Shoulder surgery using combined regional and general anesthesia versus regional anesthesia and deep sedation with a non-invasive positive pressure system: A retrospective cohort study

There are benefits to choosing deep sedation over general anesthesia as an intraoperative anesthetic for shoulder surgery. Deep sedation, however, may be challenging in patients with risk factors for hypoxemia. We conducted a retrospective case control study comparing patients who underwent shoulder surgery using deep sedation and interscalene block versus general anesthesia and cervical paravertebral or interscalene block. A non-invasive positive pressure system (SuperNO2VA mask; Vyaire Medical, Mettawa, IL, USA) was utilized as an airway adjunct in patients undergoing deep sedation. Sixty patients were included in the study (20 patients with block with sedation and 40 patients with general anesthesia). No patient who received deep sedation required conversion to general anesthesia or additional airway support measures. Induction- and emergence-related anesthesia times were lower for those who received deep sedation than those who received general anesthesia (39 [CI 31–48] vs 17 [CI 8–27] minutes; p < 0.0001). No differences were detected in post-anesthesia care unit times, operative times, or estimated blood loss between the two groups. Intravenous fluid administration was lower in patients receiving deep sedation. Sixty percent of patients under general anesthesia had a urinary catheter placed versus zero in the deep sedation group. Vasopressor administration was more common in the general anesthesia group, while antihypertensive medications were utilized more frequently in the deep sedation group. This retrospective study showed that non-invasive positive pressure ventilation facilitated the performance of deep sedation for shoulder surgery with an interscalene block for both shoulder arthroscopic procedures and shoulder arthroplasty. This technique was associated with avoidance of mechanical ventilation, decreased anesthesia time, use of vasopressors, and need for urinary catheter placement.