The Effect of Superficial Cervical Block Application on Postoperative Opioid Consumption in Patients Undergoing Anterior Cervical Discectomy Surgery

This prospective, randomized, double-blind, controlled trial is conducted at Medipol Mega University Hospital in patients undergoing microscopic anterior cervical discectomy and fusion (ACDF). The primary objective is to assess the effect of a superficial cervical plexus block on the incidence of requiring postoperative rescue analgesia. Secondary objectives are total cumulative tramadol consumption, the incidence of opioid-related adverse events (nausea, vomiting, pruritus) and postoperative Numerical Rating Scale (NRS) pain scores at rest and on movement.

Patient selection:

Eligible participants are aged 18-70 years with an American Society of Anesthesiologists (ASA) physical status of I-II, scheduled for unilateral single- or two-level microscopic ACDF under general anaesthesia. Exclusion criteria are bleeding diathesis, anticoagulant therapy, known local anaesthetic or opioid allergy, a history of chronic pain, infection of the skin at the puncture site, and refusal to participate.

Study groups:

Participants are randomly assigned to two groups. Group 1 (control) receives no regional block. Group 2 (intervention) receives a right-sided superficial cervical plexus block at the end of surgery, before awakening.

Anaesthesia management:

General anaesthesia is induced with intravenous propofol (2-3 mg/kg), fentanyl (1.5 mcg/kg) and rocuronium (0.6 mg/kg), and maintained with a remifentanil infusion (0.05-2 mcg/kg/min) and desflurane in an air-oxygen mixture. A remifentanil bolus (0.5 mcg/kg) is given if heart rate or mean arterial pressure rises more than 20% above the pre-induction baseline. All patients receive intravenous ondansetron 4 mg, paracetamol 1 g and tramadol 100 mg thirty minutes before surgery. Surgery is performed by the same team through a right-sided anterior cervical approach with a 3-4 cm transverse skin incision; no local anaesthetic or adrenaline infiltration is performed at the incision site in either group. Discectomy, neural decompression and interbody cage insertion are performed under the operating microscope.

Block technique:

Under ultrasound guidance, 20 mL of 0.25% bupivacaine is injected superficial to the investing layer of the deep cervical fascia at the posterior border of the sternocleidomastoid muscle.

Postoperative evaluation:

NRS pain scores at rest and on movement are recorded at 1, 3, 6, 12, 18 and 24 hours after surgery. Rescue analgesia (1 mg/kg intravenous tramadol) is given if the NRS score is 4 or above. Postoperative opioid consumption, adverse events (nausea, vomiting, pruritus) and block-related complications are recorded over the first 24 postoperative hours.

Inclusion criteria

• Aged between 18 and 70 years
• American Society of Anesthesiologists (ASA) physical status I-II
• Scheduled for unilateral single- or two-level microscopic anterior cervical discectomy and fusion (ACDF) under general anaesthesia

Exclusion criteria

• History of bleeding diathesis,
• Receiving anticoagulant treatment,
• Known local anesthetics and opioid allergy,
• History of chronic pain
• Infection of the skin at the site of the needle puncture,
• Patients who do not accept the procedure