Serratus Posterior Superior Intercostal Plane Block Versus Erector Spinae Plane Block in Thoracic Spine Surgeries

Spinal surgeries coincide with high level of pain due to extensive dissection and muscle retraction so inadequate pain control delays patient recovery, rehabilitation and also is an important source of patient dissatisfaction [1].

Non-steroidal anti-inflammatory drugs and opioids are used to control pain post spine surgeries. The side effects of opioids are nausea and vomiting (PONV), delirium, sedation, constipation, tolerance, respiratory depression, and high dependence [2]. Many efforts done by different studies to decrease the length of hospital stay and the dependence on opioids by using multimodal analgesic modalities including regional blocks by injection of local anesthesia before skin incision to block the pain pathway from the start. [3] The SPSM originates from C7-T2 (sometimes T3) spinous processes, progressing obliquely and inserting on the lateral of the second to fifth ribs' angle , The Serratus Posterior Superior Intercostal Plane Block (SPSIPB) first described by Tulgar et al,[4] is a novel interfascial plane block that involves the injection of a local anesthetic between the Serratus posterior superior and intercostal muscles, dermatomal analysis of the patients showed sensory block reached the C3 dermatome in all patients in the cephalic direction. In the caudal direction, it was determined that sensory block reached at least the T7 dermatome in all patients.

Erector spinae plane (ESP) block first described in 2016 by Forero et al. [5], it is a truncal block which inject (LA) between the thoracic transverse process and erector spinae muscle and spread to the thoracic paravertebral space thereby targeting the dorsal and ventral rami of spinal nerves [6]. Because they may provide an alternative to thoracic paravertebral blocks with fewer risks of pneumothorax, it is used to provide postoperative analgesia for thoracic and spine surgeries. And also used to manage chronic pain such as complex regional pain syndrome and failed back surgery syndrome [2].

Aim of the work:

Compare the efficacy of serratus posterior superior intercostal plane block versus erector spinae plane block in thoracic spine surgeries at the level between T1 to T7 Primary outcome: NRS (Numerical rating scale) Secondary outcome: 1st dose of rescue analgesia, total doses of rescue analgesia, motor block, and 1st time of ambulation

Patients and methods:

This randomized double-blinded study will be carried out on 60 adult patients of both sexes undergoing elective thoracic spine surgeries in Tanta University Hospitals for a period of from April 2026 to December 2026.

Informed written consent will be obtained from the parents. They will receive an explanation of the purpose of the study, and every patient will have a secret code number. All data of the patients will be confidential with secret codes and private files for each patient; all given data will be used for current medical research only.

Any unexpected risks that appeared during the research will be cleared to the participants and ethical committee on time. Investigator who is blinded to group allocation provided postoperative care and assessments.

Inclusion Criteria: adult patients of both sexes undergoing elective thoracic spine surgeries aged from 18 years to 60 years, ASA I or II, thoracic levels between T1 to T7

Exclusion Criteria:

Parents refusal. Coagulopathy. Allergy to local anesthesia. Local infection at the site of injection. Pregnancy. Sever motor deficit (grade < 2) and sever sensory deficit (grade < 1).

Randomization and blindness:

Computer-generated randomization numbers will be used for random allocation and each patients' code will be kept in an opaque sealed envelope. Patients will be randomly allocated with 1:1 allocation ratio into three groups in a parallel manner:

• Group S (n=35): Serratus Posterior Superior Intercostal Plane Block will receive 30 ml of 0.25% bupivacaine on each side.
• Group E (n=35): erector spinae block group will receive 20 ml of 0.25% bupivacaine on each side.

Methods:

1. Preoperative:

Medical and surgical history of the patients will be taken, clinical examination of the patients will be performed and routine laboratory investigations such as CBC, and coagulation studies. 2. Intraoperative:

Monitoring (non-invasive blood pressure, pulse oximetry, electrocardiogram and temperature probe) will be applied during induction and maintenance of anesthesia. No premedication will be administered. The intravenous line will be inserted, give preload crystalloid 500 ml, preoxygenation 5 minutes with 80% oxygen. Anesthesia will be induced by injection fentanyl 1mic/kg, xylocaine 1mg/kg, propofol 1-2 mg/kg, and atracurium 0.5 mg/kg, ventilation with mask for 3 minutes then intubation using armored tube. Anesthesia will be maintained with isoflurane, O2 to Air 50%: 50%, be sure adequate preload and adequate blood pressure then change the position of patients from supine to prone position, take precaution of prone position and make sure