title: Continuous noninvasive hemoglobin measurement is useful in patients undergoing double-jaw surgery.
abstract: OBJECTIVE
  Continuous measurement of hemoglobin by pulse CO-oximetry (SpHb; Masimo Radical 7 device, Masimo Corp, Irvine, CA) may be helpful during double-jaw surgery when massive hemorrhage is anticipated. Given the possible influence of low blood pressure on the detection of hemoglobin levels, the agreement of the SpHb was evaluated in patients undergoing orthognathic surgery when using hypotensive anesthesia.
  
  
  METHODS
  Patients who underwent elective Le Fort I osteotomy and bilateral sagittal split ramus osteotomy (BSSO) were enrolled in this observational prospective cohort study. SpHb was compared with time-matched arterial total hemoglobin (tHb) before incision, at Le Fort I osteotomy, at BSSO, and at skin closure. The correlation between simultaneous SpHb and tHb measurement pairs was evaluated. Agreement was assessed by a comparison of SpHb with tHb using the intraclass correlation coefficient (ICC) and the Bland-Altman plot.
  
  
  RESULTS
  The average age of 51 patients was 23 ± 5 years and 32 patients were male. The correlations of SpHb and tHb measurements were 0.72, 0.85, 0.89, and 0.78 before incision, at Le Fort I osteotomy, at BSSO, and at closure, respectively. Bland-Altman analysis for SpHb and tHb showed respective bias values of 0.12, 0.07, -0.09, and -0.90 g/dL. ICC values between SpHb and tHb were 0.82, 0.90, 0.91, and 0.87, respectively.
  
  
  CONCLUSIONS
  Continuous monitoring of hemoglobin may help to determine the appropriate time to perform an invasive measurement of hemoglobin in patients who undergo double-jaw surgery.
authors.affiliation: Clinical Instructor, Department of Anesthesiology and Pain Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Sung-Hoon
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Clinical Assistant Professor, Department of Anesthesiology and Pain Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea. Electronic address: superoxide@naver.com.
authors.forename: Jae Moon
authors.initials: JM
authors.lastname: Choi
authors.affiliation: Professor, Department of Dental Anesthesiology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
authors.forename: Hyun Jeong
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Assistant Professor, Department of Anesthesiology and Pain Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Seong-Soo
authors.initials: SS
authors.lastname: Choi
authors.affiliation: Professor, Department of Anesthesiology and Pain Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: In Cheol
authors.initials: IC
authors.lastname: Choi
mesh_terms: D000293:Adolescent; D000328:Adult; D001785:Blood Gas Monitoring, Transcutaneous / Q000379:methods*; D001794:Blood Pressure / Q000502:physiology; D015331:Cohort Studies; D017558:Elective Surgical Procedures; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007023:Hypotension, Controlled / Q000379:methods; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods*; D061646:Operative Time; D056948:Orthognathic Surgical Procedures / Q000379:methods*; D019340:Osteotomy, Le Fort / Q000379:methods; D059229:Osteotomy, Sagittal Split Ramus / Q000379:methods; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D006454:Hemoglobins