To reduce postoperative morbidity and mortality, aggressive monitoring of patients, early detection of life threatening complications, and immediate therapeutic interventions are important. Comprehensive monitoring in the intensive care unit (ICU) facilitates all of these elements of care [10]. On the other hand, many surgical patients are admitted to the ICU, resulting in an increased demand, and possible waste, of resources [11,12]. Hence, selective admission of surgical patients to the ICU has been suggested [13-15]. Bastounis et al. [16] evaluated the need for ICU admission among patients who have undergone vascular surgery. However, studies on the necessity of ICU admission among posthepatectomy patients have not been reported, to our knowledge.

The concept of the ICU was introduced in 1801 in the Newcastle Infirmary, England, to provide a space for seriously sick patients or patients undergoing major surgery [23]. In the 1900s, the ICU developed into a space for selective patients, and in 1923, the first ICU was built in the department of neurosurgery [24]. After the introduction of the coronary ICU in the 1960s, mortality of acute myocardial infarction was reduced by approximately 20% [25]. However, the ICU has been used excessively in caring for postoperative patients and, thus, has been considered a waste of resources and a contributing factor to unnecessarily long hospital stays in many cases [11,12]. In fact, some studies indicated that selective admission to the ICU reduced hospital stays and costs without an apparent adverse effect on postoperative morbidity and mortality. These studies then suggested guidelines for determining which postoperative patients should be admitted to the ICU [13-15]. In addition, efforts have been made to establish general guidelines for admission to and discharge from the ICU [26]. Such guidelines have been developed by the American College of Critical Care Medicine and the Society of Critical Care Medicine. Indicators for ICU admission for postoperative patients were a need for ventilator support, chronic co-morbidities that may develop into acute severe medical or surgical illnesses, and shock or hemodynamic instability [26]. However, many postoperative patients (70 to 76%) undergo monitoring only while in the ICU. This applies to posthepatectomy patients among others. In previous studies, those patients were defined as low-risk monitor (LRM) patients and "too well to benefit."

In our study, most patients (148/168 patients, 88.1%) in the ICU group underwent monitoring only. This finding suggests that all patients after liver resection may not need admission to the ICU, and the patients who are admitted to the general ward did not need ICU-level care. However, the LRM patients are not no-risk patients and guidelines for admission to the ICU in posthepatectomy patients may be needed. Even though the guidelines mentioned earlier suggest that co-morbidities indicate a need for ICU admission, co-morbidities were not associated with intensive treatment and ICU re-admission. Another study reported that co-morbidities did not affect the early outcomes of liver resection [27].

Advanced age was one of the limitations for surgery. However, according to some studies, morbidity and mortality after liver resection do not differ significantly between patients older or younger than 70 years [28]. In our study, similarly, intensive treatment and the ICU re-admission were not associated with age.

The presence of intraoperative transfusions and major liver resection were closely related with intensive treatment and ICU re-admission in univariate and multivariate analysis. Major liver resection was the most common cause of posthepatectomy liver failure. It was the most serious complication in the patients who underwent liver resection. This complication increased the cost markedly [29]. Intraoperative transfusion may affect not only oncologic outcomes but also morbidity [30]. In our study, Positive group underwent major liver resection and received intraoperative transfusion showing long ICU stay and postoperative hospital stay. They experienced more much postoperative ventilator care and mortality than negative group.