Effect of surfactant administration on cerebral haemodynamics and oxygenation in premature infants - A near infrared spectroscopy study

Objectives. The aim of this study was to assess changes in cerebral haemody namics and oxygenation induced by surfactant administration using near infr ared spectroscopy (NIRS). Methods. Eighteen premature infants, mean birth weight 960 g (range 550-156 0 g), mean gestation age 28 weeks (range 25-30 weeks), were studied during 27 surfactant administrations. Porcine surfactant was administered to treat respiratory distress syndrome in a bolus of 100 mg/kg. Manual bag ventilat ion was performed for one minute after instillation. Heart rate, arterial o xygen saturation measured by pulse oximetry, transcutaneous PO2 (TcPO2), an d PCO2 (TcPCO2), blood pressure, and cerebral oxygenated (O(2)Hb), deoxygen ated (HHb), and total haemoglobin (tHb) concentration changes obtained by N IRS were registered every second from 15 minutes before until 30 minutes af ter surfactant administration. Results. During surfactant administration, there was a shortlasting but sig nificant drop in heart rate and arterial oxygen saturation. NIRS parameters remained constant during and up to 1 minute after administration. One to t hree minutes after administration, heart rate, oxygen saturation, and TcPO2 increased significantly concomitantly with an increase in O(2)Hb and a dec rease in HHb. In 10 cases, TcPO2 increased above 100 mmHg. tHb - indicative of cerebral blood volume - did not change significantly. Five to 30 minute s after surfactant administration there was no difference of monitoring dat a from baseline levels. TcPCO2 and blood pressure remained unchanged during the measurement period. Conclusion. Cerebral blood volume remained constant in very-low-birth-weigh t infants when surfactant was administered by bolus administration followed by manual ventilation according to our protocol. Attention should be direc ted towards rapid adaptation of inspiratory oxygen concentrations after sur factant administration to avoid hyperoxaemia.