title: Continuous cardiac output during off-pump coronary artery bypass surgery: pulse-contour analyses vs pulmonary artery thermodilution.
abstract: BACKGROUND
  No gold standard method exists for monitoring continuous cardiac output (CO). In this study, the agreement between the two most frequently used methods, PiCCO pulse-contour analysis (PCCO) and STAT pulmonary artery thermodilution (STAT-CO), was assessed during multiple-vessel off-pump coronary artery bypass (OPCAB) surgery.
  
  
  METHODS
  Thirty patients were enrolled in the study. Two time periods were defined during surgery; Period 1 included positioning of the heart and stabilizer device and Period 2 included the coronary occlusion. Measurements were obtained every minute during both periods. The agreement for the continuous CO and the change in CO (DeltaCO) was estimated using the Bland-Altman method.
  
  
  RESULTS
  Significant changes in mean arterial pressure (DeltaMAP), central venous saturation, PCCO and STAT-CO were seen only during Period 1. DeltaMAP correlated only with changes in PCCO, (P < 0.001, r = 0.60). The mean difference (2sd) between PCCO and STAT-CO ranged from - 0.29 (1.82) to - 0.71 (2.57) litre min(-1), and the percentage error varied from 32 to 50%. For the CO measurements, the limits of agreements did not differ between Period 1 and Period 2. In contrast, for the DeltaCO measurements, the limits of agreements were wider in Period 1 than in the more haemodynamically stable Period 2.
  
  
  CONCLUSIONS
  CCO and STAT-CO show large discrepancies in CO during OPCAB surgery. Clinically acceptable agreement was seen only for trends in CO during haemodynamically stable periods.
authors.affiliation: The Interventional Centre, Rikshospitalet-Radiumhospitalet Medical Centre, Oslo, Norway. per.steinar.halvorsen@rikshospitalet.no
authors.forename: P S
authors.initials: PS
authors.lastname: Halvorsen
authors.forename: A
authors.initials: A
authors.lastname: Sokolov
authors.forename: M
authors.initials: M
authors.lastname: Cvancarova
authors.forename: P K
authors.initials: PK
authors.lastname: Hol
authors.forename: R
authors.initials: R
authors.lastname: Lundblad
authors.forename: T I
authors.initials: TI
authors.lastname: Tønnessen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D002302:Cardiac Output; D047549:Coronary Artery Bypass, Off-Pump; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D011651:Pulmonary Artery; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D013815:Thermodilution / Q000379:methods