Cardiac Output Measurements In Patients Research Articles

Comparison between thermodilution and Fick methods for resting and exercise-induced cardiac output measurement in patients with chronic dyspnea.

Studies comparing thermodilution (TD) and the direct Fick method (dFM) for cardiac output (CO) measurement are rare. We compared CO measurements between TD (2–5 cold water injections), the dFM, and indirect Fick method (iFM) at rest and during exercise, and assessed the effect of averaging different numbers of TD measurements during exercise. This retrospective study included 300 patients (52.3% women, mean age 66 ± 11 years) having pulmonary hypertension (76.0%) or unexplained dyspnea. Invasive hemodynamic and gas exchange parameters were measured at rest (supine; n = 300) and during unloaded cycling (semi‐supine; n = 275) and 25‐W exercise (semi‐supine; n = 240). All three methods showed significant differences in CO measurement (ΔCO) at rest (p ≤ 0.001; ΔCO > 1 L/min: 45.0% [iFM vs. dFM], 42.0% [iFM vs. TD], and 45.7% [TD vs. dFM]). ΔCO (TD vs. dFM) was significant during unloaded cycling (p < 0.001; ΔCO > 1 L/min: 56.6%) but not during 25‐W exercise (p = 0.137; ΔCO > 1 L/min: 52.8%). ΔCO (TD vs. dFM) during 25‐W exercise was significant when using one or two (p ≤ 0.01) but not three (p = 0.06) TD measurements. Mean ΔCO (TD [≥3 measurements] vs. dFM) was −0.43 ± 1.98 and −0.06 ± 2.29 L/min during unloaded and 25‐W exercise, respectively. Thus, TD and dFM CO measurements are comparable during 25‐W exercise (averaging ≥3 TD measurements), but not during unloaded cycling or at rest. Individual ΔCOs vary substantially and require critical interpretation to avoid CO misclassification.

The prognostic ability of cardiac output determined by inert gas rebreathing technique in pulmonary hypertension.

This investigation validated the inert gas rebreathing (IGR) technique and determined IGR prognostic ability compared to invasive cardiac output measurements in patients with pulmonary hypertension. IGR compared with thermodilution cardiac output demonstrated a moderate bias. IGR technique demonstrated long-term prognostic value comparable to invasive cardiac output in pulmonary hypertension patients

Noninvasive cardiac output measurements are inaccurate in patients with severe aortic valve stenosis undergoing transcatheter aortic valve implantation.

BackgroundNoninvasive cardiac output (CO) measured using ClearSight™ eliminates the need for intra-arterial catheter insertion. The purpose of this study was to examine the accuracy of non-invasive CO measurement in patients with severe aortic stenosis (AS).MethodsTwenty-eight patients undergoing elective transcatheter aortic valve implantation were prospectively enrolled in this study. The CO was simultaneously measured twice before and twice after valve deployment (total of four times) per patient, and the CO was compared between the ClearSight (COClearSight) system and the pulmonary artery catheter (PAC) thermodilution (COTD) method as a reference. The Bland-Altman analysis was used to compare the percentage errors between the methods.ResultsA total of 112 paired data points were obtained. The percentage error between the COClearSight and COTD was 43.1%. The paired datasets were divided into the following groups according to the systemic vascular resistance index (SVRI): low (< 1,200 dyne s/cm5/m2) and normal (1,200–2,500 dyne s/cm5/m2). The percentage errors were 44.9% and 49.4%, respectively. The discrepancy of CO between COClearSight and COTD was not significantly correlated with SVRI (r = −0.06, P < 0.001). The polar plot analysis showed the trending ability of the COClearSight after artificial valve deployment was 51.1% which below the acceptable cut-off (92%).ConclusionsThe accuracy and the trending ability of the ClearSight CO measurements were not acceptable in patients with severe AS. Therefore, the ClearSight system is not interchangeable with the PAC thermodilution for determining CO in this population.

Performance of a second generation pulmonary capnotracking system for continuous monitoring of cardiac output.

Technologies for minimally-invasive cardiac output measurement in patients during surgery remain little used in routine practice. We tested a redeveloped system based on CO2 elimination (VCO2) by the lungs for use in ventilated patients, which can be seamlessly integrated into a modern anesthesia/monitoring platform, and provides automated, continuous breath-by-breath cardiac output monitoring. A prototype measurement system was constructed to measure VCO2 and end-tidal CO2 concentration with each breath. A baseline measurement of non-shunt cardiac output was made during a brief oscillating change in ventilator rate, according to the differential CO2 Fick approach and repeated at 5-10min intervals. Continuous breath-by-breath monitoring of cardiac output was performed between these intervals from measurement of VCO2, using a derivation of the Fick equation applied to pulmonary CO2 elimination and cardiac output displayed in real time. Measurements were compared with simultaneous measurements by thermodilution in 50 patients undergoing cardiac surgery or liver transplantation. Overall mean bias [sd] for agreement in cardiac output measurement was - 0.3 [1.1] L/min, percentage error ± 38.7%, intraclass correlation coefficient = 0.91. Concordance in measurement of changes of at least 15% in cardiac output was 81.4%, with a mean angular bias of - 1.7°, and radial limits of agreement of ± 76.2° on polar plot analysis. The accuracy and precision compared favourably to other clinical techniques. The method is relatively seamless and automated and has potential for continuous, cardiac output monitoring in ventilated patients during anesthesia and critical care.

Pulse-contour derived cardiac output measurements in morbid obesity: influence of actual, ideal and adjusted bodyweight

The non-invasive Nexfin cardiac output (CO) monitor shows a low level of agreement with the gold standard thermodilution method in morbidly obese patients. Here we investigate whether this disagreement is related to excessive bodyweight, and can be improved when bodyweight derivatives are used instead. We performed offline analyses of cardiac output recordings of patient data previously used and partly published in an earlier study by our group. In 30 morbidly obese patients (BMI > 35 kg/m2) undergoing laparoscopic gastric bypass, cardiac output was simultaneously determined with PiCCO thermodilution and Nexfin pulse-contour method. We investigated if agreement of Nexfin-derived CO with thermodilution CO improved when ideal and adjusted—instead of actual- bodyweight were used as input to the Nexfin. Bodyweight correlated with the difference between Nexfin-derived and thermodilution-derived CO (r = −0.56; p = 0.001). Bland Altman analysis of agreement between Nexfin and thermodilution-derived CO revealed a bias of 0.4 ± 1.6 with limits of agreement (LOA) from −2.6 to 3.5 L min when actual bodyweight was used. Bias was −0.6 ± 1.4 and LOA ranged from −3.4 to 2.3 L min when ideal bodyweight was used. With adjusted bodyweight, bias improved to 0.04 ± 1.4 with LOA from −2.8 to 2.9 L min. Our study shows that agreement of the Nexfin-derived with invasive CO measurements in morbidly obese patients is influenced by body weight, suggesting that Nexfin CO measurements in patients with a BMI above 35 kg/m2 should be interpreted with caution. Using adjusted body weight in the Nexfin CO-trek algorithm reduced the bias.

Authentication of Radial Versus Femoral Arterial Pressure Waveform-Derived Cardiac Output With Transesophageal Echocardiography-Derived Cardiac Output Measurements in Patients Undergoing On-Pump Coronary Bypass Surgery

The aim of this study was to ascertain if arterial waveform-derived cardiac output measurements from radial and femoral cannulation sites were reliable as compared with transesophageal echocardiography (TEE)-derived cardiac output (CO) values, and which of the CO measurements derived from radial and the femoral arterial pressure waveforms closely tracked simultaneously measured TEE-derived CO values. This study also aimed to ascertain if cardiopulmonary bypass (CPB) would impact the accuracy of arterial pressure-derived CO values from either of the 2 sites. A prospective observational study. Tertiary care cardiac center. Cardiac surgical patients undergoing on-pump primary coronary artery bypass surgery. Waveform-derived CO monitoring through radial and femoral artery cannulation using a FloTrac/Vigileo system. Twenty-seven consecutive cardiac surgical patients undergoing on-pump primary coronary artery bypass surgery were included in the study. Cardiac output was measured sequentially by the arterial pressure waveform analysis method from radial and femoral arterial sites and compared with simultaneously measured TEE-derived CO. Cardiac output data were obtained in triplicate at 6 predefined time intervals: before and after sternotomy, 5, 15, and 30 minutes after separation from CPB and prior to shifting the patient out of the operating room. The overall bias of the study was 0.11 and 0.27, the percentage error was 19.31 and 18.45, respectively, for radial and femoral arterial waveform-derived CO values as compared with TEE-derived CO measurements. The overall precision as compared with the TEE-derived CO values was 16.94 and 15.95 for the radial and femoral cannulation sites, respectively. The bias calculated by the Bland-Altman method suggested that CO measurements from the radial arterial site were in closer agreement with TEE-derived CO values at all time periods, and the relation was not affected by CPB. However, percentage error and precision calculations showed that CO values derived from the femoral arterial waveform were in closer agreement, albeit marginally, with the TEE values at all time points. Both the radial and femoral arterial pressure waveform-derived CO measurements were comparable with the TEE measurements during the various stages of the cardiac surgery. Although the femoral cannulation site provided marginally better correlation with the reference TEE-derived CO values based on the precision and percentage error analysis; this may not be significant clinically and either of the arterial cannulation sites can be used reliably for CO measurements in clinical practice. Cardiopulmonary bypass had no impact on the radial and femoral artery pressure waveform-derived CO measurements.

OP-171 The Comparison of Estimated Continuous and Transthoracic Echocardiographic Cardiac Output Measurements in Patients with Systolic Heart Failure

A B S T R A C T S Em/Am ratio (p1⁄4 0.01 for lateral wall, p< 0.0001 for septum and inferior wall, p 1⁄4 0.016 for anterior wall) of all LV walls (table 1). At the RV segments, Sm (p 1⁄4 0.016 for apical segment, p < 0.0001 for mid segment, p 1⁄4 0.003 for basal segment), Em (p 1⁄4 0.001 for apical segment, p < 0.0001 for mid and basal segment), and Am (p 1⁄4 0.016 for apical segment, p 1⁄4 0.001 for mid segment, p < 0.0001 for basal segment) decreased significantly (table 2). Em of the anterior wall was positively related to ultrafiltration volume (r 1⁄4 0.25, p 1⁄4 0.006), whereas the decrease of Sm of RV basal segment correlated with a decrease of diastolic blood pressure (r 1⁄4 0.23, p < 0.01). Conclusion: Our data indicate that a single HD session is associated with acute changes of systolic and diastolic parameters of LV and RV.

Noninvasive Cardiac Output Measurement by Inert Gas Rebreathing in Suspected Pulmonary Hypertension

The objective of this study was to evaluate inert gas rebreathing (IGR) reliability in cardiac output (CO) measurement compared with Fick method and thermodilution. IGR is a noninvasive method for CO measurement; CO by IGR is calculated as pulmonary blood flow plus intrapulmonary shunt. IGR may be ideal for follow-up of patients with pulmonary hypertension (PH), sparing the need of repeated invasive right-sided cardiac catheterization. Right-sided cardiac catheterization with CO measurement by thermodilution, Fick method, and IGR was performed in 125 patients with possible PH by echocardiography. Patients were grouped according to right-sided cardiac catheterization-measured mean pulmonary and wedge pressures: normal pulmonary arterial pressure (n = 20, mean pulmonary arterial pressure = 18 ± 3 mm Hg, pulmonary capillary wedge pressure = 11 ± 5 mm Hg), PH and normal pulmonary capillary wedge pressure (PH-NW, n = 37 mean pulmonary arterial pressure = 42 ± 13 mm Hg, pulmonary capillary wedge pressure = 11 ± 6 mm Hg), and PH and high pulmonary capillary wedge pressure (PH-HW, n = 68, mean pulmonary arterial pressure = 37 ± 9 mm Hg, pulmonary capillary wedge pressure = 24 ± 6 mm Hg). Thermodilution and Fick measurements were comparable. Fick and IGR agreement was observed in normal pulmonary arterial pressure (CO = 4.10 ± 1.14 and 4.08 ± 0.97 L/min, respectively), whereas IGR overestimated Fick in patients with PH-NW and those with PH-HW because of intrapulmonary shunting overestimation in hypoxemic patients. When patients with arterial oxygen saturation (SO2) ≤90% were excluded, IGR and Fick agreement improved in PH-NW (CO = 4.90 ± 1.70 and 4.76 ± 1.35 L/min, respectively) and PH-HW (CO = 4.05 ± 1.04 and 4.10 ± 1.17 L/min, respectively). In hypoxemic patients, we estimated pulmonary shunt as Fick - pulmonary blood flow and calculated shunt as: -0.2423 × arterial SO2 + 21.373 L/min. In conclusion, IGR is reliable for CO measurement in patients with PH with arterial SO2 >90%. For patients with arterial SO2 ≤90%, a new formula for shunt calculation is proposed.

Noninvasive cardiac output measurements in patients with pulmonary hypertension

Pulmonary hypertension (PH) is characterised by a progressive decline in cardiac output (CO) and right heart failure. NICOM® (noninvasive cardiac output monitor) is a bioreactance-based technology that has been broadly validated, but its specific application in right heart failure and PH is unknown. Cardiac catheterisation was performed in 50 consecutive patients with PH. CO measurements were performed using three different methods (thermodilution, Fick and NICOM) at baseline and after vasodilator challenge. We compared the precision (coefficient of variation) and accuracy of NICOM compared to thermodilution and Fick. The mean CO (L·min(-1)) at baseline as measured by the three methods was 4.73±1.15 (NICOM), 5.69±1.74 (thermodilution) and 4.84±1.39 (Fick). CO measured by NICOM was more precise than by thermodilution (3.5±0.3% versus 9.6±6.1%, p<0.001). Bland-Altman analyses comparing NICOM to thermodilution and Fick revealed bias and 95% limits of agreement that were comparable to those comparing Fick to thermodilution. All three CO methods detected an increase in CO in response to vasodilator challenge. CO measured via NICOM is precise and reliably measures CO at rest and changes in CO with vasodilator challenge in patients with PH. NICOM may allow for the noninvasive haemodynamic assessment of patients with PH and their response to therapy.

Cardiac Output Derived From Arterial Pressure Waveform Analysis: Validation of the Third-Generation Software in Patients Undergoing Orthotopic Liver Transplantation

BackgroundThe upgraded third-generation software (version 3.02) for the FloTrac/Vigileo system has been developed to particularly improve the accuracy of cardiac output (CO) measurements in hyperdynamic conditions. The aim of our study was to compare the CO values obtained using the FloTrac/Vigileo system during orthotopic liver transplantation (OLT) with those obtained in the same circumstances using a Swan-Ganz catheter (bolus thermodilution method). MethodsTwenty consecutive recipients scheduled for OLT were studied. Simultaneous CO values measured by both devices were obtained at 10 predefined time points throughout the surgery. A percentage error of not more than 30% was established as the criterion for device interchangeability. ResultsA total of 200 paired measurements were obtained. The CO values derived from the FloTrac/Viligeo ranged from 2.8 to 10.9 L/min, with a mean of 5.91 ± 1.81 L/min. The values from bolus thermodilution ranged from 2.2 to 13.2 L/min, with a mean of 6.12 ± 2.07 L/min. The bias was 0.22, and the limits of agreement were −3.13 to 3.56 L/min. The percentage error between the FloTrac/Viligeo and bolus thermodilution measurements was 54.93%. The percentage errors of paired measurements in three surgical phases by subgroup analysis were 43.50% (dissecting phase), 62.9% (anhepatic phase), and 56.05% (reperfusion phase), respectively. ConclusionCO measurements obtained using the less invasive arterial waveform FloTrac/Vigileo system upgraded with the third-generation software had poor intraoperative agreement with pulmonary artery thermodilution CO measurements in patients undergoing OLT.

Continuous minimally invasive peri-operative monitoring of cardiac output by pulmonary capnotracking: comparison with thermodilution and transesophageal echocardiography

A number of technologies are available for minimally-invasive cardiac output measurement in patients during surgery but remain little used. A system has been developed based on CO(2) elimination (VCO(2)) by the lungs for use in ventilated patients, which can be fully integrated into a modern anesthesia/monitoring platform, and provides semi-automated, continuous breath-by-breath cardiac output monitoring. A prototype measurement system was constructed to measure VCO(2) and end-tidal CO(2) concentration with each breath. A baseline measurement of non-shunt cardiac output was made during a brief change in ventilator rate, according to the differential CO(2) Fick approach. Continuous breath-by-breath monitoring of cardiac output was then performed from measurement of VCO(2), using a derivation of the Fick equation applied to pulmonary CO(2) elimination. Automated recalibration was done periodically and data was processed and cardiac output displayed in real time. Measurements were compared with simultaneous measurements by bolus thermodilution in 77 patients undergoing cardiac surgery or liver transplantation. Overall mean bias [sd] for agreement in cardiac output measurement was -0.1 [1.2] L/min, percentage error +44.2%, r=0.92. Concordance in measurement of changes of at least 15% in cardiac output was 80%. The method followed sudden changes in cardiac output due to arrythmias and run onto cardiopulmonary bypass in real time. The accuracy and precision were comparable to other clinical techniques. The method is relatively seamless and largely automated and has potential for continuous, cardiac output monitoring in ventilated patients during anesthesia and critical care.

Comparison of Uncalibrated Arterial Pressure Waveform Analysis with Continuous Thermodilution Cardiac Output Measurements in Patients Undergoing Elective Off-Pump Coronary Artery Bypass Surgery

Comparison of Uncalibrated Arterial Pressure Waveform Analysis with Continuous Thermodilution Cardiac Output Measurements in Patients Undergoing Elective Off-Pump Coronary Artery Bypass Surgery

Uncalibrated Arterial Pulse Cardiac Output Measurements in Patients With Moderately Abnormal Left Ventricular Function

The aim of the study was to evaluate the accuracy and precision of the Vigileo/FloTrac system (Edwards Lifesciences, Irvine, CA) when compared with the intermittent cardiac output and continuous cardiac output measurements obtained from pulmonary arterial catheters in patients with moderately abnormal left ventricular function undergoing elective coronary artery bypass graft surgery. A prospective, observational study. Tertiary university hospital. Twenty patients with moderately abnormal left ventricular function undergoing coronary artery bypass graft surgery were enrolled. Data were collected before the induction of anesthesia (T1), after the induction of anesthesia (T2), before cardiopulmonary bypass with an open chest (T3), after cardiopulmonary bypass (T4), after sternal closure (T5), on intensive care unit admission (T6), and at 6 hours (T7) and 12 hours after surgery (T8). A total of 360 data measurements were collected; the mean bias between intermittent cardiac output (ICO) and arterial pressure cardiac output (APCO) was -0.50 ± 1.72 L/min, and the percentage error (PE) was 37.00%. The mean difference between CCO and APCO was -0.06 ± 1.84 L/min, and the PE was 37.80%. The correlation between ΔICO and ΔAPCO was r = 0.7; the correlation between ΔCCO and ΔAPCO was r = 0.73. In the intraoperative period, the mean bias between ICO and APCO was -0.41 ± 1.75 L/min, and the PE was 40.87%. The mean difference between CCO and APCO was -0.18 ± 1.90 L/min, and the PE was 41.48%. In the postoperative period, the mean bias between ICO and APCO was -0.56 ± 1.70 L/min, and the PE was 34.43%. The mean difference between CCO and APCO was -0.36 ± 1.76 L/min, and the PE was 34.87%. In cardiac surgical patients with moderately abnormal left ventricular function, the Vigileo/FloTrac 2nd generation software sensor device showed mild intraoperative and postoperative agreement when compared with a pulmonary arterial catheter.

Comparison of Uncalibrated Arterial Pressure Waveform Analysis with Continuous Thermodilution Cardiac Output Measurements in Patients Undergoing Elective Off-Pump Coronary Artery Bypass Surgery

Monitoring of cardiac output is required during anesthesia for off-pump coronary artery bypass (OPCAB) surgery. Recently, FloTrac, a new device for arterial pressure waveform analysis for cardiac output (APCO) monitoring without external calibration, was developed. The authors have compared APCO with STAT-mode continuous cardiac output (SCCO) in patients undergoing OPCAB surgery. A clinical study. A university hospital (single institution). Thirty consecutive patients undergoing elective OPCAB surgery. Arterial pressure measurement with FloTrac, pulmonary arterial catheter insertion. APCO and SCCO measurements were recorded after pulmonary artery catheter insertion (T1), after sternotomy (T2), after heart positioning for left anterior descending artery anastomosis (T3, T4), after heart positioning for obtuse marginal artery anastomosis (T5, T6), after heart positioning for posterior descending artery anastomosis (T7, T8), and after sternal closure (T9). APCO and SCCO were compared using the Bland-Altman method and the percentage error by Critchley's criteria. SCCO and APCO ranged from 2.1 to 6.9 L/min and 1.2 to 7.4 L/min, respectively, and showed low correlation (r = 0.29). The overall bias by the Bland-Altman method between SCCO and APCO was -0.23 L/min, with a precision of -1.4 to 0.9 L/min, and the overall limits of agreement were -2.5 to 2.0 L/min. The overall mean CO was 4.0 ± 0.95 L/min. The overall percentage error between SCCO and APCO measurements was 57%. Uncalibrated APCO values do not agree with thermodilution SCCO and significantly overestimated the SCCO in patients undergoing OPCAB surgery. Further evaluation is required to verify the clinical acceptance of FloTrac APCO in OPCAB surgery.

Reliability of esophageal echo-doppler cardiac output measurements in patients undergoing liver transplantation: Relevance of MELD score

Reliability of esophageal echo-doppler cardiac output measurements in patients undergoing liver transplantation: Relevance of MELD score

Cardiac Output Measurement in Patients Undergoing Liver Transplantation: Pulmonary Artery Catheter Versus Uncalibrated Arterial Pressure Waveform Analysis

Cardiac output (CO) and invasive hemodynamic measurements are useful during liver transplantation. The pulmonary artery catheter (PAC) is commonly used for these patients, despite the potential complications. Recently, a less invasive device (Vigileo/FloTrac) became available, which estimates CO using arterial pressure waveform analysis without external calibration. In this study, we compared CO obtained with a PAC using automatic thermodilution, instantaneous CO stat-mode (ICO(SM)), and CO obtained with the new device, arterial pressure waveform analysis (APCO) in patients undergoing liver transplantation. Twenty sets of simultaneous measurements of APCO and ICO(SM) were determined in sedated and mechanically ventilated patients undergoing liver transplantation. Time points were as follows: after PAC insertion (T1-3), after portal clamping (T4-6), during anhepathy (T7-9), after graft reperfusion (T10-15), and in the postoperative period in the intensive care unit (T15-20). We enrolled 20 patients and 400 measurements were obtained. No data were rejected. Bias between ICO(SM) and APCO was 0.8 L/min, 95% limits of agreement were -1.8 to 3.5 L/min. The percentage error was 43%. Bias between ICO(SM) and APCO was correlated with systemic vascular resistance [r(2) = 0.55, P < 0.0001, y = 15.8-2.2 ln(x)] and subgroup analysis revealed an increase in the bias and in the percentage error in patients with low systemic vascular resistance (Child-Pugh grade B and C patients). There was no difference between the different surgical periods. Our results suggest that Vigileo/FloTrac CO monitoring data do not agree well with those of automatic thermodilution in patients undergoing liver transplantation, especially in Child-Pugh grade B and C patients with low systemic vascular resistance.

Retracted: Semi-invasive monitoring of cardiac output by a new device using arterial pressure waveform analysis: a comparison with intermittent pulmonary artery thermodilution in patients undergoing cardiac surgery

Thermodilution technique using a pulmonary artery catheter (PAC) is a widely used method to determine cardiac output (CO). It is increasingly criticized because of its invasiveness and its unclear risk-benefit ratio. Thus, less invasive techniques for measuring CO are highly desirable. We compared a new, semi-invasive device (FloTrac/Vigileo) using arterial pressure waveform analysis for CO measurement in patients undergoing cardiac surgery with bolus thermodilution measurements. Forty patients undergoing coronary artery bypass grafting or valve repair were enrolled. A PAC was inserted and routine radial arterial access was used for semi-invasive determination of CO with the Vigileo. CO was measured simultaneously by bolus thermodilution and the Vigileo technique after induction of anaesthesia (T1), before cardiopulmonary bypass (CPB) (T2), after CPB (T3), after sternal closure (T4), on arrival in the intensive care unit (ICU) (T5), and 4 h (T6), 8 h (T7), and 24 h after surgery (T8). CO was indexed to the body surface area (cardiac index, CI). A total of 244 pairs of CI measurements were analysed. Bias and precision (1.96 sd of the bias) were 0.46 litre min(-1) m(-2) and +/- 1.15 litre min(-1) m(-2) (r = 0.53) resulting in an overall percentage error of 46%. Subgroup analysis revealed a percentage error of 51% for data pairs obtained intraoperatively (T1-T4), 42% in ICU (T5-T8), and 56% for values obtained during low CI (T1-T8). In cardiac surgery patients, CO measured by a new semi-invasive arterial pressure waveform analysis device showed only moderate agreement with intermittent pulmonary artery thermodilution measurement.

Pulse contour analysis for cardiac output measurement in patients after off-pump coronary artery bypass grafting: a comparison of FloTrac and PiCCOplus with intermittent thermodilution

Pulse contour analysis calibrated by transpulmonary thermodilution (PiCCOplus; Pulsion Medical Systems, Munich, Germany) has shown in the past years to be a reliable alternative to the pulmonary artery catheter for cardiac output (CO) assessment in different clinical settings [1,2]. A new pulse contour analysis device, which does not need an external calibration (FloTrac/ Vigileo; Edwards Lifesciences, Irvine CA, USA), recently became available. The aim of this study was to compare the CO determined by the FloTrac sensor (FCO) and by the PiCCOplus system (PCO) with the CO assessed by intermittent thermodilution (ICO).

Cardiac output measurement by pulse dye densitometry in cardiac surgery

Summary The aim of this study was to compare the accuracy of pulse dye densitometry with that of bolus thermodilution cardiac output measurement in patients before and after elective coronary artery bypass grafting. Twenty-eight patients were studied. Agreement between mean thermodilution and pulse dye densitometry cardiac output values was assessed by Bland-Altman analysis. Preoperative median [range] cardiac output was 3.87 [2.37-6.0] l.min(-1) by thermodilution, and 3.11 [1.7-5.45] l.min(-1) by pulse dye densitometry using indocyanine green 5 mg. Pulse dye densitometry underestimated cardiac output (mean bias - 0.42 l.min(-1)); the limits of agreement were +/- 1.91 l.min(-1), and mean error was 50.3%, indicating low precision. Preoperative median [range] cardiac output was 3.85 [2.2-6.0] l.min(-1) for bolus thermodilution cardiac output and 4.2 [2.0-7.2] l.min(-1) for pulse dye densitometry using indocyanine green 20 mg. Mean bias was + 0.566 l.min(-1), the limits of agreement were +/- 2.51 l.min(-1) and mean error was 60.9%. Postoperative cardiac output data were not analysed because pulse dye densitometry signals were low or absent in > 50% of the patients. We conclude that pulse dye densitometry using indocyanine green 5 mg or 20 mg is inaccurate in anaesthetised patients before coronary artery bypass surgery and cannot be used after surgery because of a high incidence of low pulse dye densitometry signal amplitudes.

Comparison of techniques for either intermittent or continuous cardiac output measurement in patients during CABG surgery

Hanekop, G. G.1; Weyland, A.1; Goetze, M.1; Grossmann, M.2; Kazmaier, S.1 Author Information