Influence of Patient Variables and Sensor Location on Regional Cerebral Oxygen Saturation Measured by INVOS 4100 Near-Infrared Spectrophotometers

Abstract

Cerebral oximeter based on near-infrared spectroscopy has been used as a continuous, noninvasive monitoring of regional cerebral oxygen saturation (rSO2). Although the absolute rSO2 values have a wide range of variability, the factors affecting a variability of rSO2 values have not been extensively investigated. The authors investigated the influence of patient variables and sensor location on rSO2 measured by the cerebral oximeter INVOS 4100 in 111 patients anesthetized with sevoflurane, fentanyl, and nitrous oxide in oxygen. The sensors for rSO2 measurements were applied on the right forehead (R), 1 cm lateral to R (R1), on the left forehead (L), 1 cm lateral to L (L1), and on the center of the forehead (C). The relationship between the rSO2 values and patient variables were also analyzed. Values of rSO2 at R1 and L1 were significantly lower than those at R and L, respectively. Values of rSO2 at C were significantly higher compared with those at other sites. There were no significant correlations between the rSO2 values and values of weight, height, and head size. Values of rSO2 were similar between males and females. A significant negative correlation between the rSO2 values and age and a positive correlation between the rSO2 values and hemoglobin concentration were observed. These data indicate that patient age, hemoglobin concentration at the measurement, and sensor location can affect rSO2 values.

Cerebrovascular Effects of Hemodialysis in Chronic Kidney Disease

“…The causes and mechanisms of this continued hypoxia are not yet known; the technique is relatively novel, and artifactual results are possible. Our control oximetry values are in very good agreement with results reported by others in normal adults and medical-surgical populations (Kishi et al, 2003), indicating the validity of our instruments and procedures. The technology itself, while fairly new, has been validated in several previous experiments.…”

Ľindex bispectral et la saturation en oxygène du sang cérébral régional pendant ľanesthésie au propofol/N2O

“…However, the data requires careful interpretation, since the rSO 2 value may be affected by many factors such as age, hemoglobin concentration, bleeding and transfusion. 10,17 The patients included in the present study experienced minimal bleeding and required no blood transfusion during the study period, and thus we can exclude the effects of such factors on rSO 2 . Thus, our data suggest that administration of 1 MAC isoflurane during propofol anesthesia has little effect on regional cerebral oxygen status.…”

“…A sampling interval of 0.5 sec was used and rSO 2 = oxy-Hb/(oxy-Hb ± deoxy-Hb) were calculated. A previous study 10 reported that, among many factors, patient age, hemoglobin concentration, and sensor location may affect rSO 2 values, and thus in all patients the rSO 2 sensors were applied on the right forehead, 3 cm away from the midline to avoid distortion from the sagittal sinus.…”

Cerebral Oximetry in Cardiac Surgery

“…М. Misra et al [36] не выявили связи нормативных значений с полом, возрастом, весом, рос том, цветом кожи, использованием табака, кофе у 94 х паци ентов. К. Kishi et al [37] исследовали влияние демографичес ких данных на rSO 2 . Измерения не зависели от веса, роста, пола, но отрицательно коррелировали с возрастом.…”

“…Ht во время ИК нужно поддерживать в диапазоне 25-29%. В случае пограничных анемий, нормаль ные показатели ЦО гарантируют достаточный rSO 2 , таким об разом, использование ЦО минимализирует риск трансфузии дополнительной эритроцитарной массы [3,12,22,37,41,44].…”