title: Assessment of moderate to severe abdominal blood loss using peripheral to central blood oxygen saturation.
abstract: OBJECTIVE
  There are various definitions and monitoring modalities for hemodynamic status. Each of them has its own advantages and shortcomings. A new hemodynamic index is proposed in this study. This index can be calculated by placing the measured hemoglobin saturation in a formula. Blood samples for this measurement are taken from arterial, antecubital and central venous blood.
  
  
  METHODS
  We calculated this index in three different groups undergoing laparatomy. The control group consisted of patients who underwent elective surgery. The case group with acute internal abdominal bleeding was divided into two groups. Those with more than 20 ml/kg of blood in their abdominal cavity were designated as the severe case group, while those bleeding less were categorized as moderate. Blood samples were taken from ten patients in each group in stable and unstable conditions.
  
  
  RESULTS
  This index differed significantly between dissimilar hemodynamic conditions. The pre-anesthesia value of this index in the control group showed a mean +/- SD of 8.5 +/- 3.2 vs. 1.6 +/- 0.4 in the moderate case group vs. 0.7 +/- 0.08 in the case group with severe hemodynamic changes (p < .001). The index approximated to the control values as the circumstances improved. After compensation for volume loss, pre-extubation values were not significantly different. These were 9.6 +/- 2 in the control group vs. 8 +/- 2 in the case group with moderate hemodynamic change vs. 8 +/- 1.8 in the severe case group. The likelihood ratio of bleeding increased as this index decreased.
  
  
  CONCLUSIONS
  As the hemodynamic condition deteriorates, this index decreases significantly. This index is an accurate indicator for predicting hemodynamic changes compared to some other modalities. Further investigations are needed into the prognostic and therapeutic advantages of this index.
authors.affiliation: Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Zadeh S
authors.initials: ZS
authors.lastname: Khorasani
authors.forename: H
authors.initials: H
authors.lastname: Elyassi
authors.forename: B
authors.initials: B
authors.lastname: Gharaei
authors.forename: P
authors.initials: P
authors.lastname: Yavari
mesh_terms: D000005:Abdomen; D000328:Adult; D001784:Blood Gas Analysis; D016063:Blood Loss, Surgical; D005260:Female; D006801:Humans; D007813:Laparotomy; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D016343:Monitoring, Intraoperative / Q000379:methods*; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D012720:Severity of Illness Index
chemical_list: D010100:Oxygen