title: Evaluation of pulse cooximetry in patients undergoing abdominal or pelvic surgery.
abstract: BACKGROUND
  Intraoperative transfusion decisions generally are guided by blood loss estimation and periodic invasive hemoglobin measurement. Continuous hemoglobin measurement by pulse cooximetry (pulse hemoglobin; Rainbow® SET Pulse CO-Oximeter, Masimo Corporation, Irvine, CA) has good agreement with laboratory hemoglobin in healthy volunteers and could aid transfusion decision-making. Because intraoperative physiology may alter performance of this device, this study investigated pulse hemoglobin during surgery.
  
  
  METHODS
  Ninety-one adult patients undergoing abdominal or pelvic surgery in which large blood loss was likely were studied. Time-matched pulse hemoglobin measurements were recorded for each intraoperative arterial hemoglobin measurement obtained. Agreement between measurements was assessed by average difference (mean ± SD, g/dl), linear regression, and multiple measures Bland-Altman analysis.
  
  
  RESULTS
  The average difference between 360 time-matched measurements (bias) was 0.50 ± 1.44 g/dl, with wider limits of agreement (-2.3 to 3.3 g/dl) than reported in healthy volunteers. The average difference between 269 paired sequential pulse and arterial hemoglobin changes was 0.10 ± 1.11 g/dl, with half between -0.6 and 0.7 g/dl of each other. The bias was larger in patients with blood loss of more than 1,000 ml; hemoglobin less than 9.0 g/dl; any intraoperative transfusion; or intraoperative decrease in arterial hemoglobin at the time of sampling ≥2 g/dl (all P < 0.001). The range of bias was narrower at deeper anesthesia (P < 0.001).
  
  
  CONCLUSIONS
  Evaluation of the sensor and software version tested suggests that although pulse cooximetry may perform well in ambulatory subjects, in patients undergoing surgery in which large blood loss is likely, an invasive measurement should be used in transfusion decision-making.
authors: Department of Anesthesiology, Loma Linda University School of Medicine, Loma Linda, California 92354, USA. rapplegate@llu.edu
authors: Richard L
authors: RL
authors: Applegate
authors: Steven J
authors: SJ
authors: Barr
authors: Carl E
authors: CE
authors: Collier
authors: James L
authors: JL
authors: Rook
authors: Dustin B
authors: DB
authors: Mangus
authors: Martin W
authors: MW
authors: Allard
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000758:Anesthesia / Q000009:adverse effects; D016063:Blood Loss, Surgical / Q000503:physiopathology; D000077324:Crystalloid Solutions; D005260:Female; D006438:Hemodilution; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007552:Isotonic Solutions / Q000008:administration & dosage / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D010092:Oximetry / Q000379:methods*; D010388:Pelvis / Q000601:surgery*; D010952:Plasma Substitutes / Q000008:administration & dosage / Q000627:therapeutic use; D012044:Regression Analysis; D055815:Young Adult
chemical_list: D000077324:Crystalloid Solutions; D006454:Hemoglobins; D007552:Isotonic Solutions; D010952:Plasma Substitutes