Volumetric assessment of left heart preload by thermodilution: comparing the PiCCO-VoLEF system with transoesophageal echocardiography.

The new Volumetric Ejection Fraction monitoring system (VoLEF), when combined with the Pulse Contour Cardiac Output monitoring system (PiCCO) system, allows measurement of left and right heart end-diastolic volumes by thermodilution. The aim of this study was to evaluate whether the left heart end-diastolic volume index determined by the VoLEF system (LHEDI) better reflects left ventricular end-diastolic area index (LVEDAI) measured by transoesophageal echocardiography than does global end-diastolic volume index (GEDI) measured by the PiCCO system alone. Following induction of anaesthesia, PiCCO, VoLEF and transoesophageal echocardiography measurements were performed before and after a fluid challenge in 20 patients scheduled for elective cardiac surgery. Both left ventricular end-diastolic area index and global end-diastolic volume index, but not left heart end-diastolic volume index, significantly increased after fluid administration. Mean bias +/- 2 SD for DeltaLHEDI-DeltaLVEDAI was -2.2 +/- 32.0% and for DeltaGEDI-DeltaLVEDAI -0.6 +/- 16.8%. In contrast to global end-diastolic volume index, the use of left heart end-diastolic volume index determined by the VoLEF system cannot be recommended as an estimate of left ventricular preload.

Volumetric preload measurement by thermodilution: a comparison with transoesophageal echocardiography.

BACKGROUND: End-diastolic volume indices determined by transpulmonary thermodilution and pulmonary artery thermodilution may give a better estimate of left ventricular preload than pulmonary capillary wedge pressure monitoring. The aim of this study was to compare volume preload monitoring using the two different thermodilution techniques with left ventricular preload assessment by transoesophageal echocardiography (TOE). METHODS: Twenty patients undergoing elective cardiac surgery with preserved left-right ventricular function were studied after induction of anaesthesia. Conventional haemodynamic variables, global end-diastolic volume index using the pulse contour cardiac output (PiCCO) system (GEDVI(PiCCO)), continuous end-diastolic volume index (CEDVI(PAC)) measured by a modified pulmonary artery catheter (PAC), left ventricular end-diastolic area index (LVEDAI) using TOE and stroke volume indices (SVI) were recorded before and 20 and 40 min after fluid replacement therapy. Analysis of variance (Bonferroni-Dunn), Bland-Altman analysis and linear regression were performed. RESULTS: GEDVI(PiCCO), CEDVI(PAC), LVEDAI and SVI(PiCCO/PAC) increased significantly after fluid load (P<0.05). An increase >10% for GEDVI(PiCCO) and LVEDAI was observed in 85% and 90% of the patients compared with 45% for CEDVI(PAC). Mean bias (2 SD) between percentage changes (delta) in GEDVI(PiCCO) and deltaLVEDAI was -3.2 (17.6)% and between deltaCEDVI(PAC) and deltaLVEDAI -8.7 (30.0)%. The correlation coefficient (r2) for deltaGEDVI(PiCCO) vs deltaLVEDAI was 0.658 and for deltaCEDVI(PAC) vs deltaLVEDAI 0.161. The relationship between deltaGEDVI(PiCCO) and deltaSVI(PiCCO) was stronger (r2=0.576) than that between deltaCEDVI(PAC) and deltaSVI(PAC) (r2=0.267). CONCLUSION: GEDVI assessed by the PiCCO system gives a better reflection of echocardiographic changes in left ventricular preload, in response to fluid replacement therapy, than CEDVI measured by a modified PAC.

Therapeutic impact of intra-operative transoesophageal echocardiography during noncardiac surgery.

The impact of transoesophageal echocardiography on haemodynamic management during elective noncardiac surgery was assessed during this observational prospective database analysis. Ninety-nine consecutive patients were studied, who were at risk of intra-operative myocardial ischaemia or haemodynamic instability (Class II indications) and were undergoing vascular, visceral or chest surgery. A total of 165 new echocardiographic findings were recorded. Based on these findings changes in drug therapy were made in 47% and changes in fluid therapy in 24% of patients. Left ventricular wall motion abnormalities were seen in 32% and other relevant diagnoses made in 10%. Echocardiography showed a significant impact on drug therapy in patients with pre-operative systolic wall motion abnormalities (vasodilators: OR = 7.1, CI 95% = 2.1/24.0; vasopressors: OR = 3.3, CI 95% = 1.2/9.1) and patients with a history of left heart failure (vasodilators: OR = 5.2, CI 95% = 1.0/31.4). Fluid therapy was significantly influenced by echocardiographic findings during liver and lung transplantation (50% compared with 24% during other surgical interventions, p < 0.05).