Tidal breathing pulmonary function after treatment in neonates with respiratory distress syndrome

Objective: To investigate the pulmonary function after treatment in neonates with respiratory distress syndrome (RDS) at varying disease severity levels and different gestational ages.

Methods: A total of 107 neonates with RDS were divided into <34 weeks group (65 neonates), late preterm group (21 neonates), full-term group (21 neonates). Another 121 non-RDS children were enrolled as the control group. According to the severity of RDS, the RDS neonates were divided into mild RDS group (grades 1 and 2; 76 neonates), and severe RDS (grades 3 and 4; 21 neonates). The tidal breathing pulmonary function was measured at a corrected gestational age of 44weeks.

Results: The pulmonary function parameters showed no significant differences across the groups of RDS neonates of different gestational ages; the tidal volume per kilogram of body weight (VT/kg) showed no significant difference between the RDS and non-RDS groups, while the RDS group had significantly higher ratio of time to peak tidal expiratory flow to total expiratory time (tPTEF/tE) and ratio of volume to peak tidal expiratory flow to total expiratory volume (vPTEF/vE) than the non-RDS group of the same gestational age (P<0.05). At a corrected gestational age of 44 weeks, the two groups of neonates with varying severity levels of RDS had significantly lower tPTEF/tE and vPTEF/vE than the control group (P<0.05), and tPTEF/tE and vPTEF/vE tended to decrease with the increasing severity level of RDS.

Conclusions: Neonates with RDS have significantly decreased pulmonary function than those without RDS. At a corrected gestational age of 44 weeks, the tidal breathing pulmonary function in neonates with RDS is not associated with gestational age, but is associated with the severity of RDS.