Erector Spinae Plane Block in Scoliotic Adolescents

All patients will be assessed clinically and investigated for Pulmonary function test and Echocardiography. Laboratory work needed will be: Complete blood count (CBC); prothrombin time and concentration (PT& PC); partial thromboplastin time (PTT); bleeding time (BT); clotting time (CT) and liver function tests.

an online randomization program (http://www.randomizer.org) will be used to generate random list and to allocate patients into the two study groups. Random allocation numbers will be concealed in opaque closed envelops.participants and those assessing/analyzing the outcome(s) will be blind to group assignment.

Eutectic Mixture of Local Anesthetics (EMLA) cream will be applied to the site of venous puncture. After insertion of venous access, all children will receive midazolam at a dose of 0.1 mg/Kg. Intraoperative monitoring will include continuous electrocardiogram (ECG), pulse oximetry, invasive arterial blood pressure, end-tidal carbon dioxide (CO2), inhaled gas analyzer and temperature monitoring.

General anesthesia will be induced in both groups (Erector Spinae group and control group) using propofol 2.5 mg/kg over 20-30 seconds, atracurium 0.5 mg/kg to facilitate endotracheal intubation and fentanyl 1 µg/kg. Anesthesia will be maintained using isoflurane (1 MAC) and atracurium infused as 0.5 mg/kg/hr. All patients will receive IV ranitidine 2 mg/kg, ondansetron 0.1 mg/kg, cefotaxime 50 mg/kg and acetaminophen 15 mg/kg. An arterial catheter and a urinary catheter will be placed. Then patients will be turned to the prone position.

In group E: will receive Erector Spinae Plane Block (ESPB) In group C: control group will receive another dose of fentanyl 1 µg/kg 1 minute before start of skin incision. After end of surgery and emergence from anesthesia, patients will receive continuous intravenous morphine with 0.03 mg/kg/hr.

In both groups, if the analgesia obtained from both methods of ESBP or IV fentanyl was inadequate in the form of increase in heart rate and or arterial blood pressure by more than 20% of baseline values during surgery, this warrants the administration of intravenous fentanyl (0.5µg/kg). Total blood loss, duration of surgery, number of vertebral levels fixed, total fentanyl consumed will be recorded. After completion of surgical procedure and emergence from anesthesia the patient will be referred to post-anaesthesia care unit (PACU). Quality of analgesia will be assessed immediately postoperative and then at 4, 8, 12, 16, and 24 hours postoperatively in the Intensive Care Unit (ICU) by using VAS pain score. All patients will receive postoperative IV acetaminophen IV 10 mg/ kg q 6 hours, ketorolac from second day 15 mg q 6 hours, not to exceed 5 days. Patients will also receive ranitidine 2 mg/kg q 12 hours. Vital signs and urinary output will be monitored. Morphine IV will be given as rescue analgesia (20 µg/kg) in all study groups if visual analogue scale (VAS) pain score more than 3. The total maximum hourly morphine is 0.75 mg/kg/hr. After reaching maximum hourly morphine and the patient is still in pain, pethidine will be used as a rescue at 0.5 mg/kg. Morphine will be stopped if maximum hourly dose is reached or the patient becomes sedated (Ramsay score >2), has a ventilatory rate of <12 bpm, or an oxygen saturation of <95%, or has a serious adverse event (allergy, hypotension, severe vomiting).

Patients will be continuously monitored in the PACU and ICU. Naloxone and full resuscitation equipment are available. Time of first need for morphine and total 24 hr morphine consumption will be recorded. Complications e.g nausea, vomiting, pruritis or respiratory depression will be recorded.

Inclusion criteria

• American society of Anesthesia classification (ASA) I-II
• Patients undergoing dorsal spine instrumentation for scoliosis.

Exclusion criteria

• Refusal of block.
• Bleeding tendency with prothrombin concentration PC less than 75 % or platelet count less than 150,000/µL.
• Skin lesion, wounds or infection at the puncture site.
• Known allergy to local anaesthetic drugs.