title: The effect of cardiac output on intraoperative blood loss during total hip arthroplasty.
abstract: OBJECTIVE
  It is not clear whether cardiac output affects intraoperative blood loss under epidural hypotensive anesthesia.
  
  
  METHODS
  Thirty patients undergoing primary total hip arthroplasty were randomly assigned to receive intravenous infusions of either low-dose epinephrine or phenylephrine to maintain mean arterial pressure at 50 to 60 mm Hg throughout surgery under lumbar epidural anesthesia. Patients were monitored with radial artery and thermodilution pulmonary artery catheters. Hemodynamic parameters were measured every 10 minutes during surgery, and blood loss was estimated by a blinded observer weighing sponges.
  
  
  RESULTS
  Mean arterial pressure was similar between groups. Cardiac output remained unchanged in patients receiving low-dose epinephrine but declined significantly in patients receiving phenylephrine (p = 0.0001). Blood loss was 228 and 236 mL in patients receiving low-dose epinephrine and phenylephrine, respectively (p = 0.86). No correlation was observed between cardiac output and blood loss at any point during surgery.
  
  
  CONCLUSIONS
  Cardiac output is not a factor influencing blood loss during hypotensive epidural anesthesia in elderly patients undergoing primary total hip arthroplasty.
authors.affiliation: Department of Anesthesiology, Hospital for Special Surgery, New York, New York 10021.
authors.forename: N E
authors.initials: NE
authors.lastname: Sharrock
authors.forename: R
authors.initials: R
authors.lastname: Mineo
authors.forename: G
authors.initials: G
authors.lastname: Go
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016063:Blood Loss, Surgical / Q000503:physiopathology*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001803:Blood Transfusion; D002302:Cardiac Output / Q000187:drug effects / Q000502:physiology*; D002303:Cardiac Output, Low / Q000188:drug therapy; D003971:Diastole / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000008:administration & dosage; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006400:Hematocrit; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D010656:Phenylephrine / Q000008:administration & dosage; D011651:Pulmonary Artery / Q000187:drug effects / Q000502:physiology; D013318:Stroke Volume / Q000187:drug effects / Q000502:physiology
chemical_list: D010656:Phenylephrine; D004837:Epinephrine