title: Effects of Hypotensive Anesthesia on Reducing Intraoperative Blood Loss, Duration of Operation, and Quality of Surgical Field During Orthognathic Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
abstract: OBJECTIVE
  The objective of this study was to evaluate the efficacy of hypotensive anesthesia in reducing intraoperative blood loss, decreasing operation time, and improving the quality of the surgical field during orthognathic surgery. A systematic review and meta-analysis of randomized controlled trials addressing these issues were carried out.
  
  
  METHODS
  An electronic database search was performed. The risk of bias was evaluated with the Jadad Scale and Delphi List. The inverse variance statistical method and a random-effects model were used.
  
  
  RESULTS
  Ten randomized controlled trials were included for analysis. Our meta-analysis indicated that hypotensive anesthesia reduced intraoperative blood loss by a mean of about 169 mL. Hypotensive anesthesia was not shown to reduce the operation time for orthognathic surgery, but it did improve the quality of the surgical field. Subgroup analysis indicated that for blood loss in double-jaw surgery, the weighted mean difference favored the hypotensive group, with a reduction in blood loss of 175 mL, but no statistically significant reduction in blood loss was found for anterior maxillary osteotomy. If local anesthesia with epinephrine was used in conjunction with hypotensive anesthesia, the reduction in intraoperative blood loss was increased to 254.93 mL.
  
  
  CONCLUSIONS
  Hypotensive anesthesia was effective in reducing blood loss and improving the quality of the surgical field, but it did not reduce the operation time for orthognathic surgery. The use of local anesthesia in conjunction with hypotensive general anesthesia further reduced the amount of intraoperative blood loss for orthognathic surgery.
authors.affiliation: Assistant Professor, Department of Oral and Maxillofacial Surgery, Vanderbilt University Medical Center, Nashville, TN; Former Craniofacial Fellow, Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, Taoyuan, Taiwan. Electronic address: ilin@bellsouth.net.
authors.forename: Susie
authors.initials: S
authors.lastname: Lin
authors.affiliation: Professor and Chairman, Department of Oral and Maxillofacial Surgery, Vanderbilt University Medical Center, Nashville, TN.
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: McKenna
authors.affiliation: Attending Surgeon, Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, and College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chuan-Fong
authors.initials: CF
authors.lastname: Yao
authors.affiliation: Professor, Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, and College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Yu-Ray
authors.initials: YR
authors.lastname: Chen
authors.affiliation: Attending Anesthesiologist, Department of Anesthesiology, Chang Gung Memorial Hospital, and College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chit
authors.initials: C
authors.lastname: Chen
mesh_terms: D000766:Anesthesia, Dental / Q000379:methods*; D016063:Blood Loss, Surgical / Q000517:prevention & control*; D006801:Humans; D007023:Hypotension, Controlled / Q000379:methods*; D061646:Operative Time; D056948:Orthognathic Surgical Procedures / Q000009:adverse effects / Q000379:methods*; D016032:Randomized Controlled Trials as Topic