title: Cerebral desaturation events during shoulder arthroscopy in the beach chair position: patient risk factors and neurocognitive effects.
abstract: BACKGROUND
  Patients undergoing shoulder surgery in the beach chair position may be at increased risk for serious neurocognitive complications due to cerebral ischemia. We sought to define the incidence, patient risk factors, and clinical sequelae of intraoperative cerebral desaturation events.
  
  
  METHODS
  Regional cerebral tissue oxygen saturation (rSO2) was monitored intra-operatively using near-infrared spectroscopy (NIRS) on 50 consecutive patients. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was administered to each patient pre- and postoperatively. Intra-operative decreases in rSO2 of 20% or greater were defined as cerebral desaturation events (CDE). The association between intraoperative CDE and postoperative cognitive decline was assessed.
  
  
  RESULTS
  The incidence of intraoperative CDE in our series was 18% (9/50). Increased body mass index (BMI) was found to have a statistically significant association with intraoperative CDE (mean BMI 37.32 vs 28.59, P < .0001). There was no statistical significance in pre- vs postoperative RBANS either in composite scores or any of the sub-indices in either group.
  
  
  CONCLUSIONS
  The degree and duration of cerebral ischemia required to produce neurocognitive dysfunction in this patient population remains undefined; however, cerebral oximetry with NIRS allows prompt identification and treatment of decreased cerebral perfusion decreasing the risk of this event. Increased BMI was found to be a statistically significant patient risk factor for the development of intra-operative CDE. The transient intra-operative CDEs were not associated with postoperative cognitive dysfunction in our patient series. We believe protocols aimed at detecting and reversing CDE minimize the risk of neurocognitive dysfunction and improve patient safety.
authors: Department of Orthopaedic Surgery and Rehabilitation, Loyola University Health System, Maywood, IL 60153, USA. dsalazar@post.com
authors: Dane
authors: D
authors: Salazar
authors: Benjamin W
authors: BW
authors: Sears
authors: Bayan
authors: B
authors: Aghdasi
authors: Arthur
authors: A
authors: Only
authors: Audrice
authors: A
authors: Francois
authors: Pietro
authors: P
authors: Tonino
authors: Guido
authors: G
authors: Marra
mesh_terms: D000328:Adult; D000368:Aged; D001182:Arthroscopy / Q000009:adverse effects*; D002545:Brain Ischemia / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007431:Intraoperative Complications; D007592:Joint Diseases / Q000601:surgery; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009483:Neuropsychological Tests; D056888:Patient Positioning; D012307:Risk Factors; D012785:Shoulder Joint; D019265:Spectroscopy, Near-Infrared
keywords: Case Series; Level IV; Prognosis Study; Shoulder arthroscopy; beach chair; cerebral desaturation; complications; neurocognitive dysfunction