Evaluation of the Severity of Patients Admitted to ICU in Japan

本研究的目的是建立一套评估日本ICU患者病情严重程度的评分系统。首先，我们使用了国外许多国家广泛使用的APACHE-II评分系统来评估ICU患者的病情严重程度，并预测他们的预后。研究对象是住进我们ICU的患者。采用APACEH-II评分系统对其严重程度和预计死亡率进行评估。总体而言，APACHE-II评分与实际观察死亡率(OM)成比例相关，总体计算的预测死亡率(PM)也与OM相符。然而，APACHE-II评分与OM之间以及PM与OM之间存在差异，尤其是在脓毒症合并多器官功能衰竭(MOF)患者中。在脓毒症患者中发现差异的原因是，APACHE-II评分系统没有评估脓毒症患者常见的肝功能障碍的评分，这是导致患者死亡的重要原因。其次，我们对APACHE-II评分系统进行了改进，设计了APACHE-肝脏评分系统(APACHE-H)，其中包括使用动脉血酮体比率(AKBR)、渗透压差、凝血酶原时间和肝素时间来评估肝功能的评分。在MOF患者中，APACHE-H的准确性和预测力均优于APACHE-II。然而，由于AKBR等增加的项目并不总是容易检查，APACHE-H被认为有必要改进其简单性。综上所述，APACHE-II评分系统似乎是一个有用的指标来分类ICU患者的严重程度，除了一些亚组患者，如脓毒症合并多器官功能衰竭。APACHE-H评分系统对MOF患者病情的评估优于APACHE-II。

The purpose of this study is to establish a scoring system by which we can evaluate the severity of ICU patients in Japan.First, we used the APACHE-II scoring system which has been widely used in many foreign countries for evaluating the severity of ICU patients and for predicting their subsequent prognosis. The subjects of the study were patients admitted to our ICUs. Their severity and predicted mortality were evaluated by using the APACEH-II scoring system. As a whole, APACHE-II scores were proportionally correlated with actual observed mortality (OM), and the overall calculated predicted mortality (PM) also fit with the OM. However, discrepancies were found between the APACHE-II scores and the OM and between the PM and the OM especially in septic patients with multiple organ failure (MOF). The reason why the discrepancies were found in septic patients was considered that the APACHE-II scoring system does not have scores evaluating liver dysfunction which was frequently observed in septic patients and was an important cause of death of the patients.Next, we modified the APACHE-II scoring system and designed the APACHE-HEPATIC scoring system (APACHE-H), which included the scores to evaluate the liver function by using an arterial blood ketone body ratio (AKBR), an osmolality gap, a prothrombin time and a hepaplastin time. The accuracy and predictive power of the APACHE-H were superior to the APACHE-II in MOF patients. However, because the added items such as AKBR were not always easy to examine, the APACHE-H was considered necessary to be improved its simplicity.In conclusion, the APACHE-II scoring system seemed to be a useful index to classify the severity of ICU patients except for some subgroups of patients such as septic ones with MOF. The APACHE-H scoring system was superior to the APACHE-II for evaluating the severity of MOF patients.