This retrospective review of neonates monitored for NAS symptoms in the newborn nursery was performed at Charleston Area Medical Center, Women and Children’s Hospital (Charleston, WV) between 9/4/2018 and 9/5/2020. Our hospital serves as a regional referral center in central Appalachia and provides care for more than 2000 newborn deliveries per year and has the only level IV NICU in the southern half of the state. The mother-baby department is comprised of a 52-crib nursery and 46 bed maternal post-care unit. In September 2019, the Mother-Baby unit transitioned from using a FNASS focused treatment protocol to the ESC model using a treatment algorithm based on that of Wachman and colleagues at Boston Medical Center, one of the earliest adopters of the ESC model [19].

Study inclusion criteria were (1) Full term neonates (gestational age from 37-42 weeks) born at our hospital between 9/4/2018 and 9/5/2020 and managed by the Mother-Baby Unit; (2) at least one documented Finnegan score greater than 0 during the birth admission or documented disruption to the infant’s ability to eat, sleep, or be consoled; and (3) documented intrauterine exposure to opioid substances including oxycodone, hydrocodone, morphine, buprenorphine, methadone, fentanyl, or heroin. Prenatal opioid exposure was identified by a positive maternal urine toxicology screen at any point during pregnancy or via neonatal cord toxicology. Our institution utilizes a universal urine drug screen for all women at time of admission for delivery. If maternal drug use is known or suspected, the neonate is further tested for intrauterine drug exposure by cord tissue toxicology, performed by United States Drug Testing Laboratories (Des Plaines, IL, USA) using a 15-drug panel.

Neonates were excluded from the study if they required transfer to the NICU, were premature (less than 37 weeks’ gestational age), had significant comorbidities (infections, asphyxia, congenital heart disease, pulmonary anomalies, transient tachypnea, spontaneous pneumothorax, lung pathology or maternal blood pressure abnormalities). Query of the hospital’s electronic medical records system for neonates having any recorded FNASS during the delivery admission generated the patient list for chart review. All aspects of the study including waiver of consent were approved by the Charleston Area Medical Center /West Virginia University-Charleston Institutional Review Board.

At our institution, both pre and post-ESC implementation, neonates suspected of NAS were admitted to Mother-Baby Unit. Neonates were only transferred to the NICU if they had prematurity or additional comorbidities requiring intensive care. During the mothers’ admission, mothers had private rooms, and rooming-in with their infant was encouraged. Upon the mother’s discharge, the newborn was cared for in the well-infant nursery.

With ESC’s implementation, additional opportunities for infant-parental rooming-in after the mother’s discharge were made available. A room, within the Mother-Baby Unit was offered to the parent/caregiver during their visitation with the infant, unless the unit was at capacity. Rooms were not designated for NAS management and could be moved during the infant’s hospitalization. Additionally, as part of the ESC model, a NAS bundle of care was deployed and included encouraging breastfeeding (when eligible), skin-to-skin contact with parent, parental presence at the bedside, feeding on demand, swaddling, as well as decreased noise and light stimulation.

Both pre and post-ESC implementation as part of standard care, FNASS scores were captured every 4 h in neonates evaluated for NAS for admission duration. In the pre-ESC period, methadone was started if a neonate scored on the FNASS three consecutive scores ≥8 or two consecutive scores ≥12 or at the physician’s discretion. After the implementation of ESC, FNASS were still obtained every 4 h but were not used for clinical decision-making, similar to other hospitals’ published procedures [20, 21]. In addition to the FNASS, neonates were assessed every 4 h by nursing staff to identify non-pharmacological therapies requiring reinforcement and performed ESC function-based assessments. Neonates were assessed every 4 h on their ability to perform three critical functions: (1) Eating: Can the newborn drink ½ to 1 oz of formula or breastfeed? (2) Sleeping: Can the newborn sleep undisturbed for an hour? and (3) Consolable: Can the newborn be consoled within 10 min? [17,18,19] If the infant was unable to eat, sleep, or be consoled due to withdrawal symptoms after all non-pharmacologic care was optimized, methadone was ordered following a meeting of the neonate’s care team. No other pharmacologic agents for NAS management in either the pre-ESC or ESC periods were used in the absence of methadone. Additionally, as part of the ESC care tool, parental/caregiver presence was recorded as the amount of time since last assessment that a parent (or other caregiver) spent in the room with infant.

For this study, our primary outcome of interest was the rate of pharmacology therapy for NAS management. Our secondary outcomes included length of stay, rate of neonates with elevated FNASS values, length of pharmacotherapy, and need for 30-day readmission. Outcomes were compared between the 12 months preceding and 12 months following the implementation of ESC in the nursery (pre-ESC period: 9/4/2018–9/4/2019 and ESC period: 9/5/2019–9/5/2020). Additionally in the ESC cohort, we examined parental (or other caregiver) presence at the bedside to determine if it was inversely associated with pharmacotherapy usage.

ESC assessments and FNASS scores were obtained from EMR records and included in analysis until pharmacological treatment for NAS was initiated, discharge, or 5 days post birth, whichever came first. Other variables collected included: sex, gestational age at birth, maternal race, parental presence, non-pharmacological therapies requiring reinforcement, maternal residential zip code, and distance to hospital (direct distance from center of the residential zip code to the study hospital in miles). Distance to hospital were dichotomized using the calculated median distance as the cut-point. In the ESC cohort, we also obtained data on the non-pharmacological therapies needing reinforcement which included parental/caregiver presence, rooming-in, skin-to-skin contact, holding by a caregiver, swaddling, optimal feeding at early hunger cues, non-nutritive sucking, quiet, low environment, limiting number of visitors, clustering care, safe-sleep/fall prevention, and parent/caregiver selfcare and rest.

We hypothesized we would experience a similar reduction of 40% in pharmacotherapy rates with ESC model adoption as reported by Wachman et al. [19]. As such, we needed a minimum of 24 infants per NAS management cohort to be able to reject the null hypothesis with a power of 0.95 and a Type I error probability of 0.05 using a two-sided chi-squared statistic (G*Power 3.1) [22]. Data was analyzed using SPSS 19 (IBM Corp., Armonk, NY, USA). Descriptive statistics, such as means and standard deviations for continuous variables and proportions and frequencies for categorical variables, were used to analyze infant characteristics. Variables of length of stays, length of pharmacological therapy, and distance to hospital were not normally distributed and were reported as medians with ranges (minimal to maximal value). Comparisons between groups for categorical variables were analyzed using Chi-square analysis, and when applicable, Fisher’s exact tests. Comparisons between groups for continuous variables were analyzed using two-sided t-test or Mann–Whitney U tests. Statistical significance was defined as p < 0.05.