Discontinuation of Car Seat Tolerance Screening and Postdischarge Adverse Outcomes in Infants Born Preterm.

OBJECTIVE: To study the association between discontinuing predischarge car seat tolerance screening (CSTS) with 30-day postdischarge adverse outcomes in infants born preterm. STUDY DESIGN: Retrospective cohort study involving all infants born preterm from 2010 through 2021 who survived to discharge to home in a 14-hospital integrated health care system. The exposure was discontinuation of CSTS. The primary outcome was a composite rate of death, 911 call-triggered transports, or readmissions associated with diagnostic codes of respiratory disorders, apnea, apparent life-threatening event, or brief resolved unexplained events within 30 days of discharge. Outcomes of infants born in the periods of CSTS and after discontinuation were compared. RESULTS: Twelve of 14 hospitals initially utilized CSTS and contributed patients to the CSTS period; 71.4% of neonatal intensive care unit (NICU) patients and 26.9% of non-NICU infants were screened. All hospitals participated in the discontinuation period; 0.1% was screened. Rates of the unadjusted primary outcome were 1.02% in infants in the CSTS period (n = 21 122) and 1.06% after discontinuation (n = 20 142) (P = .76). The aOR (95% CI) was 0.95 (0.75, 1.19). Statistically insignificant differences between periods were observed in components of the primary outcome, gestational age strata, NICU admission status groups, and other secondary analyses. CONCLUSIONS: Discontinuation of CSTS in a large integrated health care network was not associated with a change in 30-day postdischarge adverse outcomes. CSTS's value as a standard predischarge assessment deserves further evaluation.

Electrical Grounding Improves Vagal Tone in Preterm Infants.

BACKGROUND: Low vagal tone (VT) is a marker of vulnerability to stress and the risk of developing necrotizing enterocolitis in preterm infants. Electric fields produced by equipment in the neonatal intensive care unit (NICU) induce an electric potential measurable on the skin in reference to ground. An electrical connection to ground reduces the skin potential and improves VT in adults. OBJECTIVES: We aimed to measure the electric field strengths in the NICU environment and to determine if connecting an infant to electrical ground would reduce the skin potential and improve VT. We also wished to determine if the skin potential correlated with VT. METHODS: Environmental magnetic flux density (MFD) was measured in and around incubators. Electrical grounding (EG) was achieved with a patch electrode and wire that extended to a ground outlet. We measured the skin potential in 26 infants and heart rate variability in 20 infants before, during, and after grounding. VT was represented by the high-frequency power of heart rate variability. RESULTS: The background MFD in the NICU was below 0.5 mG, but it ranged between 1.5 and 12.7 mG in the closed incubator. A 60-Hz oscillating potential was recorded on the skin of all infants. With EG, the skin voltage dropped by about 95%. Pre-grounding VT was inversely correlated with the skin potential. VT increased by 67% with EG. After grounding, the VT fell to the pre-grounding level. CONCLUSION: The electrical environment affects autonomic balance. EG improves VT and may improve resilience to stress and lower the risk of neonatal morbidity in preterm infants.