Ultrasound Guided Subgluteal Sciatic Nerve Block Versus Caudal Analgesia for Cerebral Palsy Patients Undergoing Lower Limb Corrective Surgeries

Both caudal and peripheral nerve blocks are widely used for postoperative analgesia in pediatric population .The safety of both techniques has been documented especially after the application of ultrasound guidance for their performance. Patients with cerebral palsy usually require lower limb orthopedic surgeries,that extend from minor soft tissue releases, like tenotomies, tendon lengthening or transfer, to major osteotomies for correction of their limb deformities.

Study objective: to compare the efficacy of ultrasound guided caudal block with subgluteal sciatic nerve block for postoperative pain control in pediatric patients with cerebral palsy who will undergo soft tissue surgeries for knee and ankle deformities correction.

Methods: This study patients will be randomly distributed to 2 Groups to receive either US guided caudal block or US subgluteal sciatic nerve block after induction of general anesthesia.

After proper preoperative patients' anesthesia assessment; the study patients (15 per each group) will receive general anesthesia with either intravenous induction or inhalational induction if uncooperative under full monitoring of hemodynamics, temperature and oxygen saturation.

In caudal group : Patients will be positioned in lateral decubitus and their sacral hiatus will be palpated under the scanning of the ultrasound using high frequency linear probe then approached via 5 cm block needle that pierce the sacrococcygeal ligament then will be advanced to caudal canal under ultrasound guidance after which Marcaine 0.25% (1 ml/kg) will be administered in increments.

In subgluteal sciatic group : Patients will be positioned in lateral decubitus and the ultrasound scanning for the sciatic nerve in the subgluteal region will be started between the two bony landmarks (greater trochanter and ischial tuberosity ) using high frequency linear probe then approached via 5 cm block needle under ultrasound guidance after which Marcaine 0.25% (0.3 ml/kg) will be administered in increments .

Anesthesia will be maintained with sevoflurane inhalational anesthesia and incremental rocuronium and fentanyl for muscle relaxation and intraoperative analgesia respectively . Muscle relaxation will be reversed at the end of surgery by atropine-neostigmine combination and patients will be extubated fully awake. Postoperative analgesia in the form of intravenous paracetamol 15 mg/kg will be administered if revised FLACC(face,legs,activity,cry and consolability) scores are ≥ 4 and intravenous infusion of ketorolac 0.5 mg/ kg will be given if pain persisted for 15 minutes after paracetamol injection

Eligibility Criteria:
Inclusion Criteria:

* Patient with spastic cerebral palsy
* Age 2 -12 years
* Both gender
* ASA ( American society of anesthesiologists) physical status II

Exclusion Criteria:

* Parents' refusal to study participation.
* Patients with dyskinetic or ataxic cerebral palsy
* Patients need surgery for hip contracture/deformity
* Severe mental dysfunction
* Poor controlled epilepsy
* Advanced respiratory,renal or hepatic impairment
* Allergy to study medications
* Block contraindication as skin infection near to the block site, gross deformities and bleeding disorders.