title: Effect of an epinephrine mixture for interscalene block on hemodynamic changes after the beach chair position under general anesthesia: a retrospective study.
abstract: BACKGROUND
  The beach chair position (BCP) can cause significant hypotension. Epinephrine is used to prolong the duration of local anesthetics; it is also absorbed into blood and can exert systemic effects. This study determined the effects of epinephrine mixed with ropivacaine for an interscalene block (ISB) on hemodynamic changes related to BCP.
  
  
  METHODS
  Patient data collected from March 2013 to August 2014 were used retrospectively. We divided the patients into three groups: 1) ISB only, 2) I+G (general anesthesia after ISB without epinephrine), and 3) I+E+G (general anesthesia after ISB with epinephrine). Mean blood pressure (MBP) and heart rate (HR) were measured for 30 minutes at 5-minute intervals.
  
  
  RESULTS
  The study analyzed data from 431 patients. MBP tended to decrease gradually in the groups I+G and I+E+G. There were significant differences in MBP between the groups I+G and I, and between the groups I+G and I+E+G. Group I+E+G showed a significant increase in HR compared with the other two groups.
  
  
  CONCLUSIONS
  ISB with an epinephrine mixture did not prevent hypotension caused by the BCP after general anesthesia. HR increased only in response to the epinephrine mixture. A well-planned prospective study is required to compare hemodynamic changes in that context.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon, Korea.
authors.forename: Bum-June
authors.initials: BJ
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon, Korea.
authors.forename: Chae-Seong
authors.initials: CS
authors.lastname: Lim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon, Korea.
authors.forename: Boo-Hwi
authors.initials: BH
authors.lastname: Hong
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon, Korea.
authors.forename: Ji-Yong
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon, Korea.
authors.forename: Sun-Yeul
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon, Korea.
authors.forename: Jung-Un
authors.initials: JU
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon, Korea.
authors.forename: Yoon-Hee
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon, Korea.
authors.forename: Won-Hyung
authors.initials: WH
authors.lastname: Lee
authors.affiliation: Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon, Korea.
authors.forename: Seok-Hwa
authors.initials: SH
authors.lastname: Yoon
keywords: Blood pressure; Epinephrine; Heart rate; Hemodynamics; Postural balance; Shoulder arthroscopic surgery