An Clinical Study On The Regular Pattern Of Cerebral Blood Flow And The Effect Of Mechanical Ventilation In Newborns At Early Stage

Objiective To investigate the changing regularity of cerebral blood flow in early infants.Comprehensive analysis of mechanical ventilatory parameters, blood gases, mean arterial pressure and other factors impact on cerebral blood flow.Methods The cerebral blood flow of middle cerebral artery(MCA) of all research objiects early after birth monitored by transcranial Doppler. The parameters were peak systolic velocity (Vs), end diastolic velocity (Vd), mean flow velocity (Vm), resistance index (RI) and pulsatility index (PI). The research objiects include(1) 65 cases of preterm appropriate for gestational age infants,25 cases of preterm small for gestational age infants and 50 cases of term infants. They divided into seven groups according to day age which were dl, d2, d3, d4, d5, d6 and d7 after birth respectively; then depending on the gestational age, the preterm appropriate for gestational age infants divided into three sub-groups:28-30+6w,31-33+6w, 34-36+6w.(2) 40 cases of endotracheal intubation mechanical ventilation in premature infants (30 cases without brain injury,10 cases with brain injury), then divided into five groups according to age which were dl, d2, d3, d4, d5; 20 cases of nasal CPAP(18 cases without brain injury,2 cases with brain injury), according to age were divided into four groups which were dl, d2, d3, d4.Results (1) In early age of newborn, the CBFV of infants gradually increased with aging, especially the tendency of acceleration of Vs, Vd increased slowly, from second to seventh days, each group was no significantly different. Resistant index(RI), pulsatility index(PI) also showed increasing trend, within 24h after birth, high-value, and during second to seventh days, after a short period of lower, RI, PI has gradually increased. (2) Under the same age, compared among preterm infants(appropriate for gestational age, AGA) at different gestational age, then found the greater gestational age, the faster cerebral blood flow. (3) Preterm small for gestational age infants group first to fifth days after birth each time Vs, Vm, Vd were lower than those in appropriate for gestational age infants, of which the first day Vs, Vm difference was significant (P<0.05), the two groups RI, PI were no statistically significant difference. (4) The CBFV of full-term newborns are significant higher (P<0.05) than that of preterm infants.(5) When endotracheal intubation mechanical ventilation in infants, there were positive correlation among Vs, Vd, Vm and among PIP, FiO2 and PaCO2; RI, PI and mean arterial pressure (MBP), PaCO2 was negatively correlated; But there were no correlation between cerebral blood flow parameters and both the breathing machine parameters and blood gas analysis when nasal CPAP.(6) It showed no significant difference on cerebral blood flow parameters between mechanical ventilation in premature infants and the control group.Conclusion (1) the CBFV of infants gradually increased with aging. It is increasing significant within three days after born, then slowly increasing, and gradually stabilized.(2) There were correlated between cerebral blood flow parameters and among the PIP, FiO2, PaCO2, MBP when endotracheal intubation mechanical ventilation, and PaCO2 was the major influential factor. The cerebral blood flow velocity of mechanical ventilation in children is not a steady increase with age, but have a fluctuate range, and can lead to changes in cerebral blood flow spectrum. But there were no correlation between cerebral blood flow parameters and both the breathing machine parameters, blood gas analysis and MBP when nasal CPAP (P>0.05)...