The comparison between stroke volume variation and filling pressure as an estimate of right ventricular preload in patients undergoing renal transplantation.

PURPOSE: The purpose of this prospective, observational study was to respiratory variation of stroke volume (stroke volume variation, SVV) against central venous pressure (CVP) and pulmonary artery diastolic pressure (PADP) as an estimate of right and left ventricular preload. METHODS: With IRB approval and informed consent, 31 patients undergoing living related renal transplantation were analyzed. Under general anesthesia with positive pressure ventilation, stroke volume index and SVV were continuously monitored with FloTrac/Vigileo monitor. Right ventricular end-diastolic volume index (RVEDVI) as well as CVP and PADP were continuously monitored with volumetric pulmonary artery catheter. Data of every 30 min interval were used for analysis. The relationship between RVEDVI and CVP, PADP, SVV was analyzed with non-linear regression and the goodness-of-fit was assessed with coefficient of determination (R(2)) of each regression curve. The ability of CVP, PADP and SVV to correctly differentiate RVEDVI <100, <120 or >138 ml/m(2), which were used to guide fluid administration, was also assessed with ROC analysis. RESULTS: Three hundred forty-eight data sets were obtained and analyzed. The goodness of fit between RVEDVI and SVV (R(2)) = 0.48) was better than that between RVEDVI and CVP or PADP (R(2)) = 0.19 and 0.33, respectively). The area under the ROC curve of SVV was significantly high compared to CVP or PADP. CONCLUSIONS: This study confirmed the theoretical framework of right ventricular preload and ventricular filling pressure and respiratory variation of stroke volume. The result also suggests that SVV can correctly predict preload status compared to pressure-based indices.

Low molecular weight pentastarch is more effective than crystalloid solution in goal-directed fluid management in patients undergoing major gastrointestinal surgery.

BACKGROUND: This prospective observational study compared the volume effect between hydroxyethyl starch (HES) and crystalloid solution and its context dependency in intraoperative goal-directed fluid management. METHODS: With institutional review board (IRB) approval, 35 patients undergoing major gastrointestinal surgery were enrolled. Fluid challenge consisting of 250 ml of either bicarbonate Ringer solution (BRS) or low molecular weight pentastarch (HES 70/0.5) was given to maintain stroke volume index >35 ml/m2. The context of fluid challenge was classified as related to either epidural block (EB) or blood loss (BL) or as nonspecific. The primary end point was the interval between index fluid challenge and the next fluid challenge, and the secondary end point was the hemodynamic parameter at the end of fluid challenge. Differences in these parameters in each clinical context were compared between BRS and HES 70/0.5. A p value <0.05 was considered statistically significant. RESULTS: Eighty-eight, 77, and 127 fluid challenges were classified as related to EB and BL and as nonspecific, respectively. In the nonspecific condition, the median (range) interval after fluid challenge with HES 70/0.5 and BRS was 45 (11-162) min and 18 (8-44) min, respectively, and the difference was statistically significant. Also, mean arterial pressure and stroke volume index significantly increased, whereas stroke volume variation significantly decreased after fluid challenge with HES 70/0.5 compared with BRS. Such differences were not observed in the other situations. CONCLUSIONS: HES 70/0.5 exerted larger volume effects than did crystalloid under nonspecific conditions. However, similar volume effects were observed during volume loss and extensive sympathetic blockade.

[Semi-invasive monitoring of cardiac output in renal transplantation by a new device using arterial pressure waveform analysis compare with intermittent pulmonary thermodilution].

BACKGROUND: Clinical usefulness of PA catheter is controversial. We compared a new semi-invasive device (FloTrac/Vigileo) using arterial pressure waveform analysis for CO measurement in patients undergoing renal transplantation with bolus thermodilution method. Simultaneously CCO was measured, and we compared CCO with that obtained by bolus thermodilution method. METHODS: Forty seven patients undergoing renal transplantation were enrolled. A PAC was inserted and radial arterial access was used for semi-invasive determination of CO (APCO) with the Vigileo. CO was measured simultaneously by bolus thermodilution and the Vigileo technique, and after starting operation, volume loading, before surgery, and other points were measured over 1 hour during measurements. And CCO was measured simultaneously at all points. STATISTICAL ANALYSIS: Statistical analysis was performed using the method described by Bland and Altman. Bias was defined as the mean difference between the volumes obtained by pulmonary artery thermodilution and those by arterial pressure waveform analysis. Precision was expressed by the upper and lower limits of agreement. RESULTS: Means of age, height and weight were 45 years, 163.8 cm and 59.2 kg, respectively. Regression analysis of CO; APCO and ICO showed y = 0.8x + 2.2, R2 = 0.57. CCO and ICO; y = 0.8x + 1.1, R2 = 0.74. Average of APCO and ICO; bias = -0.65. SD = 1.54 average of CCO and ICO; bias = 0.38, SD = 1.23. CONCLUSIONS: In renal transplantation, CO measured by a new semi-invasive arterial pressure waveform analysis device showed good agreement with the volume obtained by intermittent pulmonary artery thermodilution method.

[A pilot assessment of the FloTrac cardiac output monitoring system comparing with pulmonary artery catheter method by three versions].

BACKGROUND: Clinical significance of PA catheter is controversial. FloTrac sensor bases its calculations on arterial waveform characteristics. We conducted a pilot assessment of the FloTrac sensor by three versions comparing with pulmonary artery catheter (PCA) methodology. METHODS: Five patients undergoing cardiac surgery and four patients undergoing renal transplantation were enrolled. A PAC was inserted and radial arterial access was used for semi-invasive determination of CO (APCO) with the Vigileo. CO was measured simultaneously by bolus thermodilution and the Vigileo technique, and CCO was measured simultaneously. RESULTS: The correlation with output obtained by FloTrac and obtained by PCA is better with the newer version. Bland Altman analyses demonstrated better agreement between FloTrac and PCA methodology of the newer version. CONCLUSIONS: CO measured by a new semi-invasive arterial pressure waveform analysis device showed better agreement with pulmonary artery thermodilution measurement of the newer version.