This study is conducted to compare the analgesic efficacy between ultrasound guided Erector Spinae Plane block Vs midpoint transverse process to Pleura block in modified radical mastectomy surgeries

Patients participants will be randomized into 3 groups:

Group M (mid-point transverse process to pleura block MTP) N=3o Patients will receive Ultrasound guided mid-point transverse process to pleura block preoperative with injection of 20 ml bupivacaine 0.25%.

Group M: The block will be performed preoperatively with full aseptic precautions. The ultrasound probe will be placed on the back in a vertical orientation on the lateral side of the posterior median line to identify the transverse processes of the 4th and 5th thoracic vertebrae and pleura.

A skin wheal using 3ml of 1% lidocaine will be made 2 to 3 cm superior to the superior aspect of the transducer. Using the in plane needling technique in the space between the transverse processes of the 4th and 5th thoracic vertebrae, the puncture needle needle tip will be placed at the mid-point between the transverse process and pleura, with no blood, gas, or cerebrospinal fluid observed on aspiration, 20 mL of 0.25% bupivacaine will be administered. The local anesthetic spread will be noted in the area midway between the transverse process and pleura is an indication of a successful puncture.

Group E (Erector Spinae Plane Block ESB) N=3o Patients will receive Ultrasound guided erector spinae plane block with injection of 20 ml bupivacaine 0.25%.

Group E: The block will be performed preoperatively with full aseptic precautions. The ultrasound probe will be placed on the back in a vertical orientation on the lateral side of the posterior median line to identify the transverse process of the 5th thoracic vertebra and erector spine muscle.

A skin wheal using 3ml of 1% lidocaine will be made 2 to 3 cm superior to the superior aspect of the transducer. The puncture will be performed using the intra-plane needling technique after local anaesthesia infiltration. A 20-gauge Tuohy needle connected to a syringe containing the anesthetic mixture or saline will be advanced. When the puncture needle touch the transverse process, with no blood, gas, or cerebrospinal fluid observed on aspiration, 20 mL of 0.25% bupivacaine will be administered between the erector spine muscle and transverse process.

Local anesthetic diffusion between the transverse process and erector spinae muscle is an indication of a successful puncture.

Group C (control group) N=30 Patients will not receive any block. Induction will be performed by using a regimen of IV by fentanyl 1 μg/kg, Additional bolus doses of fentanyl 0.5 μg/kg will be given if the mean arterial blood pressure or heart rate rises above 20% of baseline levels.

Randomization will be done by statistician and each group of the patient will revealed only when the included patient is transferred to preanesthetic room.

Inclusion Criteria:

• ASA I-II.
• Undergoing modified radical mastectomy surgery.
• Body mass index (BMI) from 18.5 to 30 kg/m2

Exclusion Criteria:

• Patient refusal.
• Known allergy to local anesthetics.
• Bleeding disorders; platelets count <50,000 , prothrombin concentration < 60% or any coagulopathy disorder.
• Use of any anti-coagulants.
• Inability to provide informed consent.
• ASA III-IV.
• Neurological disorders.
• Patient with psychiatric disorders

The patients will be randomly assigned into three equal comparable groups using computer-generated random numbers in opaque closed envelopes, each of which will include 30 patients. With allocation ratio 1:1:1

Group M (mid-point transverse process to pleura block MTP) N=3o Patients will receive Ultrasound guided mid-point transverse process to pleura block preoperative with injection of 20 ml bupivacaine 0.25%.Then patients will be transferred to operating room.

Group E (Erector Spinae Plane Block ESB) N=3o Patients will receive Ultrasound guided erector spinae plane block with injection of 20 ml bupivacaine 0.25%. Patients will be transferred to operating room.

Group C (control group) N=30 Patients will not receive any block. Induction will be performed by using a regimen of IV by fentanyl 1 μg/kg, Additional bolus doses of fentanyl 0.5 μg/kg will be given if the mean arterial blood pressure or heart rate rises above 20% of baseline levels.