ESP Block Vs. QIPB for Lumbar Stabilization Surgery

Materials and Methods:

This prospective, randomized clinical trial will include patients aged 18-80 years with American Society of Anesthesiologists (ASA) physical status I-III who are scheduled to undergo elective primary lumbar stabilization surgery under general anesthesia. Before enrollment, all patients will be informed about the study protocol and written informed consent will be obtained. Patients will be instructed on the use of the Numeric Rating Scale (NRS) for postoperative pain assessment, where 0 represents no pain and 10 represents the worst pain imaginable.

Patients with contraindications to regional anesthesia, allergy to local anesthetics, coagulopathy, infection at the injection site, chronic opioid use, pre-existing neurological deficits involving the lower extremities, cognitive impairment preventing reliable communication, revision lumbar surgery, and refusal to participate will be excluded from the study.

Patients will be randomly allocated to one of two study groups using a computer-generated randomization sequence (https://www.randomizer.org). Randomization will be performed by a team member not involved in patient management or outcome assessment. Allocation concealment will be achieved using sequentially numbered sealed opaque envelopes, which will be opened immediately before block performance.

Upon arrival in the operating room, standard monitoring including electrocardiography, non-invasive blood pressure measurement, and pulse oximetry will be applied. Following intravenous access, general anesthesia will be induced using a standardized protocol consisting of propofol, fentanyl, and rocuronium to facilitate endotracheal intubation. Anesthesia will be maintained with sevoflurane or desflurane in an oxygen/air mixture, titrated to maintain hemodynamic stability within 20% of baseline values.

Following the induction of general anesthesia and prior to surgical incision, patients will receive either ultrasound-guided quadro-iliac plane block (QIPB) or ultrasound-guided erector spinae plane block (ESPB) according to group allocation. All blocks will be performed by anesthesiologists experienced in regional anesthesia and familiar with both techniques.

All patients will receive the same multimodal postoperative analgesic regimen and standardized postoperative rehabilitation protocol. Postoperative pain scores at rest and during movement will be assessed using the NRS during the first 48 postoperative hours. Opioid consumption, incidence of quadriceps motor block, time to first ambulation, patient satisfaction, postoperative nausea and vomiting, falls, length of hospital stay, block performance time, and block-related complications will also be recorded.

Outcome assessments will be performed by investigators who are unaware of group allocation.

• Quadro iliac Plane Block (Procedure): Participants allocated to the QIPB group will receive an ultrasound-guided quadro-iliac plane block after the induction of general anesthesia. Following standard aseptic preparation, 30 mL of 0.25% bupivacaine will be administered into the target fascial plane under ultrasound guidance after confirming the absence of blood on aspiration.

Primary outcomes

• Postoperative pain scores [6,24,36,48 hours]: Postoperative pain intensity will be assessed using an 11-point Numeric Rating Scale (NRS), where 0 indicates no pain and 10 indicates the worst imaginable pain. Pain scores at rest will be recorded in the post-anesthesia care unit and at postoperative 6, 24, 36, and 48 hours. Pain scores during movement will be assessed during passive flexion of the operated hip at postoperative 6, 24, 36, and 48 hours.

Secondary outcomes

• Postoperative opioid consumption [postoperative 24 and 48 hours]: Total postoperative opioid consumption will be recorded and cumulative opioid consumption will be calculated at postoperative 24 and 48 hours.
• Incidence of quadriceps motor block [Postoperative 3, 6, and 24 hours]: Quadriceps motor block will be assessed using knee extension testing and graded as: 0 = normal strength 1. = paresis 2. = paralysis. Motor block incidence will be defined as the presence of paresis or paralysis.
• Time to first ambulation [Postoperative day 1]: Time from the end of surgery to the first successful ambulation.
• Patient satisfaction [Postoperative 48 hours]: Patient satisfaction with postoperative analgesia will be assessed using a Likert scale.
• Postoperative nausea and vomiting (PONV) [Postoperative 48 hours]: Incidence of postoperative nausea and vomiting during the first 48 postoperative hours.
• Block performance time [Periprocedural]: Time from ultrasound probe placement to completion of local anesthetic injection.
• Falls [Through postoperative day 2]: Incidence of falls during the first 48 postoperative hours.
• Length of hospital stay [Through hospital discharge, up to 30 days]: Number of days from surgery to hospital discharge.
• Block-related complications [Through hospital discharge, up to 30 days]: Hematoma Vascular puncture Local anesthetic systemic toxicity (LAST) Infection at the injection site

Sex: All, ages: 18 Years to 80 Years

Inclusion Criteria:

* Age between 18 and 80 years
* American Society of Anesthesiologists physical status I-III
* Scheduled for elective primary lumbar stabilization surgery
* Surgery planned under general anesthesia
* Ability to understand and use the Numeric Rating Scale
* Written informed consent provided

Exclusion Criteria:

* Refusal to participate
* Revision lumbar stabilization surgery
* Contraindication to regional anesthesia
* Contraindication to peripheral nerve/plane block
* Known allergy to local anesthetics or study drugs
* Coagulopathy or anticoagulant use incompatible with neuraxial/regional -anesthesia
* Infection at the block injection site
* Pre-existing neurological deficit involving the lower extremities (unrelated to t-he current spinal pathology)
* Peripheral neuropathy
* Chronic opioid use
* Cognitive impairment or inability to communicate reliably
* Severe hepatic or renal failure
* Body mass index > 35 kg/m2
* Pregnancy