Controlled hypotensive anesthesia in the beach-chair position under general anesthesia: Is it safe for shoulder arthroscopy?

Aims: The beach-chair position (BCP) imposes a risk to cerebrovascular hypoperfusion due to deep hypotensive events (DHEs) which may progress to catastrophic neurological complications. However, a controlled hypotensive anesthesia (CHA) management is often required for arthroscopic shoulder surgery to reduce blood loss and to improve visibility of surgical field. The aim of this retrospective study was to evaluate CHA managements, DHEs, and complications in patients who underwent shoulder arthroscopy in the BCP under general anesthesia (GA) between years 2017 and 2019. Methods: After hospital's ethic committee approval was obtained, medical records of 72 adult patients were retrospectively reviewed. Primary outcome measures were the frequency of CHA management and the incidence of DHE. Secondary outcome measures were to determine the stages of surgery at which DHEs have developed and the complications. Results: CHA was required in 46 of total 72 patients (63.9%). Among those 46 patients, 31 (67.4%) had at least one DHE. A total of 82 DHEs were detected in 49 patients whereas mean arterial pressure limits were normal ([+ or -] 30% of baseline) in the remaining 23 (68.1% vs. 31.9%; p