[Safe practice of oral rehydration therapy by oral rehydration solution and carbohydrate loading--evaluation by non-invasive gastric echo examination].

Many anesthesiologists are reluctant to depart from their traditional long fasting periods, even though many guidelines recommend that oral intake of clear fluids administered up to 2-3 hours prior to general anesthesia does not adversely affect the gastric contents. It also indicates that the application of these guidelines does not affect the incidence of pulmonary aspiration. One of the reasons why they have not changed their practices is that they wonder whether it is safe to administer clear fluids as recommended in the guidelines. In this review, we emphasize that oral rehydration therapy using clear fluids (such as OS-1, water and carbohydrate-rich beverage) is safe based on the non-invasive gastric echo examinations as many guidelines have already indicated. Oral rehydration therapy should be considered not only as an alternative to intravenous therapy for preoperative fluid and electrolyte management but also as one of the important modalities which can enhance the recovery of surgical patients.