and permissive hypercapnia.

IMPLICATIONS FOR PRACTICE

Literature supports the use of nasal bubble CPAP in the ELBW population. Barriers such as septal erosion, pneumothorax, inconsistent pressures, and air in the abdomen were identified and management recommendations were provided.

IMPLICATIONS FOR RESEARCH

Studies are needed comparing outcomes of nasal bubble CPAP use with other forms of CPAP in the ELBW infant, comparison of prongs to mask for nasal bubble CPAP, and comparing interventions to recommend optimal care bundles to prevent nasal septum injuries.

Preventing Continuous Positive Airway Pressure Failure: Evidence-Based and Physiologically Sound Practices from Delivery Room to the Neonatal Intensive Care Unit

Routine use of continuous positive airway pressure (CPAP) to support preterm infants with respiratory distress is an evidenced-based strategy to decrease incidence of bronchopulmonary dysplasia. However, rates of CPAP failure remain unacceptably high in very premature neonates, who are at high risk for developing bronchopulmonary dysplasia. Using the GRADE framework to assess the quality of available evidence, this article reviews strategies aimed at decreasing CPAP failure, starting with delivery room interventions and followed through to system-based efforts in the neonatal intensive care unit. Despite best efforts, some very premature neonates fail CPAP. Also reviewed are predictors of CPAP failure in this vulnerable population.

Continuous Positive Airway Pressure: To Bubble or Not to Bubble?

Continuous positive airway pressure (CPAP) systems can be broadly grouped into continuous flow or variable flow devices. Bubble CPAP (bCPAP) is a continuous flow device and has physiologic properties that could facilitate gas exchange. Its efficacy has been reported to be similar to variable flow CPAP systems when used as a primary mode of respiratory support. Post-extubation bCPAP is reported to significantly reduce extubation failure rates among preterm infants ventilated for less than 2 week when compared to Infant flow driver CPAP (variable flow). bCPAP has been successfully used in resource-poor settings. The success on CPAP is however dependant on good nursing care and clear management protocols for weaning and escalation of care.

Noninvasive Support: Does It Really Decrease Bronchopulmonary Dysplasia?

Noninvasive support of preterm infants with respiratory distress is an evidenced-based strategy to decrease the incidence of bronchopulmonary dysplasia. Continuous positive airway pressure (CPAP) is the only noninvasive strategy with sufficient evidence to support its use in acute respiratory distress syndrome. It is unclear if one method for delivering CPAP is superior to another. Future research will focus on strategies (eg, sustained lung inflation, and administration of surfactant using a thin plastic catheter) that increase the likelihood of success with CPAP, especially in infants with a gestational age of less than 26 weeks.

A Randomized Trial Comparing Efficacy of Bubble and Ventilator Derived Nasal CPAP in Very Low Birth Weight Neonates with Respiratory Distress

INTRODUCTION

Continuous Positive Airway Pressure (CPAP) has an established role in the care of Very Low Birth Weight (VLBW) babies with respiratory distress. Bubble CPAP (BCPAP) is a cheap alternative for countries where resources are limited. However, data comparing efficacy of BCPAP with conventional ventilator derived (VCPAP) is limited.

AIM

To compare CPAP failure rates between BCPAP and VCPAP among VLBW, with moderate respiratory distress. Secondary objectives were to compare the rates of Intraventricular Haemorrhage (IVH), pulmonary air leaks and deaths between the two groups and determine the predictors of CPAP failure.

MATERIALS AND METHODS

VLBW babies with moderate respiratory distress (Silverman Anderson score 4-7), born or admitted in Neonatal Intensive Care Unit (NICU) within 28 days of life were randomized to receive either BCPAP (n=34) or VCPAP (n=34). CPAP failure rate in both the groups was compared.

RESULTS

The baseline characteristics were similar in both the groups. Five out of 34 (14.70%) babies in BCPAP group and 11 out of 34 (32.35%) in VCPAP failed CPAP (p=0.08). IVH (BCPAP group 24% and VCPAP group 9%, p= 0.10) and mortality (BCPAP group 6% and VCPAP group 9%, p=0.642) were comparable in both the groups. Factors such as gestational age <30 weeks, weight <1000 grams, Respiratory Distress Syndrome (RDS), shock, pulmonary haemorrhage, Disseminated Intravascular Coagulation (DIC) and multi-organ dysfunction were significantly associated with CPAP failure in our study.

CONCLUSION

The CPAP failure rates in VLBW babies with moderate respiratory distress were found to be similar whether bubble CPAP or ventilator CPAP was used. There was no difference in complication rates of IVH or mortality with either method of CPAP.

Randomized control trial comparing physiologic effects in preterm infants during treatment with nasal continuous positive airway pressure (NCPAP) generated by Bubble NCPAP and Ventilator NCPAP: a pilot study

OBJECTIVES

Nasal continuous positive airway pressure (NCPAP) is an accepted form of non-invasive ventilation in preterm infants. Few, if any, studies have shown an advantage of one type of NCPAP over another. It has been theorized that bubble-generated NCPAP may be advantageous for the preterm neonate versus traditionally used ventilator-generated NCPAP. The aim of this study was to examine for any short-term differences in physiologic parameters in preterm subjects receiving these two different methods of NCPAP.

METHODS

We conducted a randomized, prospective, cross-over pilot study of preterm infants being treated with NCPAP in the neonatal intensive care unit. Subjects were continuously monitored for several physiologic parameters including heart rate, respiratory rate, oxygen saturation, cerebral tissue oxygen saturation and cerebral fractional oxygen extraction using routine neonatal monitors and near-infrared spectroscopy (NIRS) while on 2 h of bubble NCPAP and 2 h of ventilator NCPAP. Subjects were randomized to be monitored while either starting on bubble NCPAP and then switching to ventilator NCPAP or starting on ventilator NCPAP and switching to bubble NCPAP.

RESULTS

Eighteen subjects were included. We found no statistically significant difference in any of the physiologic parameters while subjects were receiving bubble NCPAP versus ventilator NCPAP during the monitoring time periods. While on bubble NCPAP, subjects showed a trend toward decreasing respiratory rate and decreasing cerebral fractional oxygen extraction over time, but this did not reach statistical significance.

CONCLUSION

There appears to be no difference in immediate physiologic effects between bubble NCPAP and ventilator NCPAP. This does not preclude the possibility of potential long-term differences, but any differences seen would likely be based on mechanisms that take more time to develop. A larger prospective trial is warranted to confirm our findings.

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.

Non-invasive respiratory support for infants in low- and middle-income countries

The overwhelming majority of neonatal deaths worldwide occur in low- and middle-income countries. Most of these deaths are attributable to respiratory illnesses and complications of preterm birth. The available data suggest that non-invasive continuous positive airway pressure (CPAP) is a safe and cost-effective therapy to reduce neonatal morbidity and mortality in these settings. Bubble CPAP compared to mechanical ventilator-generated CPAP reduces the need for subsequent invasive ventilation in newborn infants. There are limited data on the safety and efficacy of high-flow nasal cannulae in low- and middle-income countries, requiring further study prior to widespread implementation.

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.

Use of Nasal Bubble CPAP in Children with Hypoxemic Clinical Pneumonia-Report from a Resource Limited Set-Up

OBJECTIVE

Nasal bubble continuous positive airway pressure (bCPAP) is preferred in developing economies for easy applicability and low cost. Because its use in older children is unexplored, we sought to evaluate its utility in hypoxemic clinical pneumonia.

METHODS

Of 330 children (1 month-12 years) with clinical pneumonia enrolled prospectively over 1 year, those with increased work of breathing and/or SpO2 <92% received bCPAP delivered via an underwater 'T' tube through nasal prongs. Proportion requiring intubation despite bCPAP constituted primary outcome. Incidence of complications, duration of bCPAP and emergency stay were secondary outcomes.

RESULTS

Oxygen was initiated by nasal prongs (NPO2) in 204 (61.8%), and by bCPAP in 110 (33.3%). Sixteen (4.8%) were intubated at the outset. Fifty-three (25.9%) on NPO2 were shifted to bCPAP for worsening distress and hypoxemia. Only three (1.8%) from bCPAP group required intubation, of which one died. Failure rate and complications were negligent. The median emergency stay was 4 days.

CONCLUSIONS

Nasal bCPAP was safe and effective in children with hypoxemic clinical pneumonia.

Early Bubble Continuous Positive Airway Pressure: Investigating Interprofessional Best Practices for the NICU Team

Premature neonates delivered <32 completed weeks gestation are unprepared to handle the physiologic demands of extrauterine life. Within the respiratory system, alveolar instability and collapse can cause decreased functional residual capacity, impaired oxygenation, and hypoxemia leading to respiratory distress syndrome. Supportive measures are indicated immediately after birth to establish physiologic stability including bubble continuous positive airway pressure (CPAP) or endotracheal intubation and mechanical ventilation. CPAP is a noninvasive, gentle mode of ventilation that can mitigate the effects of lung immaturity, but prolonged use can increase the risk for nasal breakdown. Strategies to mitigate this risk must be infused as best practices in the NICU environment. The purpose of this article is to propose an evidence-based best practice care bundle for the early initiation of CPAP in the delivery room and associated skin barrier protection strategies for premature neonates <32 weeks gestation and weighing <1,500 g.

Bubble CPAP Support after Discontinuation of Mechanical Ventilation Protects Rat Lungs with Ventilator-Induced Lung Injury

<b><i>Background:</i></b> Bubble continuous positive airway pressure (BCPAP) has been used in neonates with respiratory distress for decades, but its lung-protective effect and underlying mechanism has not been investigated. <b><i>Objectives:</i></b> To test the hypothesis that BCPAP use after extubation decreases lung injury and that alterations to lung nitric oxide synthase (NOS) 3 expression may be one of the underlying mechanisms. <b><i>Methods:</i></b> We compared gas exchange, lung injury severity, and lung NOS expression among rats with ventilator-induced lung injury (VILI) treated with either BCPAP or spontaneous breathing. After high tidal volume ventilation for 30 min, the rats were randomly divided to three groups: a control group underwent spontaneous breathing (n = 7), and two BCPAP groups were treated with the bubble technique with either a 2.5-mm-diameter (n = 7) or a 5.5-mm-diameter (n = 7) expiratory limb for 2 h. <b><i>Results:</i></b> The bubble technique (2.5 and 5.5 mm diameter combined) resulted in a significantly higher Pa<smlcap>O</smlcap>₂, decreased alveolar protein levels (1.01 vs. 1.43 mg/kg, p < 0.05), a lower lung injury score (3.87 vs. 4.86, p < 0.05), and decreased NOS3 expression (1.99 vs. 3.32, p < 0.05) compared to spontaneous breathing in the control group. BCPAP with a 2.5-mm-diameter and with a 5.5-mm-diameter expiratory limb was not different with regard to gas exchange, alveolar protein levels, and lung injury scores, but there was a trend for lower NOS3 expression in the 5.5-mm group (1.41 vs. 2.56, p = 0.052). <b><i>Conclusions:</i></b> BCPAP decreases lung injury in rats with VILI after stopping mechanical ventilation. Attenuation of lung NOS3 expression may be one of the underlying mechanisms.

A randomised controlled trial of flow driver and bubble continuous positive airway pressure in preterm infants in a resource-limited setting

OBJECTIVES

The variable-flow flow driver (FD; EME) and continuous-flow bubble (Fisher-Paykel) continuous positive airway pressure (CPAP) systems are widely used. As these differ in cost and technical requirements, determining comparative efficacy is important particularly where resources are limited.

DESIGN

We performed a randomised, controlled, equivalence trial of CPAP systems. We specified the margin of equivalence as 2 days. We analysed binary variables by logistical regression adjusted for gestation, and log transformed continuous variables by multiple linear regression adjusted for gestation, sex and antenatal steroids.

SETTING

A neonatal unit with no blood gas analyser or surfactant availability and limited X-ray and laboratory facilities

PATIENTS

Neonates <37 weeks of gestation.

INTERVENTIONS

We provided CPAP at delivery followed by randomisation to FD or bubble (B).

OUTCOMES

Primary outcome included total days receiving CPAP; secondary outcomes included days receiving CPAP, supplemental oxygen, ventilation, death, pneumothorax and nasal excoriation.

RESULTS

We randomised 125 infants (B 66, FD 59). Differences in infant outcomes on B and FD were not statistically significant. The median (range) for CPAP days for survivors was B 0.8 (0.04 to 17.5), FD 0.5 (0.04 to 5.3). B:FD (95% CI) ratios were CPAP days 1.3 (0.9 to 2.1), CPAP plus supplementary oxygen days 1.2 (0.7 to 1.9). B:FD (95% CI) ORs were death 2.3 (0.2 to 28), ventilation 2.1 (0.5 to 9), nasal excoriation 1.2 (0.2 to 8) and pneumothorax 2.4 (0.2 to 26).

CONCLUSIONS

In a resource-limited setting we found B CPAP equivalent to FD CPAP in the total number of days receiving CPAP within a margin of 2 days.

TRIAL REGISTRATION NUMBER

ISRCTN22578364.

Nasal Jet-CPAP (variable flow) versus Bubble-CPAP in preterm infants with respiratory distress: an open label, randomized controlled trial

OBJECTIVE

To compare the failure rates between Jet continuous positive airway pressure device (J-CPAP-variable flow) and Bubble continuous positive airway device (B-CPAP) in preterm infants with respiratory distress.

STUDY DESIGN

Preterm newborns <34 weeks gestation with onset of respiratory distress within 6 h of life were randomized to receive J-CPAP (a variable flow device) or B-CPAP (continuous flow device). A standardized protocol was followed for titration, weaning and removal of CPAP. Pressure was monitored close to the nares in both the devices every 6 hours and settings were adjusted to provide desired CPAP. The primary outcome was CPAP failure rate within 72 h of life. Secondary outcomes were CPAP failure within 7 days of life, need for surfactant post-randomization, time to CPAP failure, duration of CPAP and complications of prematurity. An intention to treat analysis was done.

RESULTS

One-hundred seventy neonates were randomized, 80 to J-CPAP and 90 to B-CPAP. CPAP failure rates within 72 h were similar in infants who received J-CPAP and in those who received B-CPAP (29 versus 21%; relative risks 1.4 (0.8 to 2.3), P=0.25). Mean (95% confidence intervals) time to CPAP failure was 59 h (54 to 64) in the Jet CPAP group in comparison with 65 h (62 to 68) in the Bubble CPAP group (log rank P=0.19). All other secondary outcomes were similar between the two groups.

CONCLUSION

In preterm infants with respiratory distress starting within 6 h of life, CPAP failure rates were similar with Jet CPAP and Bubble CPAP.

Impact of the systematic introduction of low-cost bubble nasal CPAP in a NICU of a developing country: a prospective pre- and post-intervention study

Background

The use of Nasal Continuous Positive Airway Pressure Ventilation (NCPAP) has begun to increase and is progressively replacing conventional mechanical ventilation (MV), becoming the cornerstone treatment for newborn respiratory distress syndrome (RDS). Howerver, NCPAP use in Lower-Middle Income Countries (LMICs) is poor. Moreover, bubble NCPAP (bNCPAP), for efficacy, cost effectiveness, and ease of use, should be the primary assistance technique employed in newborns with RDS.

Objective: To measure the impact on in-hospital newborn mortality of using a bNCPAP device as the first intervention on newborns requiring ventilatory assistance.

Methods

Design: Prospective pre-intervention and post-intervention study.

Setting: The largest Neonatal Intensive Care Unit (NICU) in Nicaragua.

Participants: In all, 230 (2006) and 383 (2008) patients were included.

Intervention: In May 2006, a strategy was introduced to promote the systematic use of bNCPAP to avoid intubation and MV in newborns requiring ventilatory assistance. Data regarding gestation, delivery, postnatal course, mortality, length of hospitalisation, and duration of ventilatory assistance were collected for infants assisted between May and December 2006, before the project began, and between May and December 2008, two years afterwards.

Outcome measures: The pre- vs post-intervention proportion of newborns who died in-hospital was the primary end point. Secondary endpoints included rate of intubation and duration of NICU stay.

Results

Significant differences were found in the rate of intubation (72 vs 39%; p < 0.0001) and the proportion of patients treated exclusively with bNCPAP (27% vs 61%; p <0.0001). Mortality rate was significantly reduced (40 vs 23%; p < 0.0001); however, an increase in the mean duration of NICU stay was observed (14.6 days in 2006 and 17.5 days in 2008, p = 0.0481).

The findings contribute to the evidence that NCPAP, particularly bNCPAP, is the first-line standard of care for efficacy, cost effectiveness, and ease of use in newborns with respiratory distress in LMICs.

Conclusions

This is the first extensive survey performed in a large NICU from a LMICs, proving the efficacy of the systematic use of a bNCPAP device in reducing newborn mortality. These findings are an incentive for considering bNCPAP as an elective strategy to treat newborns with respiratory insufficiency in LMICs.

Intra-gastric pressures in neonates receiving bubble CPAP

OBJECTIVE

To study intra-gastric pressures in neonates receiving bubble continuous positive airway pressure (BCPAP) by nasopharyngeal prong.

METHODS

Twenty seven neonates were recruited for the study. BCPAP pressure of 6 cm water was used in all the neonates. A pressure sensor attached to orogastric tube, measured the intra-gastric pressure prior to starting BCPAP and again between 30 and 90 min of BCPAP. The clinical variables like Downe's score, oxygen saturation, venous blood gas pH, pCO(2) and abdominal girth were recorded alongside with pressure readings.

RESULTS

BCPAP resulted in improvement (p < 0.05) in parameters of respiratory distress such as Downe's score (DS), oxygen saturation (SpO(2)) and venous blood gas parameters (pH, pCO(2)). There was no statistical significant increase in intra-gastric pressures (p = 0.834). There were no gastrointestinal complications; abdominal distention, necrotising enterocolitis or gastric perforation during the study.

CONCLUSIONS

Nasopharyngeal BCPAP at 6 cm of water pressure is an effective modality of treating babies with respiratory distress and the present study shows that it is not associated with a significant rise in intra-gastric pressures.

Current concepts in acute respiratory support for neonates and children

Current trends in mechanical respiratory support are evolving toward gentle approaches to avoid short- and long-term problems that are historically associated with mechanical ventilation. These ventilator-associated issues include the need for long-term sedation, muscle deconditioning, ventilator-associated lung injury (VALI), and ventilator-associated pneumonia (VAP). This article will describe recent trends of ventilatory support in neonates and children: (1) utilization of volume ventilation in infants, (2) synchrony and improving patient-ventilator interaction specifically using neurally adjusted ventilatory assist (NAVA), and (3) use of noninvasive ventilation techniques. When applicable, their uses in the surgical newborn and pediatric patients are described.

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).

Safety and effectiveness of bubble continuous positive airway pressure in preterm neonates with respiratory distress

BACKGROUND

Studies on Bubble Continuous Positive Airway Pressure (B-CPAP) as respiratory support for neonates are few. The aim of our study was to determine the efficacy and safety of B-CPAP in preterm neonates requiring respiratory support.

METHODS

A prospective observation study was done on 50 preterm babies requiring respiratory support for mild to moderate respiratory distress. Support was given with short, nasal cannulae. Surfactant was administered when indicated. Monitoring was done clinically, with pulse oximeter, radiologically and with blood gases. Staff members were also asked their views. Follow-up was done for 3 months.

RESULTS

The mean gestational age was 32.46 (+3.23) weeks and mean birth weight 1454.4 (+487.42) g. Respiratory Distress Syndrome was the commonest indication (30/50). The mean maximum pressure was 6.04 cm H2O and mean maximum FiO2 was 72.16%. Mean maximum paO2, paCO2 and mean minimum paCO2 were 92.93 mm Hg (+16.97), 52.36 mm Hg (+ 7.78) and 36.46 mm Hg (+ 4.95) respectively. Early initiation resulted in lesser duration of support. Failure rate was 30%. Apnoea, >1 dose surfactant and late initiation had a statistically higher incidence of failure. Main complications were skin abrasions (30%), feed intolerance (26%) and gastric distension (26%). Survival rate was 94%. 68% of staff felt that it was as easy to use and 88% felt it was more reliable than standard CPAP.

CONCLUSIONS

Bubble Continuous Positive Airway Pressure is safe, efficacious and easy to use in preterm neonates with mild to moderate respiratory distress.

Non-invasive Ventilation in Premature Infants: Based on Evidence or Habit

Despite surfactant and mechanical ventilation being the standard of care for preterm infants with respiratory failure, non-invasive respiratory support is increasingly being employed in neonatal units. The latter can be accomplished in a variety of ways but none of them have been proven so far to be superior to intubation and mechanical ventilation. Nonetheless, they appear to be safe and effective in experienced hands. This article relates to the use of non-invasive forms of respiratory support and evidence is reviewed from the clinical trials which have evaluated the use of these techniques.

Improving delivery room management for very preterm infants

BACKGROUND AND OBJECTIVES

Events in the delivery room significantly impact the outcomes of preterm infants. We developed evidence-based guidelines to prevent heat loss, reduce exposure to supplemental oxygen, and increase use of noninvasive respiratory support to improve the care and outcomes of infants with birth weight ≤1250 g at our institution.

METHODS

The guidelines were implemented through multidisciplinary conferences, routine use of a checklist, appointment of a dedicated resuscitation nurse, and frequent feedback to clinicians. This cohort study compares a historical group (n = 80) to a prospective group (n = 80, after guidelines were implemented). Primary outcome was axillary temperature at admission to the intensive care nursery. Secondary outcomes measured adherence to the guidelines and changes in clinically relevant patient outcomes.

RESULTS

Baseline characteristics of the groups were similar. After introduction of the guidelines, average admission temperatures increased (36.4°C vs 36.7°C, P < .001) and the proportion of infants admitted with moderate/severe hypothermia fell (14% vs 1%, P = .003). Infants were exposed to less oxygen during the first 10 minutes (P < .001), with similar oxygen saturations. Although more patients were tried on continuous positive airway pressure (40% vs 61%, P = .007), the intubation rate was not significantly different (64% vs 54%, P = .20). Median durations of invasive ventilation and hospitalization decreased after the quality initiative (5 vs 1 days [P = .008] and 80 vs 60 days [P = .02], respectively).

CONCLUSIONS

We have demonstrated significantly improved quality of delivery room care for very preterm infants after introduction of evidence-based delivery room guidelines. Multidisciplinary involvement and continuous education and reinforcement of the guidelines permitted sustained change.

Machine learning to predict extubation outcome in premature infants

Though treatment of the ventilated premature infant has experienced many advances over the past decades, determining the best time point for extubation of these infants remains challenging and the incidence of extubation failures largely unchanged. The objective was to provide clinicians with a decision-support tool to determine whether to extubate a mechanically ventilated premature infant by using a set of machine learning algorithms on a dataset assembled from 486 premature infants receiving mechanical ventilation. Algorithms included artificial neural networks (ANN), support vector machine (SVM), naïve Bayesian classifier (NBC), boosted decision trees (BDT), and multivariable logistic regression (MLR). Results for ANN, MLR, and NBC were satisfactory (area under the curve [AUC]: 0.63-0.76); however, SVM and BDT consistently showed poor performance (AUC ~0.5). Complex medical data such as the data set used for this study require further preprocessing steps before prediction models can be developed that achieve similar or better performance than clinicians.

Bubble CPAP versus ventilator CPAP in preterm neonates with early onset respiratory distress--a randomized controlled trial

Bubble continuous positive airway pressure (BCPAP) is a low cost nasal CPAP delivery system with potential benefits to developing nations.

OBJECTIVE

To compare the efficacy and safety of BCPAP with ventilator-derived CPAP (VCPAP) in preterm neonates with respiratory distress.

METHODS

In a randomized controlled trial, preterm neonates with Silverman-Anderson score ≥ 4 and oxygen requirement >30% within first 6 h of life were randomly allocated to BCPAP or VCPAP. Proportion of neonates with success or failure was compared.

RESULTS

In all, 47 of 57 (82.5%) neonates from BCPAP group and 36 of 57 (63.2%) neonates from the VCPAP group completed CPAP successfully (p = 0.03). Neonates who failed CPAP had higher Silverman-Anderson score (p < 0.01), lower arterial to alveolar oxygenation ratio (p < 0.05) and needed surfactant more frequently (p < 0.01).

CONCLUSION

BCPAP has higher success rate than VCPAP for managing preterm neonates with early onset respiratory distress, with comparable safety.

Electrical impedance tomography to evaluate air distribution prior to extubation in very-low-birth-weight infants: a feasibility study

OBJECTIVES

Nasal continuous positive airway pressure is used as a standard of care after extubation in very-low-birth-weight infants. A pressure of 5 cmH2O is usually applied regardless of individual differences in lung compliance. Current methods for evaluation of lung compliance and air distribution in the lungs are thus imprecise for preterm infants. This study used electrical impedance tomography to determine the feasibility of evaluating the positive end-expiratory pressure level associated with a more homogeneous air distribution within the lungs before extubation.

METHODS

Ventilation homogeneity was defined by electrical impedance tomography as the ratio of ventilation between dependent and non-dependent lung areas. The best ventilation homogeneity was achieved when this ratio was equal to 1. Just before extubation, decremental expiratory pressure levels were applied (8, 7, 6 and 5 cmH(2)0; 3 minutes each step), and the pressure that determined the best ventilation homogeneity was defined as the best positive end-expiratory pressure.

RESULTS

The best positive end-expiratory pressure value was 6.3 ± 1.1 cmH(2)0, and the mean continuous positive airway pressure applied after extubation was 5.2 ± 0.4 cmH(2)0 (p = 0.002). The extubation failure rate was 21.4%. X-Ray and blood gases after extubation were also checked.

CONCLUSION

This study demonstrates that electrical impedance tomography can be safely and successfully used in patients ready for extubation to suggest the best ventilation homogeneity, which is influenced by the level of expiratory pressure applied. In this feasibility study, the best lung compliance was found with pressure levels higher than the continuous positive airway pressure levels that are usually applied for routine extubation.

Can Machine Learning Methods Predict Extubation Outcome in Premature Infants as well as Clinicians?

RATIONALE

Though treatment of the prematurely born infant breathing with assistance of a mechanical ventilator has much advanced in the past decades, predicting extubation outcome at a given point in time remains challenging. Numerous studies have been conducted to identify predictors for extubation outcome; however, the rate of infants failing extubation attempts has not declined.

OBJECTIVE

To develop a decision-support tool for the prediction of extubation outcome in premature infants using a set of machine learning algorithms.

METHODS

A dataset assembled from 486 premature infants on mechanical ventilation was used to develop predictive models using machine learning algorithms such as artificial neural networks (ANN), support vector machine (SVM), naïve Bayesian classifier (NBC), boosted decision trees (BDT), and multivariable logistic regression (MLR). Performance of all models was evaluated using area under the curve (AUC).

RESULTS

For some of the models (ANN, MLR and NBC) results were satisfactory (AUC: 0.63-0.76); however, two algorithms (SVM and BDT) showed poor performance with AUCs of ~0.5.

CONCLUSION

Clinician's predictions still outperform machine learning due to the complexity of the data and contextual information that may not be captured in clinical data used as input for the development of the machine learning algorithms. Inclusion of preprocessing steps in future studies may improve the performance of prediction models.

Influence of changing the diameter of the bubble generator bottle and expiratory limb on bubble CPAP: an in vitro study

BACKGROUND

The noisy component of bubble continuous positive airway pressure (CPAP) is thought to contribute to breathing efficiency and lung volume recruitment, mainly because of stochastic resonance. The magnitude and frequency of the superimposed noise are vital to this process. We wanted to evaluate the in vitro effect of changing various parameters of the bubble CPAP circuit regarding the magnitude and frequency of pressure oscillations transmitted to the lung model.

METHODS

In a bubble CPAP lung model, we immersed different sizes (3.0∼12.5 mm) of the expiratory limb of the CPAP circuit into different depths under water (2.0∼10.0 cm) and used various diameters (2.9∼9.0 cm) of bubble generator bottles. We also varied the compliance of the model lung. We measured the changes in mean, magnitude, and frequency of pressure oscillations transmitted to the lung model at three different flow rates (namely 4, 8, and 12L/minute).

RESULTS

Increasing the size and submergence depth of the expiratory limb of a CPAP circuit and decreasing the diameter of the bubble generator bottle intensified the magnitude but diminished the frequency of noise transmitted to the lung model. Decreasing compliance of the lung model intensified both the magnitude and frequency content of pressure oscillations in the model lung.

CONCLUSION

The size and submergence depth of an expiratory limb of a CPAP circuit, the diameter of the bubble generator bottle, and the compliance of the model lung all influence the magnitude and frequency of the transmitted pressure waveform. Therefore, these factors may affect lung volume recruitment and breathing efficiency in bubble CPAP.

CPAP review

Continuous positive airway pressure (CPAP) is widely used in neonatal units both as a primary mode of respiratory support and following extubation from mechanical ventilation. In this review, the evidence for CPAP use particularly in prematurely born infants is considered. Studies comparing methods of CPAP generation have yielded conflicting results, but meta-analysis of randomised trials has demonstrated that delivering CPAP via short nasal prongs is most effective in preventing re-intubation. At present, there is insufficient evidence to establish the safety or efficacy of high flow nasal cannulae for prematurely born infants. Observational studies highlighted that early CPAP use rather than intubation and ventilation was associated with a lower incidence of bronchopulmonary dysplasia (BPD), but this has not been confirmed in three large randomised trials. Meta-analysis of the results of randomised trials has demonstrated that use of CPAP reduces extubation failure, particularly if a CPAP level of 5 cm H2O or more is used. Nasal injury can occur and is related to the length of time CPAP is used; weaning CPAP by pressure rather than by "time-cycling" reduces the weaning time and may reduce BPD. In conclusion, further studies are required to identify the optimum mode of CPAP generation and it is important that prematurely born infants are weaned from CPAP as soon as possible.