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.

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.

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.

Comparative evaluation of stroke volume variation measured by pulse wave transit time and arterial pressure wave.

BACKGROUND: Several monitors have been developed that measure stroke volume (SV) in a beat-to-beat manner. Accordingly, Stroke volume variation (SVV) induced by positive pressure ventilation is widely used to predict fluid responsiveness. OBJECTIVE: The purpose of this study was to compare the ability of two different methods to predict fluid responsiveness using SVV, stroke volume variation by esCCO (esSVV) and stroke volume variation by FloTrac/VigileoTM (flSVV). METHODS: esSVV, flSVV, and stroke volume index (SVI) by both monitoring devices of 37 adult patients who underwent laparotomy surgery, were measured. Receiver operating characteristic (ROC) analysis was performed. RESULTS: The area under the ROC curve (AUC) of esSVV was significantly higher than that of flSVV (p= 0.030). esSVV and flSVV showed cutoff values of 6.1% and 10% respectively, to predict an increase of more than 10% in SVI after fluid challenge. The Youden index for esSVV was higher than flSVV, even with a cutoff value between 6% and 8%. CONCLUSION: Since esSVV and flSVV showed significant differences in AUC and cutoff values, the two systems were not comparable in predicting fluid responsiveness. Furthermore, it seems that SVV needs to be personalized to accurately predict fluid responsiveness for each patient.

[Anesthetic management of patients with pulmonary arterial hypertension (PAH)].

BACKGROUND: Pulmonary arterial hypertension (PAH) is associated with significant perioperative risk due to the severity of cardiac dysfunction related to the RV Tei index greater than 0.83. We evaluated the car- diovascular function during anesthesia to elucidate the characteristics of severity of PAH. METHODS: Nine patients undergoing central venous catheterization under general anesthesia (seven patients) and local anesthesia with sedation (two patients) were studied. RV Tei index of five patients were greater than 0.83 (severe) and in four patients RV Tei index was below 0.83 (moderate). Bioimpedance method was used to determine stroke volume (SV) and cardiac output (CO) non-invasively throughout anesthesia. The correlation between the changes in SV and CO was evaluated by using least squares method. RESULTS: Demographic data showed mean age of 16.6 years, height of 146.9 cm and weight of 39.7 kg. Correlation coefficient of SV and CO in the patients with severe cardiac dysfunction was 0.0-0.21, while in those with moderate cardiac dysfunction it was 0.49-0.93. CONCLUSIONS: In patients with severe PAH, it was demonstrated that CO is maintained by the change in heart rate (HR) but not by SV It is suggested that the control of HR in patients with PAH is of clinical importance in order to maintain CO, if RV index is greater than 0.83.

Comparison of the ability of two continuous cardiac output monitors to detect stroke volume index: Estimated continuous cardiac output estimated by modified pulse wave transit time and measured by an arterial pulse contour-based cardiac output device.

BACKGROUND: Estimated continuous cardiac output (esCCO), a non-invasive technique for continuously measuring cardiac output (CO), is based on modified pulse wave transit time, which is determined by pulse oximetry and electrocardiography. OBJECTIVE: We examined the ability of esCCO to detect stroke volume index (SVI) and changes in SVI compared with currently available arterial waveform analysis methods. METHODS: We retrospectively reanalysed 15 of the cases from our previous study on esCCO measurement. SVI was calculated using an esCCO system, measured using the arterial pressure-based CO (APCO) method, and compared with a corresponding intermittent bolus thermodilution CO (ICO) method. Percentage error measurement and statistical methods, including concordance analysis and polar plot analysis, were performed. RESULTS: The difference in the SVI values between esCCO and ICO was -3.0 ± 8.8 ml (percentage error, 33.5%). The mean angular bias was 0.8 and the radial limits of agreement were ± 27.3. The difference in the SVI values between APCO and ICO was 0.9 ± 11.2 ml (percentage error, 42.6%). The mean angular bias was -6.8 and the radial limits of agreement were ± 44.1. CONCLUSION: This study demonstrated that the accuracy, precision, and dynamic trend of esCCO are better than those of APCO.

[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.

Evaluating a Dynamic Trend in the Estimated Continuous Cardiac Output Calibrated With Invasive and Non-Invasive Methods.

OBJECTIVE: This study compared the estimated continuous cardiac output (esCCO) system and an arterial pressure-based CO (APCO) system. The goal of this study was to evaluate the dynamic trend of the esCCO calibrated with an invasive and non-invasive method. METHODS: We retrospectively identified 12 cases with complete data for the two calibration methods. Two calibration methods were analysed and compared with APCO using polar plots. RESULTS: Polar plotting revealed that the mean angular bias was 10.0°, and the radial limit of agreement was 37.1° when calibrated with the invasive method, while the mean angular bias was 3.5°, and the radial limit of agreement was 28.3° with the non-invasive method. CONCLUSION: This study suggested that the accuracy of a dynamic trend of esCCO may not be affected by the calibration methods, and the esCCO measurement by the non-invasive calibration method may be an effective device similar to that by the invasive calibration method.

Mediastinal tumor resection in a patient with spinocerebellar degeneration.

BACKGROUND: In spinocerebellar degeneration (SCD) patients, general and regional anesthesia may cause postoperative dysfunction of respiratory, nerve and muscle systems. We present the surgical case of thymoma developed in patient with SCD. CASE PRESENTATION: A 47-year-old woman with spinocerebellar degeneration was admitted because of a well-defined mass measuring 48 × 31 mm in anterior mediastinum. She showed limb, truncal, ocular, and speech ataxia; hypotonia; areflexia; sensory disturbances; and muscle weakness. Her eastern cooperative oncology group performance status was 4. Surgical resection was performed via video-assisted thoracic surgery and under general anesthesia only without epidural analgesia. The mass was diagnosed as type B1 thymoma without capsular invasion (Masaoka stage I). The patients got a good postoperative course by cooperation with anesthesiologists and neurologists in perioperative managements. She has been well over 3 years of follow-up. CONCLUSIONS: In conclusion, careful surgical and anesthesia management is essential for providing an uneventful postoperative course in patients with SCD. Especially, selection of minimal invasive approach and avoid diaphragmatic nerve damage are the most important points in surgical procedures.

[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.

[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.

Comparison of the Pulse Wave Transit Time Method and an Arterial Pressure-Based Cardiac Output System for Measuring Cardiac Output Trends During Laparotomy Without Postural Change

Objective: Perioperative intravascular volume can be optimised by identifying predictors of fluid responsiveness. This study compared the estimated continuous cardiac output (esCCO) system for non- invasive measurement and an arterial pressure-based cardiac output (APCO) system for detecting exact changes in cardiac output (CO) among patients undergoing laparotomy without postural change. Methods: This study was performed at Toho University Omori Medical Centre in Japan from April 2016 to July 2016 and included 26 adult patients undergoing elective laparotomy lasting > 2 h without postural change. We evaluated both interchangeability and dynamic trend. After entering the biometric data (age, sex, height, weight, heart rate, pulse wave transit time, and blood pressure), the esCCO device was calibrated. All patients were also monitored with the APCO system. Data were analysed and compared for 12 adult patients using Bland­Altman analysis and polar plots. Results: The CO value obtained with esCCO was 0.75 ± 0.86 L/min (percentage error: 41%) lower than that obtained with the APCO system. Polar plotting revealed that the mean angular bias was 3.5°, and the radial limit of agreement was 28.3°. Conclusion: This study demonstrated that data obtained using esCCO are not interchangeable with those obtained using the APCO system. The trending ability of the esCCO device was deemed good among patients undergoing laparotomy without postural change.

Development of an improved rapid BACpro® protocol and a method for direct identification from blood-culture-positive bottles using matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been incorporated into pathogenic bacterial identification methods and has improved their rapidity. Various methods have been reported to directly identify bacteria with MALDI-TOF MS by pretreating culture medium in blood culture bottles. Rapid BACpro® (Nittobo Medical Co., Ltd.) is a pretreatment kit for effective collection of bacteria with cationic copolymers. However, the Rapid BACpro® pretreatment kit is adapted only for MALDI Biotyper (Bruker Daltonics K.K.), and there has been a desire to expand its use to VITEK MS (VMS; bioMerieux SA). We improved the protocol and made it possible to analyze with VMS. The culture medium bacteria collection method was changed to a method with centrifugation after hemolysis using saponin; the cationic copolymer concentration was changed to 30% of the original concentration; the sequence with which reagents were added was changed; and a change was made to an ethanol/formic acid extraction method. The improved protocol enhanced the identification performance. When VMS was used, the identification rate was 100% with control samples. With clinical samples, the identification agreement rate with the cell smear method was 96.3%. The improved protocol is effective in blood culture rapid identification, being both simpler and having an improved identification performance compared with the original.

Application of the biocopolymer preparation system, rapid BACpro® II kit, for mass-spectrometry-based bacterial identification from positive blood culture bottles by the MALDI Biotyper system.

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is increasingly used for identification of microorganisms from positive blood cultures. Pretreatments to effectively remove non-bacterial components and selectively collect microorganisms are a prerequisite for successful identification, and a variety of home-brew and commercial protocols have been reported. Although commercially available kits, mainly the Sepsityper Kit, are increasingly used, the identification rates reported often are not satisfactory, particularly for Gram-positive isolates. We recently developed a method to collect bacteria from positive blood culture bottles using a polyallylamine-polystyrene copolymer that has been used in wastewater processing. This pretreatment protocol is now commercially available as the rapid BACpro® II kit (Nittobo Medical Co., Tokyo, Japan). The operation time required for processing using this novel kit is approximately 10 min, and the entire procedure can be completed within a biosafety cabinet. Since the performance of the rapid BACpro® II kit has not been tested using the MALDI Biotyper system, we prospectively evaluated the performance of the rapid BACpro® II kit as compared with the Sepsityper® kit. Performance of the rapid BACpro® II kit was evaluated using a total of 193 monomicrobial cases of positive blood culture. Medium from blood culture bottles was pretreated by the rapid BACpro® II kit or the Sepsityper® Kit, and isolated cells were subjected to direct identification by MS fingerprinting in parallel with conventional subculturing for reference identification. The overall MALDI-TOF MS-based identification rates with >1.7 score and >2.0 score obtained using the rapid BACpro® II kit were 99.5% and 80.8%, respectively, whereas those obtained using the Sepsityper® Kit were 89.1% and 68.4%, respectively (P < 0.05 for >1.7 and P < 0.05 for >2.0 by Pearsons's chi-square). In Gram-positive cases, the rapid BACpro® II kit gave identification rate of 100% with >1.7 score and 69.4% with >2.0 score, whereas there were 84.7% and 56.8%, respectively by the Sepsityper® Kit (P < 0.05 for >1.7). These results are preliminary, but considering that this new kit is easy to perform and the identification rates are promising, the rapid BACpro® II kit deserves assessment in a larger-scale study with a variety of platforms for MS-based bacterial identification.

Applications of copolymer for rapid identification of bacteria in blood culture broths using matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) can be used to identify pathogens in blood culture samples. However, sample pretreatment is needed for direct identification of microbes in blood culture bottles. Conventional protocols are complex and time-consuming. Therefore, in this study, we developed a method for collecting bacteria using polyallylamine-polystyrene copolymer for application in wastewater treatment technology. Using representative bacterial species Escherichia coli and Staphylococcus capitis, we found that polyallylamine-polystyrene can form visible aggregates with bacteria, which can be identified using MALDI-TOF MS. The processing time of our protocol was as short as 15min. Hemoglobin interference in MALDI spectra analysis was significantly decreased in our method compared with the conventional method. In a preliminary experiment, we evaluated the use of our protocol to identify clinical isolates from blood culture bottles. MALDI-TOF MS-based identification of 17 strains from five bacterial species (E. coli, Klebsiella pneumoniae, Enterococcus faecalis, S. aureus, and S. capitis) collected by our protocol was satisfactory. Prospective large-scale studies are needed to further evaluate the clinical application of this novel and simple method of collecting bacteria in blood culture bottles.

[Cardiovascular effects of human atrial natriuretic peptide during renal transplantation].

BACKGROUND: We evaluated the cardiovascular effects of human atrial natriuretic peptide (hANP) in the recipients of renal transplantation. METHODS: Anesthesia was maintained by inhalation of nitrous-oxide and isoflurane in oxygen, with epidural block. The recipients were divided into three groups; one group received no hANP infusion as control and the other groups received continuous infusion of hANP at the rate of either 0.05 microg x kg(-1) x min(-1) or 0.1 microg x kg(-1) x min(-1). Intravenous infusion of hANP was started at the anastomosis of renal artery after the fresh frozen plasma was loaded to achieve PCWP over 17 mmHg. In each group, we examined cardiovascular changes by using a pulmonary artery catheter and transesophageal echocardiography. The measurements were done before and after 15 minutes of hANP infusion. RESULTS: In comparison with control, the decreases in PCWP and CVP were significant in the 0.1 microg x kg(-1) x min(-1) group. An increase in CI and the reduction of CVP were significant in 0.05 microg x kg(-1) x min(-1) group, when compared with control group. In the 0.1 microg x kg(-1) x min(-1) group, the reductions of PCWP and CVP and MAP were significant, but the significant increase in CI was characteristic in the 0.05 microg x kg(-1) x min(-1) group. CONCLUSIONS: We conclude that the low-dose infusion of hANP in the recipients of renal transplantation is useful for the optimal anesthetic care because of the cardiovascular improvement.

[Cardiovascular effects of human atrial natriuretic peptide during pediatric renal transplantation].

BACKGROUND: We evaluated the cardiovascular effects of human atrial natriuretic peptide (hANP) in the pediatric recipients undergoing renal transplantation. METHODS: Anesthesia was maintained by inhalation of nitrous-oxide and isoflurane in oxygen. Intravenous infusion of hANP at a rate of 0.05 microg x kg(-1) x min(-1) was started on the anastomosis of the renal artery after the fresh frozen plasma had been loaded to achieve PCWP above 17 mmHg. We examined cardiovascular changes by using a pulmonary artery catheter and transesophageal echocardiography. The measurements were done before and after 15 minutes of hANP infusion. RESULTS: An increase in CI and a reduction in PCWP were significant. CONCLUSIONS: The low-dose infusion of hANP was useful in pediatric recipients undergoing renal transplantation for the optimal anesthetic care in view of the improvement of cardiovascular functions.

[Two cases of pulmonary hypertension crisis in patients with primary pulmonary hypertension].

Primary pulmonary hypertension (PPH) is an uncommon disease. We describe two cases of pulmonary hypertension crisis in patients with PPH during general anesthesia. Any factor that worsens primary pulmonary hypertension (strain, hypoxia, pain, hypercapnia, intubation, or hyperinflation) should be avoided.