This study will be carried out on 80 patients who will be presented for different spine surgeries under general anesthesia and regional anesthesia technique in Tanta university hospitals. The study was approved by the research ethics committee of the faculty of medicine.

Patients will be admitted to the OR where induction of general anesthesia was started and then, the patients will be randomly distributed into two equal groups; -

• Group I (40 patients) (ESP block): patients in this group will receive ESP block after induction of general anesthesia.
• Group II (40 patients) (TLIP block): patients in this group will receive TLIP block after induction of general anesthesia

Measurements; - The length of hospital stay as the primary outcome Postoperative pain scores and opioid consumption as the Secondary outcome

This prospective randomized double-blind study will be carried out on 80 adult patients who will be presented for different spine surgeries in Tanta university hospitals after obtaining the approval from the institutional Ethical Committee, informed written consent will be obtained from all the participants.

Patients will be randomly classified using a computer-generated software of randomization into 2 groups:

• Group I (40 patients) (ESP block): patients in this group will receive ESP block after induction of general anesthesia.
• Group II (40 patients) (TLIP block): patients in this group will receive TLIP block after induction of general anesthesia

Anesthetic technique

• The patients will be assessed preoperatively in the anesthesia clinic. On arrival of patients to the preparation room, an intravenous line will be established and the patient will be connected to a monitor. All the patients will receive pheniramine hydrogen maleate 45.5 mg intravenous as an antihistamine, Cefazolin30 mg/kg, and 40 mg pantoprazole.
• Induction of anesthesia will be carried out by fentanyl 1 ug/kg, propofol 1.5 mg/kg, and atracurium 0.5 mg/kg to facilitate tracheal intubation. After securing the airway through a suitable sized endotracheal tube, the patient was connected to a mechanical ventilator with its parameters adjusted to maintain the end-tidal carbon dioxide 34-38 mmHg.
• Maintenance of the anesthesia was performed by isoflurane 1.MAC and incremental doses of atracurium 0.1 mg/kg. A temperature probe was inserted in the nasopharynx for core temperature monitoring. The depth of anesthesia was monitored by the bispectral index (Covidien, Mansfield, MA, USA). The BIS values were kept 40-60. An additional bolus dose of fentanyl 0.5 ug/kg was used in case of increase BIS more than 60 or increase in the heart rate or mean arterial pressure by more than 15 % of the baseline values.
• All patients received tranexamic acid 30 mg/kg through intravenous infusion. Before skin incision, patients of group I will receive ultrasound-guided ESP block, while patients in group II will receive ultrasound guided TLIP block.
• At the end of the surgery, the isoflurane was switched off with reversal of muscle relaxation and awake tracheal extubation and transfer of the patient to the recovery room for postoperative monitoring and supplementation of oxygen through a nasal cannula (2-3 L/min). All the patients will receive 4 mg dexamethasone I .v after induction of anesthesia and 4 mg of ondansetron i.v at the end of the surgery to guard against postoperative nausea and vomiting. All the patients received routine postoperative analgesia in the form of paracetamol 1 gm i.v infusion every 6 hours and ketorolac 30 mg i.v every 12 hours. Rescue analgesia in the form of morphine 3 mg i.v was administrated when the pain score was more than 3.

Inclusion Criteria:

• Adult patients of both sexes aged (21-70 years) with ASA physical status I-III scheduled for spine surgeries.

Exclusion Criteria:

• Patient refusal
• Body mass index (BMI) less than 18 or higher than35 kg/m2
• Pregnant
• History of relevant allergy to related perioperative medications
• Previous lumbar spine surgery
• Existing contraindications to nerve block such as coagulopathy, local and systemic infection
• Hepatic or renal insufficiency
• Chronic opioid use

The data of primary outcome will be available with the corresponding author till 6 months after approval of the publication of the trial.

The data of primary outcome will be available with the corresponding author till 6 months after approval of the publication of the trial.

Contact the principal investigator

• The patients will be blinded to their groups.
• An anesthesia resident who will not participate in the study and have no subsequent rule in it will help in the preparation of local anesthetic mixtures under strict aseptic precautions.
• An assistant nurse who will be blinded to the study groups and will have no subsequent rule in it will help in the collection of the data of measurements.