INFLUENCE OF END-EXPIRATORY PRESSURE ON CEREBRAL BLOOD-FLOW IN PRETERM INFANTS

The effect of interruption of positive end expiratory pressure (PEEP) on cerebral blood flow velocity (CBFV) and CBF fluctuation (CBFF) in t he internal carotid arteries and on heart rate, restlessness and wakef ulness has been studied in 17 mechanically ventilated neonates with RD S. A decrease in CBFV was found, but no significant change in CBFF. Mu ltiple regression analysis showed that the decrease in CBFV is less pr onounced if the PEEP interruption is accompanied by restlessness. It f urther appeared that the decrease in CBFV is more pronounced if CBFV i s high, the ductus arteriosus is patent, or RDS follows a complicated course. These findings indicate that PEEP supports CBF, probably by a decrease in ductal stealing from the brain. Therewith PEEP protects ag ainst cerebral hypoperfusion which is one of the major risks in RDS an d immaturity. Furthermore, our findings suggest that the decrease in C BF during PEEP interruption is moderated by restlessness and accentuat ed by brain damage.