Sixty adult patients undergoing shoulder arthroscopic surgery were randomized to receive either a preoperative subacromial injection of bupivacaine and epinephrine (n=30) or bupivacaine alone (n=30). The primary outcome was surgeon-rated visual clarity using a visual analog scale (VAS) scored from 0 (worst) to 10 (best). Secondary outcomes included operative time, irrigation pump pressure adjustments, and use of blood pressure-modulating agents. Outcomes were assessed throughout the procedure. Overall, the study found that while visual clarity scores were slightly higher in the epinephrine group (mean 8.3 vs. 7.5), the difference was neither statistically significant (p=0.09) nor clinically meaningful. Secondary outcomes also showed no significant differences. These findings suggest that preoperative subacromial epinephrine injections do not provide a significant advantage in improving visualization during shoulder arthroscopy.