Low Dose Caudal VS Dorsal Penile Nerve Block for Postoperative Analgesia After Circumcision

Cases were subdivided into three groups: Group 1: included dorsal penile block patients. Group 2: included caudal block patients. Group 3: included combined block patients. Circumcision was performed under general anesthesia and dorsal slit technique was used. Study procedure: General anesthesia was induced and maintained by inhalation of sevoflurane in oxygen mixed with air gas flow. A 22-G intravenous (i.v.) cannula was placed after induction. Spontaneous respiration was maintained via a selected laryngeal mask airway, and the inhaled sevoflurane was modified and maintained as 0.8 to 1.0MAC. Block techniques: Technique of the caudal block The patient was placed in lateral decubitus position for blind caudal epidural block. A line was drawn to connect the bilateral posterior superior iliac crests and used as one side of an equilateral triangle; then the location of the sacral hiatus was approximated by palpating the sacral cornua as 2 bony prominences, the sacral hiatus was identified as a dimple in between. A needle was inserted at 45 degrees to the sacrum and redirected if the posterior surface of sacral bone was contacted. A subjective feeling of loss of resistance suggests piercing the SCL but was associated with a miss rate up to 26% even in experienced hands. The "whoosh test," performed by auscultation at the thoracolumbar region with a stethoscope while injecting 2 mL of air, had a sensitivity of 80% and a specificity of 60% in adults. Palpating for subcutaneous bulging on rapid injection of 5 mL air or saline had a positive predictive value of 83% and a negative predictive value of 44%. The inaccuracy of using blind technique for caudal epidural injection in adults, even confirmed by various tests, is clearly evident. Drugs and doses used: 0.5 ml/kg of 0.25% Bupivacaine (diluted by saline solution 0.9). Technique of Dorsal penile nerve block: Under aseptic technique and under ultrasound guidance. A 'hockey-stick' probe was used, covered by transparent sterile dressing. The probe was placed vertically over the pubic symphysis and the base of the penile shaft. With adjustment of the probe, a sagittal view of the penile shaft was produced. Scarpa's fascia was seen as a hyperechoic line superficial to the penile shaft. Under real-time guidance, the needle was inserted and advanced until its tip laid deep to Scarpa's fascia (i.e., within the subpubic space), where local anesthetic was deposited. The local anesthetic solution injected was 0.5% bupivacaine in a recommended volume. (2 ml up to 3 years and an additional 1 ml for each3 years up to maximum 6 ml). Combined block: The caudal block was performed then the patient was placed in supine position and the DPNB was done .