In February 2021, Siva and Reynolds published the results of a retrospective, single center, observational cohort study in Acta Paediatrica titled “Stabilisation of the preterm infant in the delivery room using nasal high flow: A 5—year retrospective analysis.” The analysis examined the clinical outcomes of premature neonates stabilized in the delivery room to determine the efficacy of high flow. It’s important to note that though the authors use the term “nasal high flow”, the center from which the data was collected exclusively used Vapotherm high velocity therapy to provide the primary support for respiratory stabilization. The authors concluded that high velocity therapy was effective for stabilization.1
Methods & Outcomes
The study analyzed the outcomes of 491 babies born before 32 weeks of gestation (between 22 weeks + 4 days and 31 weeks + 6 days) between April 2015 and March 2020 at one neonatal intensive care unit (NICU). The recorded and analyzed data included oxygen requirements, admission temperature, surfactant administration, invasive ventilation within 72 h of birth, bronchopulmonary dysplasia (BPD), and death.
There were four categories of treatment and outcomes into which the neonates were grouped. The majority of neonates were successfully stabilized via high velocity therapy as shown below.
- Group A—stabilized by high velocity therapy (n = 292, 59%)
- Group B—stabilized by positive end-expiratory pressure (PEEP) mask (n = 85, 17%)
- Group C—intubated (n = 93, 19%)
- Group D—required only low flow oxygen (LFNC) or were self-ventilating in air (SVIA) (n = 21, 4%)
For babies in Group A, it is worth noting that the starting flow rates of high velocity therapy were between 7 and 7.5 L/min. 45% of these babies received surfactant within the first 72hrs of treatment and of those, 93% received it via the less invasive surfactant administration method (LISA).
Babies in Groups B & D were heavier and more mature by comparison to Group A. Group C contained the most premature babies with the lowest weights, as shown in Table 1.
Table 1: Select Baseline Characteristics, Outcomes at Admission, and Outcomes at 72 Hours
|Group A (high velocity) n = 292||Group B (PEEP) n = 85||Group C (intubated) n = 93||Group D (SVIA) n = 21|
|Median gestational age at birth, weeks + days||28 + 1||29 + 6||25 + 2||31 + 1|
|Median birthweight||942 g||1215 g||680 g||1610 g|
|Median FiO2 at admission||25%||25%||30%||21%|
|Received surfactant within 72h of admission||45%||44%||100%||10%|
|Sustained on high velocity, SVIA, or LFNC within 72h of admission*||78%||81%||80%||100%|
* a small number of babies were transferred to a different hospital before 72h of age or their notes are missing. Those data were not included in the median calculations. This table is adapted from Siva et al.
Overall, the most premature neonates had the worst outcomes. The authors note that the babies who had to be intubated represented the sickest population in this study, but also assert that mechanical ventilation itself might have consequences and that it is accepted that avoidance of mechanical ventilation in the delivery room is associated with better outcomes.
They also point out that there were significant differences in outcomes for babies born before and after the 27 week mark and suggest that this could be an important benchmark in distinguishing neonatal populations rather than solely using <32 weeks as a denominator.
The authors conclude that high velocity therapy offers effective respiratory stabilization for most preterm neonates and call for a randomized controlled trial to achieve a definitive conclusion. In their discussion, they also point that they “use only the Vapotherm Precision Flow; [and that their] findings may not be reproducible using other HF systems, although evidence for this is lacking.”
“We currently use only the Vapotherm Precision Flow; our findings may not be reproducible using other HF systems …” —Siva et al. 2020
Vapotherm high velocity therapy is an advanced form of high flow and this distinction from other high flow systems may be meaningful. Though the authors cite a 2013 study to suggest that evidence of a distinction is lacking,2 a more recent randomized controlled trial suggest that high velocity therapy is noninferior to nCPAP and BiLevel as primary support for premature neonates.3 Similarly designed noninferiority trials of common high flow nasal cannula have not been able to show comparable outcomes to date.4,5
As high flow systems are used more and more to support the most vulnerable patient populations, it’s increasingly important for clinicians to understand the outcomes their various tools could be able to provide.
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 Siva NV, Reynolds PR. Stabilisation of the preterm infant in the delivery room using nasal high flow: A 5—year retrospective analysis. Acta Paediatr. 2021;00:1–7. https://doi.org/10.1111/apa.15824
 Yoder BA, Stoddard RA, Li M, King J, Dirnberger DR, Abbasi S. Heated, humidified high-flow nasal cannula versus nasal CPAP for respiratory support in neonates. Pediatrics. 2013;131(5):e1482-e1490.
 Lavizarri A, Colnaghi M, Ciuffini F, Veneroni C, Musumeci S, Cortinovis I, Mosca F. “Heated, humidified high-flow nasal cannula vs nasal continuous positive airway pressure for respiratory distress syndrome of prematurity – a randomized clinical noninferiority trial.” JAMA Pediatr. 2016 Aug 8.
 Roberts, Calum T., M.B., Ch.B., Louise S. Owen, M.D., Brett J. Manley, Ph.D., Dag H. Frøisland, Ph.D., Susan M. Donath, M.A., Kim M. Dalziel, Ph.D., Margo A. Pritchard, Ph.D., David W. Cartwright, M.B., B.S., Clare L. Collins, M.D., Atul Malhotra, M.D., and Peter G. Davis, M.D. for the HIPSTER Trial Investigators. “Nasal High-Flow Therapy for Primary Respiratory Support in Preterm Infants.” New England Journal of Medicine. September 22, 2016; 375:1142-1151.
 Manley, Brett J., et al. Nasal High-Flow Therapy for Newborn Infants in Special Care Nurseries. N Engl J Med 2019; 380:2031-2040. DOI: 10.1056/NEJMoa1812077