Hyperglycaemia has been repeatedly associated with risk of mortality and morbidity in the intensive care unit (ICU). The evidence currently available is in favour of a 'normal ≤ 6.1 mmol/l' level for blood glucose control in ICUs according to two large randomized control trials of Van den Berghe G and is not supportive of J. Miles's viewpoint in this debate. In this study, the investigators would like to evaluate that the target of blood glucose level, whether is a normal level (80-110 mg/dL) or another level (140-160 mg/dL), should be set for the reduction of perioperative mortality and complications.