Patterns of Respiratory Support by Gestational Age in Very Preterm Infants.

Introduction: A detailed understanding of respiratory support patterns in preterm infants is lacking. The aim was to explore and visualize this practice in Sweden.

Methods: Preterm infants with gestational ages of 22-31 weeks, admitted to neonatal units reporting daily to the Swedish Neonatal Quality Register and discharged alive in November 2015-April 2022, were included in this descriptive cohort study. Proportions receiving mechanical ventilation, noninvasive support, or supplemental oxygen were calculated and graphically displayed for each gestational week and postnatal day (range 0-97) up to hospital discharge or 36 weeks of postmenstrual age.

Results: Respiratory support in 148,515 days of care (3,368 infants; 54% males; median [interquartile range] birthweight = 1,215 [900-1,525] g) was evaluated. Trajectories showed distinct nonlinear patterns for each category of respiratory support, but differences in respiratory support over the gestational age range were linear: the proportion of infants on mechanical ventilation decreased by -11.7 to -7.3% (variability in estimates related to the postnatal day chosen for regression analysis) for each week higher gestational age (r = -0.99 to -0.87, p ≤ 0.001). The corresponding proportions of infants with supplemental oxygen decreased by -12.4% to -4.5% for each week higher gestational age (r = -0.98 to -0.94, p < 0.001). At 36 weeks of postmenstrual age, dependencies on mechanical ventilation, noninvasive support, and supplemental oxygen varied from 3%, 84%, and 94% at 22 weeks to 0%, 3%, and 5% at 31 weeks of gestational age, respectively.

Conclusions: Respiratory support patterns in very preterm infants follow nonlinear, gestational age-specific postnatal trajectories in a dose-response-related fashion.