Changes of the electroencephalographic background in preterm infants before and after instillation of pulmonary surfactant in different ways

Abstract

Objective To monitor the electroencephalographic background activities of preterm infants before and after using pulmonary surfactant(PS), so as to investigate an appropriate way to endotracheally instill PS through the changes of electroencephalographic background activities. Methods Thirty-five preterm infants who were hospita-lized in Neonatal Intensive Care Unit of Guangzhou Women and Children's Medical Center from Jun.2011 to Apr.2013 and treated with PS were involved.They were divided into the normal pressure group and the high pressure group, based on the peak inspiratory pressure when PS instilled.The electroencephalographic background activities of the preterm infants before using PS and 15 min, 30 min, 60 min and 120 min after using PS were monitored continuously by using cerebral function monitor.The changes of 2 groups were compared.Oxygen saturation and heart rate were recorded at the same time. Results 1.In normal pressure group, lower amplitude decreased and the duration of interburst interval(IBI) increased 15 min after instillation of PS compared with before using PS(t=-6.012, 5.202, all P 0.05). There were significant differences between the 2 groups(t=-4.832, 4.029, all P 0.05). Between the 2 groups, there were significant differences in lower amplitude(t=-2.828, P 0.05). Lower amplitude and IBI of the normal pressure group returned to the level before using PS at 60 min and 120 min after using PS(lower amplitude: t=0.557, 1.849, all P 0.05). Moreover, in the high pressure group, lower amplitude even increased at 60 min and 120 min after using PS(t=2.153, 3.112, all P<0.05).2.After using PS, desaturation happened in 8 preterm infants of the normal pressure group and 2 preterm infants of the high pressure group.There was significant difference between the 2 groups(P=0.025).3.Bradycardia accompanied with desaturation happened in 2 preterm infants of the normal pressure group, but none in the high pressure group. Conclusions Instillation of PS may cause embolism and obstruct the airway, which may induce hypoxia, and then lead to the depression of the elec-troencephalographic background.Therefore, when instilling PS, giving high pressure can shorten or avoid the hypoxia episode, and make PS reach alveoli as soon as possible to play a role in lung compliance. Key words: Pulmonary surfactant; Amplitude-integrated electroencephalogram; Background activity; Preterm infant