P0608 - Sleep Study Results After Failed Car Seat Tolerance Screens

Background/Purpose: Infants born prematurely and low birth weight (LBW, <2.5kg) are at increased risk of hypoxic and bradycardic events when placed in their car safety seats. The American Academy of Pediatrics (AAP) therefore recommends a period of observation in the car seat prior to discharge to monitor for unstable cardiorespiratory status in this semi-upright position, known as the Car Seat Tolerance Screen (CSTS). Over 500,000 infants qualify annually, and although there are growing data on incidence of failure, minimal data are available to guide follow-up after failed CSTS. One suggestion by the AAP is to consider polysomnography (PSG) to identify etiology of failed CSTS. Our objective was to describe the results of PSG in a cohort of infants who failed their CSTS.

Methods: We performed a retrospective medical record review of infants born 2012-2017 who failed an initial CSTS and underwent PSG. Inclusion criteria for CSTS include preterm birth (<37 weeks) or LBW. We identified clinical and demographic variables as well PSG results and presented descriptive statistics.

Results: We identified 13 subjects who failed an initial CSTS and underwent PSG. Of these, 69% were male, 31% were small for gestational age (<10%tile at birth), 46% were born via c-section, 31% were born with meconium stained amniotic fluid although none were diagnosed with meconium aspiration syndrome, and 23% required supplemental oxygen at 36 weeks post-menstrual age. [Table 1] Sixty-nine percent failed due to desaturations and the remainder failed due to both desaturations and bradycardia. The majority (69%) failed their CSTS while admitted to the nursery but all eventually required NICU admission. Over half underwent bedside upper airway evaluation by otolaryngology and 60% of those had some mild airway abnormality (laryngomalacia or airway edema). All 13 had abnormal PSG results with 67% diagnosed with obstructive sleep apnea (OSA) of varying severities and another 67% had both OSA and either central apnea or sleep-related hypoventilation. PSG data are presented in Table 2. Eighty-five percent were discharged home on supplemental oxygen and 92% were discharged with a monitor (either pulse oximeter or apnea monitor).

Conclusions: Appropriate follow-up of infants who fail a pre-discharge CSTS is controversial since minimal data exist to guide clinicians, although one of the potential suggestions by the AAP is to consider performing PSG to further evaluate cardiorespiratory status. This is the first study to our knowledge to describe PSG outcomes in a cohort of infants who failed an initial CSTS, providing specific values for apnea indices. Larger studies are needed to better inform if PSG is a useful test in the setting of failed CSTS, but of note almost all subjects had evidence of obstructive and/or central apnea and the vast majority required supplemental oxygen for safe discharge home.