[Doppler ultrasound monitoring of cerebral circulation during neonatal intensive care with special reference to artificial respiration].

BACKGROUND

Doppler sonographic data from routine cerebral ultrasonic examination of mechanically ventilated premature neonates were analyzed in order to find out which intensive care influence factors take effect on the cerebral 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 ventilation 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 were obtained, and resistance index (RI) and pulsatility index (PI) values were calculated from the anterior cerebral arteries (ACA) as well as from the internal carotid artery (ACI). Oscillometrically measured blood pressure, pH, pCO2, and parameters of mechanical ventilation were registered.

RESULTS

Besides the well established influence of pCO2 and blood pressure 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 on cerebral blood flow and therefore indicate the necessity of Doppler sonographic monitoring during mechanical ventilation. To our knowledge this is the first report about the influence of mechanical ventilation on cerebral blood flow in neonates.