Continuous Pulse Contour Cardiac Output Research Articles

36th International Symposium on Intensive Care and Emergency Medicine : Brussels, Belgium. 15-18 March 2016.

36th International Symposium on Intensive Care and Emergency Medicine : Brussels, Belgium. 15-18 March 2016.

Influence of tidal volume on pulse pressure variation and stroke volume variation during experimental intra-abdominal hypertension.

BackgroundPulse pressure variation (PPV) and stroke volume variation (SVV) are frequently used to assess fluid responsiveness in critically ill patients on mechanical ventilation (MV). There are many factors, in addition to preload that influence the magnitude of these cyclic variations. We sought to investigate the effect of tidal volume (VT) on PPV and SVV, and prediction of fluid responsiveness in a model of intra-abdominal hypertension (IAH).MethodsTwelve anesthetized and mechanically ventilated piglets on continuous pulse contour cardiac output monitoring. Hypovolemia was ruled out with 2 consecutive fluid boluses after instrumentation. IAH was induced by intraperitoneal instillation of colloid solution with a goal of reducing respiratory system compliance by 50 %. Subjects were classified as fluid responders if stroke volume increased >15 % after each fluid challenge. SVV and PPV were recorded with tidal volumes (VT) of 6, 12 and 18 ml/kg before IAH after IAH induction and after a fluid challenge during IAH.ResultsVT influenced PPV and SVV at baseline and during IAH, being significantly larger with higher VT. These differences were attenuated after fluid administration in both conditions. After IAH induction, there was a significant increase in SVV with the three-tested VT, but the magnitude of that change was larger with high VT: with 6 ml/kg from 3 % (3, 4) to 5 % (4, 6.25) (p = 0.05), with 12 ml/kg from 5 % (4, 6) to 11 % (8.75, 17) (p = 0.02) and 18 ml/kg from 5 % (4,7.5) to 15 % (8.75, 19.5) (p = 0.02). Similarly, PPV increased with all the tested VT after IAH induction, being this increase larger with high VT: with 6 ml/kg from 3 % (2, 4.25) to 6 % (4.75, 7) (p = 0.05), with 12 ml/kg from 5 % (4, 6) to 13.5 % (10.25, 15.5) (p = 0.02) and 18 ml/kg from 7 % (5.5, 8.5) to 24 % (13.5, 30.25) (p = 0.02). One third of subjects responded to fluid administration after IAH, but neither SVV nor PPV were able to identify the fluid responders with the tested VT.ConclusionIAH induction in non-hypovolemic subjects significantly increased SVV and PPV with the three tested VT, but the magnitude of that change was higher with larger VT. This observation reveals the dependence of functional hemodynamic markers on intrathoracic as well intra-abdominal pressures, in addition to volemic status. Also, PPV and SVV were unable to predict fluid responsiveness after IAH induction. Future studies should take into consideration these findings when exploring relationships between dynamic preload indicators and fluid responsiveness during IAH.Electronic supplementary materialThe online version of this article (doi:10.1186/s12871-015-0105-x) contains supplementary material, which is available to authorized users.

Effect of time elapsed on continuous pulse contour cardiac output measurement in septic shock patients

To evaluate the effect of time elapsed on continuous pulse contour cardiac output (PCCO) measurement in septic shock patients. Data during February 2011 to February 2013 from 25 septic shock patients equipped with a pulse indicator continuous cardiac output (PiCCO) device in Department of Critical Care Medicine of Guangzhou Medical University were retrospectively analyzed. PCCO was recorded immediately before transpulmonary thermodilution (COTPTD) calibration. After divided by ideal body surface area, cardiac index (CI) was calculated, and PCCI/CITPTD pairs were analyzed. Four subsets of CI pairs were defined according to intervals of time elapsed from the previous calibration [within the first hour (including 1 hour), between 1 and 8 hours (including 8 hours), between 8 and 16 hours (including 16 hours), and more than 16 hours]. Linear regression, the threshold value of concordance (as indicated by bias ± 2SD) and percentage error (2SD/the mean of CITPTD) were used to compare agreement between PCCI and CITPTD. A total of 162 data pairs from 25 patients were analyzed. For all data pairs, PCCI correlated significantly with CITPTD (r² = 0.494, P<0.001), the bias±2SD was -(0.06 ± 1.41) L × min⁻¹ × m⁻² and the percentage error was 37%. Among the four time-interval subsets, the percentage error was <30% only in subset between 1 and 8 hours, and the percentage error in other subsets was over 30%. Linear regression analysis between ΔPCCI and ΔCITPTD showed a r² of 0.217 (P<0.001) for the whole 162 data pairs. A r² of 0.327 (P<0.001) and a r² of 0.303 (P<0.001) were calculated for the subset of between 1 and 8 hours and between 8 and 16 hours respectively. Our study in septic shock patients suggests that the accuracy of PCCO will be decreased as the increase of the time interval for calibration. Transpulmonary thermodilution calibration should be performed again if hemodynamic changes or was inconsistent with the clinical presentation. It is suggested that re-calibration should be done within 8 hours.

Pulse contour cardiac output monitoring is less reliable in critically ill children

Intermittent cardiac output measurement using the transpulmonary thermodilution (TPTD) method is considered to be the gold standard in young children but a validated continuous cardiac output technique is not available in these patients. We compared the continuous pulse contour cardiac output (PCCO) measurements with the TPTD method in critically ill children.

Validación clínica de la valoración mínimamente invasiva de la función sistólica

Pulse contour continuous cardiac output (PiCCO) monitoring by means of transpulmonary thermodilution provides 2 indices of systolic function: the cardiac function index and the global ejection fraction. Our aim was to compare these 2 PiCCO indices to the left-ventricular ejection fraction obtained by transthoracic echocardiography. This was a prospective clinical study of 35 adult patients in the critical care unit of a university hospital. Each patient provided his or her own control data. Patients with marked changes in regional segment contractility or nonsinus rhythm were excluded. We collected patient variables, reason for admission to the critical care unit, the Acute Physiology and Chronic Health Evaluation II score, the reason for hemodynamic monitoring, and the infusion of vasoactive drugs at the time of the procedure. Statistically significant correlations were found between the left-ventricular ejection fraction and the global ejection fraction (r=0.79, P<.001) and the cardiac function index (r=0.66, P<.001). The mean (SD) difference between the left-ventricular ejection fraction and the global ejection fraction and the cardiac function index were 1.05% (10.2%) (range, 19.0% to 29.1%) and 0.001% (12.4%) (range, -24.3% to 24.3%), respectively. For predicting a left-ventricular ejection fraction of less than 40%, the area under the curve was 0.879 for the global ejection fraction and 0.805 for the cardiac function index of A global ejection fraction less than 13.5% and a cardiac function index less than 3.15 min(-1) predicted a left-ventricular ejection fraction less than 40% with sensitivities of 97% and 96% and specificities of 85% and 77%, respectively. In patients without marked changes in regional segment contractility, the global ejection fraction and the cardiac function index calculated by the PiCCO monitor offer a reliable and simple way to assess left-ventricular systolic function. Low values for these indicators suggest the need for echocardiographic assessment of left- and right-ventricular function.

Calibration of pulse contour continuous cardiac output analysis

We evaluated the effect of the calibration interval on the reliability of pulse contour cardiac output (COpc) measurement [1].

Reliability of continuous pulse contour cardiac output measurement

To evaluate the reliability of continuous cardiac output monitoring using pulse-contour analysis in critically ill patients.

Reliability of Continuous Pulse Contour Cardiac Output Measurement during Hemodynamic Instability

Arterial pulse contour analysis is gaining widespread acceptance as a monitor of continuous cardiac output (CO). While this type of CO measurement is thought to provide acceptable continuous measurements, only a few studies have tested its accuracy and repeatability under unstable hemodynamic conditions. We compared continuous CO measurement using the pulse contour method (PCCO) before and after calibration with intermittent transpulmonary thermodilution cardiac output (TpCO). We compared the two methods of CO measurements in 15 Landrace pigs weighing 20-25 kg in an experimental model of sepsis. Nine pigs were given an infusion of E. coli lipopolysacchride (LPS), and six pigs acted as controls. PCCO values before and after calibration (PCCO1 and PCCO2 respectively) were registered, and their errors relative to TpCO measurements were compared. The mean coefficient of variation for repeated PCCO measurements was 6.85% for the control group, and 13.99% for the endotoxin group. The range of TpCO was 1.01-3.15 L/min. In the control group the bias +/-2SD was 0.11 +/- 0.53 L/min (TpCO vs PCCO1) and -0.02 +/- 0.38 L/min (TpCO vs PCCO2). In the endotoxin group, the agreement was poor between TpCO and PCCO1, 0.08 +/- 1.02 L/min. This improved after calibration (TpCO vs PCCO2) to 0.01 +/- 0.31 L/min. In hemodynamically stable pigs, both pre- and post-calibration PCCO measurements agreed well with the intermittent transpulmonary thermodilution technique. However, during hemodynamic instability, and pre-calibration PCCO values had wide limits of agreement compared with TpCO. This was reflected by larger coefficients of variation for PCCO in hemodynamic instability. The error of PCCO measurement improved markedly after calibration, with bias and limits of agreement within clinically acceptable limits.

Continuous cardiac output monitoring by blood pressure analysis

to the editor: Monitoring of continuous cardiac output (CO) allows for the detection of rapid changes in systemic flow that would otherwise be unnoticed by the recording of arterial pressure and heart rate. Continuous tracking of changes in stroke volume (SV) can be obtained by arterial pulse wave

Effect of semi-invasive cardiovascular monitoring on the perioperative outcome of kidney or lung xenotransplantation in cynomolgus monkeys

Summary >Background: Cynomolgus monkeys (Macaca fascicularis) are one of the predominant primate models in experimental transplantation. Particularly in xenotransplantation experiments, they can be subjected to profound cardiovascular instability by surgical trauma, volume shifts and inflammatory mediator release. Meticulous perioperative management including deliberate intraoperative monitoring is therefore required. Methods: 26 porcine kidneys (group A) and 3 single lung lobes (group B), obtained from unmodified pigs or from pigs transgenic for human complement regulators, were transplanted into 29 cynomolgus monkeys. In group A 1 (n = 11) the monkeys were monitored intraoperatively by ECG, non-invasive arterial, and central venous blood pressure (standard cardiovascular monitoring, SCVM). In group A 2 (n = 15) measurements of cardiac output (CO), intrathoracic blood volume and extravascular lung water (extended cardiovascular monitoring, XCVM) were added to the intraoperative monitoring regime. XCVM plus continuous pulse contour CO was used in the 3 monkeys undergoing porcine single lung xenotransplantation. Results: In group A 2 significantly more animals had initial graft function if compared to group A 1 . 40% of the monkeys of group A 2 but 73% of group A 1 died within the first postoperative week. Group A 2 displayed a trend towards greater overall survival rates, but this difference did not reach statistical significance (p = 0,07). In group B stable lung xenograft reperfusion was achieved in all 3 recipients despite recurrent phases of severe cardiovascular instability. Two lung recipients could be weaned from the ventilator, and 1 monkey survived more than 24 hours postoperatively. Conclusions: The application of XCVM in small primates undergoing kidney xenotransplantation led to significantly better early postoperative results and longer survival times. In single lung xenotransplantation XCVM plus continuous pulse contour CO showed to be indispensable for the therapeutic management of the profound cardiovascular instabilities observed. Our data indicate that comprehensive anaesthesiologic monitoring can contribute substantially to the advancement of experimental organ transplantation in small monkeys.

Comparison of cardiac output assessed by pulse-contour analysis and thermodilution in patients undergoing minimally invasive direct coronary artery bypass grafting

Objective: To investigate the precision and accuracy of continuous pulse contour cardiac output (PCCO) compared with intermittent transcardiopulmonary (TCPCO) and pulmonary artery thermodilution (TDCO) measurements in patients undergoing minimally invasive coronary bypass surgery (MIDCAB). Design: Prospective, controlled, clinical study. Setting: University hospital. Participants: Twelve patients undergoing MIDCAB. Interventions: Thirty-six measurements of PCCO and thermodilution cardiac output (CO) were simultaneously performed after the start of surgery, during bypass grafting, and at the end of surgery. TCPCO and TDCO were simultaneously assessed by three injections of ice-cold saline randomly spread over the respiratory cycle. The pulse contour device was initially calibrated with an additional set of aortic thermodilution measurements. Measurements and Main Results: Absolute values of CO ranged between 1.6 and 9.2 L/min. A close agreement among the three techniques was observed at all measurements. Mean bias between PCCO and TDCO and TCPCO was 0.003 L/min (2 SD of differences between methods = 1.26 L/min) and 0.27 L/min (2 SD of differences between methods = 1.16 L/min), respectively. The correlation coefficients were r 2 = 0.90 for TCPCO versus PCCO and r 2 = 0.88 for TDCO versus PCCO. Conclusion: The results of the present study show that compared with thermodilution CO, pulse contour analysis enables accurate measurement of continuous CO in patients undergoing MIDCAB.

Clinical evaluation of pulse contour continuous cardiac output measurement

Inlroduction Continuous monitoring of cardiac output is important in the managcmcnt of critically ill patients since their haemodynamic situation oltcn changes rapidly and unexpectedly. Unfortunately, the method used most often clinically, the thcrmodilution technique, allows only intermittent measurements. However, the pulse contour method allows a heat-to-beat estimation of changes in cardiac output. We studied the accuracy of this interesting method in perand postoperative patients.

A509 Pulse contour continuous cardiac output When does vascular compliance change?

A509 Pulse contour continuous cardiac output When does vascular compliance change?