116 - Blood pressure rather than ductal caliber predicted early pharmacological or spontaneous closure of ductus arteriosus in very preterm infants.

Monday, May 1, 2023

9:30 AM – 11:30 AM ET

Poster Number: 116
Publication Number: 116.427

Tiina M. Ukkonen, Oulu University Hospital, Oulu, Pohjois-Pohjanmaa, Finland; Pia Härkin, Oulu Univ.hospital, Oulu, Pohjois-Pohjanmaa, Finland; Antti Härmä, Lapland Central Hospital, Rovaniemi, Lappi, Finland; Markku Leskinen, Oulu University Hospital, Oulu, Pohjois-Pohjanmaa, Finland; Marita Valkama, University of Oulu, Finland, Oulu, Pohjois-Pohjanmaa, Finland; Timo Saarela, Oulu University Hospital, Oulu, Pohjois-Pohjanmaa, Finland; Mikko Hallman, Oulun Yliopisto, Oulu, Pohjois-Pohjanmaa, Finland; Outi Aikio, Oulu University Hospital, Oulu, Pohjois-Pohjanmaa, Finland

Presenting Author(s)

Tiina M. Ukkonen, MD (she/her/hers)

PhD trainee
Oulu University Hospital
Oulu, Pohjois-Pohjanmaa, Finland

Background: Spontaneous closure of ductus arteriosus is associated with decreased morbidity in very low gestational age infants (gestation < 32wk, VLGA). The factors affecting ductal closure (DC) in VLGA infants are not yet clear. Paracetamol is used for pain treatment and closing patent ductus arteriosus.

Objective: To study VLGA infants’ hemodynamic conditions before and after the DC and the intravenous (iv) paracetamol effect on the blood pressure (BP).

Design/Methods: In a previous controlled, double-blind trial (Preparas; Härkin, JPeds 2016), VLGA infants were randomly assigned to iv paracetamol (loading dose 20mg/kg, maintenance 7.5mg/kg q6h) or placebo (NaCl) within 24h from birth for 4d. Multiple ultrasound examinations of ductal calibers and other measurements were performed before the 1^st dose until 1d after the last dose. DC was judged upon ultrasound scans. BP was invasively monitored throughout the study period. The BP preceding and following the closure scans and the control periods were captured from the database. For infants without DC, the control BP period was the mean ductal closure time during the study drug (paracetamol group day 2, controls day 3). Mean BP in 1h periods were calculated and analyzed. The highest momentaneous increases in BP were searched and set as the assumed exact DC time points (Evans, Arch Dis Child 1993).

Results: Of 48 randomized infants, 23 had paracetamol and 25 placebo. Before the intervention, their ductal calibers were similar. Ductus closed in 19 (83%) cases of the paracetamol group and in 16 (64%) controls. The assumed DC time points were established as mean BP up to 4h afterwards were higher vs mean BP 4h preceding the closing moment (p< .001). During a period of 24h before and up to 24h after the assumed closure, infants with DC had higher mean (MAP), systolic and diastolic BP vs. infants with open ductus (n=30, Figure). In logistic regression adjusted for all MAP values preceding closure (± antenatal steroids; ± gestation weeks), mean MAP 8 to 0h predicted DC, OR 2.133, 95%CI 1.219-3.733, p=.008. Paracetamol had no significant effect on any reviewed BP levels.

Conclusion(s): The time of ductal closure associated with highest increase in BP. Infants with both pharmacological and spontaneous DC had higher pre-closure BP compared to infants whose ductus remained open. However, there was no detectable difference in the pre-closure ductal rings. Paracetamol had no effect on the BP around the closure time. Early BP stabilization for optimizing DC may be indicated in VLGA infants.