Value of Doppler sonographic monitoring of the cerebral circulation in mechanically ventilated premature neonates

Background: Doppler sonographic data from routine cerebral ultrasonic exami nation of mechanically ventilated premature neonates were analyzed in order to find out which intensive care influence factors take effect on the cere bral circulation. It was to be demonstrated if Doppler sonographic results are changed by current intensive medical influences especially mechanically ventilation. Patients and Methods: In 24 premature neonates (mean gestational age 29.6+/ -4 weeks, mean birth weight 1367+/-660 g) treated with mechanical ventilati on for IRDS cerebral blood flow parameters were assessed by pulsed Doppler sonography A single Doppler sonographic investigation was performed during the first week of life (median: day 5). Doppler flow velocity waveforms wer e obtained, and resistance index (RI) and pulsatility index (PI) values wer e calculated from the anterior cerebral arteries (ACA) as well as from the internal carotid artery (ACI). Oscillometrically measured blood pressure, p H, pCO(2), and parameters of mechanical ventilation were registered. Results: Besides the well established influence of pCO(2) and blood pressur e parameters of mechanical ventilation PEEP and time of inspiration have an influence on cerebral blood flow. Conclusions: Our results demonstrate the impact of mechanical ventilation o n cerebral blood flow and therefore indicate the necessity of Doppler sonog raphic monitoring during mechanical ventilation. To our knowledge this is t he first report about the influence of mechanical ventilation on cerebral b lood flow in neonates.