Sandeep Shetty

Review finds insufficient evidence to support the routine use of heated, humidified high-flow nasal cannula use in neonates.

A literature review was carried out following concerns about the use of heated, humidified, high‐flow nasal cannulae (HHFNC) in premature infants. Randomised trials following extubation showed that HHFNC was associated with similar or greater reintubation rates than nasal continuous positive airway pressure, but significantly better nasal trauma scores. Infections with Ralstonia bacteria were an issue.

Changes in the use of humidified high flow nasal cannula oxygen

Humidified high flow nasal cannula (HHFNC) has gained popularity in neonatal care. A systematic review1 of the results of nine trials, which included a total of 1112 infants, however, demonstrated that HHFNC was not superior to other modes of non-invasive ventilation in infants of >28 weeks gestational age. We, therefore, sought to determine whether clinical practice regarding HHFNC had changed since 2012 when all UK units were surveyed2 and also to identify why practitioners preferred HHFNC or continuous positive airway pressure (CPAP). In 2015, lead clinicians of all 194 UK neonatal units were identified from the National Neonatal Audit …

Work of breathing during CPAP and heated humidified high-flow nasal cannula

Objective To determine whether continuous positive airway pressure (CPAP) compared with heated humidified, high-flow nasal cannula (HHFNC) in infants with evolving or established bronchopulmonary dysplasia (BPD) reduced the work of breathing (WOB) and thoracoabdominal asynchrony (TAA) and improved oxygen saturation (SaO2). Design Randomised crossover study. Setting Tertiary neonatal unit. Patients 20 infants (median gestational age of 27.6 weeks (range 24.6–31.9 weeks)) were studied at a median postnatal age of 30.9 weeks (range 28.1–39.1 weeks). Interventions Infants were studied on 2 consecutive days. On the first study day, they were randomised to either CPAP or HHFNC each for 2 h, the order being reversed on the second day. Main outcome measures The WOB was assessed by measuring the pressure time product of the diaphragm (PTPdi). PTPdi, TAA and SaO2 were assessed during the final 5 min of each 2 h period and the results on the two study days were meaned. Results There were no significant differences in the results on CPAP versus HHFNC: mean PTPdi 226 (range 126–294) versus 224 cm H2O/s/min (95% CI for difference: −27 to 22; p=0.85) (range 170–318) (p=0.82), mean TAA 13.4° (range 4.51°–23.32°) versus 14.01° (range 4.25°–23.86°) (95% CI for difference: −3.9 to 2.8: p=0.73) (p=0.63) and mean SaO2 95% (range 93%–100%) versus 95% (94%–99%), (95% CI for difference −1.8 to 0.5; p=0.25) (p=0.45). Conclusion In infants with evolving or established BPD, CPAP compared with HHFNC offered no significant advantage with regard to the WOB, degree of asynchrony or oxygen saturation.

High-flow nasal cannula oxygen and nasal continuous positive airway pressure and full oral feeding in infants with bronchopulmonary dysplasia

Objective To determine whether the time to achieve full oral feeding differed between infants with bronchopulmonary dysplasia (BPD) supported by nasal continuous positive airway pressure (nCPAP) compared with those supported by nCPAP and subsequently transferred to heated, humidified, high-flow nasal cannula oxygen (HHFNC). Design Two-cohort comparison. Setting Tertiary neonatal unit. Patients –72 infants, median gestational age 27 (range 24–32) weeks in the nCPAP group, and 44 infants, median gestational age 27 (range 24–31) weeks in the nCPAP/HHFNC group. Interventions Between 2011 and 2013, infants post extubation were supported by nCPAP and from 2013 infants were supported by nCPAP and then HHFNC. Main outcome measures The postnatal age at which oral feeds were first trialled and full oral feeds established. The length of respiratory support as either nCPAP or nCPAP/HHFNC and the total length of respiratory support and hospital stay were also determined. Subanalysis was undertaken of infants requiring respiratory support beyond 34 weeks postmenstrual age (PMA). Results The postnatal age at trial of first oral feeds was earlier in the nCPAP/HHFNC group (p=0.012), but infants were a shorter time on nCPAP compared with nCPAP/HHFNC (p=0.003). On subgroup analysis, the age to achieve full oral feeds was earlier in the nCPAP/HHFNC group (p<0.001). Conclusions In infants with BPD who required respiratory support beyond 34 weeks PMA, use of nCPAP then HHFNC was associated with earlier establishment of full oral feeds. Consideration should be given to assessing stable BPD infants with regard to oral feeding while on CPAP.

Neonatal ventilation strategies and long-term respiratory outcomes.

Long-term respiratory morbidity is common, particularly in those born very prematurely and who have developed bronchopulmonary dysplasia (BPD), but it does occur in those without BPD and in infants born at term. A variety of neonatal strategies have been developed, all with short-term advantages, but meta-analyses of randomized controlled trials (RCTs) have demonstrated that only volume-targeted ventilation and prophylactic high-frequency oscillatory ventilation (HFOV) may reduce BPD. Few RCTs have incorporated long-term follow-up, but one has demonstrated that prophylactic HFOV improves respiratory and functional outcomes at school age, despite not reducing BPD. Results from other neonatal interventions have demonstrated that any impact on BPD may not translate into changes in long-term outcomes. All future neonatal ventilation RCTs should have long-term outcomes rather than BPD as their primary outcome if they are to impact on clinical practice.

G407(P) HHFNC and nCPAP and full oral feeding in BPD infants

Aims Infants born extremely prematurely and who develop bronchopulmonary dysplasia (BPD) may require respiratory support for many months, including when they could be able to take oral feeds (usually 34 weeks postmenstrual age (PMA)). Our aim was to test the hypothesis that full oral feeding in infants with BPD would be achieved earlier in those supported by humidified high flow nasal cannula (HHFNC) rather than nCPAP. Methods Data were compared from infants born prior to 33 weeks of gestational age between 2011 to 2013, who were extubated onto and supported by nCPAP until they required only low flow oxygen (nCPAP group) to those born between 2013 to 2015 who were extubated onto nCPAP and then transferred to HHFNC if they continued to require nCPAP for more than two weeks and had a supplementary oxygen requirement of less than 40% (nCPAP/HHFNC group). Results There were 72 infants in the nCPAP group and 44 infants in the nCPAP/HHFNC group. There were no significant differences with regard to gestational age or birth weight between the two groups. The PMA at trial of first oral feeds was lower (p = 0.015) and the weight at 36 weeks of gestational age (p = 0.001) was higher in the nCPAP/HHFNC group. The length of time spent on CPAP and HHFNC was longer than compared to CPAP alone in the nCPAP group (p = 0.003), but the duration of low flow oxygen was lower in the nCPAP/HHFNC group (p = 0.035). A subgroup analysis was performed of infants requiring non-invasive respiratory support after 34 weeks PMA (27 infants nCPAP group and 33 infants nCPAP/HHFNC group). The PMA at trial of first (p < 0.001) and full oral (p < 0.001) feeds was earlier in the nCPAP/HHFNC group. The duration of low flow supplementary oxygen (p = 0.002) and total length of hospital stay (p = 0.003) were lower in the nCPAP/HHFNC group. Conclusion In infants with BPD who required respiratory support beyond 34 weeks PMA, use of nCPAP then HHFNC was associated in earlier establishment of full oral feeds and a shorter length of stay.

G393 Work of breathing during CPAP and heated humidified high flow nasal cannula: Abstract G393 Table 1

Aims Heated and humidified gas delivered at flow rates between 2–8 l/min via nasal cannulae (HHFNC) is increasingly being used as an alternative to continuous positive airway pressure (CPAP). Studies comparing the work of breathing (WOB) on CPAP and HHFNC, however, have given conflicting results. Our aim was to determine in infants with evolving or established bronchopulmonary dysplasia (BPD), whether CPAP compared to HHFNC reduced the WOB and thoraco-abdominal asynchrony (TAA) and improved oxygen saturation (SaO2). Methods Infants born at less than 32 weeks of gestation and who were on CPAP and more than 40% oxygen at or beyond two weeks of age were eligible for this study. Infants were studied on two consecutive days. They were randomised on the first day to CPAP or HHFNC each for two hours and on the second day the order in which the modes was studied was reversed. The WOB was assessed by measuring the pressure time product using a dual pressure transducer tipped catheter and TAA by respiratory inductance plethysmography. WOB, TAA and SaO2 were assessed during the last five minutes at the end of each two hour period. The results from the two study periods were meaned. Results Twenty infants with a median gestational age of 28 (range 24–32) weeks and birth weight of 888 (range 512–1500) grams were studied at a median postconceptional age of 31 (range 28–39) weeks. There were no significant differences in the results (data expressed as median, range) of the physiological measurements (see Table 1).Abstract G393 Table 1 CPAP HHFNC P value TAA (degrees) 12.6 (4.5–23.3) 13.1 (4.2–23.8) 0.73 PTP (cmH20/s/min) 244 (126–294) 220 (169.5–318) 0.85 SaO2 (%) 95 (93–100) 96 (94–99) 0.48 Conclusion In infants with evolving or established BPD, CPAP compared to HHFNC offered no significant advantage with regard to the WOB, degree of asynchrony or oxygen saturation.