Continuous noninvasive measurement of cerebral arterial and venous oxygen saturation at the bedside in mechanically ventilated neonates.
OBJECTIVE
To test the practicablity of a new spectrophotometric method using pulse oximetric techniques in combination with special filters for the noninvasive determination of cerebral arterial and venous oxygen saturation and oxygen extraction in neonatal intensive care unit patients. The spectrophotometer used three different wavelengths at a sampling rate of 100 Hz.


METHODS
Clinical evaluation of a new method and comparison with previously published data.


METHODS
Design and construction of the special spectrophotometer at the Biomedical Engineering Laboratory of the Swiss Federal Institute of Technology. Measurements in the neonatal intensive care unit of the University Hospital, Zurich, Switzerland.


METHODS
Convenience sample of 15 clinically stable newborn infants, who were mechanically ventilated and receiving supplemental oxygen. Median gestational age was 29 5/7 wks (range 26 3/ 7 to 36 0/7), median birth weight was 1555 g (720 to 2500), median postnatal age was 4 days (1 to 10).


METHODS
The emitter and receiver were placed on the forehead near the sagittal sinus, between 2 and 2.8 cm apart, and the pulsating light attenuations (arterial and venous pulse waves) were recorded.


RESULTS
Arterial and venous pulse waves were satisfactory in 10 of 15 infants. Mean cerebral arterial oxygen saturation was 89.9 +/- 5.4% (SD), mean cerebral venous oxygen saturation was 73.0 +/- 8.9%, and mean cerebral oxygen extraction was 16.9 +/- 11.7%. A linear regression analysis demonstrated a significant correlation between mean PCO2 and venous oxygen saturation (slope 1.0%/torr, p < .05) and between mean PCO2 and cerebral oxygen extraction (slope -1.3%/torr, p < .05).


CONCLUSIONS
This new method has the potential for monitoring continuously, noninvasively, and simultaneously cerebral arterial and venous oxygen saturation and oxygen extraction in mechanically ventilated preterm infants.
Wolf
M
M
Clinic for Neonatology, University Hospital, Zurich, Switzerland.
Duc
G
G
Keel
M
M
Niederer
P
P
von Siebenthal
K
K
Bucher
H U
HU
D001784:Blood Gas Analysis / Q000379:methods*; D001923:Brain Chemistry; D006801:Humans; D007231:Infant, Newborn; D015931:Intensive Care, Neonatal; D016014:Linear Models; D008991:Monitoring, Physiologic / Q000379:methods / Q000592:standards; D010100:Oxygen / Q000378:metabolism*; D019095:Point-of-Care Systems / Q000592:standards*; D015203:Reproducibility of Results; D012121:Respiration, Artificial; D013053:Spectrophotometry / Q000379:methods* / Q000592:standards
D010100:Oxygen