SAN DIEGO—Sleep studies in infants are often a reasonable option when there is nasal obstruction, but they are not always necessary, experts said during a panel held here at the Triological Society Combined Sections Meeting.
Explore This IssueMarch 2020
Romaine Johnson, MD, MPH, associate professor of otolaryngology-head and neck surgery at the University of Texas Southwestern in Dallas, said the infant airway is more compliant and more prone to collapse. Making matters more challenging, an infant’s mechanisms for protecting itself against obstructions are not well developed.
“Things are going to be worse if they do have obstructions,” he said. “They have to breathe faster, they have low lung volumes, and everything gets worse when they get into REM sleep. So all of those things need to be considered in terms of respiratory physiology.”
Infants don’t get aroused in states of hypoxemia as adults do. Instead, there is a “vicious cycle,” and activation of dilators actually drops, just worsening the situation, he said.
Clinical signs and symptoms are poor predictors of obstructive sleep apnea (OSA) in infant patients, so Dr. Johnson is “very comfortable” using sleep studies and endoscopy liberally when OSA is suspected, he said.
Stacey Ishman, MD, MPH, surgical director of the Upper Airway Center at Cincinnati Children’s, said clinicians need to distinguish between children who need further testing and those who don’t. That is because about 25% of normal infants have some features that suggest OSA, such as noisy breathing and paradoxical breathing, in which the chest wall moves in rather than out when a breath is taken. Snoring is often not a prominent symptom in these very young children and infants, she said.
Unless I’m looking for laryngomalacia or vocal fold motion, I tend to go straight to the DISE. —Stacey Ishman, MD, MPH
Sleep study parameters that call for treatment are an obstructive apnea-hypopnea index (oAHI) above five events per hour, oxygen saturations below 90% for 2% or more of total sleep time, carbon dioxide levels of 50 mmHG for at least 10% of total sleep time or a peak partial pressure of CO2 (pCO2) of 60 mmHG, or more than five central events per hour, she said.
In a study of 1,258 children, including infants, who underwent sleep studies for suspected OSA, Dr. Ishman and colleagues found that 53.2% did have OSA. But they also found a variety of other conditions, including central sleep apnea in about 1%, periodic limb movements of sleep in 7%, hypoventilation in 7%, and non-OSA snoring in 15%. About 3% had alveolar hypoventilation syndrome, and another 2% had non-apneic hypoxemia (Otolaryngol Head Neck Surg. 2017;157:1053-1059).
This, Dr. Ishman said, suggests that, beyond OSA, “the sleep study itself may have some value in [identifying] conditions that would be treated differently.”