Aminophylline-associated irritable behaviour in preterm neonates

Abstract

AimThis study investigated the effect of aminophylline on behaviour and autonomic function in the preterm period. MethodSubjects were preterm infants cared for in the Oita University hospital from August 2012 to October 2014. The group that was administered aminophylline (Am+) and the group that received no aminophylline (Am−) included 11 cases that exhibited a mean gestational age of 28weeks 5days and a mean birth weight of 1109g and 8 cases that exhibited a mean gestational age of 30weeks 5days and a mean birth weight of 1223g, respectively. Intravenous aminophylline was administered continuously at a dose of 4–6mg/kg/day followed by oral therapy when the infant suffered repetitive apnoea.Two-hour video recordings were obtained every 2weeks, and electrocardiograms were performed simultaneously. Onset-offset and tremulous movements in general movement (GM) optimality list were used as indices of behaviour. Autonomic functions were investigated via heart-rate and heart-rate variability measurements using frequency domain spectral analysis and the MemCalc method. We compared indices in 4 periods: 30–31, 32–33, 34–35 and 36–37weeks gestation. ResultsThe Am+ group exhibited significantly low optimality of tremulous movements at 32–33weeks gestation. The autonomic parameters did not differ significantly between the Am+ and Am− groups. There was no significant correlation between GMs optimality score and serum theophylline concentration. ConclusionAminophylline administration was associated with transient irritable behaviour without autonomic changes in the preterm period.