Effect of Anesthesia Technique on Surgical View in Shoulder Arthroscopy

Shoulder arthroscopy is a minimally invasive surgical procedure where the clarity of the surgeon's visual field is critical for technical success and operative efficiency. The quality of the intraoperative view is heavily influenced by perioperative variables, particularly intraoperative bleeding and hemodynamic stability. Consequently, the anesthetic management strategy-whether General Anesthesia (GA) or Regional Anesthesia (RA) [interscalene nerve block/superficial cervical block] combined with sedation-may significantly alter these conditions. This study aims to prospectively evaluate and compare how these two distinct anesthesia methods impact the clarity of the surgical field, and the operating surgeon's satisfaction.

This is a prospective, observational cohort study will conducted at the Sabuncuoğlu Serefeddin Training and Research Hospital. The study utilizes a naturalistic, non-randomized design. There is no interference with the choice of anesthesia; group assignment is determined solely by routine clinical decision-making and patient preference during the preoperative assessment. Patients are recruited and observationally assigned to one of two cohorts based on the technique administered:

• General Anesthesia Group: Patients who elect or are clinically selected to receive general anesthesia.
• Regional Anesthesia Group: Patients who elect or are clinically selected to receive an interscalene nerve block/superficial cervical block combined with sedation.

Intraoperative physiological variables, including heart rate, systolic and diastolic blood pressure, oxygen saturation, and respiratory rate, will be continuously monitored throughout the procedure. The study will also record the feasibility of implementing controlled hypotension and analyze its correlation with intraoperative bleeding amounts. To provide a holistic comparison between anesthesia methods, the study will track postoperative recovery metrics, including the total duration of surgery and anesthesia. Additionally, postoperative pain will be assessed using the Numeric Rating Scale (NRS) at 1, 2, 4, 8, 16, and 24 hours post-procedure. The incidence of opioid-related side effects, such as nausea and vomiting, will be monitored and recorded during the postoperative period .

Primary Assessment:

• Surgical View Evaluation: The clarity of the surgical field and the extent to which bleeding obscures visualization are evaluated using a 5-point Likert scale (1 = Poor/No Visualization: Severe bleeding that completely obscures the field; surgery is extremely difficult or impossible without constant suction/lavage; 2 = Fair Visualization: Significant bleeding obscuring the field; frequent suction/lavage is required to proceed; 3 = Moderate Visualization: Moderate bleeding; the anatomy is visible, but occasional suction/lavage is needed to maintain a clear view; 4 = Good Visualization: Mild bleeding; the surgical field is clear with only rare need for suction/lavage; 5 = Excellent/Crystal Clear Visualization: No significant bleeding; the surgical field is perfectly clear throughout the procedure.)

Sample Size: Based on a preliminary analysis conducted at our center, a distinct difference in the primary outcome (Surgical view evaluation) was observed between the two groups (RA: 3.1 ± 1.2 vs. GA: 4.0 ± 1.5). To detect this difference with a Power (1-beta) of 0.80 and an alpha error of 0.05, a sample size of 37 patients per group is required. Accounting for a 10% dropout rate, the study will enroll a total of 82 patients (41 in the GA group and 41 in the RA group).

Inclusion criteria

• Volunteers aged 18 to 75 years.
• Patients scheduled for elective shoulder arthroscopy.
• Patients with an ASA (American Society of Anesthesiologists) physical status score of I, II, or III.
• Patients capable of providing informed consent.

Exclusion criteria

• Previous surgical procedure performed on the same shoulder.
• Presence of medical contraindications that could affect the choice of anesthesia (coagulopathy, active infection, severe pulmonary diseases)
• Known allergy to local anesthetics or general anesthesia agents
• History of opioid dependence or chronic pain syndrome
• Presence of neurological disorders, particularly those involving the brachial plexus