Elective breast reduction surgery is associated with moderate-to-severe postoperative pain and a risk of developing chronic postsurgical pain. Enhanced Recovery After Surgery (ERAS) protocols and the Procedure-Specific Postoperative Pain Management (PROSPECT) guidelines emphasize the importance of multimodal analgesia to reduce pain, minimize opioid consumption, and accelerate functional recovery following surgical procedures, including breast surgery.

The erector spinae plane block (ESPB) has demonstrated effectiveness in breast reduction surgery by reducing postoperative pain intensity, perioperative opioid and non-opioid analgesic consumption, and improving patient satisfaction and recovery time. Furthermore, the use of ESPB has been associated with a reduced incidence of postoperative nausea and vomiting. ESPB is performed with the patient in the sitting position and involves ultrasound-guided identification of the vertebral transverse processes on the side of the block, typically in the interscapular region, followed by the injection of approximately 20 mL of local anesthetic adjacent to the transverse process. When required, the procedure is performed bilaterally at the same vertebral level. ESPB is considered one of the simplest regional anesthesia techniques to perform.

Intravenous lidocaine infusion has been shown to significantly reduce opioid requirements and postoperative pain intensity across a wide range of surgical procedures, particularly in abdominal and breast surgery. Moreover, intraoperative lidocaine infusion has been associated with a reduced risk of chronic postsurgical pain following breast surgery.

This study was designed to investigate whether intraoperative intravenous lidocaine infusion is non-inferior to ESPB in reducing postoperative pain and improving the quality of recovery following non-oncological breast reduction surgery. Intravenous lidocaine infusion may provide analgesic efficacy and recovery outcomes comparable to those achieved with ESPB, thereby representing a less invasive alternative within a multimodal analgesic strategy.

High-quality evidence supports the effectiveness of the erector spinae plane block (ESPB) in reducing postoperative pain following both non-oncological breast reduction surgery and oncological breast reconstructive procedures. In one of the prospective studies bilateral ESPB reduced strong opioid consumption during the first 24 postoperative hours by approximately 50%, from nearly 14 mg to 7 mg of morphine equivalents, while also significantly decreasing patient-reported pain intensity at all assessed time points during the first postoperative day. These findings demonstrate the analgesic efficacy of ESPB compared with standard care without regional anesthesia.

An accompanying editorial highlighted both the methodological quality of the study and the reliability of its findings, while noting that breast reduction surgery is not typically associated with severe postoperative pain. This observation is indirectly supported by the reported opioid requirements, as a total consumption of 14 mg of morphine during the first postoperative day is relatively low, whereas a reduction of approximately 6-7 mg, although statistically significant, may be of limited clinical relevance. The editorial further suggested that, despite its excellent safety profile, bilateral ESPB may be considered unnecessary by some clinicians when postoperative pain can be adequately controlled using pharmacological multimodal analgesia without the need for strong opioids.

Intraoperative intravenous lidocaine infusion is a well-established component of contemporary anesthetic practice and is widely used within multimodal analgesic protocols. A meta-analysis including twelve high-quality studies of oncological breast surgery demonstrated beneficial effects of intravenous lidocaine on both intraoperative and postoperative opioid consumption, as well as a reduction in the incidence of chronic postsurgical pain.

Based on the available evidence, this study was designed as prospective randomized non-inferiority trial to determine whether intraoperative intravenous lidocaine infusion provides postoperative pain control and quality-of-recovery outcomes comparable to those achieved with ESPB in patients undergoing non-oncological breast reduction surgery.

The study will include patients of the Department of Plastic, Reconstructive and Aesthetic Surgery, Centre of Postgraduate Medical Education, W. Orlowski Hospital, Warsaw, Poland, aged 18-75 years, American Society of Anesthesiology (ASA) physical status I-III, scheduled for elective breast reduction for non-oncological indications.

During the pre-anesthetic assessment or following hospital admission on the day preceding surgery, patients will receive detailed information about the study and a written informed consent form. They will have the opportunity to ask questions and receive comprehensive answers regarding study participation. Signed consent forms will be collected on the morning of surgery.

Participants will be randomly assigned to one of two study groups:

Erector Spine Plane Block (ESPB) Group: Bilateral ESPB performed before induction of general anesthesia using 20 mL of 0.25% bupivacaine on each side.

Lidocaine (LIDO) Group: Intravenous lidocaine administered before induction of anesthesia as a bolus of 1.5 mg/kg over 10 minutes, followed by a continuous infusion at 1.5 mg/kg/h until completion of surgery.

Randomization will be performed using the randomizer.org website with a 1:1 allocation ratio.

Allocation concealment will be achieved using sequentially numbered opaque sealed envelopes. The envelope corresponding to the participant's randomization number will be opened on the day of surgery before the patient arrives in the operating room. Group allocation information will be communicated only to the anesthesiologist responsible for perioperative management.

Patient data will be recorded in a secure database inaccessible to unauthorized individuals. The following variables will be collected:

• Demographic data: age, height, body weight, ASA physical status, comorbidities, smoking status and other substance use, and type of surgical procedure.
• Surgical data: intraoperative fluid therapy, duration of surgery, estimated blood loss, and weight of resected breast tissue.
• Intervention-related data: amount of study medication administered and perioperative adverse events commonly associated with general anesthesia, including hypotension and bradycardia requiring vasoactive treatment.

Upon arrival in the operating room, standard monitoring will be initiated and prophylactic antibiotic administration commenced according to institutional perioperative antibiotic prophylaxis protocols.

ESPB Group: Bilateral ESPB will be performed before induction of anesthesia. LIDO Group: Patients will receive an intravenous lidocaine infusion as described above.

General anesthesia will be induced and maintained according to institutional standards using opioids and anesthetic agents at the discretion of the attending anesthesiologist. Maintenance of anesthesia will be achieved with sevoflurane.

Postoperatively, all patients will receive standardized multimodal analgesia consisting of paracetamol 1 g every 6 hours, metamizole 1 g every 6 hours, and dexketoprofen 50 mg intravenously three times daily. If analgesia is insufficient, an opioid buprenorphine 0.3 mg will be administered intravenously or intramuscularly, with repeat doses permitted every 2 hours as needed. Pain intensity will be assessed with Numeric Rating Scale (NRS) (0-10, 0 indicating no pain and 10 worst pain imaginable). NRS score >3 will indicate the need for opioid administration. Additional intravenous boluses of 0.3 mg may be administered for breakthrough pain.

Pain intensity will be assessed during the first 48 postoperative hours using the NRS at rest and during coughing at predefined time points: 2, 4, 8, 24, and 48 hours after surgery.

Total opioid consumption during the first 24 postoperative hours (expressed as cumulative buprenorphine dose) and time to first opioid administration will also be recorded.

Before hospital discharge, patients will be asked to complete the validated Polish version of the Quality of Recovery questionnaire - 15 (QoR-15).

Assessment of Chronic Postsurgical Pain Patients will be contacted by telephone at 1, 3, and 6 months after surgery and asked about the presence of persistent pain in the surgical area.

If pain is reported, patients will be asked to assess its intensity using the NRS (0-10) and its neuropathic characteristics using the Douleur Neuropathique 4 (DN4) questionnaire. A DN4 score of ≥4 will be considered indicative of neuropathic pain.

Inclusion Criteria:

• ASA physical status I-III
• Scheduled for elective breast reduction surgery for non-oncological indications

Exclusion Criteria:

• Refusal or inability to provide written informed consent
• History of chronic somatic or neuropathic pain
• Current psychiatric disorders or ongoing treatment with antidepressant medications
• Poorly controlled cardiovascular disease
• Known allergy or intolerance to amide local anesthetics, including lidocaine and bupivacaine
• Current alcohol abuse or substance use disorder

Assessment of the outcomes is performed by investigator blinded to type of intervention