title: Intraoperative evaluation of tissue perfusion in high-risk patients by invasive and noninvasive hemodynamic monitoring.
abstract: OBJECTIVE
  Although invasive monitoring has not been effective in late stages after organ failure has occurred, early postoperative monitoring revealed differences in survivor and nonsurvivor patterns and provided goals for improving outcome. We searched for the earliest divergence of survivor and nonsurvivor circulatory changes as an approach to earlier preventive therapy. The aim was to describe the intraoperative time course of circulatory dysfunction in survivors and nonsurvivors among high-risk elective surgery patients using both the thermodilution pulmonary artery catheter (PAC) and multicomponent noninvasive monitoring.
  
  
  METHODS
  Prospective intraoperative description of circulatory dysfunction.
  
  
  METHODS
  University-run county hospital.
  
  
  METHODS
  Two hundred nine consecutively monitored high-risk elective surgery patients.
  
  
  RESULTS
  We evaluated the data of high-risk elective surgery patients using both PAC and multicomponent noninvasive monitoring. The latter consisted of the following: a) an improved bioimpedance method for estimating cardiac output; b) the standard pulse oximetry to screen for pulmonary problems; c) transcutaneous oxygen and carbon dioxide tension sensors to evaluate tissue perfusion; and d) routine noninvasive blood pressure and heart rate. The current noninvasive impedance cardiac output estimations closely approximated those of the thermodilution method; r2 = .74, p < .001; the precision and bias was -0.124 +/- 0.75 L/min/m2. Outcome measures included intraoperative description of circulatory patterns of high-risk surgical patients who survived compared with nonsurvivors. Hypotension, low cardiac index, arterial hemoglobin desaturation, low transcutaneous oxygen, high transcutaneous carbon dioxide tensions, low oxygen delivery, and low oxygen consumption developed intraoperatively gradually over time; the abnormalities were more pronounced in the nonsurvivors than in the survivors.
  
  
  CONCLUSIONS
  The survivors had slightly higher mean arterial pressure, cardiac index, and mixed venous oxygen saturation, as well as significantly higher oxygen delivery, oxygen consumption, transcutaneous oxygen tension, and transcutaneous oxygen tension/FIO2 ratios, than did the nonsurvivors. The data suggest that blood flow, oxygen delivery, and tissue oxygenation of the nonsurvivors became inadequate toward the end of the operation. Noninvasive monitoring provides similar information to that of the PAC; both approaches revealed low-flow and poor tissue perfusion that were worse in the nonsurvivors. The continuous on-line real-time displays of hemodynamic trends facilitate early recognition of acute circulatory dysfunction.
authors.affiliation: Department of Anesthesiology, University of Southern California School of Medicine, Los Angeles 90033, USA.
authors.forename: W C
authors.initials: WC
authors.lastname: Shoemaker
authors.forename: D
authors.initials: D
authors.lastname: Thangathurai
authors.forename: C C
authors.initials: CC
authors.lastname: Wo
authors.forename: K
authors.initials: K
authors.lastname: Kuchta
authors.forename: M
authors.initials: M
authors.lastname: Canas
authors.forename: M J
authors.initials: MJ
authors.lastname: Sullivan
authors.forename: J
authors.initials: J
authors.lastname: Farlo
authors.forename: P
authors.initials: P
authors.lastname: Roffey
authors.forename: V
authors.initials: V
authors.lastname: Zellman
authors.forename: R L
authors.initials: RL
authors.lastname: Katz
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism; D002405:Catheterization, Central Venous; D017097:Electric Impedance; D005260:Female; D006439:Hemodynamics; D006766:Hospitals, County; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D010092:Oximetry; D010101:Oxygen Consumption; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D012773:Shock, Surgical / Q000175:diagnosis; D013815:Thermodilution
chemical_list: D002245:Carbon Dioxide