Influence of Behavioural State on Blood Pressure in Preterm Infants during the First 5 Days of Life

ABSTRACT. The influence of behavioural state on neonatal blood pressure was studied in 19 healthy preterm infants. During the first five days of life every three hours a series of oscillometric blood pressure measurements was made. During the measurements the behavioural state was scored. The predominant states were quiet and active sleep. We confirmed the age-dependency of blood pressure with a steep increase during the first day of life. After the first day blood pressure and heart rate were slightly higher when the infant was awake than when asleep. Paired comparison ( t -test) before and after spontaneous state transitions showed significant differences in median heart rate and ranges of heart rate and blood pressure, but not in median blood pressure. We conclude that especially movements influence oscillometric determination of blood pressure and heart rate.