Comparison Low-volume Versus Standard-volume Ultrasound-guided Bilateral Intermediate Cervical Plexus Block

Phase 4RecruitingNCT07789548

Assiut University60 enrolled

Overview

Thyroidectomy is commonly associated with mild-to-moderate postoperative pain that may affect respiratory function and recovery. Bilateral intermediate cervical plexus block provides effective analgesia, but larger local anesthetic volumes may increase phrenic nerve spread and diaphragmatic dysfunction. Low-volume ultrasound-guided block may provide adequate analgesia while better preserving diaphragmatic function and postoperative respiratory performance

Thyroidectomy requires effective perioperative analgesia to facilitate swallowing, coughing, deep breathing, and early mobilization. Bilateral intermediate cervical plexus block improves postoperative pain control and reduces opioid requirements, while ultrasound guidance enhances safety and accuracy. However, larger local anesthetic volumes may increase phrenic nerve involvement and diaphragmatic impairment. Ultrasound assessment of diaphragmatic excursion and thickening fraction provides objective evaluation of respiratory function. Low-volume block may preserve diaphragmatic function while maintaining satisfactory analgesic efficacy

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Enrollment

Conditions

Post Operative Pain Relief After Thyroidectomy

Eligibility

Sex: ALLMin age: 18 YearsMax age: 65 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Adult patients aged between 18 and 65 years. * Patients scheduled for elective thyroidectomy under general anesthesia. * American Society of Anesthesiologists (ASA) physical status I-II. * Both sexes will be included. * Patients able to understand the study protocol and provide written informed consent. Exclusion Criteria: * Patient refusal. * Other endocrine diseases (as uncontrolled diabetes mellitus, adrenal disorders, pituitary disorders) * Known allergy or hypersensitivity to local anesthetics. * Coagulopathy or ongoing anticoagulant therapy contraindicating regional anesthesia. * Local infection at the site of needle insertion. * Preexisting diaphragmatic dysfunction or phrenic nerve palsy. * Significant chronic respiratory disease affecting pulmonary function (e.g., severe COPD, restrictive lung disease, uncontrolled asthma). * Morbid obesity (BMI ≥ 35 kg/m²). * Psychiatric or neurological diseases affecting respiratory muscles. * Previous neck surgery or anatomical deformity interfering with cervical plexus --block performance or diaphragmatic ultrasound assessment. * Pregnancy..

Outcomes

Primary Outcomes

Change in diaphragmatic excursion in patient undergoing thyroidectomy

Ultrasound-measured diaphragmatic excursion (cm), assessed at baseline before block and at predefined postoperative time points, to compare the effect of low-volume versus standard-volume bilateral intermediate cervical plexus block on diaphragmatic function.

Time frame: Baseline before block, 30 minutes after block.4 hour after block

Secondary Outcomes

Postoperative Pain Score visual analog scale (vas)

Postoperative pain assessed using the Visual Analog Scale (VAS, 0-10) at rest and during swallowing.

Time frame: Postoperative pain score PACU arrival (0 hour), 6 hour, 12 hour, and 24 hour postoperatively

Total opioid consumption in 24hr postoperative

Total amount of opioid consumption in patient undergoing thyroidectomy for first 24hr postoperative

Time frame: After 24hour PACu arrival