title: Three-dimensional transoesophageal echocardiography for cardiac output in critically ill patients: A pilot study of ultrasound versus the thermodilution method.
abstract: BACKGROUND
  Three-dimensional transoesophageal echocardiography (3D-TOE) is a new noninvasive tool for quantitative assessment of left ventricular (LV) volumes and ejection fraction.
  
  
  OBJECTIVE
  The objective of this pilot study was to evaluate the feasibility and accuracy of 3D-TOE for the estimation of cardiac output (CO), using transpulmonary thermodilution with the Pulse index Contour Continuous Cardiac Output (PiCCO) system as the reference method, in intensive care unit (ICU) patients.
  
  
  METHODS
  Fifteen ICU patients on mechanical ventilation prospectively underwent PiCCO catheter implantation and 3D-TOE. 3D-TOE LV end-diastolic and end-systolic volumes were determined using semi-automated software. CO was calculated as the product of LV stroke volume (end-diastolic volume-end-systolic volume) multiplied by heart rate. CO was also determined invasively by transpulmonary thermodilution as the reference method.
  
  
  RESULTS
  Among 30 haemodynamic evaluations, 29 (97%) LV 3D-TOE datasets were suitable for CO calculation. The mean 3D-TOE image acquisition and post-processing times were 46 and 155seconds, respectively. There was a correlation (r=0.78; P<0.0001) between PiCCO and 3D-TOE CO. Compared with PiCCO, the 3D-TOE CO mean bias was 0.38L/min, with limits of agreement of -1.97 to 2.74L/min.
  
  
  CONCLUSIONS
  Noninvasive estimation of CO by 3D-TOE is feasible in ICU patients. This new semi-automated modality is an additional promising tool for noninvasive haemodynamic assessment of ICU patients. However, the wide limits of agreement with thermodilution observed in this pilot study require further investigation in larger cohorts of patients.
authors.affiliation: Université Paris 6, Département de Cardiologie, Institut de Cardiologie (AP-HP), CHU Pitié-Salpêtrière, Institute of Cardiometabolism and Nutrition (ICAN), Inserm UMRS 1166, ACTION Study Group, 75013 Paris, France. Electronic address: nadjib.hammoudi@psl.aphp.fr.
authors.forename: Nadjib
authors.initials: N
authors.lastname: Hammoudi
authors.affiliation: Université Paris 6, Département de Réanimation Médicale, Institut de Cardiologie (AP-HP), CHU Pitié-Salpêtrière, Institute of Cardiometabolism and Nutrition (ICAN), 75013 Paris, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Hékimian
authors.affiliation: Université Paris 6, Département de Cardiologie, Institut de Cardiologie (AP-HP), CHU Pitié-Salpêtrière, Institute of Cardiometabolism and Nutrition (ICAN), Inserm UMRS 1166, ACTION Study Group, 75013 Paris, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Laveau
authors.affiliation: Université Paris 6, Département de Cardiologie, Institut de Cardiologie (AP-HP), CHU Pitié-Salpêtrière, Institute of Cardiometabolism and Nutrition (ICAN), Inserm UMRS 1166, ACTION Study Group, 75013 Paris, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Achkar
authors.affiliation: Université Paris 6, Département de Cardiologie, Institut de Cardiologie (AP-HP), CHU Pitié-Salpêtrière, Institute of Cardiometabolism and Nutrition (ICAN), Inserm UMRS 1166, ACTION Study Group, 75013 Paris, France.
authors.forename: Richard
authors.initials: R
authors.lastname: Isnard
authors.affiliation: Université Paris 6, Département de Réanimation Médicale, Institut de Cardiologie (AP-HP), CHU Pitié-Salpêtrière, Institute of Cardiometabolism and Nutrition (ICAN), 75013 Paris, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Combes
mesh_terms: D000368:Aged; D001331:Automation; D002302:Cardiac Output / Q000187:drug effects; D002317:Cardiovascular Agents / Q000627:therapeutic use; D016638:Critical Illness; D018618:Echocardiography, Doppler, Color; D019560:Echocardiography, Three-Dimensional; D017548:Echocardiography, Transesophageal; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012121:Respiration, Artificial; D013815:Thermodilution
chemical_list: D002317:Cardiovascular Agents
keywords: 3D; Cardiac output; Débit cardiaque; ETO; Intensive care unit; Réanimation; TOE; Ultrasons; Ultrasound