Inclusion Criteria:  ASA physical status II patients aged 21-65 years known to have type1 or 2 diabetes mellitusw pre-operative fasting blood glucose level ˂ 350 mg/dl scheduled to undergo elective laparotomy surgeries expected to exceed 2 hours duration under general anesthesia  Exclusion Criteria:  Patients' refusal diabetic ketoacidosis hyperglycemic hyperosmolar syndrome serum potassium ˂3.5 mEq/L HbA1c >8.5%.