Evaluation of a new arterial pressure-based cardiac output device requiring no external calibration

<p>Abstract</p> <p>Background</p> <p>Several techniques have been discussed as alternatives to the intermittent bolus thermodilution cardiac output (CO_PAC) measurement by the pulmonary artery catheter (PAC). However, these techniques usually require a central venous line, an additional catheter, or a special calibration procedure. A new arterial pressure-based cardiac output (CO_AP) device (FloTrac™, Vigileo™; Edwards Lifesciences, Irvine, CA, USA) only requires access to the radial or femoral artery using a standard arterial catheter and does not need an external calibration. We validated this technique in critically ill patients in the intensive care unit (ICU) using CO_PACas the method of reference.</p> <p>Methods</p> <p>We studied 20 critically ill patients, aged 16 to 74 years (mean, 55.5 ± 18.8 years), who required both arterial and pulmonary artery pressure monitoring. CO_PACmeasurements were performed at least every 4 hours and calculated as the average of 3 measurements, while CO_APvalues were taken immediately at the end of bolus determinations. Accuracy of measurements was assessed by calculating the bias and limits of agreement using the method described by Bland and Altman.</p> <p>Results</p> <p>A total of 164 coupled measurements were obtained. Absolute values of CO_PACranged from 2.80 to 10.80 l/min (mean 5.93 ± 1.55 l/min). The bias and limits of agreement between CO_PACand CO_APfor unequal numbers of replicates was 0.02 ± 2.92 l/min. The percentage error between CO_PACand CO_APwas 49.3%. The bias between percentage changes in CO_PAC(ΔCO_PAC) and percentage changes in CO_AP(ΔCO_AP) for consecutive measurements was -0.70% ± 32.28%. CO_PACand CO_APshowed a Pearson correlation coefficient of 0.58 (<it>p </it>< 0.01), while the correlation coefficient between ΔCO_PACand ΔCO_APwas 0.46 (<it>p </it>< 0.01).</p> <p>Conclusion</p> <p>Although the CO_APalgorithm shows a minimal bias with CO_PACover a wide range of values in an inhomogeneous group of critically ill patients, the scattering of the data remains relative wide. Therefore, the used algorithm (V 1.03) failed to demonstrate an acceptable accuracy in comparison to the clinical standard of cardiac output determination.</p

Roadmap on holography

From its inception holography has proven an extremely productive and attractive area of research. While specific technical applications give rise to 'hot topics', and three-dimensional (3D) visualisation comes in and out of fashion, the core principals involved continue to lead to exciting innovations in a wide range of areas. We humbly submit that it is impossible, in any journal document of this type, to fully reflect current and potential activity; however, our valiant contributors have produced a series of documents that go no small way to neatly capture progress across a wide range of core activities. As editors we have attempted to spread our net wide in order to illustrate the breadth of international activity. In relation to this we believe we have been at least partially successful