[Cerebral perfusion in newborn infants treated with high-frequency oscillation ventilation].
The effects of high-frequency oscillatory ventilation (HFOV) on hemodynamic parameters have been shown in animal as well as in clinical studies. In a further study we could demonstrate, that after change of a conventional positive pressure ventilation (CMV) to HFOV flow velocities in cerebral arteries decreased. In the following we added to the dopplerflow method the continuous examination of cerebral oxygenation with near infrared spectroscopy (NIRS).


METHODS
19 measurements were prospectively conducted in 18 neonates. The infants were mechanically ventilated with HFOV and were in a stable condition.


METHODS
Before change from HFOV to CMV doppler signals of the anterior cerebral artery were measured. We repeated this at the end of the study in each patient. NIRS-optodes were placed on the front and the os parietale of each infant. After stabilization of the system we changed from HFOV to CMV without disconnection of the patient from the machine. PCO2 was registered continuously via a transcutaneous probe, as well as oxygen saturation via pulse oxymetry. Statistical analysis was performed with Wilcoxon test.


RESULTS
There were no significant changes of doppler-signals during the study (median vs. 25 cm/s (+/- 6) during HFOV, 28 cm/s (+/-/) during CMV). The parameter of NIRS, oxygenated hemoglobin HbO [-1.5 U (+/- 22.78)] at 15 minutes after change), reduced hemoglobin HbR [-1.17 U (+/- 5.26)] and total hemoglobin HbT [-2.68 U (+/- 18.7)] remained stable during the change from HFOV to CMV, too. In five infants there was a decrease and in two an increase of HbO 15 minutes after change, which correlated with decrease or increase of pCO2.


CONCLUSIONS
In a combined measurement of dopplerflow and NIRS we found no special effect of HFOV on cerebral hemodynamics comparing with CMV. Changes of cerebral oxygenation in NIRS correlated with pCO2.
Schlösser
R L
RL
Zentrum für Kinderheilkunde und Jugendmedizin, Abteilung für Neonatologie, Universität Frankfurt. rschloesser@zki.uni-frankfurt.de
Voigt
B
B
von Loewenich
V
V
D020771:Anterior Cerebral Artery / Q000000981:diagnostic imaging; D001783:Blood Flow Velocity / Q000502:physiology; D001921:Brain / Q000098:blood supply*; D006612:High-Frequency Ventilation; D006801:Humans; D007231:Infant, Newborn; D010100:Oxygen / Q000097:blood*; D011175:Positive-Pressure Respiration; D012127:Respiratory Distress Syndrome, Newborn / Q000000981:diagnostic imaging / Q000628:therapy*; D019265:Spectroscopy, Near-Infrared; D017585:Ultrasonography, Doppler, Transcranial
D010100:Oxygen