Comparison of the ability of two continuous cardiac output monitors to measure trends in cardiac output: estimated continuous cardiac output measured by modified pulse wave transit time and an arterial pulse contour-based cardiac output device.

Estimated continuous cardiac output (esCCO), a noninvasive technique for continuously measuring cardiac output (CO), is based on modified pulse wave transit time, which in turn is determined by pulse oximetry and electrocardiography. However, its trending ability has never been evaluated in patients undergoing non-cardiac surgery. Therefore, this study examined esCCO's ability to detect the exact changes in CO, compared with currently available arterial waveform analysis methods, in patients undergoing kidney transplantation. CO was measured using an esCCO system and arterial pressure-based CO (APCO), and compared with a corresponding intermittent bolus thermodilution CO (ICO) method. Percentage error and statistical methods, including concordance analysis and polar plot analysis, were used to analyze results from 15 adult patients. The difference in the CO values between esCCO and ICO was -0.39 ± 1.15 L min(-1) (percentage error, 35.6 %). And corrected precision for repeated measures was 1.16 L min(-1) (percentage error for repeated measures, 36.0 %). A concordance analysis showed that the concordance rate was 93.1 %. The mean angular bias was -1.8° and the radial limits of agreement were ±37.6°. The difference between the APCO and ICO CO values was 0.04 ± 1.37 L min(-1) (percentage error, 42.4 %). And corrected precision for repeated measures was 1.37 L min(-1) (percentage error for repeated measures, 42.5 %). The concordance rate was 89.7 %, with a mean angular bias of -3.3° and radial limits of agreement of ±42.2°. This study demonstrated that the trending ability of the esCCO system is not clinically acceptable, as judged by polar plots analysis; however, its trending ability is clinically acceptable based on a concordance analysis, and is comparable with currently available arterial waveform analysis methods.

Evaluation of the estimated continuous cardiac output monitoring system in adults and children undergoing kidney transplant surgery: a pilot study.

Evaluation of the estimated continuous cardiac output (esCCO) allows non-invasive and continuous assessment of cardiac output. However, the applicability of this approach in children has not been assessed thus far. We compared the correlation coefficient, bias, standard deviation (SD), and the lower and upper 95 % limits of agreement for esCCO and dye densitography-cardiac output (DDG-CO) measurements by pulse dye densitometry (PDD) in adults and children. On the basis of these assessments, we aimed to examine whether esCCO can be used in pediatric patients. DDG-CO was measured by pulse dye densitometry (PDD) using indocyanine green. Modified-pulse wave transit time, obtained using pulse oximetry and electrocardiography, was used to measure esCCO. Correlations between DDG-CO and esCCO in adults and children were analyzed using regression analysis with the least squares method. Differences between the two correlation coefficients were statistically analyzed using a correlation coefficient test. Bland-Altman plots were used to evaluate bias and SD for DDG-CO and esCCO in both adults and children, and 95 % limits of agreement (bias ± 1.96 SD) and percentage error (1.96 SD/mean DDG-CO) were calculated and compared. The average age of the adult patients (n = 10) was 39.3 ± 12.1 years, while the average age of the pediatric patients (n = 7) was 9.4 ± 3.1 years (p < 0.001). For adults, the correlation coefficient was 0.756; bias, -0.258 L/min; SD, 1.583 L/min; lower and upper 95 % limits of agreement for DDG-CO and esCCO, -3.360 and 2.844 L/min, respectively; and percentage error, 42.7 %. For children, the corresponding values were 0.904; -0.270; 0.908; -2.051 and 1.510 L/min, respectively; and 35.7 %. Due to the high percentage error values, we could not establish a correlation between esCCO and DDG-CO. However, the 95 % limits of agreement and percentage error were better in children than in adults. Due to the high percentage error, we could not confirm a correlation between esCCO and DDG-CO. However, the agreement between esCCO and DDG-CO seems to be higher in children than in adults. These results suggest that esCCO can also be used in children. Future studies with bigger study populations will be required to further investigate these conclusions.

[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.

[Anesthetic management of caesarean section following the Fontan procedure by using TaskForce Monitor].

The Fontan procedure is performed for patients with a corrected transposition of great arteries, and pregnancies following this surgery are likely to increase in number. We present a parturient with the Fontan physiology. In this case, we used thoracic bio-impedance cardiac output monitoring system "TaskForce Monitor". It was shown that the cardiovascular management by using TaskForce Monitor was useful because of the non-invasive beat-to-beat cardiac output monitoring.

[Effect of ropivacaine on Ca function of skinned skeletal muscle].

It is well know that the amide-linked local anesthetics such as lidocaine accelerate Ca induced Ca release (CICR) rate. Since ropivacaine is a new amide-linked local anesthetic, effects of ropivacaine on Ca functions were studied using skinned skeletal muscle. The extensor digitorum longus muscle of male Hartley guinea pigs of about 500 g was prepared for this study. According to Endo's method, CICR rates were measured using chemically skinned fibers. Ropivacaine accelerated the (CICR) rate only at concentrations of 3 mM and 10 mM with pCa 5.0. Ropivacaine at a concentration of 10 mM inhibited initial rate of Ca uptake by sarcoplasmic reticulum. Ca sensitivity of the contractile system was not affected with 10 mM of ropivacaine. These results suggest that ropivacaine can be used safely in patients susceptible to malignant hyperthermia since ropivacaine 3 mM is not a concentration for clinical use.