title: Accuracy of Continuous Cardiac Output Measurement With the LiDCOplus System During Intra-Aortic Counterpulsation After Cardiac Surgery.
abstract: OBJECTIVE
  To evaluate the effect of intra-aortic counterpulsation on precision, accuracy, and concordance of continuous pulse contour cardiac output determined using LiDCOplus (LiDCO Group, London).
  
  
  METHODS
  Prospective trial.
  
  
  METHODS
  University hospital critical care unit.
  
  
  METHODS
  Patients with intra-aortic balloon pump support in the 1:1 mode after elective or urgent cardiac surgery.
  
  
  METHODS
  Lithium dilution calibrated pulse contour cardiac output was compared with pulmonary artery bolus thermodilution cardiac output during hemodynamically stable conditions in the course of standardized postoperative management.
  
  
  RESULTS
  Fifty-one paired measurements demonstrated good correlation between the 2 methods (r = 0.88, p<0.001). Mean bias was -0.14±0.81 L/min, limits of agreement 1.48 to -1.77 L/min, and percentage error 28%. Concordance between the 2 techniques regarding directional changes>±10% cardiac output was 100% (p = 0.008). Trending ability was moderate when paired cardiac output changes were assessed using linear regression, 4-quadrant table, and polar plots. When changes <±10% of the reference cardiac output were excluded, 90% of the data pairs still lay within the 30° radial limits. Optimal timing of the balloon pump was indispensable for proper determination of pulse contour cardiac output.
  
  
  CONCLUSIONS
  Because of the LiDCOplus-specific algorithm in determining stroke volume from the arterial pulse waveform, which differs from other devices, accuracy and precision of continuous pulse contour cardiac output only are affected insignificantly by intra-aortic counterpulsation. The authors nevertheless caution that the device should be recalibrated after major hemodynamic alterations or otherwise inexplicable changes of the pulse contour cardiac output to improve trending.
authors.affiliation: Division of Cardiothoracic and Vascular Anesthesia and Intensive Care Medicine.
authors.forename: Johannes
authors.initials: J
authors.lastname: Menger
authors.affiliation: Division of Cardiothoracic and Vascular Anesthesia and Intensive Care Medicine.
authors.forename: Bruno
authors.initials: B
authors.lastname: Mora
authors.affiliation: Division of Cardiothoracic and Vascular Anesthesia and Intensive Care Medicine.
authors.forename: Keso
authors.initials: K
authors.lastname: Skhirtladze
authors.affiliation: Division of Cardiothoracic and Vascular Anesthesia and Intensive Care Medicine.
authors.forename: Arabella
authors.initials: A
authors.lastname: Fischer
authors.affiliation: Department of Surgery, and Christian Doppler Laboratory for Cardiac and Thoracic Diseases, General Hospital Vienna, Medical University of Vienna, Vienna, Austria.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Jan Ankersmit
authors.affiliation: Division of Cardiothoracic and Vascular Anesthesia and Intensive Care Medicine. Electronic address: martin.dworschak@meduniwien.ac.at.
authors.forename: Martin
authors.initials: M
authors.lastname: Dworschak
mesh_terms: D000368:Aged; D000465:Algorithms; D002302:Cardiac Output / Q000502:physiology*; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass; D002407:Catheterization, Swan-Ganz / Q000379:methods; D015908:Counterpulsation / Q000379:methods*; D003422:Critical Care / Q000379:methods; D005260:Female; D006801:Humans; D008094:Lithium; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D011182:Postoperative Care / Q000379:methods*; D011446:Prospective Studies; D013815:Thermodilution / Q000379:methods
chemical_list: D008094:Lithium
keywords: cardiac output; cardiac surgery; intra-aortic counterpulsation; monitoring; pulse contour analysis