Aminophylline-associated irritable behaviour in preterm neonates

Abstract

Aim: This study investigated the effect of aminophylline on behaviour and autonomic function in the preterm period.

Method: Subjects 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.

Results: The 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.

Conclusion: Aminophylline administration was associated with transient irritable behaviour without autonomic changes in the preterm period.

Keywords: Aminophylline; Behaviour; Developmental care; General movements; Methylxanthine.