新儀器rSO2來囉！

Indication 適應症：

The noninvasive INVOS 5100C is intended for use as an adjunct monitor of regional hemoglobin oxygen saturation of blood in the brain or in other tissue beneath the sensor. It is intended for use in individuals greater than 2.5kg at risk of reduced flow or non-flow ischemic states. It is also intended for use as a an adjunct trend monitor of regional hemoglobin saturation in the brain or in other tissues beneath the sensor in any individual.

Regional SO2 monitor, 是一種可以監測「一個區域的血氧飽和度」的機器，針對體重>2.5kg、有局部缺血風險的病人均可以使用。

和一般夾手指的Pulse Oximetry概念類似，rSO2會發出一個near-infrared光源，在接近光源處有一個接收頭皮反射的接收器，另外在較遠離光源處有一個接受較深、大腦表面反射的接收器。

根據這兩個接受器收到的光線，電腦可以計算出大腦中的血氧飽和度大致為多少。

由於此處組織約有70%來自靜脈，30%來自動脈，故計算出來的數值也可以用來估算該區域的耗氧量（類似SjvO2或SvO2的功能）

Anesthesiology. 1998 Jan;88(1):58-65.

這樣的估計到底準不準呢？目前已經有許多論文指出rSO2的數值和直接抽取Jugular vein blook測定的血氧飽和度有極高的相關性。"During isocapnic hypoxia in healthy persons, cerebral oxygenation as estimated by near infrared spectroscopy precisely tracks changes in measured S(jv)O2 within individuals" (Anesthesiology. 1998 Jan;88(1):58-65.); "Cerebral oxygen saturation measured by cerebral oximetry compares well to the measured SjvO2 in normal subjects, despite multiple physiological reasons for differences." (J Clin Monit Comput. 2000;16(3):191-9.)
但是這些論文也都指出，這兩者之間的關聯性、兩者之間的換算公式都會受到許多條件影響，包括病人本身疾病因素、手術種類、病人擺位等等；若使用的環境與論文設定的條件差異太大，結果就不一定適用。但是觀察rSO2的趨勢，可以推估實際血氧飽和度的趨勢，應該是沒有問題的。


使用方法稍等補上～