This study aims to evaluate the effect of the erector spinae plane block (ESPB), performed after surgery, on quality of recovery, postoperative pain, and time to return to daily activities in patients undergoing open inguinal hernia repair under spinal anesthesia.

Postoperative pain following inguinal hernia surgery may delay recovery and negatively affect patients' return to normal daily life. Although ESPB has been widely used as an effective analgesic technique in various surgical procedures, its effectiveness in inguinal hernia repair remains limited and not well established.

In this randomized controlled study, patients will be divided into two groups: one group will receive ESPB after surgery, while the control group will not receive any block. All patients will receive standard postoperative analgesia.

Quality of recovery, acute pain scores, and analgesic consumption will be assessed within the first 24 hours after surgery, and return to daily activities will be evaluated 30 days after surgery.

The primary outcome of this study is quality of recovery assessed using the Quality of Recovery-15 (QoR-15) questionnaire. QoR-15 scores range from 0 to 150, with higher scores indicating better recovery. Scores will be recorded preoperatively and 24 hours after surgery.

Secondary outcomes include postoperative pain intensity, total opioid consumption, and time to return to daily activities. Pain intensity will be assessed using the Numeric Rating Scale (NRS), where 0 indicates no pain and 10 indicates the worst pain imaginable, at 15, 30, 60, and 120 minutes, as well as 6, 12, and 24 hours after surgery.

Total opioid consumption will be determined by recording the cumulative dose of intravenous tramadol administered as rescue analgesia within the first 24 hours after surgery. Time to return to daily activities will be evaluated via telephone follow-up 30 days after surgery.

This prospective, randomized, controlled study is designed to evaluate the effect of erector spinae plane block (ESPB) on postoperative recovery in patients undergoing open inguinal hernia repair under spinal anesthesia.

After obtaining written informed consent, eligible patients aged 18-65 years will be enrolled. Standard monitoring, including electrocardiography, non-invasive blood pressure, and peripheral oxygen saturation, will be applied upon arrival in the operating room. An intravenous line will be established, and isotonic saline infusion (15 mL/kg/h) will be initiated. Sedation will be provided with intravenous midazolam (0.03 mg/kg).

Spinal anesthesia will be performed at the L3-L4 interspace using 13 mg hyperbaric bupivacaine combined with 15 µg fentanyl.

At the end of surgery, patients will be randomized into two groups using a computer-generated randomization list prepared by an independent statistician. Group allocation will be concealed in sealed opaque envelopes and revealed to the anesthesiologist performing the intervention.

In the ESPB group, an ultrasound-guided erector spinae plane block will be performed at the T11-T12 level on the side of surgery. Patients will be positioned in the lateral decubitus position. After sterile preparation, a 2-5 MHz convex ultrasound probe (Fujifilm Sonosite, USA) will be placed in a paramedian sagittal orientation and then shifted laterally to visualize the transverse process and erector spinae muscle. A 22-gauge, 100-mm needle will be advanced using an in-plane technique, and 30 mL of 0.25% bupivacaine will be injected into the fascial plane between the transverse process and erector spinae muscle.

Patients in the control group will not receive any regional block.

All patients will receive a standardized postoperative analgesic regimen consisting of intravenous dexketoprofen (50 mg every 6 hours). Rescue analgesia will be provided with intravenous tramadol (1 mg/kg) if the Numeric Rating Scale (NRS) score is ≥4.

Postoperative monitoring will be conducted in the recovery unit and surgical ward according to institutional protocols. Clinical data, including spinal anesthesia parameters such as block duration, motor block level, and sensory block level, will be recorded.

Follow-up assessments will be performed within the first 24 hours after surgery and via telephone contact 30 days after surgery to evaluate functional recovery.

Inclusion Criteria:

1. Patients aged between 18 and 65 years
2. Patients scheduled to undergo open IHT surgery under spinal anesthesia (unilateral)
3. Both male and female patients

Exclusion Criteria:

1. Patients with coagulation disorders
2. Patients with chronic opioid use
3. Patients who develop intraoperative complications
4. Patients with a preoperative Numeric Rating Scale (NRS) pain score ≥4
5. Patients with a history of revision (recurrent) surgery
6. Patients unable to communicate for any reason
7. Patients who decline to participate in the study