Comparison Between Ultra Sound Guided Rectus Sheath Block and Field Block for Midline Hernia Repair

75 patients undergoing midline hernia repair under general anesthesia will be recruited and will be randomly allocated using closed envelope technique as follows: Control group, Local infilteration (Field block infilteration) group, Ultra sound Guided Rectus sheath block group.

General anesthesia will be standardized for all patients with :

2 µg kg-1 fentanyl and 2 mg kg-1 propofol. Neuromuscular blockade will be achieved with 0.5 mg kg-1 atracurium followed by tracheal intubation.

Muscle relaxation will be maintained by 0.1mg / kg / 30 minute of Atracrurium. Anesthesia will be maintained by sevoflurane. Mechanical ventilation will be adjusted with fresh gas flow oxygen in air 30-50% at a rate of 1 L min-1to maintain end-tidal carbon dioxide of 35-40 mm Hg and Spo2 greater than 94%.

BIS values will be maintained between 40 and 60. All surgical procedures will be done in the range between 10 am and 1 pm and by the same surgical team.

• Control group : will receive field block using 0.3 ml/kg of normal saline at site of the hernia plus ultra- sound guided rectus sheath injection using 0.3 ml / kg of normal saline.
• Field block group: will receive 0.3 ml / kg of 0.5% bupivicaine subcutaneously surrounding the site of the hernia following the induction of anesthesia and ultra-sound guided rectus sheath block with 0.3 ml / kg of normal saline.
• Ultrasound guided rectus sheath block : Under sterile conditions a 21/22 G , 50- 100 milli meter length echogenic needle guided by the ultrasound into rectus sheath at the level of the umbilicus , using an - in plane technique. After -ve aspiration 0.3 ml/ kg of 0.5 % bupivicaine will be deposited on each side and the spread of local anesthesia will be observed by ultrasound plus 0.3 ml/kg of normal saline subcutaneously at the site of the hernia.

All solutions used will be prepared by a colleague who will not participate into the study.

Inclusion criteria

• Elective midline hernia repair surgery.
• Age: adult patients between 18 - 60 years old.
• Gender: Both male and female.
• ASA Class: I & II.

Exclusion criteria

• Refusal of patient.
• Pregnancy and lactation.
• Fever or sepsis.
• Patients ASA III or IV.
• Addicts and drug abusers.
• Patients taking corticosteroids or any cardio - active drugs.
• Local infection at site of the injection.
• Allergy to any of the study medications.