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High-Flow Nasal Cannulas in Pre-Term Babies

By Jonathan Pelletier

Each year, more than 500,000 babies are born pre-term. (1) The lungs are one of the last organs to develop, and so some of these pre-term babies will require breathing assistance after birth. The earlier a neonate is born, the more likely they are to require breathing assistance. This is because during the last weeks of pregnancy, fetal lungs make a substance known as “surfactant,” which helps the lungs to expand. (2) Pre-term neonates often have low levels of surfactant, meaning that their lungs are harder to expand, and their muscles have to work harder to allow them to breathe. In some cases, these neonates’ respiratory muscles can tire out, preventing them from breathing well and getting enough oxygen. Neonatal nurseries sometimes need to intervene to prevent this from happening.

There are different levels of support available. In severe cases, some neonates require the placement of a breathing tube (known as intubation) and a machine that helps them breathe (called a ventilator). Intubation and ventilation takes away the “work of breathing,” meaning that the neonate no longer has to use his or her own muscles, such as the diaphragm, to breathe. This prevents the pre-term neonates’ respiratory muscles from wearing out while their lungs mature. In some cases, highly trained doctors can also directly administer surfactant. (3)

Intubation and ventilation work as a temporary measure while the lungs mature, but the long-term goal is to wean neonates from the ventilator so that they are capable of breathing on their own. A new study published last month in the New England Journal of Medicine examined ways to help neonates through this weaning process. (4) The best way to wean neonates from ventilators is still under debate; some providers prefer a method known as “high-flow nasal cannula,” and others prefer “nasal continuous positive airway pressure (nasal CPAP).” Both methods provide continuous oxygen to the neonate through a nosepiece. The high-flow nasal cannulas are thought to be easier to use and less damaging to neonates’ noses. However, until now there was a relatively small amount of data showing that high-flow cannulas were as safe and effective as nasal CPAP. (5-8)

The study published last month showed that neonates born between 26 and 32 weeks gestation could safely and effectively be weaned off ventilation with high-flow nasal cannulas. Slightly more (8.4% more) neonates failed this treatment than failed nasal CPAP, although the difference was not statistically significant. About half (48%) of the infants that failed treatment with high flow nasal cannulas were then able to be treated with nasal CPAP or another similar method, and the rest had to have their breathing tube replaced. Those neonates that were successfully treated with high flow nasal cannulas were less likely to have damage to their nose resulting from the treatment. (4)

As with all studies, this study has its limitations. It was designed to show “non-inferiority,” which means that it can’t answer the question “do high flow nasal cannulas work better than nasal CPAP?” Also, while the difference was not statistically significant, neonates on high flow nasal cannulas were more likely to fail and require a change in their treatment than those on nasal CPAP. Finally, while the study was intended to study all infants born at less than 32 weeks gestation, the numbers were insufficient to make similar conclusions about infants born before 26 weeks gestation.

What this means for you?
Neonates born pre-term are more likely to require respiratory support than those born at term. Breathing tubes and ventilators help to keep infants alive while their lungs mature, but the eventual goal is for these children to be able to breathe on their own. The best way to transition off the ventilator is still under debate, but it may be reasonable for doctors to try less-invasive high-flow nasal cannulas in neonates born between 26 and 32 weeks first, as they cause less nasal trauma. Neonates that cannot breathe adequately with this less-invasive treatment can then be put on nasal CPAP, or, if this fails, have their breathing tube replaced.

Citations:

1. Preterm Birth. Centers for Disease Control and Prevention, 2013. (Accessed 11/3/13, at http://www.cdc.gov/reproductivehealth/maternalinfanthealth/pretermbirth.htm.)
2. Levitzky MG. Chapter 2. Mechanics of Breathing. Pulmonary Physiology. 8th ed: McGraw-Hill; 2013.
3. Respiratory distress syndrome (RDS) of the newborn. DynaMed, 2013. (Accessed 11/3/13, at https://dynamed.ebscohost.com.)
4. Manley BJ, Owen LS, Doyle LW, et al. High-flow nasal cannulae in very preterm infants after extubation. The New England journal of medicine 2013;369:1425-33.
5. Hough JL, Shearman AD, Jardine LA, Davies MW. Humidified high flow nasal cannulae: current practice in Australasian nurseries, a survey. Journal of paediatrics and child health 2012;48:106-13.
6. Manley BJ, Owen L, Doyle LW, Davis PG. High-flow nasal cannulae and nasal continuous positive airway pressure use in non-tertiary special care nurseries in Australia and New Zealand. Journal of paediatrics and child health 2012;48:16-21.
7. Campbell DM, Shah PS, Shah V, Kelly EN. Nasal continuous positive airway pressure from high flow cannula versus Infant Flow for Preterm infants. Journal of perinatology : official journal of the California Perinatal Association 2006;26:546-9.
8. Collins CL, Holberton JR, Barfield C, Davis PG. A randomized controlled trial to compare heated humidified high-flow nasal cannulae with nasal continuous positive airway pressure postextubation in premature infants. The Journal of pediatrics 2013;162:949-54 e1.