Safe sleep after 1 year of age

An 18-month-old toddler with end-stage renal disease was noted to have severe nocturnal hypoxemia episodes during a febrile illness. On physical examination, he was lean and mildly hypotonic but with normal awake gas exchange, no evidence of adenotonsillar enlargement, and no craniofacial abnormalities. Diagnostic polysomnography was performed on a standard infant mattress with a fitted sheet and blanket underneath him. At 01:00, the infant aroused from sleeping in the prone position and rotated his head to the midline (Figure 1). His face became embedded face-down in the linen and he begin to rebreathe carbon dioxide. During the next 6 minutes, there was a rapid increase in his end-tidal CO₂ of 10 torr, and a decrease in his oxygen saturation to 88%. After 6 minutes, he aroused again and turned his head to the side, resulting in a rapid normalization of gas exchange.

Figure 1. Facial entrapment during overnight polysomnogram.

Ten-minute tracing from an overnight polysomnogram in an 18-month-old with truncal hypotonia. During prone sleep, an arousal results in a head movement to the face-down position, resulting in rebreathing of carbon dioxide as evidenced by an increase in the baseline and peak end-tidal carbon dioxide by 10 torr, and a decrease in the oxygen saturation by 10%. After 6 minutes, the entrapment is terminated with an arousal and head turn to the side. EtCO2, end-tidal carbon dioxide; RLEG, Right Leg; NAP, Nasal air pressure; ORL/NS, oro-nasal thermistor; ABD, Abdomen; CAPNO, capnogram; PWAVE, plethysmograph waveform; S_aO₂’ oxygen saturation; CO₂, carbon dioxide.

QUESTION: What is the most appropriate safe sleep advice for toddlers?

ANSWER: Beyond the first year of life, safe sleep advice generally focuses on injuries related to climbing or falling out of bed. Beds should be placed as close to the ground as possible. Nothing should be placed in the crib making it easier to climb out or get tangled, including window-blind cords, curtains, or electrical cords. Care should be taken to ensure that toddlers can’t reach small items that may pose a choking hazard. In addition, as this case demonstrates, toddlers with hypotonia may also potentially experience injury related to the prone positioning, especially in a sleep environment with soft bedding.

DISCUSSION

This case highlights the risk posed by prone positioning and soft bedding in medically complex children after infancy. Sudden entrapment of the face can occur when hypotonic toddlers sleep on a standard firm infant mattress with loose linen, resulting in a rapid elevation in end-tidal CO₂ and hypoxemia triggering an arousal response.¹ In this case, the arousal resulted in a successful head turn that unobstructed the airway, but it is conceivable that an event like this could have been fatal. Most toddlers who die unexpectedly are indeed found in the prone position, face-down,² and most cases of sudden unexplained death in epilepsy (SUDEP) are also found prone.³ An elevated CO₂ arousal threshold during sleep may be observed in children with neurological impairments, such as Prader-Willi syndrome, that may further contribute to their risk of sudden death.⁴

In 1992, the American Academy of Pediatrics advised against prone sleeping for infants.⁵ Supine positioning (“back to sleep”) for infants during sleep is associated with a lower risk of the sudden infant death syndrome (SIDS).⁶ In 2016, the American Academy of Pediatrics made further “safe to sleep” recommendations for infants, including using a firm sleep surface, breastfeeding, having infants sleep in the parents’ room on a separate surface, keeping soft objects and loose bedding away from the infant’s sleep area, and consideration of a pacifier during sleep.⁷ Other recommendations included avoidance of the following; smoke exposure, alcohol/illicit drug use before or after birth, overheating or head covering, commercial sleep positioners, and cardiorespiratory monitors to reduce the risk of SIDS.⁷ The Committee further advised that “once an infant can roll from supine to prone and from prone to supine, the infant can be allowed to remain in the sleep position that he or she assumes.” However, the American Academy of Pediatrics’ policy makes no recommendations for safe sleep in the many toddlers with medical conditions resulting in decreased tone that may also place them at risk for sleep-related suffocation.

Medically complex children have more severe gastroesophageal reflux which may be exacerbated in the supine position. Prone and left lateral positioning may result in less gastroesophageal reflux in premature infants.⁸ Nevertheless, in weighing the risks of prone positioning, the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition advises against positional therapy (head elevation, lateral/prone positioning) to treat gastroesophageal reflux in sleeping infants, but does recommend to consider positioning therapy in children.⁹ However, as the present case demonstrates, the prone position also poses a risk for older medically complex children, who may need enhanced monitoring and supervision during sleep to rapidly respond to life threatening situations. Indeed, a case-control study of SUDEP found that direct supervision and monitoring devices were protective.¹⁰

SLEEP MEDICINE PEARLS

1. The current safe sleep guidelines for infants in the first year of life are essential and should be extended to older children with hypotonia of any etiology.

2. Sleep laboratories should be vigilant in their prestudy evaluation to identify children at risk for sleeping prone and with soft bedding in order to provide enhanced monitoring and supervision.

DISCLOSURE STATEMENT

All authors have seen and approved the manuscript. Work for this study was performed at Boston Children’s Hospital, Boston, MA. The authors report no conflicts of interest.