Kathleen Tinsley Research Fellow, Monash University, Department of Paediatrics
Identifying the appropriate mode of respiratory support for premature babies.
Being born too early (premature) is the leading cause of newborn death worldwide. Every year 15 million infants are born prematurely, and more than 1 million die from complications of prematurity. Lung disease is one of the most common complications of prematurity, and around 1/4 of premature babies will require breathing support. High Flow is a type of breathing support that has become very popular in premature babies, as it is more comfortable and less likely to damage skin around the nose, it is preferred by parents, and is easy to use. High Flow had not been adequately studied in babies who need breathing support soon after birth, who are currently treated with continuous positive airway pressure (CPAP). CPAP is effective, but has some disadvantages: it is bulky, requires highly trained nurses to use effectively, and can damage the skin around the nose. My PhD study, The HIPSTER Trial, compared High Flow with CPAP, and identified which group of premature babies requiring early breathing support could safely receive High Flow and benefit from its advantages, and which group should still receive early treatment with CPAP (those who are more premature, or have more severe lung disease). These findings are being used by newborn intensive care units to guide their choice of treatment for premature babies with breathing difficulties.
Abstract: The use of high-flow nasal cannula (HF) therapy as respiratory support for preterm infants is rapidly increasing, due to its perceived ease of use and other potential benefits over the standard 'non-invasive' respiratory support, continuous positive airway pressure (CPAP). The evidence from randomized trials suggests that HF is an alternative to CPAP for post-extubation support of preterm infants. Limited data are available from randomized trials comparing HF with CPAP as primary support, and few trials have included extremely preterm infants. This review discusses the proposed mechanisms of action of HF, the evidence from clinical trials of HF use in preterm infants, and proposes recommendations for evidence-based practice.
Pub.: 13 Feb '16, Pinned: 24 Aug '17
Abstract: This study aims to assess nursing perceptions of high-flow nasal cannulae (HFNC) in comparison with nasal continuous positive airway pressure (NCPAP) as post-extubation respiratory support for very preterm infants.A standardised questionnaire form was distributed in person to nursing staff in The Royal Women's Hospital neonatal unit, where HFNC had been recently introduced in the context of a clinical trial. Nursing staff were eligible to participate if they routinely cared for infants receiving respiratory support.The survey was completed by 99/144 eligible nurses. The majority of the 99 nurses surveyed felt that HFNC was less likely than NCPAP to prevent re-intubation of infants 24-26 weeks' gestation but equally likely to prevent re-intubation of infants 28-30 weeks' gestation. Nurses preferred NCPAP for post-extubation support of 24- and 26-week infants, and HFNC for 28- and 30-week infants, despite being less experienced with HFNC. Perceptions of HFNC compared with NCPAP included increased ease-of-use, improved infant comfort and reduced nasal trauma.Neonatal nurses preferred NCPAP for post-extubation support of infants <28 weeks' gestation and HFNC for infants of 28 or 30 weeks' gestation. Nurses accurately predicted varying efficacy of HFNC across different gestational ages, consistent with the findings of a contemporaneous randomised trial. In the context of clinical non-inferiority, as shown in the randomised trial, nursing preference for HFNC over NCPAP in preterm infants ≥28 weeks' gestation supports the use of HFNC as post-extubation support in this population.
Pub.: 20 Jun '14, Pinned: 24 Aug '17
Abstract: 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.To compare the safety and efficacy of HFNC with other forms of non-invasive respiratory support in preterm infants.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.Randomised or quasi-randomised trials comparing HFNC with other non-invasive forms of respiratory support in preterm infants immediately after birth or following extubation.The authors extracted and analysed data, and calculated risk ratio, risk difference and number needed to treat for an additional beneficial outcome.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.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.
Pub.: 24 Feb '16, Pinned: 24 Aug '17
Abstract: Clinicians aim to extubate preterm infants as early as possible, to minimize the risks of mechanical ventilation. Extubation is often unsuccessful owing to lung disease or inadequate respiratory drive.To conduct a systematic review and meta-analysis of interventions to improve rates of successful extubation in preterm infants.Searches were undertaken in PubMed and The Cochrane Library.The review was conducted using the methods of the Cochrane Collaboration and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were included if they were randomized clinical trials published in English, enrolled intubated preterm infants (born <37 weeks' gestation), and reported 1 or both of the primary outcomes.One thousand three hundred seventy-nine titles were screened independently by 2 investigators to assess need for full-text review. Disagreements were resolved via consensus of all authors. Where no Cochrane Review existed for an intervention, or not all identified studies were included, a new pooled analysis was performed.Primary outcomes were treatment failure or reintubation within 7 days of extubation.Fifty studies were eligible for inclusion. Continuous positive airway pressure reduced extubation failure in comparison with head-box oxygen (risk ratio [RR], 0.59; 95% CI, 0.48-0.72; number needed to treat [NNT], 6; 95% CI, 3-9). Nasal intermittent positive pressure ventilation was superior to continuous positive airway pressure in preventing extubation failure (RR, 0.70; 95% CI, 0.60-0.81; NNT, 8; 95% CI, 5-13). High-flow nasal cannula therapy and continuous positive airway pressure had similar efficacy (RR, 1.11; 95% CI, 0.84-1.47). Methylxanthines reduced extubation failure (RR, 0.48; 95% CI, 0.32-0.71; NNT, 4; 95% CI, 2-7) compared with placebo or no treatment. Corticosteroids (RR, 0.18; 95% CI, 0.04-0.97; NNT, 12; 95% CI, 6-100) and chest physiotherapy (RR, 0.32; 95% CI, 0.13-0.82; NNT, 15; 95% CI, 7-50) both reduced extubation failure rates but were associated with significant adverse effects. Doxapram did not aid successful extubation (RR, 0.80; 95% CI, 0.22-2.97).Preterm infants should be extubated to noninvasive respiratory support. Caffeine should be used routinely, while corticosteroids should be used judiciously, weighing up the competing risks of bronchopulmonary dysplasia and neurodevelopmental harm.
Pub.: 06 Dec '16, Pinned: 24 Aug '17
Abstract: 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.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.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.Australian and New Zealand Clinical Trials Registry (ANZCTR): ACTRN12614001203640; pre-results.
Pub.: 25 Jun '17, Pinned: 24 Aug '17
Abstract: 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.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).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.Australian New Zealand Clinical Trials Registry ID: ACTRN12613000303741.
Pub.: 26 Jun '15, Pinned: 24 Aug '17
Abstract: Randomised trials suggest that high-flow (HF) therapy is comparable with continuous positive airway pressure (CPAP) for postextubation respiratory support in neonates, and HF has been widely adopted in neonatal intensive care.We conducted a population-based study of very preterm infants born <32 weeks' gestation within the Australian and New Zealand Neonatal Network (ANZNN) data set from 2009 to 2012, who received respiratory support with HF.3372 very preterm infants were treated with HF. HF use in this population increased significantly from 15% in 2009 to 35% in 2012. In 2012, 53% (542/1029) of extremely preterm infants born <28 weeks' gestation received HF. 98% (3308/3372) of infants had received endotracheal ventilation or CPAP prior to receiving HF. The maximum HF gas flow was ≤8 L/min in almost all infants.HF use in extremely preterm and very preterm infants increased significantly within the ANZNN from 2009 to 2012.
Pub.: 19 Dec '15, Pinned: 24 Aug '17