Car Seat Tolerance Screening for Infants With Trisomy 21

Predischarge car seat tolerance screening (CSTS) is common but controversial, performed on infants deemed at-risk for unstable cardiorespiratory status while in the semi-upright position. Currently, the American Academy of Pediatrics1 (AAP) recommends CSTS for premature infants but also notes that nurseries and neonatal intensive care units (NICUs) may screen additional at-risk infants, including those with trisomy 21 (T21).2,3 These infants can have hypotonia, relative macroglossia, obstructive sleep apnea, and congenital heart disease (CHD), all of which can increase risk of breathing difficulties when semi-upright.4 Although CSTS studies have included infants with T21,5 none have focused exclusively on this group. The objective of this study was to evaluate the incidence of CSTS failure in a cohort of neonates with T21.This is a retrospective medical record review of infants with confirmed T21 born from 2013 to 2022 and admitted to the University of Maryland Children’s Hospital (Baltimore, MD). The study was deemed Institutional Review Board exempt. The inclusion criteria were as follows: (1) laboratory confirmation of T21 and (2) survival to discharge. The exclusion criterium was as follows: (1) deemed inappropriate for CSTS by medical team.Indication for CSTS at our institution include birth gestational age (GA) younger than 37 weeks, birth weight less than 2.5 kg, and those with medical conditions placing them at high risk for apnea, bradycardia, or desaturation including but not limited to those with hypotonia, airway anomalies, and CHD. Participants were tested in their personal car seat at the appropriate angle for 90 to 120 minutes in the location of discharge. Study failure criteria included the following: (1) apnea longer than 20 seconds, (2) bradycardia at less than 80 bpm for longer than 10 seconds, and (3) desaturation (SpO2) less than 90% (or drop >10% from baseline for infants with cyanotic heart lesions) for more than 10 seconds. Options after failed CSTS include child passenger team consultation, repeating after 12 to 24 hours, repeating in different car seat, or repeating on oxygen if indicated. We do not routinely discharge home in car beds.Baseline characteristics were evaluated based on CSTS completion and on initial CSTS result. T tests, Wilcoxon rank-sum, χ2, and Fisher exact tests were used as appropriate for continuous, binary or categorical variables. Statistical analyses were performed using SAS 9.4 (Cary, NC).We identified 84 infants with T21 of whom 75 (89%) underwent CSTS. Readmission rates were higher but not significantly different for those who did not undergo CSTS (Table 1). We found a significant difference in CSTS completion based on location of discharge.We had results from 99% (n = 74) of those tested. The cohort included 22% born prematurely, 13.5% small for GA, 96% noted to have hypotonia, and 10% with laryngomalacia. Failure incidence of initial CSTS was 11% (n = 8). Seven failed secondary to desaturation events, whereas 1 had no failure reason documented.We compared infants who passed vs failed an initial CSTS and found no significant differences in birth anthropometrics, resuscitation requirements, length of stay, or cardiac, neurologic, or respiratory/airway diagnoses (Table 2). Although not statistically significant, we found that none of those who failed were born prematurely, and postmenstrual age at testing was similar. Significantly, more infants who failed required readmission within 30 days of discharge, although most were related to respiratory tract infections.The most recent (2022) AAP Clinical Report on health supervision for children with Down syndrome recommends evaluation for desaturations and/or bradycardia in a car safety seat prior to discharge, recognizing the increased risk attributable to upper airway obstruction, hypotonia, and potential cardiac anomalies.4 Despite this, only about 11% of nurseries and approximately 20% of NICUs surveyed specifically included T21 diagnosis as a criterion for screening.2,3 We found a relatively high incidence (11%) of unstable cardiorespiratory status while in the semi-upright position. Interestingly, none were born prematurely, meaning guidelines to test based on prematurity would have missed these infants. Those infants who failed did not have longer lengths of stay but were significantly more likely to require readmission within a month, with half readmitted owing to respiratory issues.Study limitations include a small sample size despite a 10-year cohort, single center study, and a retrospective design with risk of missing data; however, this study remains the largest to date, focusing exclusively on infants with T21.Although CSTS remains controversial, additional research must be performed on infants at high risk of desaturation events in the semi-upright position, including those with congenital neuromuscular disorders, hypotonia, and T21. To reduce burden on the health care system while not missing opportunities to optimize safety and follow-up, we must identify which clinical characteristics increase risk of unsafe cardiorespiratory status and use this to guide CSTS protocols.