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）是通过动脉血测量反映肝脏线粒体氧化还原状态的指标，在日本得到提倡，并已在移植手术、胃肠道手术和急诊及重症监护医学领域得到广泛测定。认为AKBR正常范围的下限为1.0。当AKBR低于正常范围时，会发生各种肝功能障碍。另一方面，当AKBR恢复到正常范围时，肝功能应该恢复正常，但在重症监护医学中，在许多病例中观察到AKBR升高至2.5或更高的超常水平。关于AKBR超常水平的含义，目前尚无讨论。本研究对AKBR超常水平的发生及意义进行了探讨。在许多严重的应激损伤如失血性休克和严重脓毒症时，降低的AKBR不仅恢复到正常范围，而且继续升高到超常水平。本研究探讨了AKBR与SOFA评分的关系，即AKBR与SOFA评分之间的关系。SOFA评分是目前公认的多器官功能衰竭的诊断标准。结果显示，在AKBR水平高于正常的病例中，SOFA评分> 10分，表明MOF仍在进行中。这表明，在AKBR超常水平阶段，肝线粒体处于功能亢进状态，以增强能量产生，满足增加的能量需求。认为AKBR水平异常反映了肝线粒体功能增强，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.