Background: Many thyroidectomy patients suffer from postoperative pain that could delay early hospital discharge and place a significant burden on both the patient and the healthcare team. Bilateral intermediate cervical plexus block (ICPB) provides good analgesia for neck surgery, including thyroidectomy. However, the duration of a single-shot nerve block is usually short. Therefore, adjuvants are used in peripheral nerve blocks.

Objectives: To compare the safety and efficacy of dexmedetomidine versus dexamethasone as adjuvants to bupivacaine in ultrasound-guided intermediate cervical plexus block in patients undergoing total thyroidectomy under general anesthesia.

Patients and Methods: This is a randomized, double-blind, phase four, prospective clinical trial; carried out on 60 patients, who were candidates for total thyroidectomy under general anesthesia at our hospital. Patients were randomly allocated into two equal groups; group A, received bilateral ICPB with isobaric bupivacaine plus dexmedetomidine, and group B, received bilateral ICPB with isobaric bupivacaine plus dexamethasone.

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) physical status ≤ II
• Age from 21 to 60 years
• Body Mass Index (BMI) ≤ 35 kg/m2

Exclusion Criteria:

• ASA physical status > II
• Age < 21 years or > 50 years
• BMI > 35 kg/m2
• Bronchial asthma
• Chronic obstructive pulmonary disease
• Restrictive lung diseases
• Sick sinus syndrome
• Sinus bradycardia
• Hypertension
• Chronic hypotension
• Ischemic heart disease
• Coagulopathies
• Hepatic insufficiency
• Renal insufficiency
• Diabetes mellitus
• Peripheral neuropathy
• Thyroid malignancy
• Hyperthyroidism
• Substernal goiter
• Patients on beta-blockers
• Patients using pacemakers
• Alcohol or drug abuse
• Allergy to the study drugs