Continuous Cervical Erector Spinae Plane Block Versus Interscalene Nerve Block in Shoulder Arthroscopic Surgery

Continuous Cervical Erector Spinae Plane Block Versus Interscalene Nerve Block in Shoulder Arthroscopic Surgery- A Randomized Controlled Trial

Shoulder arthroscopic surgery is associated with moderate to severe postoperative pain, which may hinder early mobilization and functional recovery. Interscalene block (ISB) is commonly used to provide effective analgesia but is frequently associated with hemidiaphragmatic paralysis due to phrenic nerve involvement. Cervical erector spinae plane block (ESPB) has been proposed as an alternative regional technique that may provide analgesia while reducing respiratory-related adverse effects. This randomized controlled trial aims to compare the analgesic efficacy and safety of cervical ESPB versus continuous ISB in patients undergoing shoulder arthroscopic surgery.

This study is a prospective randomized controlled trial designed to evaluate whether continuous cervical erector spinae plane block (ESPB) is non-inferior to continuous interscalene block (ISB) for postoperative pain control in adult patients undergoing elective shoulder arthroscopic surgery. Eligible participants will be allocated to one of three groups: continuous cervical ESPB, continuous ISB, or a prospective observational control group receiving standard institutional analgesia with single-shot ISB.

Randomization with allocation concealment will be applied to the two interventional groups. Patients and outcome assessors will be blinded to group allocation. All regional anesthesia techniques will be performed as part of a standardized multimodal analgesic protocol.

The primary outcome is postoperative pain intensity measured using the visual analogue scale (VAS) at 24 hours after surgery. Secondary outcomes include pain scores at additional postoperative time points, cumulative opioid consumption expressed as oral morphine equivalents, measures of functional recovery, and the incidence of block-related adverse events. Respiratory-related outcomes, including hemidiaphragmatic paralysis assessed by ultrasound, as well as motor and sensory deficits and postoperative nausea and vomiting, will also be evaluated.

Analyses of the randomized intervention groups will be conducted on an intention-to-treat basis. Data from the observational control group will be analyzed descriptively to provide reference information on usual-care outcomes.

Inclusion Criteria:

• Adult patients scheduled for elective shoulder arthroscopic surgery

Exclusion Criteria:

• Contraindications to regional analgesia
• BMI >40
• ASA physical status IV
• history of drug or opioid abuse
• preoperative upper limb motor impairment
• postoperative ventilator support or ICU admission
• Inability to provide self-reported pain assessments