Comparison of short-term outcomes of 35-weeks' gestation infants cared for in a level II NICU vs mother-baby, a retrospective study.

BACKGROUND: Late preterm infants are at high risk for medical complications and represent a growing NICU population. While 34-weeks' gestation infants are generally admitted to the NICU and 36-weeks'gestation infants stay in mother-baby, there is wide practice variation for 35-weeks'gestation infants. The objective of this study was to compare short-term outcomes of 35-weeks' gestation infants born at two hospitals within the same health system (DUHS), where one (DRH) admits all 35-weeks' gestation infants to their level II NICU and the other (DUH) admits all 35-weeks' gestation infants to mother-baby, unless clinical concern. METHODS: We conducted a retrospective cohort analysis of 35-weeks' gestation infants born at DUHS from 2014-2019. Infant specific data were collected for birth, demographics, medications, medical therapies, LOS, ED visits and readmissions. 35-weeks' gestation infants at each hospital (DRH vs DUH) that met inclusion criteria were compared, regardless of unit(s) of care. RESULTS: 726 infants of 35-weeks' gestation were identified, 591 met our inclusion criteria (DUH -462, DRH -129). Infants discharged from DRH were more likely to receive medical therapies (caffeine, antibiotics, blood culture, phototherapy, NGT), had a 4 day longer LOS, but were more likely to feed exclusively MBM at discharge. There were no differences in ED visits; however, more infants from DUH were readmitted within 30 days of discharge. CONCLUSIONS: Our findings suggest admitting 35-weeks' gestation infants directly to the NICU increases medical interventions and LOS, but might reduce hospital readmissions.

Cholinergic mechanisms involved with histamine hyperreactivity in immune rabbit airways challenged with ragweed antigen.

The present study examines the effects of aerosolized ragweed antigen (RAg) on tracheal (TSM) and bronchial (BSM) smooth muscle contraction in rabbits actively immunized with RAg. Airway segments were isolated 48 h after aerosol challenge with either saline or RAg, and airway contractile responses to histamine were measured. Histamine remained a weak agonist in TSM segments after RAg challenge. In contrast, BSM responsivity to histamine was significantly increased after RAg challenge as evidenced by a parallel shift to the left (i.e., Fslope = 3.2; degrees of freedom (df) = 1,224; p = NS and Felev = 19.4; df = 1,225; p less than 0.001) of the mean dose-response relationship. In sham-immunized rabbits, the BSM contractile responses to histamine were similar after aerosol challenge with either RAg or normal saline. After the BSM segments were treated with 10(-6) M atropine, there was no significant difference in histamine reactivity between the RAg- and saline-challenged groups. The augmented BSM contractile response to histamine was only partially inhibited in the presence of either tetrodotoxin or hexamethonium. We conclude that 48 h after a single in vivo exposure to antigen in immune rabbits, the airway contractile responses to histamine in vitro are increased in BSM but not in TSM and that the mechanism of the augmented contractile responses in BSM likely involves the facilitated neural release of acetylcholine from both preganglionic and postganglionic sites.