Meaning of the supernormal level of arterial ketone body ratio(AKRB) during the phase recovering from a severe stress.

动脉酮体比（AKBR）是日本倡导的通过动脉血测量反映肝脏线粒体氧化还原状态的指标，在移植外科、胃肠外科、急诊重症医学等领域得到了广泛的应用。认为AKBR正常范围下限为1.0。当AKBR低于正常值时，可发生多种肝功能障碍。另一方面，当AKBR恢复到正常范围时，肝功能也应恢复正常。然而，在重症监护医学中，许多病例的AKBR水平升高至2.5或更高。关于AKBR超常水平的含义尚未有讨论。在本研究中，我研究了AKBR的发生及意义。在许多严重应激损伤如失血性休克、严重脓毒症的病例中，AKBR的下降不仅恢复到正常范围，而且继续上升到超正常水平。我研究了AKBR异常水平与SOFA评分的关系，SOFA评分被广泛接受为多器官功能衰竭的诊断标准。结果显示，在AKBR水平异常的病例中，SOFA评分高于10分，表明MOF仍在继续。这表明，在AKBR水平异常的阶段，肝线粒体处于功能亢进状态，以增强能量的产生，以满足增加的能量需求。我们认为AKBR水平的异常反映了肝脏线粒体功能的增强，以补偿肝细胞能量水平恢复不足。

Arterial ketone body ratio(AKBR) which reflects hepatic mitochondrial redox status through arterial blood measurements was advocated in Japan, and has been widely determined in the fields of transplantation surgery, gastroentrological surgery, and emergency and critical care medicine. The lower limit of normal range of AKBR is considered to be 1.0. Various kinds of hepatic dysfunction occurs when AKBR is below the normal limit. On the other hand, when AKBR recovered to normal range, hepatic function was supposed to be recovered to normal.However, supernormal level of AKBR elevating to 2.5 or higher were observed in many cases in critical care medicine. There has been no discussion on the meaning of supernormal level of AKBR. In this study, I have studied the occurrence and meaning of supernormal level of AKBR. In many cases with severe stress insult such as hemorrhagic shock and severe sepsis, decreased AKBR not only recovers to normal range but continue to rise to supernormal level. I have studied the meaning of the supernormal level of AKBR in relation to SOFA score which is widely accepted as a diagnostic criteria of multiple organ failure. It is revealed that in many cases with supernormal AKBR level, SOFA score was higher than 10 points indicating that MOF was still on-going. This indicates that hepatic mitochondria are under hyperfunction to enhance energy generation that meets to the increased energy demand during the phase with AKBR supernormal level. It was considered that supernormal AKBR level reflects enhanced hepatic mitochondrial function to compensate the insufficient recovery of hepatocyte energy level.