Arterial Pressure-based Cardiac Output Research Articles

Comparison of noninvasive cardiac output and stroke volume measurements using electrical impedance tomography with invasive methods in a swine model.

Pulmonary artery catheterization (PAC) has been used as a clinical standard for cardiac output (CO) measurements on humans. On animals, however, an ultrasonic flow sensor (UFS) placed around the ascending aorta or pulmonary artery can measure CO and stroke volume (SV) more accurately. The objective of this paper is to compare CO and SV measurements using a noninvasive electrical impedance tomography (EIT) device and three invasive devices using UFS, PAC-CCO (continuous CO) and arterial pressure-based CO (APCO). Thirty-two pigs were anesthetized and mechanically ventilated. A UFS was placed around the pulmonary artery through thoracotomy in 11 of them, while the EIT, PAC-CCO and APCO devices were used on all of them. Afterload and contractility were changed pharmacologically, while preload was changed through bleeding and injection of fluid or blood. Twenty-three pigs completed the experiment. Among 23, the UFS was used on 7 pigs around the pulmonary artery. The percentage error (PE) between COUFS and COEIT was 26.1%, and the 10-min concordance was 92.5%. Between SVUFS and SVEIT, the PE was 24.8%, and the 10-min concordance was 94.2%. On analyzing the data from all 23 pigs, the PE between time-delay-adjusted COPAC-CCO and COEIT was 34.6%, and the 10-min concordance was 81.1%. Our results suggest that the performance of the EIT device in measuring dynamic changes of CO and SV on mechanically-ventilated pigs under different cardiac preload, afterload and contractility conditions is at least comparable to that of the PAC-CCO device. Clinical studies are needed to evaluate the utility of the EIT device as a noninvasive hemodynamic monitoring tool.

The Incidence of Perioperative Hypotension in Patients Undergoing Major Abdominal Surgery with the Use of Arterial Waveform Analysis and the Hypotension Prediction Index Hemodynamic Monitoring-A Retrospective Analysis.

Intraoperative hypotension (IH) is common in patients receiving general anesthesia and can lead to serious complications such as kidney failure, myocardial injury and increased mortality. The Hypotension Prediction Index (HPI) algorithm is a machine learning system that analyzes the arterial pressure waveform and alerts the clinician of an impending hypotension event. The purpose of the study was to compare the frequency of perioperative hypotension in patients undergoing major abdominal surgery with different types of hemodynamic monitoring. The study included 61 patients who were monitored with the arterial pressure-based cardiac output (APCO) technology (FloTrac group) and 62 patients with the Hypotension Prediction Index algorithm (HPI group). Our primary outcome was the time-weighted average (TWA) of hypotension below < 65 mmHg. The median TWA of hypotension in the FloTrac group was 0.31 mmHg versus 0.09 mmHg in the HPI group (p = 0.000009). In the FloTrac group, the average time of hypotension was 27.9 min vs. 8.1 min in the HPI group (p = 0.000023). By applying the HPI algorithm in addition to an arterial waveform analysis alone, we were able to significantly decrease the frequency and duration of perioperative hypotension events in patients who underwent major abdominal surgery.

Multi-Channel Trans-Impedance Leadforming for Cardiopulmonary Monitoring: Algorithm Development and Feasibility Assessment Using In Vivo Animal Data.

The objectives of this study were to develop a multi-channel trans-impedance leadforming method for beat-to-beat stroke volume (SV) and breath-by-breath tidal volume (TV) measurements and assess its feasibility on an existing in vivo animal dataset. A deterministic leadforming algorithm was developed to extract a cardiac volume signal (CVS) and a respiratory volume signal (RVS) from 208-channel trans-impedance data acquired every 20 ms by an electrical impedance tomography (EIT) device. SVEIT and TVEIT values were computed as a valley-to-peak value in the CVS and RVS, respectively. The method was applied to the existing dataset from five mechanically-ventilated pigs undergoing ten mini-fluid challenges. An invasive hemodynamic monitor was used in the arterial pressure-based cardiac output (APCO) mode to simultaneously measure SVAPCO values while a mechanical ventilator provided TVVent values. The leadforming method could reliably extract the CVS and RVS from the 208-channel trans-impedance data measured with the EIT device, from which SVEIT and TVEIT were computed. The SVEIT and TVEIT values were comparable to those from the invasive hemodynamic monitor and mechanical ventilator. Using the data from 5 pigs and a simple calibration method to remove bias, the error in SVEIT and TVEIT was 9.5% and 5.4%, respectively. We developed a new leadforming method for the EIT device to robustly extract both SV and TV values in a deterministic fashion. Future animal and clinical studies are needed to validate this leadforming method in various subject populations. The leadforming method could be an integral component for a new cardiopulmonary monitor in the future to simultaneously measure SV and TV noninvasively, which would be beneficial to patients.

Accuracy of Estimated Continuous Cardiac Output Monitoring (esCCO) Using Pulse Wave Transit Time (PWTT) Compared to Arterial Pressure-based CO (APCO) Measurement during Major Surgeries.

BackgroundPulse wave transit time is a novel method of estimating continuous cardiac output (esCCO). Since there are not many studies evaluating esCCO, we compared it with arterial pressure based cardiac output (APCO) method (FloTrac).MethodsIn this prospective single-center observational study, we included 50 adult patients planned to undergo supramajor oncosurgeries, where major blood loss and extensive fluid shifts were expected. Cardiac output (CO) measurements were obtained by both methods at five distinct time points, giving us 250 paired readings of stroke volume index (SVI) and cardiac index (CI). We analyzed these readings using Pearson's correlation coefficient and Bland–Altman plots, along with other appropriate statistical tests.ResultsThere was significant correlation between CI and SVI measured by the esCCO and APCO. Bland–Altman plot analysis for CI showed a bias of −0.44 L/minute/m2, precision of 0.74, and the limits of agreement of −1.89 and +1.01, while the percentage error was 46.29%. Bland–Altman analysis for SVI showed a bias −5.07 mL with a precision of 9.36, and the limits of agreement to be −23.4 to +13.28. The percentage error was 46.56%.ConclusionThis study demonstrated that esCCO tended to underestimate the CI to a large degree, particularly while estimating the cardiac output in the lower range. We found that the limits of agreement between two methods were wide, which are not likely to be clinically acceptable. Further studies with larger number of data points, obtained in a similar subset of patients, for cardiac output measurement in the perioperative period will certainly help determine if pulse wave transit time (PWTT) is here to stay (CTRI No.: CTRI/2019/08/020543).How to cite this articleJoshi M, Rathod R, Bhosale SJ, Kulkarni AP. Accuracy of Estimated Continuous Cardiac Output Monitoring (esCCO) Using Pulse Wave Transit Time (PWTT) Compared to Arterial Pressure-based CO (APCO) Measurement during Major Surgeries. Indian J Crit Care Med 2022;26(4):496–500.

Development and Validation of an Arterial Pressure-Based Cardiac Output Algorithm Using a Convolutional Neural Network: Retrospective Study Based on Prospective Registry Data.

BackgroundArterial pressure-based cardiac output (APCO) is a less invasive method for estimating cardiac output without concerns about complications from the pulmonary artery catheter (PAC). However, inaccuracies of currently available APCO devices have been reported. Improvements to the algorithm by researchers are impossible, as only a subset of the algorithm has been released.ObjectiveIn this study, an open-source algorithm was developed and validated using a convolutional neural network and a transfer learning technique.MethodsA retrospective study was performed using data from a prospective cohort registry of intraoperative bio-signal data from a university hospital. The convolutional neural network model was trained using the arterial pressure waveform as input and the stroke volume (SV) value as the output. The model parameters were pretrained using the SV values from a commercial APCO device (Vigileo or EV1000 with the FloTrac algorithm) and adjusted with a transfer learning technique using SV values from the PAC. The performance of the model was evaluated using absolute error for the PAC on the testing dataset from separate periods. Finally, we compared the performance of the deep learning model and the FloTrac with the SV values from the PAC.ResultsA total of 2057 surgical cases (1958 training and 99 testing cases) were used in the registry. In the deep learning model, the absolute errors of SV were 14.5 (SD 13.4) mL (10.2 [SD 8.4] mL in cardiac surgery and 17.4 [SD 15.3] mL in liver transplantation). Compared with FloTrac, the absolute errors of the deep learning model were significantly smaller (16.5 [SD 15.4] and 18.3 [SD 15.1], P<.001).ConclusionsThe deep learning–based APCO algorithm showed better performance than the commercial APCO device. Further improvement of the algorithm developed in this study may be helpful for estimating cardiac output accurately in clinical practice and optimizing high-risk patient care.

Hemodynamic changes of anesthesia, pneumoperitoneum, and head-down tilt during laparoscopic surgery in elderly patients.

BackgroundThe hemodynamic variations of cardiac and cerebral blood monitoring during pneumoperitoneum and head-down tilt position in general anesthetized elderly patients remain unresolved. We evaluated the time course of cerebral tissue oxygen saturation (SctO2) and cardiac output (CO) and investigated how the changes in hemodynamic values during the surgery would affect cerebral perfusion in elderly patients.MethodsIn this prospective observational study of 47 elderly patients (≥65 years old, American Society of Anesthesiologists Physical status I to III) undergoing laparoscopic colorectal radical resection with head-down position, SctO2 by near-infrared spectroscopy and arterial pressure-based cardiac output (APCO), Cardiac index (CI), stroke volume (SV), and SV index (SVI) according to FloTrac/Vigileo were measured at 9 time points. Heart rate (HR), mean arterial blood pressure (MAP), end-tidal carbon dioxide (ETCO2), bispectral index (BIS), central venous pressure (CVP), and ventilator settings were recorded. Results are reported as medians [95% confidence interval (CI)].ResultsHeart Rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), MAP, CO, CI, SV, SVI, and SctO2 before incision decreased significantly compared with the waking state (P<0.05). SBP, CO, CI, SV, and SVI before incision decreased significantly compared with induction and intubation (P<0.05). SBP, DBP, MAP, and CVP increased significantly after pneumoperitoneum and head-down tilt, and then decreased during the following hour. CO and SVI decreased, while CI and SV increased after pneumoperitoneum and head-down tilt. CO, CI, SV and SVI decreased at the following 20, 40, and 60 minutes respectively. SctO2 increased after pneumoperitoneum and head-down tilt and remained stable during the following hour. CVP decreased while CO, CI, SV, and SVI increased significantly at the end of pneumoperitoneum and head-down tilt (P<0.05). HR and MAP increased significantly at the end of surgery compared to at the end of pneumoperitoneum and head-down tilt (P<0.05). CI was associated with SctO2 as indicated by a Pearson r of 0.035 (P<0.05).ConclusionsAnesthesia, pneumoperitoneum, and head-down tilt affect cardiac function and cerebral perfusion in elderly patients. cardiac index independently affects elderly patients’ cerebral blood flow.

Management of cesarean section in a patient with Fontan circulation: a case report of dramatic reduction of maternal oxygen consumption after delivery

BackgroundThe anesthetic management of cesarean sections in Fontan-palliated parturients requires strict hemodynamic control. However, patient management with central venous oxygen saturation (ScvO2) and oxygen consumption (VO2) has never been reported.Case presentationA 30-year-old woman, who had received a total cavopulmonary connection for tricuspid atresia, was planned to undergo cesarean section at 38 weeks’ gestation. During combined spinal-epidural anesthesia, ScvO2 in addition to arterial pressure-based cardiac output (APCO) and central venous pressure (CVP) was monitored, and the change of VO2 was evaluated. After delivery, her APCO was almost unchanged. However, her ScvO2 increased dramatically from 42.1 to 67.3% and her CVP increased from 9 to 11 mm Hg. The calculated mean maternal VO2 changed from 443 to 295 mL/min.ConclusionsIn a cesarean section for a Fontan-palliated parturient, ScvO2 dramatically increased and maternal VO2 decreased by more than 25% after delivery.

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.

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. We examined the ability of esCCO to detect stroke volume index (SVI) and changes in SVI compared with currently available arterial waveform analysis 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. 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. This study demonstrated that the accuracy, precision, and dynamic trend of esCCO are better than those of APCO.

Relationship between changes in regional cerebral blood volume and oxygenation and changes in cardiac output and systemic vascular resistance during spinal anesthesia in women undergoing cesarean section

The decrease in maternal regional cerebral blood volume (rCBV) and oxygenation (rCBO) during spinal anesthesia for cesarean section depends on the severity of hypotension. We examined the relationships between changes in the systemic circulatory parameters, cardiac output (CO) and systemic vascular resistance (SVR), and rCBV and rCBO after induction of spinal anesthesia, evaluated by near-infrared spectroscopy (NIRS) and an arterial pressure-based cardiac output monitoring system (APCOs). Seventeen patients undergoing elective cesarean section under spinal anesthesia were monitored every 1min for mean arterial pressure (MAP), heart rate (HR), end-tidal carbon dioxide (EtCO2) and oxygen saturation (SpO2), and at 20s intervals for CO, SVR, concentrations of oxy-hemoglobin (Hb), deoxy-Hb, total-Hb, and tissue oxygenation index (TOI), until 15 min after the intrathecal injection of bupivacaine. We investigated changes in the parameters from baseline and evaluated correlations between the changes in total-Hb and TOI and changes in CO and SVR, respectively, at the same timepoints. Oxy-Hb, total-Hb, TOI, and SVR significantly decreased and HR significantly increased with a decrease in MAP (P < 0.01). Deoxy-Hb, CO, SpO2, and EtCO2 levels did not change from baseline. There were statistically significant, although weak, positive correlations between both total-Hb and TOI with SVR (total-Hb; r = 0.18, P < 0.01, TOI; r = 0.38, P < 0.01). The decreases in both rCBV and rCBO after induction of spinal anesthesia for cesarean section are probably dependent on the decrease in SVR due to spinal anesthesia.

Effects of cardiac output on the onset of rocuronium-induced neuromuscular block in elderly patients.

The aim of this study was to elucidate the relationship between the onset of rocuronium-induced neuromuscular block and arterial pressure-based cardiac output (CO) in elderly patients. Forty elderly patients aged 65-83years were enrolled in this study. After induction of anesthesia, contractions of the adductor pollicis muscle to ulnar nerve train-of-four stimulation were acceleromyographically evaluated and 1mg/kg rocuronium was administered following CO measurement. The correlation between onset of rocuronium action and CO was analyzed. The mean [SD] CO reduced after induction of anesthesia from 5.1 [1.8] L/min to 3.8 [1.1] L/min. The onset time of rocuronium-induced neuromuscular block was 110.3 [23.9] s (range 60-165). There was a statistically significant inverse correlation between the onset time of rocuronium and CO [onset time (s) = - 13.2·CO + 159.7, R2 = 0.376]. In the elderly, CO influences the onset of action of rocuronium.

Intraoperative hemodynamics monitoring in a patient with pheochromocytoma multisystem crisis: a case report

BackgroundPheochromocytoma is a rare catecholamine-secreting tumor. To evaluate the intraoperative hemodynamics with precision is difficult.Case presentationA 42-year-old man, who suddenly developed a life-threatening pheochromocytoma multisystem crisis that occurred during preoperative prophylactic medication, underwent urgent bilateral adrenalectomy. For the purpose of evaluating the intraoperative hemodynamics, we monitored both pulmonary artery catheter-based cardiac output (PACO) and arterial pressure-based cardiac output (APCO; FloTrac™). APCO fluctuated in poor agreement with the change in PACO, especially in the state of cytokine storming.ConclusionsOverall, the value of stroke volume variation derived from FloTrac™ changed in tandem with the intraoperative volume status, indicating its utility as a marker of circulatory hemodynamics.

Significant decreases in blood propofol concentrations during adrenalectomy for phaeochromocytoma.

The kinetics of propofol are influenced by cardiac output. The aim of this study was to examine changes in blood propofol concentrations during phaeochromocytoma surgery using target-controlled infusion (TCI) anaesthesia with propofol. This is a prospective observational study. Ten patients with phaeochromocytoma who underwent unilateral adrenalectomy were included. Cardiac output was measured using an arterial pressure-based cardiac output analysis method. The target blood propofol concentrations were adjusted to maintain an approximate bispectral index (BIS) value of 40 before initiating surgery. The settings remained constant during surgery. Blood samples for propofol concentrations were collected from the radial artery at seven time points: two before tumour manipulation (T1, 2), two during tumour manipulation (T3, 4), and three after tumour vein ligation (T4-7). BIS values, the arterial pressure cardiac index (APCI) and haemodynamic parameters were measured at the same time points as the blood samples. The prop-ratio was calculated by dividing blood propofol concentrations by target concentrations of TCI. APCI increased during tumour manipulation and after tumour vein ligation. The prop-ratio was reduced significantly by approximately 40% and showed a significant negative correlation with APCI. BIS values increased significantly and showed a significant negative correlation with the prop-ratio. The increased APCI during tumour manipulation and after tumour vein ligation was associated with markedly reduced blood propofol concentrations. These results reveal that significant decreases in the anaesthetic effect may be observed in patients undergoing phaeochromocytoma surgery even if TCI anaesthesia is used with propofol.

Effective evaluation of arterial pulse waveform analysis by two-dimensional stroke volume variation-stroke volume index plots.

Arterial pulse waveform analysis (APWA) with a semi-invasive cardiac output monitoring device is popular in perioperative hemodynamic and fluid management. However, in APWA, evaluation of hemodynamic data is not well discussed. In this study, we analyzed how we visually interpret hemodynamic data, including stroke volume variation (SVV) and stroke volume (SV) derived from APWA. We performed arithmetic estimation of the SVV-SV relationship and applied measured values to this estimation. We then collected measured values in six anesthesia cases, including three liver transplantations and three other types of surgeries, to apply them to this SVV-SVI (stroke volume variation index) plot. Arithmetic analysis showed that the relationship between SVV and SV can be drawn as hyperbolic curves. Plotting SVV-SV values in the semi-logarithmic scale showed linear correlations, and the slopes of the linear regression lines theoretically represented average mean cardiac contractility. In clinical measurements in APWA, plotting SVV and SVI values in the linear scale and the semi-logarithmic scale showed the correlations represented by hyperbolic curves and linear regression lines. The plots approximately shifted on the rectangular hyperbolic curves, depending on blood loss and blood transfusion. Arithmetic estimation is close to real measurement of the SVV-SV interaction in hyperbolic curves. In APWA, using SVV as an index of preload and the cardiac index or SVI derived from arterial pressure-based cardiac output as an index of cardiac function, is likely to be appropriate for categorizing hemodynamic stages as a substitute for Forrester subsets.

An application of arterial pressure-based cardiac output measurements in fluid management strategies of critically ill patients

To discuss the clinical significance of fluid management of severe patients according to arterial pressure-based cardiac output (APCO) monitoring volume responsiveness index. A retrospective cohort study was conducted. The severe patients were selected from the intensive care unit (ICU) of the First Hospital of Jilin University from June 1st, 2012 to December 31st, 2013. The hemodynamic parameters were monitored by APCO, and the fluid resuscitation was managed by stroke volume variation (SVV) and passive leg-raising test (PLR) when the acute physiology and chronic health evaluation II (APACHEII) score ≥ 15, heart rate >100 bpm with the result that the preload and heart function could not be evaluated. The heart rate, SVV, lactic acid (Lac) and central venous pressure (CVP) and curative effect were recorded before and after carrying out fluid management strategy. The criteria of clinical effective was defined as heart rate decreased and (or) stroke volume (SV) increased ≥ 10%, accompanied by blood Lac and SVV decreased, other than, the cases did not meet above criteria were considered ineffective. Sixty-eight patients were enrolled in the study. (1) Before carrying out fluid management strategy: 40 cases with CVP>12 cmH₂O (1 cmH₂O=0.098 kPa), and 16 cases with 5-12 cmH₂O, 12 with <5 cmH₂O. SVV>13% in 35 cases, SVV <13% in 9 cases. PLR positive in 18 cases, and PLR negative in 6 cases. It was implicated that the patients with poor preload (SVV>13% and PLR positive) accounted by 77.9% (53/68). (2) There were 49 effective cases and 19 ineffective cases 4 hours after carrying out fluid management strategy, and the effective rate was 72.06% (49/68). While there were 56 effective cases and 12 ineffective cases after 12 hours, and the total effective rate was 82.35% (56/68). (3) In effective group, heart rate, SVV, Lac after fluid management strategy were significantly lower than those before fluid management strategy [4 hours after fluid management strategy: heart rate (bpm) 112.45 ± 13.53 vs. 129.55 ± 15.49, SVV (15.47 ± 6.32)% vs. (21.20 ± 7.40)%, Lac (mmol/L) 4.16 ± 3.12 vs. 6.21 ± 4.11; 12 hours after fluid management strategy: heart rate (bpm) 110.02 ± 13.92 vs. 129.61 ± 14.93, SVV (14.61 ± 15.52)% vs. (20.66 ± 7.40)%, Lac (mmol/L) 3.35 ± 2.26 vs. 6.11 ± 4.02, P<0.05 or P<0.01], while there was no significant difference in those markers between before and after fluid management strategy in ineffective group [4 hours after fluid management strategy: heart rate (bpm) 119.53 ± 11.68 vs. 125.79 ± 11.58, SVV (16.95 ± 6.48)% vs. (18.47 ± 4.96)%, Lac (mmol/L) 5.55 ± 3.80 vs. 6.54 ± 3.72; 12 hours after fluid management strategy: heart rate (bpm) 115.92 ± 11.71 vs. 123.40 ± 11.59, SVV (17.17 ± 6.09)% vs. (19.42 ± 8.25)%, Lac (mmol/L) 6.33 ± 3.40 vs. 7.21 ± 3.81, all P>0.05]. CVP only at 12 hours after fluid management strategy in effective group was significantly higher than that before fluid management strategy (cmH₂O: 12.8 8 ± 3.38 vs. 11.27 ± 4.97, P<0.05). SVV monitored by APCO is a good indicator of volume responsiveness index, which can be used as an important reference combined with PLR for fluid management of severe patients.

Uncalibrated arterial pressure-based cardiac output obtained with LiDCOrapid in cardiovascular surgical patients

Uncalibrated arterial pressure-based cardiac output obtained with LiDCOrapid in cardiovascular surgical patients

Performance of pulse contour and pulse wave transit time-based continuous cardiac output analyses: clinical validation of two methods in Thai patients undergoing cardiac surgery

The aim was to evaluate the performance of arterial pressure-based cardiac output (APCO) [1] and pulse wave transit time- based cardiac output (esCCO) [2] monitors in Thai patients undergoing coronary artery bypass graft surgery (CABG) with cardiopulmonary bypass.

Cardiac output and stroke volume in acute phase in ST elevation myocardial infarction～Arterial pressure-based cardiac output measurement by FloTrackTM～

Cardiac output and stroke volume in acute phase in ST elevation myocardial infarction～Arterial pressure-based cardiac output measurement by FloTrack^TM～

Agreement between cardiac index measured with arterial pressure-based cardiac output and pulmonary artery catheter during cesarean section in parturients with congenital heart disease and severe pulmonary hypertension

Objective To determine if the cardiac index (CI) measured with arterial pressure-based cardiac output (APCO) agrees with that measured with pulmonary artery catheter (PAC) during cesarean section in parturients with congenital heart disease and severe pulmonary hypertension.Methods Thirty parturients with congenital heart disease and severe pulmonary hypertension,scheduled for elective cesarean section,were enrolled in the study.APCO and PAC were used for cardiac output and other parameters of hemodynamics monitoring during operation in all patients.Continuous epidural anesthesia was performed.CI was recorded immediately before epidural administration (T1),at 5 and 10 min after epidural administration (T2-3),immediately before delivery (T4),and at 2 and 5 min after delivery (T5-6).The correlation was tested by Pearsone correlation analysis.CI derived from APCO and PAC was compared by Bland-Altman analysis for agreement.Results CI measured with PAC was significantly higher than that measured with APCO (P ＜ 0.05).Compared with the baseline value at T1,no significant difference in CI measured with PAC and APCO was found at T11-T4 and T6 (P ＞ 0.05),and CI measured with PAC and APCO was significantly increased at T5 (P ＜ 0.05).Bland-Ahman analysis showed poor agreement between CI measured with the two methods.The correlation analysis showed that there was positive correlation between CI derived from the two methods at T1-6 (the correlation coefficient was 0.93,0.95,0.94,0.89,0.96 and 0.91 at T1-6,respectively,P ＜ 0.05).Conclusion CI value obtained with APCO agrees poorly with that obtained with PAC during cesarean section in parturients with congenital heart disease and severe pulmonary hypertension,but agrees well in monitoring the changing trend of CI. Key words: Heart defects, congenital; Hypertension, pulmonary; Monitoring, intraoperative; Cesarean section

Clinical research of goal-directed fluid management based on the cardiac index/stroke volume index/stroke volume variation in geriatric patients undergoing thoracic lobectomy

Objective To evaluate the influence of goal-directed fluid management strategies based on cardiac index/stroke volume index/stroke volume variation (CI/SVI/SVV) in geriatric patients undergoing thoracic lobectomy.Methods Thirty patients undergoing elective lobectomy,age ≥ 65 y,ASA Ⅰ-Ⅱ,were randomly assigned to the S group (CI/SVI/SVV-directed,n=15) and the C group (CVP-directed,n=15).The parameters including heart rate (HR),mean arterial pressure (MAP),arterial oxygen saturation (SpO2),end-tidal carbon dioxide partial pressure (PETCO2),airway pressure (Pmax) and bispectral index (BIS) were recorded.CI/SVI/SVV-directed fluid management strategy and the traditional CVP guided fluid management strategy were compared by clinical outcomes.Results There was no statistically significant difference in general informations between the two groups.No statistically significant difference in HR,MAP,SpO2,PETCO2,Pmax and BIS was found.Fluid intake during operation (1 310±310) ml and positive fluid balance during post-operation period(516±412) ml were lower in the S group compared with the C group (1 820± 459),(757±667) ml (P＜O.05).The stay time in ICU of S group was shorter than C group,while the oxygen index of S group was higher than C group.The incidence of post-operation hypertension was lower in S group (6.67％) than C group (40％) (P＜0.05).Conclusions CI/SVI/SVV-directed geriatric perioperative fluid management strategy is more noninvasive and managable than the traditional CVP guided fluid management.The Individual CI / SVI / SVV-directed fluid management strategy is beneficial to improve postoperative outcome of geriatric patients. Key words: Geriatric patients; Thoracic lobectomy; Arterial pressure-based cardiac output; Goal-directed therapy; Anesthesia; Fluid management; Postoperative outcome

Outcome impact of goal directed fluid therapy during high risk abdominal surgery in low to moderate risk patients: a randomized controlled trial

Intraoperative goal directed fluid therapy (GDT) guided by an arterial pressure-based cardiac output system has been reported to improve gastrointestinal (GI) recovery in high-risk patients. This study evaluates the impact of this approach on GI recovery in low to moderate risk patients undergoing major abdominal surgery. IRB approved randomized controlled trial in low to moderate risk adults scheduled for major surgery. Patients were randomized to standard (n = 20) or GDT (n = 18) groups, whose fluids were managed to maintain stroke volume variation (SVV) <12 %. The primary outcome measure was GI recovery. Additional measures included quality of recovery score. Continuous, non-normally distributed by Mann-Whitney test; ordinal and nominal by Chi square analysis. GDT patients had lower average intraoperative SVV. The GDT group had faster return of GI function (p = 0.004) and higher quality of recovery scores. In low to moderate risk patients undergoing major abdominal surgery, intraoperative GDT guided by SVV optimization was associated with faster restoration of GI recovery and higher quality of recovery scores. These results suggest that outcome benefits related to the use of an intraoperative goal directed fluid protocol guided by SVV are not limited to high-risk patients.