Continuous Cervical Erector Spinae Plane Block Versus Interscalene Nerve Block in 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.

• Continuous Cervical Erector Spinae Plane Block (Procedure): An ultrasound-guided cervical erector spinae plane block with catheter placement will be performed. Local anesthetic will be administered through the catheter to provide continuous postoperative analgesia according to institutional protocol as part of a standardized multimodal analgesic regimen.
• Continuous Interscalene Block (Procedure): An ultrasound-guided interscalene block with catheter placement will be performed. Local anesthetic will be administered through the catheter to provide continuous postoperative analgesia according to institutional protocol as part of a standardized multimodal analgesic regimen.
• No intervention (Procedure): as observational group

Primary outcomes

• Postoperative pain intensity within postoperative 24 hours [2 hour, 6 hours, 12 hours, and 24 hours postoperatively]: Postoperative pain intensity will be assessed using a 0-10 visual analogue scale (VAS) at 2, 6, 12, and 24 hours after surgery.

Secondary outcomes

• Motor blockade severity [Up to 48 hours postoperatively]: Motor blockade severity in the operated upper extremity will be assessed using a standardized muscle strength grading scale ranging from 0 to 5, where 0 indicates no muscle contraction and 5 indicates normal muscle strength.
• analgesic consumption [48 hours]: Rescue analgesic requirements and cumulative opioid consumption will be recorded and converted to oral morphine equivalent doses.
• Adverse events [7 days]: Adverse events will include postoperative nausea and vomiting, signs or symptoms of local anesthetic systemic toxicity, infection, neurologic symptoms, and catheter-related complications.
• Duration of motor blockade [Up to 48 hours postoperatively]: The duration of motor blockade will be defined as the time from completion of surgery to recovery of normal motor function, defined as a muscle strength grade of 5 on the standardized 0-5 muscle strength scale, in the operated upper extremity.
• Sensory blockade distribution [Up to 48 hours postoperatively]: The anatomical distribution of sensory blockade will be assessed using standardized sensory examination (e.g., response to pinprick or cold sensation) across predefined dermatomal regions of the operated upper extremity.
• Duration of sensory blockade [Up to 48 hours postoperatively]: The duration of sensory blockade will be defined as the time from completion of surgery to recovery of normal sensation in the operated upper extremity, as assessed by standardized clinical sensory examination.

Sex: All, ages: 18 Years to 80 Years

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