The aim of this study is to evaluate the effect of the ultrasound guided rectus sheath block (RSB) on both intraoperative sevoflurane consumption and postoperative analgesia.

Prospective, randomized study.Forty patients with American Society of Anaesthesiologists (ASA) I-II physical status, aged 3-15 years.Patients are randomly allocated into two groups and are administered general anesthesia and before the beginning of surgery ultrasound guided RSB with 0.2 ml.kg-1, 0.25% of levobupivacaine and thirty minutes before the surgery the loading dose of morphine of 0.1 mg.kg-1 intravenously are received in group RSB and group M, respectively. Patient controlled analgesia (PCA) device with 0.01 mg.kg-1 bolus dose of morphine and 30 minutes lockout interval is set up postoperatively in both groups.

Inclusion Criteria:

• ASA physical status I-II
• 3-15 years of age children
• Abdominal surgery including liver, gall bladder, spleen, small intestine, cecum, colon, rectum, intra-abdominal masses, umbilical, paraumbilical, and inguinal hernia with transverse incision

Exclusion Criteria:

• ASA physical status III and above
• Parents who did not consider to participate in the study
• Having systemic (septicemia, bacteremia) or local infection, bleeding and shock, predisposition for bleeding and anticoagulant therapy given, central nervous system disease, allergy to local anesthetics, severe respiratory, hepatic, and renal failure