A depression of cerebral electrical activity (CEA) following surfactant administration in preterm infants has been shown in some studies but not in other. Aim of the study was to evaluate the effects on CEA of surfactant administration in preterm infants.
METHOD We have studied 10 infants of gestational age 27 ± 2 (25-31) weeks, birth weight 1019 ± 295 (780-1320) g, mechanically ventilated for respiratory distress syndrome (RDS) during bolus endotracheal instillation of natural bovine surfactant (100 mg/kg). Parietal and occipital electrodes were connected by a bipolar longitudinal recording system. The signal was sent simultaneously to a cerebral function monitor (CFM), to analyze the amplitude of CEA, to the EEG and, from this, to a Berg Fourier Analyzer (BFA), to analyze the frequency distribution of the CEA. Vital parameters, including non-invasive arterial blood pressure were also recorded. Qualitative analysis of EEG recording was performed according to the criteria of Lombroso and Tharp; analysis of CFM recordings involved quantification of percentage continuous activity (%CA) >3μ Volts and of the number of bursts > 15 μVolts per hour. Analysis of BFA recording involved assessment of percentage CEA at frequencies between 2 and 16 Hz. Values for the 1 hour period before surfactant administration were compared to values for the 1 h period immediately after surfactant.
