 The test drugs are an active drug, which is a capsule filled with dexamethasone powder and lactose, and a placebo, which is a capsule filled with only lactose. The test drugs will be prepared by the Department of Pharmacy manager: Professor Masuda, Kyushu University Hospital in accordance with the procedures for preparation of the test drugs. Dexamethasone powder and lactose will be purchased by Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University from Tomita Pharmaceutical and delivered to the pharmacy department. Research funds will be used for the purchase. The capsule will be purchased from Tomita Pharmaceutical. The test drugs will be delivered to CReS-Kyushu enrollmentdata center and managed using a double-blind method in accordance with the procedures. The double-blind code will be kept by the person responsible for management of the test drugs Shoji Tokunaga, Medical Information Center, Kyushu University, and a backup of the code will be kept by Hidekazu Aratani of CReS-Kyushu. 