Early brainstem volume and the need for respiratory and vasoactive support in very preterm infants

To assess whether early brainstem volume (BV) is associated with the intensity of respiratory and hemodynamic support in very preterm (PT) infants.

We performed a prospective cohort study of very low birthweight infants (VLBWI) (birthweight ≤1500 g and/or gestational age ≤32 weeks) admitted to the NICU between 2018 and 2021. Infants with major congenital anomalies, chromosomal syndromes, metabolic disease, or CNS infection were excluded. Early brain MRI was obtained before 36 weeks' postmenstrual age (PMA), and BV was quantified using an atlas-based segmentation pipeline. Respiratory support in the first 72 h of life was classified as no ventilation, non-invasive ventilation, or invasive mechanical ventilation, and hemodynamic support was quantified with the vasoactive-inotropic score (VIS; 0 vs >0). Associations between BV and ventilation or VIS were assessed using linear, multinomial, and logistic regression models adjusted for gestational age (GA) at birth and PMA.

Early MRI was performed in 79 infants (mean GA 29.1 ± 2.5 weeks; mean PMA 31.9 ± 2.4 weeks). Mean BV was 4.09 ± 0.17 cm³ in infants without ventilation, 3.35 ± 0.57 cm³ with non-invasive ventilation, and 2.60 ± 0.74 cm³ with invasive ventilation, and 3.17 vs 2.45 cm³ in those with VIS = 0 vs VIS>0. In adjusted models, both respiratory support and VIS>0 were independently associated with smaller BV, and, conversely, lower BV was associated with higher odds of invasive ventilation and VIS > 0 (p < 0.05).

Early BV is closely associated to the intensity of respiratory and vasoactive support in PT infants and support further evaluation as a potential imaging biomarker for risk stratification in this population.