Evolving blood pressure dynamics for extremely preterm infants

ObjectiveTo examine changes in arterial blood pressure (ABP) after birth in extremely preterm infants.Study DesignProspective observational study of infants 230/7 – 266/7 weeks gestational age (GA). Antihypotensive therapy use and ABP measurements were recorded for the first 24 hours.ResultsA cohort of 367 infants had 18,709 ABP measurements recorded. ABP decreased for the first three hours, reached a nadir at 4 – 5 hours, then increased at an average rate of 0.2 mmHg / hour. The rise in ABP from hour 4 – 24 was similar for untreated infants (n=164) and infants given any antihypotensive therapy (n=203), a fluid bolus (n=135), or dopamine (n=92). GA specific trends were similar. ABP tended to be lower as GA decreased, but varied widely at each GA.ConclusionArterial blood pressure increased spontaneously over the first 24 postnatal hours for extremely preterm infants. The rate of rise in ABP did not change with antihypotensive therapy