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Patrick A Ross - One of the best experts on this subject based on the ideXlab platform.
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cardiac output and Systemic Vascular Resistance clinical assessment compared with a noninvasive objective measurement in children with shock
Journal of Critical Care, 2017Co-Authors: Asma Razavi, Christopher J L Newth, Robinder G Khemani, Fernando Beltramo, Patrick A RossAbstract:Purpose To evaluate physician assessment of cardiac output and Systemic Vascular Resistance in patients with shock compared with an ultrasonic cardiac output monitor (USCOM). To explore potential changes in therapy decisions if USCOM data were available using physician intervention answers. Study design Double-blinded, prospective, observational study in a tertiary hospital pediatric intensive care unit. Forty children (< 18 years) admitted with shock, requiring ongoing volume resuscitation or inotropic support. Two to 3 physicians clinically assessed cardiac output and Systemic Vascular Resistance, categorizing them as high, normal, or low. An investigator simultaneously measured cardiac index (CI) and Systemic Vascular Resistance index (SVRI) with USCOM categorized as high, normal, or low. Results Overall agreement between physician and USCOM for CI (48.5% [κ = 0.18]) and SVRI (45.9% [κ = 0.16]) was poor. Interobserver agreement was also poor for CI (58.7% [κ = 0.33]) and SVRI (52.3% [κ = 0.28]). Comparing theoretical physician interventions to “acceptable” or “unacceptable” clinical interventions, based on USCOM measurement, 56 (21%) physician interventions were found to be “unacceptable.” Conclusions There is poor agreement between physician-assessed CI and SVRI and USCOM, with significant interobserver variability among physicians. Objective measurement of CI and SVRI may reduce variability and improve diagnostic accuracy.
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Cardiac output and Systemic Vascular Resistance: Clinical assessment compared with a noninvasive objective measurement in children with shock
Journal of critical care, 2016Co-Authors: Asma Razavi, Christopher J L Newth, Robinder G Khemani, Fernando Beltramo, Patrick A RossAbstract:Purpose To evaluate physician assessment of cardiac output and Systemic Vascular Resistance in patients with shock compared with an ultrasonic cardiac output monitor (USCOM). To explore potential changes in therapy decisions if USCOM data were available using physician intervention answers. Study design Double-blinded, prospective, observational study in a tertiary hospital pediatric intensive care unit. Forty children (
James D. Thomas - One of the best experts on this subject based on the ideXlab platform.
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The effects of regurgitant orifice size, chamber compliance, and Systemic Vascular Resistance on aortic regurgitant velocity slope and pressure half-time
American Heart Journal, 1991Co-Authors: Brian P. Griffin, Frank A. Flachskampf, Samuel Siu, Arthur E. Weyman, James D. ThomasAbstract:The determinants of the aortic regurgitant velocity profile have been investigated using computer and in vitro simulations in which regurgitant orifice area, ventricular and aortic compliance, and Systemic Vascular Resistance could be independently varied. In the study, regurgitant fraction was altered, either by changing the size of the regurgitant orifice or by holding the regurgitant orifice constant and changing chamber compliance or Systemic Vascular Resistance. Upon increasing regurgitant fraction by increasing the size of the regurgitant orifice, the slope got steeper and the pressure half-time shortened, the response anticipated in current clinical practice. However, when the regurgitant orifice was kept constant and regurgitation fraction was increased by increasing the Systemic Vascular Resistance or by increasing the compliance of the left ventricle, slope became less steep and pressure half-time lengthened. Multivariate analysis was used to quantify the relationship of regurgitant fraction to slope and pressure half-time. When orifice area was allowed to vary, slope was related directly (multiple r = 0.78, p < 0.001) and half-time was related inversely (multiple r = 0.66, p < 0.001) to regurgitant fraction. With the orifice area fixed, however, directionally opposite responses were seen; slope varied inversely (multiple r = 0.87, p < 0.001), whereas half-time varied directly (multiple r = 0.88, p < 0.001) with regurgitant fraction. This study suggests that the utility of the slope and pressure half-time of the regurgitant velocity tracing in clinical practice relates to their ability to discriminate regurgitant orifices of differing sizes. However, these findings also suggest caution in the conventional interpretation of these indices in individual patients in whom changes in regurgitant fraction are produced by pharmacologic manipulation of the Systemic Vascular Resistance.
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The effects of regurgitant orifice size, chamber compliance, and Systemic Vascular Resistance on aortic regurgitant velocity slope and pressure half-time.
American heart journal, 1991Co-Authors: Brian P. Griffin, Frank A. Flachskampf, Samuel Siu, Arthur E. Weyman, James D. ThomasAbstract:The determinants of the aortic regurgitant velocity profile have been investigated using computer and in vitro simulations in which regurgitant orifice area, ventricular and aortic compliance, and Systemic Vascular Resistance could be independently varied. In the study, regurgitant fraction was altered, either by changing the size of the regurgitant orifice or by holding the regurgitant orifice constant and changing chamber compliance or Systemic Vascular Resistance. Upon increasing regurgitant fraction by increasing the size of the regurgitant orifice, the slope got steeper and the pressure half-time shortened, the response anticipated in current clinical practice. However, when the regurgitant orifice was kept constant and regurgitation fraction was increased by increasing the Systemic Vascular Resistance or by increasing the compliance of the left ventricle, slope became less steep and pressure half-time lengthened. Multivariate analysis was used to quantify the relationship of regurgitant fraction to slope and pressure half-time. When orifice area was allowed to vary, slope was related directly (multiple r = 0.78, p less than 0.001) and half-time was related inversely (multiple r = 0.66, p less than 0.001) to regurgitant fraction. With the orifice area fixed, however, directionally opposite responses were seen; slope varied inversely (multiple r = 0.87, p less than 0.001), whereas half-time varied directly (multiple r = 0.88, p less than 0.001) with regurgitant fraction. This study suggests that the utility of the slope and pressure half-time of the regurgitant velocity tracing in clinical practice relates to their ability to discriminate regurgitant orifices of differing sizes.(ABSTRACT TRUNCATED AT 250 WORDS)
Woojong Choi - One of the best experts on this subject based on the ideXlab platform.
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unreliable tracking ability of the third generation flotrac vigileo system for changes in stroke volume after fluid administration in patients with high Systemic Vascular Resistance during laparoscopic surgery
PLOS ONE, 2015Co-Authors: Jihyun Chin, Wookjong Kim, Jeonghyun Choi, Yun A Han, Seonok Kim, Woojong ChoiAbstract:Background The FloTrac/Vigileo™ system does not thoroughly reflect variable arterial tones, due to a lack of external calibration. The ability of this system to measure stroke volume and track its changes after fluid administration has not been fully evaluated in patients with the high Systemic Vascular Resistance that can develop during laparoscopic surgery. Methods In 42 patients undergoing laparoscopic prostatectomy, the stroke volume derived by the third-generation FloTrac/Vigileo™ system (SV-Vigileo), the stroke volume measured using transesophageal echocardiography (SV-TEE) as a reference method, and total Systemic Vascular Resistance were evaluated before and after 500 ml fluid administration during pneumoperitoneum combined with the Trendelenburg position. Results Total Systemic Vascular Resistance was 2159.4 ± 523.5 dyn·s/cm5 before fluid administration. The SV-Vigileo was significantly higher than the SV-TEE both before (68.8 ± 15.9 vs. 57.0 ± 11.0 ml, P < 0.001) and after (73.0 ± 14.8 vs. 64.9 ± 12.2 ml, P = 0.003) fluid administration. During pneumoperitoneum combined with the Trendelenburg position, Bland-Altman analysis for repeated measures showed a 53.8% of percentage error between the SV-Vigileo and the SV-TEE. Four-quadrant plot (69.2% of a concordance rate) and polar plot analysis (20.6° of a mean polar angle, 16.4° of the SD of a polar angle, and ±51.5° of a radial sector containing 95% of the data points) did not indicate a good trending ability of the FloTrac/Vigileo™ system. Conclusions The third-generation FloTrac/Vigileo™ system may not be useful in patients undergoing laparoscopic surgery, based on unreliable performance in measuring the stroke volume and in tracking changes in the stroke volume after fluid administration during pneumoperitoneum combined with the Trendelenburg position.
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Unreliable Tracking Ability of the Third-Generation FloTrac/Vigileo™ System for Changes in Stroke Volume after Fluid Administration in Patients with High Systemic Vascular Resistance during Laparoscopic Surgery.
PloS one, 2015Co-Authors: Jihyun Chin, Wookjong Kim, Jeonghyun Choi, Yun A Han, Seonok Kim, Woojong ChoiAbstract:Background The FloTrac/Vigileo™ system does not thoroughly reflect variable arterial tones, due to a lack of external calibration. The ability of this system to measure stroke volume and track its changes after fluid administration has not been fully evaluated in patients with the high Systemic Vascular Resistance that can develop during laparoscopic surgery. Methods In 42 patients undergoing laparoscopic prostatectomy, the stroke volume derived by the third-generation FloTrac/Vigileo™ system (SV-Vigileo), the stroke volume measured using transesophageal echocardiography (SV-TEE) as a reference method, and total Systemic Vascular Resistance were evaluated before and after 500 ml fluid administration during pneumoperitoneum combined with the Trendelenburg position. Results Total Systemic Vascular Resistance was 2159.4 ± 523.5 dyn·s/cm5 before fluid administration. The SV-Vigileo was significantly higher than the SV-TEE both before (68.8 ± 15.9 vs. 57.0 ± 11.0 ml, P < 0.001) and after (73.0 ± 14.8 vs. 64.9 ± 12.2 ml, P = 0.003) fluid administration. During pneumoperitoneum combined with the Trendelenburg position, Bland-Altman analysis for repeated measures showed a 53.8% of percentage error between the SV-Vigileo and the SV-TEE. Four-quadrant plot (69.2% of a concordance rate) and polar plot analysis (20.6° of a mean polar angle, 16.4° of the SD of a polar angle, and ±51.5° of a radial sector containing 95% of the data points) did not indicate a good trending ability of the FloTrac/Vigileo™ system. Conclusions The third-generation FloTrac/Vigileo™ system may not be useful in patients undergoing laparoscopic surgery, based on unreliable performance in measuring the stroke volume and in tracking changes in the stroke volume after fluid administration during pneumoperitoneum combined with the Trendelenburg position.
Sheldon Magder - One of the best experts on this subject based on the ideXlab platform.
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low Systemic Vascular Resistance state in patients undergoing cardiopulmonary bypass
Critical Care Medicine, 1999Co-Authors: Arnold S. Kristof, Sheldon MagderAbstract:Objective: To determine the prevalence, hemodynamic characteristics, and risk factors for the low Systemic Vascular Resistance (SVR) state in patients who have undergone cardiopulmonary bypass. Design: Prospective cohort study. Setting: The intensive care unit of a tertiary care hospital. Patients: Seventy-nine consecutive patients who underwent coronary artery bypass graft, mitral valve, or aortic valve procedures. Interventions: None. Measurements and Main Results: Low SVR was defined as an indexed Systemic Vascular Resistance (SVR 1 ) of <1800 dyne.sec/ cm 5 .m 2 at two consecutive times postoperatively. SVR 1 , cardiac index, mean arterial pressure, temperature, and central venous pressure were recorded before bypass and at 0, 1, 2, 4, 8, and 16 hrs after bypass. We recorded age, gender, urgency of operation, use of angiotensin-converting enzyme inhibitors and calcium channel blockers, ejection fraction, pump time, cross-clamp time, use of antifibrinolytics, type of oxygenator, amrinone use, postoperative biochemical and hematologic values, medication use, fluid balance, Intensive care unit admission duration, and hospital admission duration. We assessed the role of diabetes mellitus, current smoking, and Systemic hypertension. The incIdence of the low-SVR state was 35 of 79 patients during a 3-month period (44%). At 8 hrs postoperatively, the SVR 1 in low-SVR and non-low-SVR patients was 1594 ± 50 (SEM) and 2103 ± 56 (SEM) dyne.sec/cm 5 .m 2 , respectively (p <.001). In low-SVR patients, there was an Initial and sustained increase in cardiac index and central venous pressure that preceded the decrease in mean arterial pressure. The decrease in mean arterial pressure was maximal at 8 hrs postoperatively. Patients with low SVR were more likely to have longer cross-clamp times, to be male, and to have lower postoperative platelet counts (p <.05 for all). Low-SVR patients were less likely to require dobutamine In the first 4 hrs postoperatively. Conclusions: Low SVR, a probable manifestation of Systemic inflammatory response syndrome, is common in patients after cardiopulmonary bypass. These patients may respond better to a vasopressor to restore Vascular tone than to volume loading to further increase cardiac index.
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Low Systemic Vascular Resistance state in patients undergoing cardiopulmonary bypass
Critical care medicine, 1999Co-Authors: Arnold S. Kristof, Sheldon MagderAbstract:Objective: To determine the prevalence, hemodynamic characteristics, and risk factors for the low Systemic Vascular Resistance (SVR) state in patients who have undergone cardiopulmonary bypass. Design: Prospective cohort study. Setting: The intensive care unit of a tertiary care hospital. Patients: Seventy-nine consecutive patients who underwent coronary artery bypass graft, mitral valve, or aortic valve procedures. Interventions: None. Measurements and Main Results: Low SVR was defined as an indexed Systemic Vascular Resistance (SVR 1 ) of
Brian P. Griffin - One of the best experts on this subject based on the ideXlab platform.
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The effects of regurgitant orifice size, chamber compliance, and Systemic Vascular Resistance on aortic regurgitant velocity slope and pressure half-time
American Heart Journal, 1991Co-Authors: Brian P. Griffin, Frank A. Flachskampf, Samuel Siu, Arthur E. Weyman, James D. ThomasAbstract:The determinants of the aortic regurgitant velocity profile have been investigated using computer and in vitro simulations in which regurgitant orifice area, ventricular and aortic compliance, and Systemic Vascular Resistance could be independently varied. In the study, regurgitant fraction was altered, either by changing the size of the regurgitant orifice or by holding the regurgitant orifice constant and changing chamber compliance or Systemic Vascular Resistance. Upon increasing regurgitant fraction by increasing the size of the regurgitant orifice, the slope got steeper and the pressure half-time shortened, the response anticipated in current clinical practice. However, when the regurgitant orifice was kept constant and regurgitation fraction was increased by increasing the Systemic Vascular Resistance or by increasing the compliance of the left ventricle, slope became less steep and pressure half-time lengthened. Multivariate analysis was used to quantify the relationship of regurgitant fraction to slope and pressure half-time. When orifice area was allowed to vary, slope was related directly (multiple r = 0.78, p < 0.001) and half-time was related inversely (multiple r = 0.66, p < 0.001) to regurgitant fraction. With the orifice area fixed, however, directionally opposite responses were seen; slope varied inversely (multiple r = 0.87, p < 0.001), whereas half-time varied directly (multiple r = 0.88, p < 0.001) with regurgitant fraction. This study suggests that the utility of the slope and pressure half-time of the regurgitant velocity tracing in clinical practice relates to their ability to discriminate regurgitant orifices of differing sizes. However, these findings also suggest caution in the conventional interpretation of these indices in individual patients in whom changes in regurgitant fraction are produced by pharmacologic manipulation of the Systemic Vascular Resistance.
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The effects of regurgitant orifice size, chamber compliance, and Systemic Vascular Resistance on aortic regurgitant velocity slope and pressure half-time.
American heart journal, 1991Co-Authors: Brian P. Griffin, Frank A. Flachskampf, Samuel Siu, Arthur E. Weyman, James D. ThomasAbstract:The determinants of the aortic regurgitant velocity profile have been investigated using computer and in vitro simulations in which regurgitant orifice area, ventricular and aortic compliance, and Systemic Vascular Resistance could be independently varied. In the study, regurgitant fraction was altered, either by changing the size of the regurgitant orifice or by holding the regurgitant orifice constant and changing chamber compliance or Systemic Vascular Resistance. Upon increasing regurgitant fraction by increasing the size of the regurgitant orifice, the slope got steeper and the pressure half-time shortened, the response anticipated in current clinical practice. However, when the regurgitant orifice was kept constant and regurgitation fraction was increased by increasing the Systemic Vascular Resistance or by increasing the compliance of the left ventricle, slope became less steep and pressure half-time lengthened. Multivariate analysis was used to quantify the relationship of regurgitant fraction to slope and pressure half-time. When orifice area was allowed to vary, slope was related directly (multiple r = 0.78, p less than 0.001) and half-time was related inversely (multiple r = 0.66, p less than 0.001) to regurgitant fraction. With the orifice area fixed, however, directionally opposite responses were seen; slope varied inversely (multiple r = 0.87, p less than 0.001), whereas half-time varied directly (multiple r = 0.88, p less than 0.001) with regurgitant fraction. This study suggests that the utility of the slope and pressure half-time of the regurgitant velocity tracing in clinical practice relates to their ability to discriminate regurgitant orifices of differing sizes.(ABSTRACT TRUNCATED AT 250 WORDS)