The Effect of Preoperative Assessment Clinic on Prognosis and Economic Results of Patients With Coexisting Diseases.

To assess the effect of preoperative assessment clinic on prognosis and economic results of patients with coexisting diseases, the investigators designed a prospective cohort study. The investigators will recruit 250 patients preparing to undergo a selective epigastrium surgery with coexisting medical diseases which need an anesthetic consultation. The patients will be randomly assigned into two groups. The intervention group will be seen in the preoperative clinic before hospitalization, while the control group will get anesthetic consultation after hospitalization without clinic service. No additional interventions will be given during and after surgery. The length of stay, hospitalization expense, postoperative complication rate and mortality rate of the two groups will be compared. The investigator assume that consultation in preoperative assessment clinic will improve the prognosis and decrease the hospitalization expenses.