Subglottic Stenosis and Life Sustaining Measures

The July issue of NeoReviews features the most recent in an Outcomes of NICU Graduates series, Follow-up for a Preterm Infant with Subglottic Stenosis. The article chronicles the course of a 4-year-old twin girl born at 25 5/7 weeks’ gestational age with respiratory struggles during her NICU course. Multiple difficult intubation attempts and failed extubation attempts during her NICU progression ultimately led to a tracheostomy for airway safety and respiratory support before being ready for discharge. Later, she was diagnosed with subglottic and glottic stenosis requiring multiple airway procedures to repair the damage.

The consequences of intubation are rarely discussed, owing in part to the necessity and general urgency of the procedure when performed. Unfortunately, subglottic stenosis is the most common acquired airway complication with 90% of cases being related to airway trauma from intubation.¹ Though more and more extremely preterm infants are being managed on non-invasive ventilation, intubation remains an often-necessary intervention, even if just for surfactant administration.² The subglottis is the most narrow section of the airway, at only 3–4mm wide depending on the gestation of the infant, making it more susceptible to injury.¹

In the event intubation is required, one must first select the most appropriately sized endotracheal tube to avoid damage to the delicate mucosal surface.¹ Additional mechanisms to prevent injury include appropriate sedation to avoid excessive movement of the tube in the airway, and managing reflux symptoms.¹ Providers must also carefully evaluate the risk versus benefits of maintaining an infant with very low birth weight on non-invasive ventilation. Infants of less than 28 weeks gestation are more likely to suffer from apnea, and thus hypoxemia, when on non-invasive support. However, intubation and prolonged ventilation can cause chronic lung disease and even death.² While the LISA approach (less invasive surfactant administration) has been effective in avoiding intubation for infants generally >28 weeks gestation, infants born at lower gestations, specifically at the edge of viability, are likely to require intubation and prolonged ventilation.²

The skill of intubation is a difficult procedure to teach, and one difficult to have learners achieve competence and confidence in without resulting in airway injury. It is necessary for facilities to have an educational plan of action to decrease negative outcomes as much as possible. Unfortunately, despite completing pediatric residency, most providers are not competent in the skill of neonatal intubation.³ Even the best simulations and manikins do not adequately prepare fellows for intubation due to the lack of a complex clinical situation, as well as the actual look and feel of the simulators.³ There is nothing like the real act of intubating a neonate. Secretions, color, and position of airway as well as the stress, pressure, and anxiety one may feel while attempting the procedure cannot be replicated in practice settings.¹

Working in an academic center with learners present, (including residents, neonatal nurse practitioners, transport nurses, and transport respiratory therapists) there are always numerous people eager to intubate an infant when it is needed. The question then arises, how do we allow them to gain experience while protecting the most vulnerable patients? In order to best provide clinical experience and protect the most vulnerable, our unit developed an intubation algorithm to delineate who may attempt intubation and in what conditions (Figure). It is important to allow learners the opportunity to hone their skills, but to keep in mind that intubation alone creates trauma to the airway. Additionally, multiple attempts at intubation can create added damage, and can potentially require years of reconstructive procedures.

Our algorithm allows learners the opportunity to work with infants at an older gestational age initially, gaining confidence in their skills. Once they have mastered intubation in infants greater than 30 weeks gestational age, they may begin intubations on infants at 25 to 30 weeks. We continue to reserve infants less than 25 weeks for the most experienced provider available. In addition to structural harm of the airway, it is important to remember that with any episode of hypoxemia there can be damage to the neonate’s neurodevelopment. With that in mind, our algorithm strives to maintain the ability for residents and other learners to obtain experience while minimizing risk to the vulnerable NICU population.

If you have a case that you believe would make a good addition to the Outcomes of NICU Graduates feature, please consult the guidelines here.

References:

1. Marston AP, White DR. Subglottic Stenosis. Clin Perinatol. 2018;45(4):787-804. doi:10.1016/j.clp.2018.07.013
2. Schulzke SM, Stoecklin B. Update on ventilatory management of extremely preterm infants—A Neonatal Intensive Care Unit perspective. Von Ungern‐Sternberg B, ed. Pediatr Anesth. 2022;32(2):363-371. doi:10.1111/pan.14369
3. Soghier LM, Walsh HA, Goldman EF, Fratantoni KR. Simulation for Neonatal Endotracheal Intubation Training: How Different Is It From Clinical Practice? Simul Healthc J Soc Simul Healthc. 2022;17(1):e83-e90. doi:10.1097/SIH.0000000000000551