Evaluation of Perineural Dexmedetomidine Dosing with Ropivacaine and Intravenous Dexamethasone in Interscalene Plexus Block for Shoulder Surgery

The primary objective of this study is to evaluate the **efficacy** of different doses of perineural dexmedetomidine in prolonging the duration of the analgesic block following an interscalene plexus block. This is clinically relevant as optimizing the duration of analgesia can significantly enhance postoperative pain management for patients undergoing shoulder operations, potentially reducing the need for additional analgesics and improving overall patient outcomes.

Secondary objectives include:

• Assessing the potential side effects of higher doses of perineural dexmedetomidine, specifically **hypotension** and **bradycardia**.
• Evaluating the potential benefits of adding dexmedetomidine, such as reduced opioid consumption, improved patient satisfaction, decreased postoperative nausea and vomiting, and enhanced sleep quality.

The clinical trial involves **patients scheduled for shoulder operations**, specifically those undergoing elective shoulder surgery. The study population includes both male and female participants, with an age range corresponding to categories 3 and 4, which typically represent adults and older adults. The trial does not involve a vulnerable population. Participants were selected based on their scheduled elective shoulder surgeries, ensuring a relevant and specific cohort for the study's objectives. The sponsor has not provided information regarding the total number of participants. No specific lifestyle considerations such as diet or physical activity are highlighted in the available data.

The clinical trial is designed as a **randomized**, **double-blind**, controlled study to evaluate the efficacy of different doses of perineural **dexmedetomidine** as an adjuvant to **ropivacaine** for interscalene plexus block in patients scheduled for elective shoulder surgery. The trial aims to determine the optimal dose of dexmedetomidine to prolong the analgesic effect of the block. The study will involve the administration of **dexamethasone** intravenously as part of the treatment protocol. The trial is expected to commence recruitment on July 3, 2023, and conclude by June 30, 2025.

Participants will undergo a series of study visits, beginning with an inclusion (screening) visit to assess eligibility based on the principal inclusion criteria. This visit will ensure that participants are scheduled for elective shoulder surgery and meet other study requirements. Following the screening, participants will be randomized to receive one of the study treatments. Subsequent follow-up visits will be conducted to monitor the primary endpoint, which is the length of analgesia, and secondary endpoints, including the length of sensory and motor blocks, postoperative nausea and vomiting, recovery time, side effects, pain scores, and opioid consumption over 48 hours. The end-of-study visit will occur after the final follow-up assessments are completed.

The expected duration of participant involvement in the trial is approximately 48 hours post-surgery, during which the primary and secondary endpoints will be evaluated. Conditions that may lead to early termination from the study include adverse reactions to the study drugs, withdrawal of consent, or any medical condition that contraindicates continued participation. The trial is categorized as a low-intervention phase 3/4 study, ensuring that the procedures and interventions are consistent with standard clinical practice while maintaining rigorous scientific evaluation.

The clinical trial involves the administration of **Dexamethasone**, marketed as Dexamethason CF 20 mg/ml, in the form of a **solution for injection**. This medication is produced by CENTRAFARM B.V. and is administered intravenously. The maximum daily and total dose is 10 mg, with a treatment period limited to one day. The active substance, dexamethasone, is of chemical origin and is utilized in this study to evaluate its efficacy in conjunction with other treatments.

**Ropivacaine Hydrochloride**, marketed as Ropivacaine 7.5 mg/ml solution for injection, is another experimental medication used in this trial. Manufactured by SINTETICA GMBH, it is administered via perineural use. The maximum daily and total dose is 135 mg, with a treatment period of one day. Ropivacaine hydrochloride is a chemically derived substance, and its role in the trial is to serve as a local anesthetic in combination with other agents.

The trial also includes the use of **Sodium Chloride**, marketed as Natriumklorid B. Braun 9 mg/ml innrennslislyf, lausn, produced by B.BRAUN MELSUNGEN AG. This solution for injection/infusion is administered perineurally, with a maximum daily and total dose of 18 mg, and a treatment period of one day. Sodium chloride, a chemical substance, is used as an auxiliary treatment in the study.

**Dexmedetomidine**, marketed as Dexdor 100 micrograms/ml concentrate for solution for infusion, is produced by ORION CORPORATION. It is administered perineurally, with a maximum daily and total dose of 0.20 mg, and a treatment period of one day. Dexmedetomidine, a chemical substance, is used as an analgesic adjuvant in the trial to assess its efficacy in prolonging the analgesic block when used with ropivacaine.

Efficacy in this clinical trial will be assessed by evaluating the primary and secondary endpoints. The primary endpoint is the **length of analgesia**, defined as the time until the intake of an analgesic. Secondary endpoints include the length of the sensoric block, length of the motoric block, percentage of postoperative nausea and vomiting within the first 48 hours, time to recovery after anesthesia, percentage of side effects during anesthesia such as hypotension and bradycardia, the Numeric Rating Scale score for pain during the first 48 hours, and cumulative opioid consumption over 48 hours.

The trial aims to determine the efficacy of different doses of perineural dexmedetomidine in prolonging the analgesic block following an interscalene plexus block. The study is designed as a single-center, double-blinded, randomized controlled trial. The trial will involve patients scheduled for elective shoulder surgery, and the efficacy parameters will be measured and collected at specified time points throughout the study duration. The trial is expected to conclude by June 30, 2025.