The Experts below are selected from a list of 1302 Experts worldwide ranked by ideXlab platform
Jay B Brodsky - One of the best experts on this subject based on the ideXlab platform.
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comparison of arterial tonometry with Radial Artery Catheter measurements of blood pressure in anesthetized patients
Anesthesiology, 1991Co-Authors: Lawrence C Siegel, John G Brockutne, Jay B BrodskyAbstract:BACKGROUND Arterial tonometry has been introduced for continuous noninvasive measurement of blood pressure. The accuracy of this method depends on the performance of two components: a piezoelectric crystal array and an oscillometric cuff. This study evaluates overall performance of arterial tonometry in terms of the performance of these two components by comparing it with simultaneous recording of blood pressure from an intraarterial Catheter. METHODS Seventeen adult patients were studied during general anesthesia. Blood pressure was measured with an intraarterial Catheter and with an arterial tonometry system. Analog pressure waveforms were sampled at 100 Hz. Blood pressure measurements obtained by oscillometry were recorded by computer. Comparisons of mean blood pressure on a beat-by-beat basis were made with and without correction for the calibration error introduced by oscillometry. RESULTS The difference between pairs of blood pressure determined by arterial tonometry and intraarterial measurement was 1.3 +/- 9.4 mmHg (mean +/- SD, bias +/- precision) with 88,158 pairs of measurements. The difference between blood pressure determined by oscillometry and intraarterial measurement was 2.4 +/- 7.5 mmHg (mean +/- SD) with 401 comparisons. After correcting for calibration error, the difference between the tonometry measurements and intraarterial measurements was -1.0 +/- 5.6 mmHg. Continuous episodes of discrepancy from intraarterial measurements in excess of 10 mmHg and lasting 5-60 s occurred 4.6 +/- 0.8 times per hour with tonometry and 12.6 +/- 1.4 times per hour with oscillometry. CONCLUSIONS Discrepancies in blood pressure readings by arterial tonometry versus intraarterial measurement result from both the piezoelectric crystal array and the oscillometry used for calibration. Accuracy for individual measurement is inferior to oscillometry alone. The ability to detect significant changes of blood pressure more rapidly than with oscillometry alone is limited by the accuracy of the piezoelectric crystal component but is enhanced by the reduced interval between measurements.
Frederick G Mihm - One of the best experts on this subject based on the ideXlab platform.
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measurement of cardiac output by transpulmonary arterial thermodilution using a long Radial Artery Catheter a comparison with intermittent pulmonary Artery thermodilution
Anaesthesia, 2004Co-Authors: R Le M Orme, David W. Pigott, Frederick G MihmAbstract:Summary Cardiac output can be measured accurately by transpulmonary arterial thermodilution using the PiCCO � (Pulsion Medical Systems, Munich, Germany) system with a femoral Artery Catheter. We have investigated the accuracy of a new 50 cm 4 French gauge Radial Artery Catheter and the ability to use the system with a shorter Radial Catheter. We studied 18 patients who had undergone coronary Artery surgery and made three simultaneous measurements of cardiac output by arterial thermodilution and with a pulmonary Artery Catheter. The Radial Catheter was withdrawn in 5 cm increments and the measurements were repeated. We found close agreement between arterial thermodilution and pulmonary Artery thermodilution with a mean (SD) bias of 0.38 (0.77) l.min )1 . Arterial thermodilution became unreliable once the Catheter had been withdrawn by more than 5 cm. We conclude that cardiac output measurement with arterial thermodilution with a Radial Catheter is interchangeable with that derived from a pulmonary Artery Catheter, and that a centrally sited arterial Catheter is required for accurate determination of cardiac output by transpulmonary arterial thermodilution.
Ronald D Miller - One of the best experts on this subject based on the ideXlab platform.
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a new noninvasive method to measure blood pressure results of a multicenter trial
Anesthesiology, 1999Co-Authors: Kumar G Belani, Makoto Ozaki, James M Hynson, T Hartmann, H Reyford, Jean Marc Martino, Marius Poliac, Ronald D MillerAbstract:Background: Blood pressure (BP) monitoring with arterial waveform display requires an arterial cannula. We evaluated a new noninvasive device, Vasotrac (Medwave, Arden Hills, MN) that provides BP measurements approximately every 12-15 beats and displays pulse rate and a calibrated arterial waveform for each BP measurement. Methods: Surgical and critically ill patients (n = 80) served as subjects for the study. BPs, pulse waveforms, and pulse rates measured via a Radial Artery Catheter were compared with those obtained by the Vasotrac from the opposite Radial Artery. Data were analyzed to determine agreement between the two systems of measurement. Results: Blood pressure measured noninvasively by the Vasotrac demonstrated excellent correlation (P < 0.01) with BP measured via a Radial arterial Catheter (systolic r 2 = 0.93; diastolic r 2 = 0.89; mean r 2 = 0.95). Differences in BP measured by the Vasotrac versus the Radial arterial Catheter were small. The mean ± SD bias and precision were as follows: systolic BP 0.02 ± 5.4 mmHg and 3.9 ± 3.7 mmHg; diastolic BP -0.39 ± 3.9 mmHg and 2.7 ± 2.8 mmHg; mean BP -0.21 ± 3.0 mm Hg and 2.1 ± 2.2 mmHg compared with Radial Artery measurements. The Vasotrac pulse rates were almost identical to those measured directly (r 2 = 0.95). The Vasotrac BP waveform resembled those directly obtained Radial Artery pulsatile waveforms. Conclusions: In surgical and critically ill patients, the Vasotrac measured BP, pulse rate, and displayed Radial Artery waveform, which was similar to direct Radial arterial measurements. It should be a suitable device to measure BP frequently in a noninvasive fashion.
Jeffery S Vender - One of the best experts on this subject based on the ideXlab platform.
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retrograde air embolization during routine Radial Artery Catheter flushing in adult cardiac surgical patients an ultrasound study
Anesthesiology, 2004Co-Authors: Glenn S Murphy, Joseph W Szokol, Jesse H Marymont, Michael J Avram, Jeffery S VenderAbstract:Background Rapid flushing of Radial Artery Catheters may result in retrograde embolization of air into the cerebral circulation. This study examined the incidence of central air embolization during and after flushing of an arterial pressure monitoring system. Methods One hundred adult patients undergoing cardiac surgical procedures were enrolled in this study. Ten ml of saline and blood were withdrawn into a syringe in the arterial flushing-sampling pressure system and then readministered to the patient through a 20-gauge Radial Artery Catheter over 3-12 s. The right carotid Artery, left carotid Artery, and aortic arch were visualized using ultrasound imaging techniques during three manual flushes of the system. The left and right common carotid arteries were examined for the presence of macrobubbles or microbubbles using a linear array ultrasound transducer. The aortic arch was imaged using transesophageal echocardiography to detect retrograde air emboli. The severity of air embolization was quantified using a modification of an established grading system. Results A total of 298 ultrasound studies in 100 patients were recorded and analyzed after Radial Artery Catheter flushing. Two aortic arch images were not obtained because of an inability to place the probe. Most clinicians (54%) returned flush solution to patients at near-maximal injection rates (2-3 ml per second). No air emboli (macrobubbles or microbubbles) were detected in the carotid arteries or aortic arch of any subject. Conclusion Retrograde air embolization is a rare event after routine Radial Artery Catheter flushing in adult patients with stable hemodynamic conditions.
Jeanluc Fellahi - One of the best experts on this subject based on the ideXlab platform.
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non invasive continuous arterial pressure and cardiac index monitoring with nexfin after cardiac surgery
BJA: British Journal of Anaesthesia, 2012Co-Authors: Marcolivier Fischer, Jeanlouis Gerard, Jeanluc Hanouz, R Avram, I Cârjaliu, Massimo Massetti, Jeanluc FellahiAbstract:Background This observational study was designed to evaluate the reliability and precision of a new digital photoplethysmographic device (Nexfin, BMEYE B.V., Amsterdam, The Netherlands) for continuous and non-invasive assessment of arterial pressure and cardiac output. Methods Fifty consecutive adult subjects were prospectively enrolled at admission to the intensive care unit after conventional cardiac surgery and investigated hourly from T0 to T4. Simultaneous comparative systolic, diastolic, and mean arterial pressures and cardiac index (CI) data points were collected from an invasive Radial Artery Catheter, transpulmonary thermodilution Catheter, and the Nexfin device. Correlations were determined by linear regression. The Bland–Altman analysis was used to compare bias, precision, and limits of agreement. Results Six (12%) subjects were excluded from the analysis because of the inability to obtain a reliable photoplethysmographic signal. No complications were observed. A significant relationship was found between absolute values of photoplethysmographic and Radial systolic (r2=0.56, P Conclusions The Nexfin device is safe, convenient, and reliable in measuring continuous non-invasive arterial pressure but not interchangeable with transpulmonary thermodilution to monitor CI.
