Rhomboid Intercostal Block Versus Retrolaminar Plane Block for Postoperative Analgesia in Patients Undergoing Video Assisted Thoracic Surgery.

• Type of Study: a prospective, double-blinded, randomized clinical trial conducted after the approval of the Local Ethics Committee
• Study Setting: ELDEMERDASH HOSPITAL AIN SHAMS UNIVERSITY
• Study Period :3months
• Study Population patient receiving VATS with general anaesthesia with

• - Inclusion Criteria:

  1. 18-80 years of age;
  2. American Society of Anesthesiologists (ASA) Class I-III; and

  3. written informed consent was obtained.

     • Exclusion Criteria:

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  1. Allergy to local anesthetics, nonsteroidal anti-inflammatory drugs, and opioids;
  2. infection of the skin at the puncture site;
  3. peptic ulcer disease or inflammatory bowel disease;
  4. renal deficiency;
  5. transferring to thoracotomy;
  6. daily use of opioids; and (7) bilateral operation.
• Sampling Method
• Sample Size
• Ethical Considerations
• Study Tools AND/ OR
• Blinding Eligible patients were randomly assigned to the three groups: the general anesthesia (GA) group, the RIB group, and the RLB group. A statistician who was not involved in the data analysis prepared a computer-generated list of random numbers and sealed them in separate envelopes. The list of random numbers determines the allocation.
• The study coordinators, attending anesthesiologists and postoperative follow-up personnel, and the patients were all blinded to the group assignment.

Study Procedures : All patients will be taught how to interpret the visual analogue scale (VAS) of 0 to 10 with 0 experiencing no pain and 10 being the worst pain imaginable. All patients will fast for 8 hours prior to surgery and will be allowed to consume clear fluids for up to 2 hours before surgery. On the day of surgery. Basic monitors will be attached to the patients (NIBP, ECG, pulse oximetry, ETCO2).

Both ultrasound guided blocks will be done by experienced anesthesiologists specialized in regional anesthesia.

The patient will be kept in the lateral decubitus position. Following sterilization and draping of the skin, a high frequency ultrasound probe (Siemens Medical Solutions, Inc., Mountain View, CA 94043, USA) will be used For RLB, the ultrasound probe will be placed in a sagittal orientation on the lateral side of the posterior median line to identify the lamina, erector spine muscle, and transvers spinalis muscles at the target thoracic segment [12]. A 20G puncture needle will be inserted using an intra-plane technique in a cephalocaudal direction. Once the needle contact the lamina and aspiration reveals with no blood, gas, or cerebrospinal fluid, 20 mL of local anesthetic solution, comprising 20 mL of 0.25% bupivacaine will be administered between the transvers spinalis muscle and lamina.

The patient was kept in the lateral position, and the ipsilateral arm was extended to move the scapula laterally and open the space. The skin was sterilized and draped, followed by the placement of a linear probe (Siemens Medical Solutions, Inc., Mountain View, CA 94043, USA) in an oblique sagittal plane medial to the lower border of the scapula, the triangle of auscultation, at the level of the T5 to T6 vertebrae. The rhomboid major muscle is located beneath the trapezius muscle. The pleura, lungs and intercostal muscles were also identified [18]. Using an in-plane approach, a 22-gauge, 80 mm stimuplex needle was placed in the craniocaudal direction into the fascial plane between the rhomboid major and the inter costal muscles. The needle tip position was confirmed via hydrodissection with 1 ml of normal saline, after which 20 ml of 0.25% bupivacaine was injected underneath the rhomboid major muscle.

Participants of the two interventional groups under went sensory assessment using standardized cold sensation test with iced solutions every 5 min for 30 min after injecting LA. The data was recorded as the area of sensory loss at the midclavicular line (MCL), midaxillary line (MAL)and at scapular line (SL)compared to the ipsilateral shoulder's intact sensibility.

A block was considered successful if at least three dermatomes from T3-T6 at MAL and MAL, were covered bilaterally; otherwise, a failed block was declared after 30 min of LA injection, and this case was withdrawn from the study. The onset time of the block (from injecting LA until achieving the desired successful sensory level) and its maximum dermatomal level were recorded. An assistant who was not involved in the block performance or the following study steps conducted a block assessment

Anesthesia induction and nerve blocks for all patients were performed by a group of independent experienced anesthesiologists in the preanesthesia room according to the random number before the operation (the GA group, only performed induction). Afterwards, the patients were transferred to the operating room to start the operationThe postoperative analgesia regimen comprises an ibuprufen and patient-controlled intravenous naluphen. Postoperative VAS scores, consumption of opioids were documented to estimate the analgesic effect.

Anesthesia Introduction and Maintenance will be done by propofol until loss of verbal response, atracurium (0.5 mg/ kg), fentanyl (1mic/kg). Intubation of trachea will be done. Maintenance of anesthesia by using isoflurane (MAC1.2-1.5), mechanical ventilation (to keep ETCO2 35-40 mm. Hg), and atracurium top-up doses according to the train of four (TOF).

After that arterial cannula will be inserted with monitoring of invasive arterial blood pressure All patients will be given fluids according to the standardized guidelines. An appropriate type of antibiotics and paracetamol (15 mg/kg) will be given at the start of surgery. Ondansetron IV (4-8 mg) and ketorolac IV (30 mg) will be given at the end of surgery.

Heart rate (HR) and mean arterial blood pressure (MAP) will be measured until the end of surgery. Incremental doses of fentanyl were given if inadequate anal gesia was detected (increased HR or MAP > 20% from baseline values) after exclusion of other causes. The total dose of fentanyl consumed intraoperatively will be recorded.

Surgical Management Patients in the three groups were scheduled for wedge resection, segment resection, and lobectomy, which were determined by preoperative chest CT and intraoperative pathological results. All operations were performed by the same group of surgeons. All surgical procedures were completed by video-assisted thoracic surgery (VATS) with two ports. The trochal ports were made at the fourth/seventh intercostal levels.

All the resection material was removed by a surgical glove without excessive expansion of the incision. A chest drain (22F) was inserted at the seventh intercostal level before the skin closure. When suturing the wound, carefully identify the position of the intercostal nerve to avoid injuring the intercostal nerve. No wound retractor was used during the operation.

Reversal of muscle relaxant will be done by using neostigmine (0.07 mg/kg) and atropine (0.01 mg/kg) and extubate the patient when having the criteria of extubation. Patients then will be transferred to the post- anesthesia care unit (PACU) for 2 hr for observation of any complications and early assessment of pain then will be transferred to the ward.

. Pain Management all patients in the surgical ward received 200 mg celecoxib orally twice daily and paracetamol 1 gm/8 hours (maximum dose: 4 g/day) as standard postoperative analgesics. Rescue analgesia in the form of 0.1 mg/kg IV of nalbuphine was injected if the patient reported VAS score of ≥ 3 or was asked for more analgesia according to the VAS score during the first 24 h after surgery (the maximum single dose was 20 mg, and the maximum daily dose was 160 mg).

2.4. Outcome Measures The primary outcome The 1st rescue analgesic time was the time it took to request the first postoperative analgesic (nalbuphine) from the end of surgery until the patient reported a VAS score of ≥ 3.

The secondary outcomes include

• The total dose of nalbuphine, a rescue analgesic, was taken during the first 24 hours after surgery. > The technique time (min) was defined as the time between placing the ultrasound probe on the patient's skin and injecting the LA.
• The visual analogue scale (VAS) score was assessed at rest and during movement (arm movement of 90° and sitting from the lying down position) at PACU, 1 h, 3 h, 6 h, 12 h, and 24 h postoperatively. > The number of covered dermatomes was counted after 30 minutes of finishing the block via cold loss sensation with iced solutions.
• Heart rate (HR) and mean arterial blood pressure (MAP) were recorded at baseline before the fascial plane blocks and then immediately and 15, 30, 60, 120, 180, and 240 min after skin incision and at the end of surgery.
• Intraoperative cumulative fentanyl (µg).
• Operative time (min).
• The perioperative complications included opioid complications such as respiratory depression, nausea, vomiting, bradycardia, and hypotension and block complications such as needle injury to essential organs and local anesthetic systemic toxicity [LAST].
• the QoR15 score at 24 h and 48 h postoperatively.