High flow nasal cannula for respiratory support in preterm infants

Heated and humidified high flow therapy (HHHFT) in extreme and very preterm neonates with respiratory distress syndrome (RDS): a retrospective cohort from a tertiary care setting in Pakistan

OBJECTIVE

To determine the role of heated humidified high flow therapy (HHHFT) as primary respiratory support in spontaneously breathing moderate-late, very and extreme preterm neonates with respiratory distress syndrome (RDS) at a tertiary care hospital from a developing country.

DESIGN

Retrospective cohort study.

SETTING

Neonatal intensive care unit of Indus Hospital and Health Network, Karachi, Pakistan.

PATIENTS

All preterm neonates with RDS and who received HHHFT as primary respiratory support were included retrospectively, while neonates with orofacial anomalies, congenital heart and lung diseases other than RDS, abdominal wall defects, encephalopathy, congenital pneumonia and received continuous positive airway pressure or invasive ventilation were excluded.

INTERVENTIONS

HHHFT as primary respiratory support for RDS.

MAIN OUTCOME MEASURES

Effectiveness, duration, failure rate and complications of HHHFT as a primary respiratory support in moderate-late, very and extremely preterm neonates were evaluated.

RESULTS

The cohort included 138 neonates during a period of 12 months. The median gestational age was 32 weeks, and the median birth weight was 1607 g. Grade 1-2 RDS was seen in 97%, surfactant instillation was done in 10.8% and HHHFT was provided in all the neonates as primary respiratory support. The total duration of HHHFT support was <1 week in 94% of neonates. Bronchopulmonary dysplasia and pneumothorax until discharge or death were observed in one neonate, haemodynamically significant Patent Ductus Artriosus (HsPDA) in two neonates and intraventricular haemorrhage Grade ≥2 in five neonates, while only one neonate died.

CONCLUSION

This study appears to show that HHHFT is a simple, safe, efficient and cheap mode of primary respiratory support that can be given to spontaneously breathing moderate-late, very and extremely preterm neonates with RDS, especially in low- or middle-income countries.

High flow nasal cannula for respiratory support in term infants

BACKGROUND

Respiratory failure or respiratory distress in infants is the most common reason for non-elective admission to hospitals and neonatal intensive care units. Non-invasive methods of respiratory support have become the preferred mode of treating respiratory problems as they avoid some of the complications associated with intubation and mechanical ventilation. High flow nasal cannula (HFNC) therapy is increasingly being used as a method of non-invasive respiratory support. However, the evidence pertaining to its use in term infants (defined as infants ≥ 37 weeks gestational age to the end of the neonatal period (up to one month postnatal age)) is limited and there is no consensus of opinion regarding the safety and efficacy HFNC in this population.

OBJECTIVES

To assess the safety and efficacy of high flow nasal cannula oxygen therapy for respiratory support in term infants when compared with other forms of non-invasive respiratory support.

SEARCH METHODS

We searched the following databases in December 2022: Cochrane CENTRAL; PubMed; Embase; CINAHL; LILACS; Web of Science; Scopus. We also searched the reference lists of retrieved studies and performed a supplementary search of Google Scholar.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that investigated the use of high flow nasal cannula oxygen therapy in infants ≥ 37 weeks gestational age up to one month postnatal age (the end of the neonatal period).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility, performed data extraction, and assessed risk of bias in the included studies. Where studies were sufficiently similar, we performed a meta-analysis using mean differences (MD) for continuous data and risk ratios (RR) for dichotomous data, with their respective 95% confidence intervals (CIs). For statistically significant RRs, we calculated the number needed to treat for an additional beneficial outcome (NNTB). We used the GRADE approach to evaluate the certainty of the evidence for clinically important outcomes.

MAIN RESULTS

We included eight studies (654 participants) in this review. Six of these studies (625 participants) contributed data to our primary analyses. Four studies contributed to our comparison of high flow nasal cannula (HFNC) oxygen therapy versus continuous positive airway pressure (CPAP) for respiratory support in term infants. The outcome of death was reported in two studies (439 infants) but there were no events in either group. HFNC may have little to no effect on treatment failure, but the evidence is very uncertain (RR 0.98, 95% CI 0.47 to 2.04; 3 trials, 452 infants; very low-certainty evidence). The outcome of chronic lung disease (need for supplemental oxygen at 28 days of life) was reported in one study (375 participants) but there were no events in either group. HFNC may have little to no effect on the duration of respiratory support (any form of non-invasive respiratory support with or without supplemental oxygen), but the evidence is very uncertain (MD 0.17 days, 95% CI -0.28 to 0.61; 4 trials, 530 infants; very low-certainty evidence). HFNC likely results in little to no difference in the length of stay at the intensive care unit (ICU) (MD 0.90 days, 95% CI -0.31 to 2.12; 3 trials, 452 infants; moderate-certainty evidence). HFNC may reduce the incidence of nasal trauma (RR 0.16, 95% CI 0.04 to 0.66; 1 trial, 78 infants; very low-certainty evidence) and abdominal overdistension (RR 0.22, 95% CI 0.07 to 0.71; 1 trial, 78 infants; very low-certainty evidence), but the evidence is very uncertain. Two studies contributed to our analysis of HFNC versus low flow nasal cannula oxygen therapy (LFNC) (supplemental oxygen up to a maximum flow rate of 2 L/min). The outcome of death was reported in both studies (95 infants) but there were no events in either group. The evidence suggests that HFNC may reduce treatment failure slightly (RR 0.44, 95% CI 0.21 to 0.92; 2 trials, 95 infants; low-certainty evidence). Neither study reported results for the outcome of chronic lung disease (need for supplemental oxygen at 28 days of life). HFNC may have little to no effect on the duration of respiratory support (MD -0.07 days, 95% CI -0.83 to 0.69; 1 trial, 74 infants; very low-certainty evidence), length of stay at the ICU (MD 0.49 days, 95% CI -0.83 to 1.81; 1 trial, 74 infants; very low-certainty evidence), or hospital length of stay (MD -0.60 days, 95% CI -2.07 to 0.86; 2 trials, 95 infants; very low-certainty evidence), but the evidence is very uncertain. Adverse events was an outcome reported in both studies (95 infants) but there were no events in either group. The risk of bias across outcomes was generally low, although there were some concerns of bias. The certainty of evidence across outcomes ranged from moderate to very low, downgraded due to risk of bias, imprecision, indirectness, and inconsistency.

AUTHORS' CONCLUSIONS

When compared with CPAP, HFNC may result in little to no difference in treatment failure. HFNC may have little to no effect on the duration of respiratory support, but the evidence is very uncertain. HFNC likely results in little to no difference in the length of stay at the intensive care unit. HFNC may reduce the incidence of nasal trauma and abdominal overdistension, but the evidence is very uncertain. When compared with LFNC, HFNC may reduce treatment failure slightly. HFNC may have little to no effect on the duration of respiratory support, length of stay at the ICU, or hospital length of stay, but the evidence is very uncertain. There is insufficient evidence to enable the formulation of evidence-based guidelines on the use of HFNC for respiratory support in term infants. Larger, methodologically robust trials are required to further evaluate the possible health benefits or harms of HFNC in this patient population.

Nasal high flow therapy for primary respiratory support in preterm infants

BACKGROUND

Nasal high flow (nHF) therapy provides heated, humidified air and oxygen via two small nasal prongs, at gas flows of more than 1 litre/minute (L/min), typically 2 L/min to 8 L/min. nHF is commonly used for non-invasive respiratory support in preterm neonates. It may be used in this population for primary respiratory support (avoiding, or prior to the use of mechanical ventilation via an endotracheal tube) for prophylaxis or treatment of respiratory distress syndrome (RDS). This is an update of a review first published in 2011 and updated in 2016.

OBJECTIVES

To evaluate the benefits and harms of nHF for primary respiratory support in preterm infants compared to other forms of non-invasive respiratory support.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date March 2022.

SELECTION CRITERIA

We included randomised or quasi-randomised trials comparing nHF with other forms of non-invasive respiratory support for preterm infants born less than 37 weeks' gestation with respiratory distress soon after birth.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane Neonatal methods. Our primary outcomes were 1. death (before hospital discharge) or bronchopulmonary dysplasia (BPD), 2. death (before hospital discharge), 3. BPD, 4. treatment failure within 72 hours of trial entry and 5. mechanical ventilation via an endotracheal tube within 72 hours of trial entry. Our secondary outcomes were 6. respiratory support, 7. complications and 8. neurosensory outcomes. We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included 13 studies (2540 infants) in this updated review. There are nine studies awaiting classification and 13 ongoing studies. The included studies differed in the comparator treatment (continuous positive airway pressure (CPAP) or nasal intermittent positive pressure ventilation (NIPPV)), the devices for delivering nHF and the gas flows used. Some studies allowed the use of 'rescue' CPAP in the event of nHF treatment failure, prior to any mechanical ventilation, and some allowed surfactant administration via the INSURE (INtubation, SURfactant, Extubation) technique without this being deemed treatment failure. The studies included very few extremely preterm infants less than 28 weeks' gestation. Several studies had unclear or high risk of bias in one or more domains. Nasal high flow compared with continuous positive airway pressure for primary respiratory support in preterm infants Eleven studies compared nHF with CPAP for primary respiratory support in preterm infants. When compared with CPAP, nHF may result in little to no difference in the combined outcome of death or BPD (risk ratio (RR) 1.09, 95% confidence interval (CI) 0.74 to 1.60; risk difference (RD) 0, 95% CI -0.02 to 0.02; 7 studies, 1830 infants; low-certainty evidence). Compared with CPAP, nHF may result in little to no difference in the risk of death (RR 0.78, 95% CI 0.44 to 1.39; 9 studies, 2009 infants; low-certainty evidence), or BPD (RR 1.14, 95% CI 0.74 to 1.76; 8 studies, 1917 infants; low-certainty evidence). nHF likely results in an increase in treatment failure within 72 hours of trial entry (RR 1.70, 95% CI 1.41 to 2.06; RD 0.09, 95% CI 0.06 to 0.12; number needed to treat for an additional harmful outcome (NNTH) 11, 95% CI 8 to 17; 9 studies, 2042 infants; moderate-certainty evidence). However, nHF likely does not increase the rate of mechanical ventilation (RR 1.04, 95% CI 0.82 to 1.31; 9 studies, 2042 infants; moderate-certainty evidence). nHF likely results in a reduction in pneumothorax (RR 0.66, 95% CI 0.40 to 1.08; 10 studies, 2094 infants; moderate-certainty evidence) and nasal trauma (RR 0.49, 95% CI 0.36 to 0.68; RD -0.06, 95% CI -0.09 to -0.04; 7 studies, 1595 infants; moderate-certainty evidence). Nasal high flow compared with nasal intermittent positive pressure ventilation for primary respiratory support in preterm infants Four studies compared nHF with NIPPV for primary respiratory support in preterm infants. When compared with NIPPV, nHF may result in little to no difference in the combined outcome of death or BPD, but the evidence is very uncertain (RR 0.64, 95% CI 0.30 to 1.37; RD -0.05, 95% CI -0.14 to 0.04; 2 studies, 182 infants; very low-certainty evidence). nHF may result in little to no difference in the risk of death (RR 0.78, 95% CI 0.36 to 1.69; RD -0.02, 95% CI -0.10 to 0.05; 3 studies, 254 infants; low-certainty evidence). nHF likely results in little to no difference in the incidence of treatment failure within 72 hours of trial entry compared with NIPPV (RR 1.27, 95% CI 0.90 to 1.79; 4 studies, 343 infants; moderate-certainty evidence), or mechanical ventilation within 72 hours of trial entry (RR 0.91, 95% CI 0.62 to 1.33; 4 studies, 343 infants; moderate-certainty evidence). nHF likely results in a reduction in nasal trauma, compared with NIPPV (RR 0.21, 95% CI 0.09 to 0.47; RD -0.17, 95% CI -0.24 to -0.10; 3 studies, 272 infants; moderate-certainty evidence). nHF likely results in little to no difference in the rate of pneumothorax (RR 0.78, 95% CI 0.40 to 1.53; 4 studies, 344 infants; moderate-certainty evidence). Nasal high flow compared with ambient oxygen We found no studies examining this comparison. Nasal high flow compared with low flow nasal cannulae We found no studies examining this comparison.

AUTHORS' CONCLUSIONS

The use of nHF for primary respiratory support in preterm infants of 28 weeks' gestation or greater may result in little to no difference in death or BPD, compared with CPAP or NIPPV. nHF likely results in an increase in treatment failure within 72 hours of trial entry compared with CPAP; however, it likely does not increase the rate of mechanical ventilation. Compared with CPAP, nHF use likely results in less nasal trauma and likely a reduction in pneumothorax. As few extremely preterm infants less than 28 weeks' gestation were enrolled in the included trials, evidence is lacking for the use of nHF for primary respiratory support in this population.

Treatment of Pediatric Patients With High-Flow Nasal Cannula and Considerations for Oral Feeding: A Review of the Literature

PURPOSE

High-Flow Nasal Cannula (HFNC) has become an increasingly common means of noninvasive respiratory support in pediatrics and is being used in infants and children with respiratory distress both inside and outside of the intensive care units. Despite the widespread use of HFNC, there remains a paucity of data on optimal flow rates and its impact on morbidity, mortality, and desired outcomes. Given the scarcity of information in these critical areas, it is not surprising that guidelines for initiation of oral feeding do not exist. This review article will review HFNC mechanisms of action, its use in specific populations and settings, and finally what is known about initiation of feeding during this therapy.

CONCLUSIONS

The practice of withholding oral feeding solely, because of HFNC, is not supported in the literature at the time of this writing, but in the absence of safety data from clinical trials, clinicians should proceed with caution and consider patient-specific factors while making decisions about oral feeding. Well-controlled prospective clinical trials are needed for development of best practice clinical guidelines and attainment of optimal outcomes.

Heated and Humidified High Flow Nasal Canal Oxygen Supplementation as an Effective Treatment for High-Risk Prethreshold Retinopathy of Prematurity

PURPOSE

We evaluated the effect of heated and humidified high flow nasal cannula (HFNC) oxygen supplementation to promote regression of high-risk prethreshold retinopathy of prematurity (Hrp-ROP) in premature infants.

METHODS

A prospective study was designed for Hrp-ROP premature infants undergoing HFNC oxygen supplementation to evaluate its capacity for promoting ROP regression. Statistical analysis with independent samples t-tests and Fisher's exact tests was performed, and forest plots were created to illuminate the odds ratio of factors associated with ROP regression as well as HFNC complication.

RESULTS

With HFNC, 16 of 20 infants with Hrp-ROP experienced regression, which is higher than the natural regression rate, comparing to the data in other clinical trials (52% in the STOP-ROP study). Among four progressed ROP infants, three were treated with laser photocoagulation and one received anti-vascular endothelial growth factor (VEGF) therapy. The anti-VEGF treated patient encountered ROP recurrence one month after injection and was treated successfully by additional HFNC. No significant differences between regression and progression cases were found for gestational age, birth weight, plus disease, age for HFNC, and SO2 level. The blood saturation of oxygen was significantly increased after HFNC (92 ± 1.3% vs. 96.6 ± 0.8%, P < 0.001), while the heartbeat rate (HR) and respiratory rate (RR) had no significant differences (139.4 ± 5.4 vs. 140.6 ± 4.5, P = 0.409; 37.7 ± 2.3 vs. 37 ± 1.9, P = 0.330, respectively). The main complication of HNFC was nasal erosion associated with airflow and HFNC duration (RR = 1.8, P = 0.026; RR = 1.8, P = 0.026, respectively).

CONCLUSIONS

The progression of Hrp-ROP was significantly decreased after HFNC oxygen supplementation with slightly tolerable complication.

TRANSLATIONAL RELEVANCE

Our study suggests that HNFC can be an alternative treatment for Hrp-ROP, potentially avoiding the problems caused by other invasive treatment.

The clinical effectiveness and cost-effectiveness of heated humidified high-flow nasal cannula compared with usual care for preterm infants: systematic review and economic evaluation

BACKGROUND

Respiratory problems are one of the most common causes of morbidity in preterm infants and may be treated with several modalities for respiratory support such as nasal continuous positive airway pressure (NCPAP) or nasal intermittent positive-pressure ventilation. The heated humidified high-flow nasal cannula (HHHFNC) is gaining popularity in clinical practice.

OBJECTIVES

To address the clinical effectiveness of HHHFNC compared with usual care for preterm infants we systematically reviewed the evidence of HHHFNC with usual care following ventilation (the primary analysis) and with no prior ventilation (the secondary analysis). The primary outcome was treatment failure defined as the need for reintubation (primary analysis) or intubation (secondary analysis). We also aimed to assess the cost-effectiveness of HHHFNC compared with usual care if evidence permitted.

DATA SOURCES

The following databases were searched: MEDLINE (2000 to 12 January 2015), EMBASE (2000 to 12 January 2015), The Cochrane Library (issue 1, 2015), ISI Web of Science (2000 to 12 January 2015), PubMed (1 March 2014 to 12 January 2015) and seven trial and research registers. Bibliographies of retrieved citations were also examined.

REVIEW METHODS

Two reviewers independently screened all titles and abstracts to identify potentially relevant studies for inclusion in the review. Full-text copies were assessed independently. Data were extracted and assessed for risk of bias. Summary statistics were extracted for each outcome and, when possible, data were pooled. A meta-analysis was only conducted for the primary analysis, using fixed-effects models. An economic evaluation was planned.

RESULTS

Clinical evidence was derived from seven randomised controlled trials (RCTs): four RCTs for the primary analysis and three RCTs for the secondary analysis. Meta-analysis found that only for nasal trauma leading to a change of treatment was there a statistically significant difference, favouring HHHFNC over NCPAP [risk ratio (RR) 0.21, 95% confidence interval (CI) 0.10 to 0.42]. For the following outcomes, there were no statistically significant differences between arms: treatment failure (reintubation < 7 days; RR 0.76, 95% CI 0.54 to 1.09), bronchopulmonary dysplasia (RR 0.92, 95% CI 0.72 to 1.17), death (RR 0.56, 95% CI 0.22 to 1.44), pneumothorax (RR 0.33, 95% CI 0.03 to 3.12), intraventricular haemorrhage (grade ≥ 3; RR 0.41, 95% CI 0.15 to 1.15), necrotising enterocolitis (RR 0.41, 95% CI 0.15 to 1.14), apnoea (RR 1.08, 95% CI 0.74 to 1.57) and acidosis (RR 1.16, 95% CI 0.38 to 3.58). With no evidence to support the superiority of HHHFNC over NCPAP, a cost-minimisation analysis was undertaken, the results suggesting HHHFNC to be less costly than NCPAP. However, this finding is sensitive to the lifespan of equipment and the cost differential of consumables.

LIMITATIONS

There is a lack of published RCTs of relatively large-sized populations comparing HHHFNC with usual care; this is particularly true for preterm infants who had received no prior ventilation.

CONCLUSIONS

There is a lack of convincing evidence suggesting that HHHFNC is superior or inferior to usual care, in particular NCPAP. There is also uncertainty regarding whether or not HHHFNC can be considered cost-effective. Further evidence comparing HHHFNC with usual care is required.

STUDY REGISTRATION

This review is registered as PROSPERO CRD42015015978.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

A multicentre, randomised controlled, non-inferiority trial, comparing nasal high flow with nasal continuous positive airway pressure as primary support for newborn infants with early respiratory distress born in Australian non-tertiary special care nurseries (the HUNTER trial): study protocol

INTRODUCTION

Nasal high-flow (nHF) therapy is a popular mode of respiratory support for newborn infants. Evidence for nHF use is predominantly from neonatal intensive care units (NICUs). There are no randomised trials of nHF use in non-tertiary special care nurseries (SCNs). We hypothesise that nHF is non-inferior to nasal continuous positive airway pressure (CPAP) as primary support for newborn infants with respiratory distress, in the population cared for in non-tertiary SCNs.

METHODS AND ANALYSIS

The HUNTER trial is an unblinded Australian multicentre, randomised, non-inferiority trial. Infants are eligible if born at a gestational age ≥31 weeks with birth weight ≥1200 g and admitted to a participating non-tertiary SCN, are <24 hours old at randomisation and require non-invasive respiratory support or supplemental oxygen for >1 hour. Infants are randomised to treatment with either nHF or CPAP. The primary outcome is treatment failure within 72 hours of randomisation, as determined by objective oxygenation, apnoea or blood gas criteria or by a clinical decision that urgent intubation and mechanical ventilation, or transfer to a tertiary NICU, is required. Secondary outcomes include incidence of pneumothorax requiring drainage, duration of respiratory support, supplemental oxygen and hospitalisation, costs associated with hospital care, cost-effectiveness, parental stress and satisfaction and nursing workload.

ETHICS AND DISSEMINATION

Multisite ethical approval for the study has been granted by The Royal Children's Hospital, Melbourne, Australia (Trial Reference No. 34222), and by each participating site. The trial is currently recruiting in eight centres in Victoria and New South Wales, Australia, with one previous site no longer recruiting. The trial results will be published in a peer-reviewed journal and will be presented at national and international conferences.

TRIAL REGISTRATION NUMBER

Australian and New Zealand Clinical Trials Registry (ANZCTR): ACTRN12614001203640; pre-results.

Heated Humidified High-Flow Nasal Cannula for Prevention of Extubation Failure in Preterm Infants

OBJECTIVES

To compare extubation failure rate between the heated humidified high-flow nasal cannula (HHHFNC) and continuous positive airway pressure (CPAP) groups.

METHODS

Intubated infants with gestational age (GA) <32 wk, who were ready to extubate, were randomized to receive respiratory support with either CPAP or HHHFNC after extubation. In CPAP group, nasal mask CPAP with preset pressure and fraction of inspired oxygen (FiO₂) equal to positive end-expiratory pressure (PEEP) and FiO₂ of ventilator before extubation was applied. In the HHHFNC group, predefined flow rate according to the protocol was applied. Primary outcome was extubation failure within 72 h after endotracheal tube removal.

RESULTS

Forty-nine infants were enrolled; 24 in the HHHFNC and 25 in the CPAP group. Baseline demographic and respiratory conditions before extubation were similar. There was no difference in infants who met failed extubation criteria between the two groups [8 (33%) in HHHFNC vs. 6 (24%) in CPAP group (p = 0.47)]. However, 6 infants (75%) in HHHFNC and 4 infants (66%) in CPAP group who met failed extubation criteria could be rescued by bilevel CPAP. Therefore, the reintubation rate was comparable [2 infants (8.3%) in HHHFNC vs. 2 infants (8%) in CPAP group]. Morbidities or related complications were not different but infants in the HHHFNC group had significantly less nasal trauma (16.7% vs. 44%; p = 0.03).

CONCLUSIONS

In the index study, the extubation failure rate was not statistically different between infants who were on HHHFNC or CPAP support.

The Effect of the Treatment with Heated Humidified High-Flow Nasal Cannula on Neonatal Respiratory Distress Syndrome in China: A Single-Center Experience

Background. Noninvasive respiratory support is considered the optimal method of providing assistance to preterm babies with breathing problems, including nasal continuous positive airway pressure (NCPAP) and humidified high flow nasal cannula (HHHFNC). The evidence of the efficacy and safety of HHHFNC used as the primary respiratory support for respiratory distress syndrome (RDS) is insufficient in low- and middle-income countries. Objective. To investigate the effect of heated humidified high flow nasal cannula on neonatal respiratory distress syndrome compared with nasal continuous positive airway pressure. Methods. An observational cross-sectional study was performed at a tertiary neonatal intensive care unit in suburban Wenzhou, China, in the period between January 2014 and December 2015. Results. A total of 128 infants were enrolled in the study: 65 in the HHHFNC group and 63 in the NCPAP group. The respiratory support with HHHFNC was similar to that with NCPAP with regard to the primary outcome. There is no significant difference between two groups in secondary outcomes. Comparing with NCPAP group, the incidence of nasal damage was lower in HHHFNC group. Conclusions. HHHFNC is an effective and well-tolerated strategy as the primary treatment of mild to moderate RDS in preterm infants older than 28 weeks of GA.

Physiologic Basis for Nasal Continuous Positive Airway Pressure, Heated and Humidified High-Flow Nasal Cannula, and Nasal Ventilation

Noninvasive support modalities have become ever more present in the care of newborns with a wide variety of disease processes. As clinicians have continued to avoid intubation and mechanical ventilation in preterm and term infants, the technologies available to support these groups have grown. Despite this rapid growth they can be broken down into 3 large categories of support, all attempting to deliver both flow and pressure to the nasopharynx supporting both phases of spontaneous breathing. The goal of all of the therapies is to stabilize a heterogeneous group of disorders with some common pathologies and avoid invasive support modalities.

High flow nasal cannula versus conventional oxygen therapy and non-invasive ventilation in adults with acute hypoxemic respiratory failure: A systematic review

INTRODUCTION

Humidified oxygen via a high flow nasal cannula (HFNC) is a form of supplemental oxygen therapy that has significant theoretical advantages over conventional oxygen therapy (COT). However, the clinical role of HFNC in acute hypoxemic respiratory failure (AHRF) has not been well established. This review compares the efficacy of HFNC with COT and non-invasive ventilation (NIV) in patients with AHRF.

METHODS

Studies reviewed were selected based on relevance from a systematic literature search conducted in Medline and EMBASE to include all published original research through May 2016. Twelve studies matched the inclusion criteria.

RESULTS

In the majority of the studies, HFNC was associated with superior comfort and patient tolerance as compared to NIV or COT. HFNC was associated with reduced work of breathing in comparison with COT in some, but not all, studies in the review. COT and NIV were associated with a higher 90-day mortality rate compared to HFNC in only one multicenter randomized trial versus no mortality difference reported by others. Three out of four studies demonstrated a decreased need for escalation of oxygen therapy with HFNC. Six out of eight studies demonstrated improved oxygenation with HFNC as compared to COT. Two of three studies revealed worse oxygenation with HFNC as compared to NIV.

CONCLUSION

This review suggests that HFNC may be superior to COT in AHRF patients in terms of oxygenation, patient comfort, and work of breathing. It may be reasonable to consider HFNC as an intermediate level of oxygen therapy between COT and NIV.

High Flow Nasal Cannulae versus Nasal Continuous Positive Airway Pressure in Neonates with Respiratory Distress Syndrome Managed with INSURE Method: A Randomized Clinical Trial

BACKGROUND

In recent years, various noninvasive respiratory support (NRS) of ventilation has been provided more in neonates. The aim of this study was to compare the effect of HFNC with NCPAP in post-extubation of preterm infants with RDS after INSURE method (intubation, surfactant, extubation).

METHODS

A total of 54 preterm infants with RDS (respiratory distress syndrome) were enrolled in this study. Using a randomized sequence, they were assigned into two groups after INSURE method. The first group received HFNC while the second group received NCPAP for respiratory support after extubation. A comparison was made between these two groups by the rate of reintubation, air leak syndrome, duration of oxygen therapy, hospitalization, the rate of bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH), retinopathy of prematurity (ROP), and mortality. Data were analyzed by using the SPSS version 18 software. The statistical analyses included Student's t-test for continuous data and compared proportions using Chi-squared test and Fisher's exact test for categorical data.

RESULT

The rate of reintubation was higher in the HFNC compared with the NCPAP group. The rate of either IVH or ROP had no significant differences between the two groups. In addition, duration of oxygen requirement and hospitalization were not statistically different. There was no case of BPD or mortality among these patients.

CONCLUSION

This study showed that preterm infants with RDS could manage post-extubation after INSURE method with either NCPAP or HFNC. However, in this single-center study, the rate of reintubation was higher in the HFNC group while further multicenter study might be assigned. Trial Registration Number: IRCT201201228800N1.

High flow nasal cannula in children: a literature review

High flow nasal cannula (HFNC) is a relatively new non-invasive ventilation therapy that seems to be well tolerated in children. Recently a marked increase in the use of HFNC has been seen both in paediatric and adult care settings. The aim of this study was to review the current knowledge of HFNC regarding mechanisms of action, safety, clinical effects and tolerance in children beyond the newborn period.We performed a systematic search of the databases PubMed, Medline, EMBASE and Cochrane up to 12th of May 2016. Twenty-six clinical studies including children on HFNC beyond the newborn period with various respiratory diseases hospitalised in an emergency department, paediatric intensive care unit or general ward were included. Five of these studies were interventional studies and 21 were observational studies. Thirteen studies included only children with bronchiolitis, while the other studies included children with various respiratory conditions. Studies including infants hospitalised in a neonatal ward, or adults over 18 years of age, as well as expert reviews, were not systematically evaluated, but discussed if appropriate.The available studies suggest that HFNC is a relatively safe, well-tolerated and feasible method for delivering oxygen to children with few adverse events having been reported. Different mechanisms including washout of nasopharyngeal dead space, increased pulmonary compliance and some degree of distending airway pressure may be responsible for the effect. A positive clinical effect on various respiratory parameters has been observed and studies suggest that HFNC may reduce the work of breathing. Studies including children beyond the newborn period have found that HFNC may reduce the need of continuous positive airway pressure (CPAP) and invasive ventilation, but these studies are observational and have a low level of evidence. There are no international guidelines regarding flow rates and the optimal maximal flow for HFNC is not known, but few studies have used a flow rate higher than 10 L/min for infants.Until more evidence from randomized studies is available, HFNC may be used as a supplementary form of respiratory support in children, but with a critical approach regarding effect and safety, particularly when operated outside of a paediatric intensive care unit.

Prophylactic nasal continuous positive airway pressure for preventing morbidity and mortality in very preterm infants

BACKGROUND

Cohort studies have suggested that nasal continuous positive airways pressure (CPAP) starting in the immediate postnatal period before the onset of respiratory disease (prophylactic CPAP) may be beneficial in reducing the need for intubation and intermittent positive pressure ventilation (IPPV) and in preventing bronchopulmonary dysplasia (BPD) in preterm or low birth weight infants.

OBJECTIVES

To determine if prophylactic nasal CPAP started soon after birth regardless of respiratory status in the very preterm or very low birth weight infant reduces the use of IPPV and the incidence of bronchopulmonary dysplasia (BPD) without adverse effects.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 1), MEDLINE via PubMed (1966 to 31 January 2016), EMBASE (1980 to 31 January 2016), and CINAHL (1982 to 31 January 2016). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

All trials using random or quasi-random patient allocation of very preterm infants (under 32 weeks' gestation) or less than 1500 grams at birth were eligible. We included trials if they compared prophylactic nasal CPAP started soon after birth regardless of the respiratory status of the infant with 'standard' methods of treatment such as IPPV, oxygen therapy or supportive treatment. We excluded studies where prophylactic CPAP was compared with CPAP along with other interventions.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane and its Neonatal Review Group, including independent study selection, assessment of trial quality and extraction of data by two authors. Data were analysed using risk ratio (RR) and the meta-analysis was performed using a fixed-effect model.

MAIN RESULTS

Seven trials recruiting 3123 babies were included in the meta-analysis. Four trials recruiting 765 babies compared CPAP with supportive care and three trials (2364 infants) compared CPAP with mechanical ventilation. Apart from a lack of blinding of the intervention all studies were of low risk of bias.In the comparison of CPAP with supportive care there was a reduction in failed treatment (typical risk ratio (RR) 0.66, 95% confidence interval (CI) 0.45 to 0.98; typical risk difference (RD) -0.16, 95% CI -0.34 to 0.02; 4 studies, 765 infants, very low quality evidence). There was no reduction in bronchopulmonary dysplasia (BPD) or mortality.In trials comparing CPAP with assisted ventilation with or without surfactant, CPAP resulted in a small but clinically significant reduction in the incidence of BPD at 36 weeks, (typical RR 0.89, 95% CI 0.79 to 0.99; typical RD -0.04, 95% CI -0.08 to 0.00; 3 studies, 772 infants, moderate-quality evidence); and death or BPD (typical RR 0.89, 95% CI 0.81 to 0.97; typical RD -0.05, 95% CI -0.09 to 0.01; 3 studies, 1042 infants, moderate-quality evidence). There was also a clinically important reduction in the need for mechanical ventilation (typical RR 0.50, 95% CI 0.42 to 0.59; typical RD -0.49, 95% CI -0.59 to -0.39; 2 studies, 760 infants, moderate-quality evidence); and the use of surfactant in the CPAP group (typical RR 0.54, 95% CI 0.40 to 0.73; typical RD -0.41, 95% CI -0.54 to -0.28; 3 studies, 1744 infants, moderate-quality evidence).

AUTHORS' CONCLUSIONS

There is insufficient evidence to evaluate prophylactic CPAP compared to oxygen therapy and other supportive care. However when compared to mechanical ventilation prophylactic nasal CPAP in very preterm infants reduces the need for mechanical ventilation and surfactant and also reduces the incidence of BPD and death or BPD.

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.

High Flow Nasal Cannula Use Is Associated with Increased Morbidity and Length of Hospitalization in Extremely Low Birth Weight Infants

OBJECTIVE

To determine differences in the incidence of bronchopulmonary dysplasia (BPD) or death in extremely low birth weight infants managed on high flow nasal cannula (HFNC) vs continuous positive airway pressure (CPAP).

STUDY DESIGN

This is a retrospective data analysis from the Alere Neonatal Database for infants born between January 2008 and July 2013, weighing ≤1000 g at birth, and received HFNC or CPAP. Baseline demographics, clinical characteristics, and neonatal outcomes were compared between the infants who received CPAP and HFNC, or HFNC ± CPAP. Multivariable regression analysis was performed to control for the variables that differ in bivariate analysis.

RESULTS

A total of 2487 infants met the inclusion criteria (941 CPAP group, 333 HFNC group, and 1546 HFNC ± CPAP group). The primary outcome of BPD or death was significantly higher in the HFNC group (56.8%) compared with the CPAP group (50.4%, P < .05). Similarly, adjusted odds of developing BPD or death was greater in the HFNC ± CPAP group compared with the CPAP group (OR 1.085, 95% CI 1.035-1.137, P = .001). The number of ventilator days, postnatal steroid use, days to room air, days to initiate or reach full oral feeds, and length of hospitalization were significantly higher in the HFNC and HFNC ± CPAP groups compared with the CPAP group.

CONCLUSIONS

In this retrospective study, use of HFNC in extremely low birth weight infants is associated with a higher risk of death or BPD, increased respiratory morbidities, delayed oral feeding, and prolonged hospitalization. A large clinical trial is needed to evaluate long-term safety and efficacy of HFNC in preterm infants.

Nitric oxide in paediatric respiratory disorders: novel interventions to address associated vascular phenomena?

Nitric oxide (NO) has a significant role in modulating the respiratory system and is being exploited therapeutically. Neonatal respiratory failure can affect around 2% of all live births and is responsible for over one third of all neonatal mortality. Current treatment method with inhaled NO (iNO) has demonstrated great benefits to patients with persistent pulmonary hypertension, bronchopulmonary dysplasia and neonatal respiratory distress syndrome. However, it is not without its drawbacks, which include the need for patients to be attached to mechanical ventilators. Notably, there is also a lack of identification of subgroups amongst abovementioned patients, and homogeneity in powered studies associated with iNO, which is one of the limitations. There are significant developments in drug delivery methods and there is a need to look at alternative or supplementary methods of NO delivery that could reduce current concerns. The addition of NO-independent activators and stimulators, or drugs such as prostaglandins to work in synergy with NO donors might be beneficial. It is of interest to consider such delivery methods within the respiratory system, where controlled release of NO can be introduced whilst minimizing the production of harmful byproducts. This article reviews current therapeutic application of iNO and the state-of-the-art technology methods for sustained delivery of NO that may be adapted and developed to address respiratory disorders. We envisage this perspective would prompt active investigation of such systems for their potential clinical benefit.

Neonatal pneumonia in sub-Saharan Africa

Neonatal pneumonia is a devastating condition. Most deaths in sub-Saharan Africa can be attributed to preventable diseases, including pneumonia, diarrhoea and malaria, which together killed an estimated 2.2 million children under the age of 5 years in 2012, accounting for a third of all under-five deaths in this region. Some countries are making progress in reducing mortality through community-based health schemes; however, most countries in this region are far from achieving the World Health Organization Sustainable Development Goals for reducing childhood morbidity and mortality. The microorganisms causing neonatal pneumonia are well known. Both bacteria and viruses are commonly responsible, while fungal organisms occur in the context of nosocomial disease, and parasites occur in HIV-infected children. The common bacterial pathogens are group B streptococci (and other streptococcal species) and Gram-negative organisms, most notably Escherichia coli and Klebsiella spp. The viruses that predominate are the common respiratory pathogens, namely respiratory syncytial virus, human rhinovirus, and influenza virus. Viral disease is often nosocomial and transmitted to infected neonates in the neonatal intensive care unit or other neonatal facilities by infected parents and staff. Neonatal pneumonia often presents with non-specific respiratory distress in newborns. In the premature infant it is often indistinguishable from surfactant deficiency-associated respiratory distress syndrome. Therefore, diagnostic testing that is cheap and reliable is urgently sought in this region. All neonates with pneumonia must receive broad-spectrum antibiotic cover. This usually entails the combination of penicillin and an aminoglycoside. A lack of appropriate drugs and neonatal intensive care unit facilities are hampering progress in managing neonatal pneumonia.

High flow nasal cannula for respiratory support in preterm infants

BACKGROUND

High flow nasal cannulae (HFNC) are small, thin, tapered binasal tubes that deliver oxygen or blended oxygen/air at gas flows of more than 1 L/min. HFNC are increasingly being used as a form of non-invasive respiratory support for preterm infants.

OBJECTIVES

To compare the safety and efficacy of HFNC with other forms of non-invasive respiratory support in preterm infants.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 1), MEDLINE via PubMed (1966 to 1 January 2016), EMBASE (1980 to 1 January 2016), and CINAHL (1982 to 1 January 2016). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised trials comparing HFNC with other non-invasive forms of respiratory support in preterm infants immediately after birth or following extubation.

DATA COLLECTION AND ANALYSIS

The authors extracted and analysed data, and calculated risk ratio, risk difference and number needed to treat for an additional beneficial outcome.

MAIN RESULTS

We identified 15 studies for inclusion in the review. The studies differed in the interventions compared (nasal continuous positive airway pressure (CPAP), nasal intermittent positive pressure ventilation (NIPPV), non-humidified HFNC, models for delivering HFNC), the gas flows used and the indications for respiratory support (primary support from soon after birth, post-extubation support, weaning from CPAP support). When used as primary respiratory support after birth compared to CPAP (4 studies, 439 infants), there were no differences in the primary outcomes of death (typical risk ratio (RR) 0.36, 95% CI 0.01 to 8.73; 4 studies, 439 infants) or chronic lung disease (CLD) (typical RR 2.07, 95% CI 0.64 to 6.64; 4 studies, 439 infants). HFNC use resulted in longer duration of respiratory support, but there were no differences in other secondary outcomes. One study (75 infants) showed no differences between HFNC and NIPPV as primary support. Following extubation (total 6 studies, 934 infants), there were no differences between HFNC and CPAP in the primary outcomes of death (typical RR 0.77, 95% CI 0.43 to 1.36; 5 studies, 896 infants) or CLD (typical RR 0.96, 95% CI 0.78 to 1.18; 5 studies, 893 infants). There was no difference in the rate of treatment failure (typical RR 1.21, 95% CI 0.95 to 1.55; 5 studies, 786 infants) or reintubation (typical RR 0.91, 95% CI 0.68 to 1.20; 6 studies, 934 infants). Infants randomised to HFNC had reduced nasal trauma (typical RR 0.64, 95% CI 0.51 to 0.79; typical risk difference (RD) -0.14, 95% CI -0.20 to -0.08; 4 studies, 645 infants). There was a small reduction in the rate of pneumothorax (typical RR 0.35, 95% CI 0.11 to 1.06; typical RD -0.02, 95% CI -0.03 to -0.00; 5 studies 896 infants) in infants treated with HFNC. Subgroup analysis found no difference in the rate of the primary outcomes between HFNC and CPAP in preterm infants in different gestational age subgroups, though there were only small numbers of extremely preterm and late preterm infants. One trial (28 infants) found similar rates of reintubation for humidified and non-humidified HFNC, and two other trials (100 infants) found no difference between different models of equipment used to deliver humidified HFNC. For infants weaning from non-invasive respiratory support (CPAP), two studies (149 infants) found that preterm infants randomised to HFNC had a reduced duration of hospitalisation compared with infants who remained on CPAP.

AUTHORS' CONCLUSIONS

HFNC has similar rates of efficacy to other forms of non-invasive respiratory support in preterm infants for preventing treatment failure, death and CLD. Most evidence is available for the use of HFNC as post-extubation support. Following extubation, HFNC is associated with less nasal trauma, and may be associated with reduced pneumothorax compared with nasal CPAP. Further adequately powered randomised controlled trials should be undertaken in preterm infants comparing HFNC with other forms of primary non-invasive support after birth and for weaning from non-invasive support. Further evidence is also required for evaluating the safety and efficacy of HFNC in extremely preterm and mildly preterm subgroups, and for comparing different HFNC devices.

Post-extubation atelectasis in newborns with surgical diseases: a report of two cases involving the use of a high-flow nasal cannula

Atelectasis is a pulmonary disorder that lengthens the hospitalization time of newborns in intensive care units, resulting in increased morbidity among these infants. High-flow nasal cannulae have been used in newborns to prevent atelectasis and/or expand pulmonary regions affected by atelectasis; however, to date, no evidence-based data regarding this approach have been reported. In this paper, we report on the cases of two male newborn patients. The first and second patients described in this report were hospitalized for a neurosurgical procedure and the treatment of abdominal disease, respectively, and were subjected to invasive mechanical ventilation for 4 and 36 days, respectively. After extubation, these patients continued receiving oxygen therapy but experienced clinical and radiological worsening typical of atelectasis. In both cases, by 24 hours after the implantation of an high-flow nasal cannulae to provide noninvasive support, radiological examinations revealed the complete resolution of atelectasis. In these cases, the use of an high-flow nasal cannulae was effective in reversing atelectasis. Thus, this approach may be utilized as a supplemental noninvasive ventilatory therapy to avoid unnecessary intubation.

Heated Humidified High-Flow Nasal Cannula for Weaning from Continuous Positive Airway Pressure in Preterm Infants: A Randomized Controlled Trial

BACKGROUND

Heated humidified high-flow nasal cannula (HHHFNC) therapy has been widely used in preterm infants. However, evidence to support its use as a continuous positive airway pressure (CPAP) weaning method is still controversial.

OBJECTIVES

We aimed to compare time to wean directly off CPAP vs. weaning by using HHHFNC.

METHODS

Infants with a gestational age (GA) of <32 weeks who met the predefined criteria for weaning off CPAP, i.e. with a CPAP of ≤6 cm H2O and a fraction of inspired oxygen (FiO2) of ≤0.3 for at least 24 h, were randomly assigned to wean by using HHHFNC or wean directly from CPAP. In the HHHFNC group, flow rate was reduced by 1 liter/min every 24 h to 2-3 liters/min depending on body weight (i.e. < or ≥1,000 g), and then HHHFNC was discontinued. In the CPAP group, pressure was reduced by 1 cm H2O every 24 h until stable on CPAP 4 cm H2O and then discontinued. The primary outcome was the time it took to wean off the use of the CPAP or HHHFNC devices.

RESULTS

One-hundred and one infants were enrolled, 51 in the HHHFNC and 50 in the CPAP group. Both groups had similar demographics and respiratory conditions before enrollment. There was no difference in time to successfully wean between the 2 groups [median (IQR): 11 (4-21) days in the HHHFNC group vs. 11 (4-29) days in the CPAP group; p = 0.12]. There were no differences in morbidities or related complications. Infants in the HHHFNC group had significantly less nasal trauma (20 vs. 42%; p = 0.01).

CONCLUSIONS

In our study, the time to wean off CPAP using HHHFNC was not different from when weaning directly from CPAP.

Randomised controlled trial of weaning strategies for preterm infants on nasal continuous positive airway pressure

BACKGROUND

The optimal strategy for weaning very preterm infants from nasal continuous positive airway pressure (NCPAP) is unclear. Reported strategies include weaning NCPAP to a predefined pressure then trialling stopping completely (abrupt wean); alternate periods of increased time off NCPAP whilst reducing time on until the infant is completely weaned (gradual wean); and using high flow nasal cannula (HFNC) to assist the weaning process. The aim of this study was to determine the optimal weaning from NCPAP strategy for very preterm infants.

METHODS

A pilot single centre, factorial design, 4-arm randomised controlled trial. Sixty infants born <30 weeks gestation meeting stability criteria on NCPAP were randomly allocated to one of four groups. Group 1: abrupt wean with HFNC; Group 2: abrupt wean without HFNC; Group 3: gradual wean with HFNC; Group 4: gradual wean without HFNC. The primary outcomes were duration of respiratory support, chronic lung disease, length of hospital stay and time to full suck feeds.

RESULTS

The primary outcome measures were not significantly different between groups. Group 1 had a significant reduction in duration of NCPAP (group 1: median 1 day; group 2: 24 days; group 3: 15 days; group 4: 24 days; p = 0.002) and earlier corrected gestational age off NCPAP. There was a significant difference in rate of parental withdrawal from the study, with group 2 having the highest rate. Group 3 had a significantly increased duration on HFNC compared to group 1.

CONCLUSIONS

Use of high flow nasal cannula may be effective at weaning infants from NCPAP but did not reduce duration of respiratory support or time to full suck feeds. Abrupt wean without the use of HFNC was associated with an increased rate of withdrawal by parent request.

TRIAL REGISTRATION

This study is registered at the Australian New Zealand Clinical Trials Registry ( www.anzctr.org.au/). (Registration Number =  ACTRN12610001003066).

Weaning preterm infants from continuous positive airway pressure: evidence for best practice

BACKGROUND

Nasal continuous positive airway pressure (NCPAP) is frequently used in preterm infants. However, there is no consensus on when and how to wean them from NCPAP.

DATA SOURCES

Based on recent publications, we have reviewed the criteria of readiness-to-wean and factors affecting weaning success. A special focus is placed on the methods of weaning from NCPAP in preterm infants.

RESULTS

Practical points of when and how to wean from NCPAP in preterm infants are explained. Preterm infants are ready to be weaned from NCPAP when they are stable on a low NCPAP pressure with no (or minimal) oxygen requirement. Methods used to wean from NCPAP include: sudden weaning of NCPAP, gradual decrease of NCPAP pressure, graded-timeoff NCPAP (cycling), weaning to high or low flow nasal cannula, and a combination of these methods. The best strategy for weaning is yet to be determined. Cyclingoff NCPAP increases the duration of NCPAP and length of hospital stay without beneficial effect on success of weaning. Gradual decrease of NCPAP pressure is more physiological and better tolerated than cycling-off NCPAP.

CONCLUSION

Further studies are needed to reach a consensus regarding the optimal timing and the best method for weaning from NCPAP in preterm infants.

A multicentre, randomised controlled, non-inferiority trial, comparing high flow therapy with nasal continuous positive airway pressure as primary support for preterm infants with respiratory distress (the HIPSTER trial): study protocol

INTRODUCTION

High flow (HF) therapy is an increasingly popular mode of non-invasive respiratory support for preterm infants. While there is now evidence to support the use of HF to reduce extubation failure, there have been no appropriately designed and powered studies to assess the use of HF as primary respiratory support soon after birth. Our hypothesis is that HF is non-inferior to the standard treatment--nasal continuous positive airway pressure (NCPAP)--as primary respiratory support for preterm infants.

METHODS AND ANALYSIS

The HIPSTER trial is an unblinded, international, multicentre, randomised, non-inferiority trial. Eligible infants are preterm infants of 28-36(+6) weeks' gestational age (GA) who require primary non-invasive respiratory support for respiratory distress in the first 24 h of life. Infants are randomised to treatment with either HF or NCPAP. The primary outcome is treatment failure within 72 h after randomisation, as determined by objective oxygenation, blood gas, and apnoea criteria, or the need for urgent intubation and mechanical ventilation. Secondary outcomes include the incidence of intubation, pneumothorax, bronchopulmonary dysplasia, nasal trauma, costs associated with hospital care and parental stress. With a specified non-inferiority margin of 10%, using a two-sided 95% CI and 90% power, the study requires 375 infants per group (total 750 infants).

ETHICS AND DISSEMINATION

Ethical approval has been granted by the relevant human research ethics committees at The Royal Women's Hospital (13/12), The Royal Children's Hospital (33144A), The Mercy Hospital for Women (R13/34), and the South-Eastern Norway Regional Health Authority (2013/1657). The trial is currently recruiting at 9 centres in Australia and Norway. The trial results will be published in peer-reviewed international journals, and presented at national and international conferences.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry ID: ACTRN12613000303741.

Strategies for the discontinuation of humidified high flow nasal cannula (HHFNC) in preterm infants

BACKGROUND

Humidified high flow nasal cannula (HHFNC) delivers humidified gas at increased flow rates via binasal prongs and is becoming widely accepted as a method of non-invasive respiratory support for preterm infants. While indications for the use of (HHFNC) and its associated risks and benefits are being investigated, the best strategy for the discontinuation of HHFNC remains unknown. At what point an infant is considered stable enough to attempt to start withdrawing their HHFNC is not known. The criteria for a failed attempt at HHFNC discontinuation is also unclear.

OBJECTIVES

To determine the risks and benefits of different strategies used for the discontinuation of HHFNC in preterm infants.

SEARCH METHODS

We searched the Cochrane Neonatal Review Group Specialized Register, PubMed (1966 to March 2015), CINAHL (1982 to March 2015), EMBASE (1980 to March 2015), and the Cochrane Central Register of Controlled Trials (CENTRAL). Also, we checked previous reviews, including cross references. We searched for following web sites for ongoing trials: ClinicalTrials.gov and controlled-trials.com.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs in which either individual newborn infants or clusters of infants (such as separate neonatal units) were randomised to different HHFNC withdrawal strategies (from the first time they come off HHFNC and any subsequent weaning, or withdrawal attempt, or both).

DATA COLLECTION AND ANALYSIS

We used standard methods of Cochrane and the Cochrane Neonatal Review Group.

MAIN RESULTS

We identified no eligible studies examining the best strategy to wean or withdraw HHFNC once started as respiratory support in preterm infants

AUTHORS' CONCLUSIONS

There is currently no evidence available to suggest the best strategy for weaning and withdrawing HHFNC as a respiratory support in preterm infants. Research is required into the best strategy for withdrawal of HHFNC and to which subgroups this applies. Clear criteria for the definition of stability prior to attempting to withdraw HHFNC needs to be established. Furthermore, clear definitions are needed as to what constitutes failure of HHFNC.

High flow nasal cannula for continuous positive airway pressure weaning in preterm neonates: A single-centre experience

AIM

High flow nasal cannula therapy (HFNC) is an emerging method of non-invasive respiratory support therapy for premature infants. Recent evidence around its safety and efficacy for post-extubation respiratory support is encouraging. However, its effect on long-term respiratory outcomes is not known. The aim of this study is to determine the effect of HFNC on respiratory outcomes (chronic lung disease (CLD), need for home oxygen) when used to wean babies from continuous positive airway pressure (CPAP).

METHODS

This retrospective study compared respiratory outcomes in infants born <32 weeks gestation needing any respiratory support at birth in two epochs - epoch I (2004-2007) verus epoch II (2008-2011). HFNC was available to be used as a CPAP weaning modality in epoch II.

RESULTS

A total of 1286 infants (epoch I: 597 vs. epoch II: 689), mean (standard deviation) gestation, 28.1 (2.2) versus 28.5 (2.3) weeks were enrolled, with 222 (32%) receiving HFNC in epoch II. Overall median duration of respiratory support increased by 150 h in epoch II (P = 0.03), primarily as HFNC hours. A reduction in duration of invasive ventilation and CPAP along with 6% (P = 0.01) reduction in CLD rates was observed in epoch II. No change in home oxygen therapy rates was noted. In logistic regression, HFNC had no significant effect on rates of CLD or home oxygen.

CONCLUSIONS

Introduction of HFNC for weaning nasal CPAP seems to have a minimal effect on CLD rates. The effect of HFNC on long-term outcomes needs to be further evaluated.

Unraveling the Links Between the Initiation of Ventilation and Brain Injury in Preterm Infants

The initiation of ventilation in the delivery room is one of the most important but least controlled interventions a preterm infant will face. Tidal volumes (V T) used in the neonatal intensive care unit are carefully measured and adjusted. However, the V Ts that an infant receives during resuscitation are usually unmonitored and highly variable. Inappropriate V Ts delivered to preterm infants during respiratory support substantially increase the risk of injury and inflammation to the lungs and brain. These may cause cerebral blood flow instability and initiate a cerebral inflammatory cascade. The two pathways increase the risk of brain injury and potential life-long adverse neurodevelopmental outcomes. The employment of new technologies, including respiratory function monitors, can improve and guide the optimal delivery of V Ts and reduce confounders, such as leak. Better respiratory support in the delivery room has the potential to improve both respiratory and neurological outcomes in this vulnerable population.

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.

The evidence for high flow nasal cannula devices in infants

High flow nasal cannula (HFNC) devices deliver an adjustable mixture of heated and humidified oxygen and air at a variable flow rate. Over recent years HFNC devices have become a frequently used method of non-invasive respiratory support in infants and preterm neonates that is generally popular amongst clinicians and nursing staff due to ease of use and being well tolerated by patients. Despite this rapid adoption relatively little is known about the exact mechanisms of action of HFNC however and only recently have data from randomised controlled trials started to become available. We describe the features of a modern HFNC device and discuss current knowledge about the mechanisms of action and results of clinical studies in preterm neonates and infants with bronchiolitis. We also highlight future areas of research that are likely to increase our understanding, inform best clinical practice and strengthen the evidence base for the use of HFNC.

High-flow nasal cannula therapy for respiratory support in children

BACKGROUND

Respiratory support is a central component of the management of critically ill children. It can be delivered invasively via an endotracheal tube or non-invasively via face mask, nasal mask, nasal cannula or oxygen hood/tent. Invasive ventilation can be damaging to the lungs, and the tendency to use non-invasive forms is growing. However, non-invasive delivery is often poorly tolerated by children. High-flow nasal cannula (HFNC) oxygen delivery is a relatively new therapy that shows the potential to reduce the need for intubation and be better tolerated by children than other non-invasive forms of support. HFNC therapy differs from other non-invasive forms of treatment in that it delivers heated, humidified and blended air/oxygen via nasal cannula at rates > 2 L/kg/min. This allows the user to deliver high concentrations of oxygen and to potentially deliver continuous distending pressure; this treatment often is better tolerated by the child.

OBJECTIVES

To determine whether HFNC therapy is more effective than other forms of non-invasive therapy in paediatric patients who require respiratory support.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 4); MEDLINE via PubMed (January 1966 to April 2013); EMBASE (January 1980 to April 2013); CINAHL (1982 to April 2013); and LILACS (1982 to April 2013). Abstracts from conference proceedings, theses and dissertations and bibliographical references to relevant studies were also searched. We applied no restriction on language.

SELECTION CRITERIA

We planned to included randomized controlled trials (RCTs) and quas-randomized trials comparing HFNC therapy with other forms of non-invasive respiratory support for children. Non-invasive support encompassed cot, hood or tent oxygen; low-flow nasal cannulae (flow rates ≤ 2 L/min); and continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP) delivered via facial or nasal mask/cannula. Treatment failure was defined by the need for additional respiratory support. We excluded children with a diagnosis of bronchiolitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed all studies for selection and data extraction. We used standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

Our search yielded 922 records. A total of 109 relevant records were retrieved with reference to our search criteria. After duplicates and irrelevant studies were removed, 69 studies were further scrutinized. Of these, 11 studies involved children. No study matched our inclusion criteria.

AUTHORS' CONCLUSIONS

Based on the results of this review, no evidence is available to allow determination of the safety or effectiveness of HFNC as a form of respiratory support in children.

Definitions of extubation success in very premature infants: a systematic review

OBJECTIVE

Studies of extubation in preterm infants often define extubation success as a lack of reintubation within a specified time window. However, the duration of observation that defines extubation success in preterm infants has not been validated. The purpose of this study was to systematically review published definitions of extubation success in very preterm infants and to analyse the effect of the definition of extubation success on the reported rates of reintubation.

DESIGN

Studies including very preterm infants published between 1 January 2002 and 30 June 2012 that reported reintubation as an outcome were reviewed for definitions of extubation success. Stepwise multivariable linear regression was used to explore variables associated with rate of reintubation.

RESULTS

Two independent reviewers performed the search with excellent agreement (κ=0.93). Of the 44 eligible studies, 31 defined a window of observation that ranged from 12 to 168 h (7 days). Extubation and reintubation criteria were highly variable. The mean±SD reintubation rate across all studies was 25±9%. In studies of infants with median birth weight (BW) ≤1000 g, reintubation rates steadily increased as the window of observation increased, without apparent plateau (p = 0.001). This trend was not observed in studies of larger infants (p = 0.85).

CONCLUSIONS

Variability in the reported definitions of extubation success makes it difficult to compare extubation strategies across studies. The appropriate window of observation following extubation may depend on the population. In infants with BW ≤1000 g, even a week of observation may fail to identify some who will require reintubation.

Safety and Long Term Outcomes with High Flow Nasal Cannula Therapy in Neonatology: A Large Retrospective Cohort Study

OBJECTIVE

High flow nasal cannula therapy (HFT) has been shown to be similar to nasal continuous positive airway pressure (nCPAP) in neonates with respect to avoiding intubation. The objective of the current study is to determine if there are trends for adverse safety and long-term respiratory outcomes in very low birth weight infants (<1500 g) from centers using HFT as their primary mode of non-invasive respiratory support compared to data from the largest neonatal outcomes database (Vermont Oxford Network; VON).

METHODS

A multicenter, retrospective analysis of pulmonary outcomes data was performed for the calendar years 2009, 2010 and 2011. Performance of five HFT centers was compared with population outcomes from the VON database. The five HFT centers routinely use flow rates between 4-8 L/min as described by the mechanistic literature. Weighted average percentages from the five HFT centers were calculated, along with the 95% confidence intervals (CI) to allow for comparison to the VON means.

RESULTS

Patient characteristics between the HFT centers and the VON were not different in any meaningful way, despite the HFT having a greater percentage of smaller infants. The average VON center primarily used nCPAP (69% of all infants) whereas the HFT centers primarily used HFT (73%). A lesser percentage of VLBW infants in the HFT cohort experienced mortality and nosocomial infection. Compared to VON data, an appreciably lesser percent of the HFT cohort were receiving oxygen at 36 weeks and less went home on oxygen.

CONCLUSIONS

Considering there was no trend for adverse events, and there was a trend for better outcomes pertaining to long-term oxygen use, these data support claims of safety for HFT as a routine respiratory management strategy in the NICU.

The potential of non-invasive ventilation to decrease BPD

Bronchopulmonary dysplasia (BPD), the most common chronic lung disease in infancy, has serious long-term pulmonary and neurodevelopmental consequences right up to adulthood, and is associated with significant healthcare costs. BPD is a multifactorial disease, with genetic and environmental factors interacting to culminate in the characteristic clinical and pathological phenotype. Among the environmental factors, invasive endotracheal tube ventilation is considered a critical contributing factor to the pathogenesis of BPD. Since BPD currently has no specific preventive or effective therapy, considerable interest has focused on the use of non-invasive ventilation as a means to potentially decrease the incidence of BPD. This article reviews the progress made in the last 5 years in the use of nasal continuous positive airways pressure (NCPAP) and nasal intermittent positive pressure ventilation (NIPPV) as it pertains to impacting on BPD rates. Research efforts are summarized, and some guidelines are suggested for clinical use of these techniques in neonates.

High-flow nasal cannula oxygen for bronchiolitis in a pediatric ward: a pilot study

High-flow nasal cannula (HFNC) is a widely used ventilatory support in children with bronchiolitis in the intensive care setting. No data is available on HFNC use in the general pediatric ward. The aim of this study was to evaluate the feasibility of HFNC oxygen therapy in infants hospitalized in a pediatric ward for moderate-severe bronchiolitis and to assess the changes in ventilatory parameters before and after starting HFNC support. This prospective observational pilot study was carried out during the bronchiolitis season 2011-2012 in a pediatric tertiary care academic center in Italy. Interruptions of HFNC therapy and possible side effects or escalation to other forms of respiratory support were recorded. Oxygen saturation (SpO2), end-tidal carbon dioxide (ETCO2), and respiratory rate (RR), measured for a baseline period of 1 h before and at specific time intervals in 48 h after the start of HFNC were recorded. Twenty-seven infants were included (median age 1.3 months; absolute range 0.3-8.5). No adverse events, no premature HFNC therapy termination, and no escalation to other forms of respiratory support were recorded. Median SpO2 significantly increased by 1-2 points after changing from standard oxygen to HFNC (p <0.001). Median ETCO2 and RR rapidly decreased by 6-8 mmHg and 13-20 breaths per minute, respectively, in the first 3 h of HFNC therapy (p <0.001) and remained steady thereafter.

CONCLUSIONS

Use of HFNC for oxygen administration is feasible for infants with moderate-severe bronchiolitis in a general pediatric ward. In these children, HFNC therapy improves oxygen saturation levels and seems to be associated with a decrease in both ETCO2 and RR.

Use of high flow nasal cannula in critically ill infants, children, and adults: a critical review of the literature

BACKGROUND

High flow nasal cannula (HFNC) systems utilize higher gas flow rates than standard nasal cannulae. The use of HFNC as a respiratory support modality is increasing in the infant, pediatric, and adult populations as an alternative to non-invasive positive pressure ventilation.

OBJECTIVES

This critical review aims to: (1) appraise available evidence with regard to the utility of HFNC in neonatal, pediatric, and adult patients; (2) review the physiology of HFNC; (3) describe available HFNC systems (online supplement); and (4) review ongoing and planned trials studying the utility of HFNC in various clinical settings.

RESULTS

Clinical neonatal studies are limited to premature infants. Only a few pediatric studies have examined the use of HFNC, with most focusing on this modality for viral bronchiolitis. In critically ill adults, most studies have focused on acute respiratory parameters and short-term physiologic outcomes with limited investigations focusing on clinical outcomes such as duration of therapy and need for escalation of ventilatory support. Current evidence demonstrates that HFNC generates positive airway pressure in most circumstances; however, the predominant mechanism of action in relieving respiratory distress is not well established.

CONCLUSION

Current evidence suggests that HFNC is well tolerated and may be feasible in a subset of patients who require ventilatory support with non-invasive ventilation. However, HFNC has not been demonstrated to be equivalent or superior to non-invasive positive pressure ventilation, and further studies are needed to identify clinical indications for HFNC in patients with moderate to severe respiratory distress.

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.

Weaning infants from mechanical ventilation

Protracted mechanical ventilation is associated with increased morbidity and mortality in preterm infants and thus the earliest possible weaning from mechanical ventilation is desirable. Weaning protocols may be helpful in achieving more rapid reduction in support. There is no clear consensus regarding the level of support at which an infant is ready for extubation. An improved ability to predict when a preterm infant has a high likelihood of successful extubation is highly desirable. In this article, available evidence is reviewed and reasonable evidence-based recommendations for expeditious weaning and extubation are provided.