patient enrollment was failed.

Elective colectomy procedures typically require bowel preparation starting 2 days prior to the surgery. Osmotic laxatives such as Colyte® are administered 2 days prior, and Nothing by mouth (NPO) is required 1 day prior to ensure no fecal residue is left in the bowel. Though it may ensure a cleaner and safer surgery, this longer period of starvation increases insulin resistance and may increase post-op complications. However, there is evidence that administration of oral rehydration solution(ORS) prior to surgery reduces insulin resistance. Our purpose is to evaluate the difference of insulin resistance in those who received ORS 1 day prior to surgery and those who did not.

1. Enhanced Recovery After Surgery (ERAS) Enhanced Recovery After Surgery(ERAS) was introduced in the early 2000s by Kehlet et.al., and was applied primarily to patients receiving colectomy. As the knowledge and understanding of this concept continues to grow, we are now able to change the way we treat pre- and post- operative patients. In Europe, it has been proven that applying this concept to patients resulted in decreased length of post-operative hospital stay, post-op complications and overall hospital costs.

2. The change in HOMA-IR with shorter preoperative Nothing by mouth (NPO) period in ERAS patients

   1. HOMA-IR Index equation (evaluation of Insulin resistance)

      = Insulin (μU/ml) X blood glucose (mg/dl) / 405

   2. HOMA-IR was statistically proven to have been lowered in patients who received ORS 2hr prior to surgery.

   3. Reference

      • Increased insulin resistance induces hyperglycemia
      • Toxicity of post-op hyperglycemia and their relation to post-op complications
      • Insulin resistance increases in procedures such as herniorrhaphy or laparoscopic cholecystectomy. Administration of preoperative carbohydrates decrease post-op nausea and vomiting
      • Conventional pre-op 8hr fasting increases insulin resistance and influences increased glucose levels

3. Additional benefits of shorter preoperative fasting

   1. Relieve of stress of fasting
   2. Help stabilize post-op triglyceride, cortisol, and glucose levels
   3. Reduce infectious complications

Inclusion Criteria:

• ASA grade I~II (DM, CVA, COPD, ESRD, MI, TIA etc. excluded)
• Age: adults age 19~75
• Patients undergoing elective colon cancer surgery
• Able to take the ORS per orally. Able to swallow without trouble of aspiration tendencies
• BMI of less than 27.5
• Child-Turcotte-Pugh Classification score of less than 6

Exclusion Criteria:

• emergency cases such as obstruction or perforation
• food allergy
• abdominal distension at present
• prior gastric surgery