Retrolaminar Thoracic Paravertebral Block

This clinical study will be conducted on female patients admitted to The General Surgery Department of Tanta Faculty of Medicine for a period of 9 months.

Patients will be randomly allocated into one of the following two groups;- • Ordinary approach group (30 patients): The patients in this group will receive ordinary ultrasound-guided thoracic paravertebral block.

• Retro-laminar approach group (30 patients): The patients in this group will be receive real ultrasound-guided Retrolaminar thoracic paravertebral block.

All the patients will receive general anesthesia with attachment to a monitor (5 ASA Monitoring) In addition to bispectral index.

This prospective randomized controlled study will be carried out on female patients who will be presented for breast surgery in the General Surgery Department in Tanta university hospitals over 3 month duration and 6 months follow up that starts immediately after obtaining ethical committee approval, an informed written consent will be obtained from all the participants, all patients data will be confidential and will be used for the current study only.

Any unexpected risks that will appear during the research will be announced to the participants and to the ethical committee at time and adequate measures will be taken to resolve and avoid these risks.

Expected risks to the patients: patients enrolled in this study will have a very minimal risk of pleural puncture that will be managed by adequate observation and chest tube insertion whenever indicated. They may have a minimal risk of hypotension that will be managed by intravenous fluids and intravenous ephedrine 10 mg.

There will be adequate supervision to maintain the privacy of patients and confidentiality of data that will be used in the current study only.

There will be no conflict of interest, nor conflict with religion, law, or society standards.

The research will be beneficial to the society and has no risk of environmental pollution.

Once the patients will arrive to the operating room, intravascular access will be established, fluid preload will be started, and basic monitor will be attached. After positioning and adequate sterilization of the back. The patients will be randomly allocated into two equal groups by the aid of computer-generated software of randomization; - • Ordinary approach group (30 patients): The patients in this group will receive ordinary ultrasound-guided thoracic paravertebral block.

• Retro-laminar approach group (30 patients): The patients in this group will be receive real ultrasound-guided Retrolaminar thoracic paravertebral block.

Anesthesia will be induced by fentanyl 1.5 ug/kg, propofol 1.5 mg/kg, and cis-atracurium 0.15 mg/kg to facilitate tracheal intubation. After endotracheal intubation, the patients will be connected to a mechanical ventilator with its parameters adjusted to maintain etCo2 34-38 mmhg. Anesthesia will be maintained by isoflurane 1.5% in mixture of oxygen:air 1:1 with the use of low flow (1 ml/min).

All the patients will be connected to a bispectral index monitor with maintaining its value ranging 40-60. Increase in the BIS value over 60 will be managed by additional dose of fentanyl 1ug/kg till decrease the BIS below 60. If the BIS is still over 60, increasing the isoflurane 0.2 % MAC till it decreased below 60.

At the end of the surgery, switching off the inhalational anesthetics, reversal of muscle relaxation, and awake tracheal extubation will be done with transporting the patients to the PACU for postoperative follow up and monitoring.

Eligibility Criteria:
Inclusion Criteria:

* Female patients
* Aged 40-60 years
* ASA class I-II.
* Presented for elective breast surgery.

Exclusion Criteria:

* Patients refused to participate
* Patients with known or suspected or known allergy to the used medication.
* Patients with spinal deformities.
* Patients with preoperative chronic pain,
* Patients received preoperative opioids or gabapentoids.
* Patients with major cardiac, renal, respiratory, or hepatic disease.
* Patients with suspected or diagnosed coagulopathy
* Uncooperative patients.
* Obese patients with BMI \>36