Preoperative Block for Anterior Cervical Spine Surgery

The purpose of this clinical trial study is to compare the analgesic effects of ultrasound-guided intermediate cervical plexus block Versus cervical erector spinae block in patients undergoing anterior cervical spine surgery.

* The main questions it aims to answer are:

  * The primary outcome will be recording postoperative pain intensity using Numerical Rating Scale (NRS).
  * The secondary outcomes will be measuring the performance time, onset of the sensory block, intraoperative fentanyl consumption, time to the first call for rescue analgesia (nalbuphine), postoperative total nalbuphine consumption, and postoperative complications such as nausea, vomiting, hypotension, and bradycardia.
* We will compare two blocks to a placebo.
* Participants will:

  * undergo ultrasound-guided intermediate cervical plexus block or cervical erector spinae block or a placebo
  * Be assessed for pain after 2 h, 4 h, 6 h, 12 h, and 24 h postoperatively

Anterior cervical spine surgery is a common procedure for treating disc herniation, spinal cord vascular diseases, cervical spondylosis, and tumors. Cervical spine surgery is one of the most painful surgical operations, ranked among the 6 most painful out of 179 assessed surgical procedures, underscoring the challenges in pain management for this patients. Many patients requiring spine surgery are also overweight, have substance use disorders and other comorbidities related to aging.

Surgeons have been able to effectively treat patients with various cervical spine conditions by using specialized retractors, natural muscle planes, and paying careful attention to surrounding structures. However, despite the high success rates associated with these surgeries, patients often experience postoperative pain between the shoulder blades and in the neck.

Improper perioperative pain management after anterior cervical spine surgery can impact a patient's recovery, overall health, ability to swallow, may lead to nausea, vomiting, and chronic pain. Thus, effective pain management techniques are crucial to enhance postoperative care for these patients.

A regional analgesia block is a technique used to suppress nerve transmission and alleviate or prevent pain. It is commonly used in combination with general anesthesia or as the sole anesthetic technique, particularly in plastic, orthopedic and vascular surgeries to reduce the amount of anesthetic and analgesic agents needed, minimize systemic side effects, improve recovery, provide better postoperative pain relief, and shorten hospital stays.

The cervical plexus is made up of the ventral rami of the C1-C4 spinal nerves. The cervical plexus consists of motor (phrenic nerve, direct muscle branches) and terminal sensory branches (C2-C4): the supraclavicular nerves, the lesser occipital nerve, greater auricular nerve, and transverse cervical nerve. The latter is formed in the compartment between the prevertebral and superficial layer of the cervical fascia, deep to the sternocleidomastoid. Before 2004, any cervical plexus blocks that were performed superficially to the prevertebral fascia were termed superficial cervical plexus blocks. However, Telford and Stoneham suggested the term intermediate cervical plexus block to distinguish between the superficial block (subcutaneous or subplatysmal) and the block in the interfascial compartment. Intermediate cervical plexus block is a safe, popular, easy, and effective technique for regional analgesia of cervical region. The use of ultrasound guidance reduces the risk of complications, allows for real-time visualization of anatomical structures, and helps guide needle placement.

Bilateral cervical erector spinae block using ultrasound has recently been studied for shoulder surgery. Since the brachial plexus, phrenic nerves, cervical nerve roots, and deep cervical muscles are enclosed in the prevertebral fascia, injecting a local anesthetic near the cervical transverse process can spread to nearby structures within the prevertebral compartment. In a cadaver study, it was found that injecting a 20 mL dye solution into the transverse process of C6 or C7 resulted in staining of the C5-T1 nerve roots.

With the increasing number of nerve block techniques available, anesthesiologists may have difficulty determining the most appropriate technique to achieve optimal recovery after anterior cervical spine surgery. Therefore, this study will conducted to compare the efficacy of ultrasound-guided intermediate cervical plexus block and cervical erector spinae block in patients undergoing anterior cervical spine surgery.

Eligibility Criteria:
Inclusion Criteria:

* Both sex
* Age: between 21 and 60 years
* Physical status: belongs to American Society of Anesthesiologists (ASA) I, II
* Body mass index (BMI): from 25 to 30 kg/m2
* Type of surgery: elective anterior cervical spine surgery under general anesthesia

Exclusion Criteria:

* Refusal of participation.
* local infection at the puncture site.
* Mental or physical disability.
* History of allergy to study drugs (bupivacaine, fentanyl).
* Hematological disorders including coagulation abnormalities.
* Severe hepatic or kidney impairment.
* Chronic pain.