title: The accuracy of preload assessment by different transesophageal echocardiographic techniques in patients undergoing cardiac surgery.
abstract: OBJECTIVE
  The aim of this study was to compare the following approaches to assess left ventricular preload by transesophageal echocardiography (TEE): left ventricular end-diastolic volume index (LVEDVI) determined by using the method of disc summation (LVEDVI(Md)) and left ventricular end-diastolic area index (LVEDAI) were compared with LVEDVI assessed by the modified Simpson formula (LVEDVI(Si)). Global end-diastolic volume index (GEDVI) and stroke volume index (SVI) measured by the PiCCO(plus) system (Pulsion Medical Systems, Munich, Germany) were used as TEE-independent reference variables.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Community hospital.
  
  
  METHODS
  Twenty-two patients undergoing elective cardiac surgery.
  
  
  METHODS
  After the induction of anesthesia, hemodynamic assessment by TEE and the PiCCO(plus) system was made 20 (T(1)) and 10 minutes (T(2)) before and 10 (T(3)) and 20 minutes (T(4)) after a fluid trial. At each time point, LVEDVI(Md), LVEDAI, LVEDVI(Si), GEDVI, and SVI were determined.
  
  
  RESULTS
  The fluid trial resulted in a significant increase of all preload variables measured at T(3). At T(4), all preload variables but LVEDVI(Md) showed a significant decrease. The mean bias +/- 2 SD for percent changes (Delta) of LVEDVI(Md) - DeltaLVEDVI(Si) was 1.5% +/- 59.0% and for DeltaLVEDAI - Delta LVEDVI(Si) 0.9% +/- 23.6%. The correlation between LVEDVI(Md) and LVEDVI(Si) was significantly weaker than between LVEDAI and LVEDVI(Si) (p < 0.001). Comparing TEE measurements with GEDVI and SVI, strong correlations were observed for LVEDAI and LVEDVI(Si) only.
  
  
  CONCLUSIONS
  The method of disc summation cannot be recommended for preload assessment during a fluid challenge in cardiac surgery patients. By contrast, single-plane area measurements provided reliable information when compared with the application of the modified Simpson formula.
authors: Institute of Anesthesiology and Intensive Care Medicine, Triemli City Hospital Zurich, Zurich, Switzerland.
authors: Christoph K
authors: CK
authors: Hofer
authors: Michael T
authors: MT
authors: Ganter
authors: Andreas
authors: A
authors: Rist
authors: Richard
authors: R
authors: Klaghofer
authors: Sonja
authors: S
authors: Matter-Ensner
authors: Andreas
authors: A
authors: Zollinger
mesh_terms: D000368:Aged; D002302:Cardiac Output / Q000502:physiology; D047549:Coronary Artery Bypass, Off-Pump / Q000379:methods*; D017548:Echocardiography, Transesophageal / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology*