title: Lack of agreement between pulmonary arterial thermodilution cardiac output and the pressure recording analytical method in postoperative cardiac surgery patients.
abstract: BACKGROUND
  Pulse-contour analysis method (PCM) cardiac output (CO) monitors are increasingly used for CO monitoring during anaesthesia and in the critically ill. Very recently, several systems have been introduced that do not need calibration; among them the pressure recording analytical method (PRAM). Sparse data comparing the accuracy of the PRAM-CO with conventional thermodilution CO (ThD-CO) in cardiac surgery patients are available.
  
  
  METHODS
  In this prospective comparison study, paired CO measurements with a pulmonary artery catheter and a PRAM monitoring set were obtained 20-30 min apart (t1, t2) in 23 extubated patients on the first postoperative day after cardiac surgery. Data were analysed by the Bland-Altman method.
  
  
  RESULTS
  A total of 46 paired CO measurements (23 for each interval) were collected. The Bland-Altman analysis showed a mean difference (bias) of 0.0 litre min(-1) and limits of agreement (1.96 sd) of 4.53 to -4.54 litre min(-1) [upper 95% confidence interval (CI), 3.26-5.80; lower 95% CI, -5.8 to -3.27]. The percentage error (1.96 sd/mean of the reference method) was 87%.
  
  
  CONCLUSIONS
  These results question the reliability of the PRAM technology for the determination of CO in postoperative cardiac surgery patients.
authors.affiliation: Department of Anesthesiology, University of Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Paarmann
authors.forename: H V
authors.initials: HV
authors.lastname: Groesdonk
authors.forename: B
authors.initials: B
authors.lastname: Sedemund-Adib
authors.forename: T
authors.initials: T
authors.lastname: Hanke
authors.forename: H
authors.initials: H
authors.lastname: Heinze
authors.forename: M
authors.initials: M
authors.lastname: Heringlake
authors.forename: J
authors.initials: J
authors.lastname: Schön
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology; D006328:Cardiac Catheterization; D002302:Cardiac Output / Q000502:physiology*; D006348:Cardiac Surgical Procedures; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D011182:Postoperative Care / Q000379:methods*; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000503:physiopathology; D015203:Reproducibility of Results; D013815:Thermodilution / Q000379:methods