ABSTRACT
The accurate quantification of cardiac output (CO) is given vital importance in modern medical practice, especially in high-risk surgical and critically ill patients. CO monitoring together with perioperative protocols to guide intravenous fluid therapy and inotropic support with the aim of improving CO and oxygen delivery has shown to improve perioperative outcomes in high-risk surgical patients. Understanding of the underlying principles of CO measuring devices helps in knowing the limitations of their use and allows more effective and safer utilization. At present, no single CO monitoring device can meet all the clinical requirements considering the limitations of diverse CO monitoring techniques. The evidence for the minimally invasive CO monitoring is conflicting; however, different CO monitoring devices may be used during the clinical course of patients as an integrated approach based on their invasiveness and the need for additional hemodynamic data. These devices add numerical trend information for anesthesiologists and intensivists to use in determining the most appropriate management of their patients and at present, do not completely prohibit but do increasingly limit the use of the pulmonary artery catheter.
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Objective To study the influence of continuous blood purification(CBP) on cardiac out-put of pediatric patients using bioreactance. Methods Patients underwent CBP in PICU and nephrology ward from March 2014 were prospectively enrolled after approval by ethics committee. CBP therapies were all performed by Fresenius Medical Care hemodialysis machine. Cardiac output values were obtained using the non-invasive cardiac output monitoring ( NICOM) device ( Cheetah Medical). Blood pressure, heart rate, cardiac index(CI) and stroke volume index(SVI) were recorded before the therapy,at the beginning of ther-apy,during the course of therapy,and at the end of each therapy. Results Twenty-one pediatric patients (from 1. 0 year to 15. 5 years) were recruited and 69 treatments were recorded from March 2014 to Decem-ber 2016. The basic CI was 3. 4 (2. 4,6. 1) L/(min·m2),basic SVI was 43 (26,75) ml/(m2·beat). Dur-ing the beginning of therapy,mean arterial pressure(MAP),CI and SVI all dropped from the baseline ( P<0. 001),whereas heart rate increased. During the course of CBP,CI and SVI (were both recorded every 4 hours) kept on dropping and stayed at a relatively lower level. Course CI was 3. 0 (2. 4,4. 6) L/(min·m2) and course SVI was 28 (21,57) ml/(m2·beat). At the end of therapy,CI was 3. 4 (2. 5,5. 3) L/(min· m2),with no significant difference from the baseline CI (P＝0. 073). However,the SVI at the end of therapy was 35 (25,67) ml/(m2·beat),higher than the course SVI but still lower than the basic SVI,the differences were statistically significant ( P<0. 05). Conclusion CI and SVI continue to decline at the beginning of CBP treatment and remain at a lower level throughout the course of treatment. After the therapy, CI has returned to the basic level whereas SVI has not recovered.
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Objective To investigate the value of measurement of cardiac output in children by bio-reactance versus echocardiography.Methods Pediatric patients admitted in pediatric department of Peking University First Hospital from September to December 2012 who needed hemodynamic monitoring were enrolled prospectively.Cardiac index(CI)and stroke volume(SV)were measured by echocardiography and non-invasive cardiac output measurement(NICOM)and compared by Spearman correlation and Bland-Alt-man analysis.Results Thirty patients were included.The median age was 7.25 years.CI[M(P5 ,P95 )] measured by NICOM and echocardiography were correlated significantly[3.42(2.28,4.92)L /(min?m2 ) vs.3.51 (2.94,4.85 )L/(min?m2 ),R =0.385,P =0.035 ].Bland-Altman analysis revealed a bias of-0.22 L/(min?m2 )(P =0.051 ),limits of agreement of -1.40 to 0.95 L/(min?m2 ).SV[M(P5 ,P95 )] measured by NICOM and echocardiography were correlated more significantly [36.3 (12.6,87.8 )ml vs.39.4(14.7,86.9)ml,R =0.768,P ﹤0.001 ].Bland-Altman analysis revealed a bias of -3.1 ml(P =0.176),limits of agreement of -27.4 to 21.2 ml.Conclusion There is no significant difference between NICOM and echocardiography for the measurement of CI and SV in pediatric patients.Further validation studies need to be conducted before routine clinical use.
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JUSTIFICATIVA E OBJETIVOS: O monitoramento da pressão arterial oferece uma compreensão limitada das consequências hemodinâmicas da raquianestesia para cesariana. O objetivo deste estudo foi avaliar, com o auxílio do monitor de débito cardíaco não invasivo baseado na biorreatância, as alterações hemodinâmicas durante cesariana eletiva sob raquianestesia, na qual doses intermitentes de fenilefrina foram utilizados para prevenir e tratar a hipotensão. MÉTODOS: Este estudo observacional foi realizado após aprovação da comissão de ética na pesquisa e assinatura do consentimento informado. Pacientes saudáveis marcadas para cesariana eletiva sob raquianestesia foram avaliadas. Doses intermitentes de fenilefrina foram administrados para manter a pressão arterial sistólica nos níveis basais e as pacientes foram avaliadas com o monitor de débito cardíaco não invasivo baseado na biorreatância. Os dados hemodinâmicos foram colhidos continuamente no momento basal e durante os períodos pós-raquianestesia e pós-nascimento do feto. Os dados foram analisados usando ANOVA para modelos mistos e um p < 0,05 foi considerado significativo. RESULTADOS: A pressão arterial sistólica foi mantida entre 79,2 por cento ± 14,2 e 105,9 por cento ± 10,0 dos valores basais durante o período pós-raquianestesia e 78,4 por cento ± 11,13 e 100,9 por cento ± 10,7 dos valores basais no período pós-nascimento do feto (média ± DP). Flutuações significativas foram observadas na pressão arterial sistólica, frequência cardíaca e débito cardíaco no período pós-nascimento. CONCLUSÕES: Um novo monitor não invasivo, baseado na biorreatância, revelou flutuações hemodinâmicas significativas durante a cesariana sob raquianestesia, a despeito das tentativas de manter a pressão arterial nos níveis basais com doses intermitentes de fenilefrina.
BACKGROUND AND OBJECTIVES: Blood pressure monitoring offers a limited understanding of the hemodynamic consequences of spinal anesthesia for cesarean delivery. The purpose of this study was to assess, with the aid of a non-invasive cardiac output monitor based on bioreactance, the hemodynamic changes during elective cesarean delivery under spinal anesthesia in which intermittent boluses of phenylephrine were used to prevent and treat hypotension. METHODS: This observational study was conducted with the Research Ethics Board approval, and all participants provided written informed consent. Healthy patients undergoing elective cesarean delivery under spinal anesthesia were enrolled. Intermittent boluses of phenylephrine were administered in an attempt to maintain systolic blood pressure at baseline levels, and patients were assessed with a non-invasive cardiac output monitor based on bioreactance. Hemodynamic data was collected continuously at baseline, and during the postspinal and postdelivery periods. Data was analyzed using a mixed model ANOVA, and a p < 0.05 was considered significant. RESULTS: Systolic blood pressure was maintained within 79.2 ± 14.2 and 105.8 ± 10.0 percent of baseline during the postspinal period, and 78.4 ± 11.3 and 100.9 ± 10.7 percent of baseline in the postdelivery period (mean ± SD) There were significant fluctuations in systolic blood pressure, heart rate, and cardiac output during the postspinal period, and significant fluctuations in systolic blood pressure and cardiac output in the postdelivery period. CONCLUSIONS: A new non-invasive monitor based on bioreactance reveals significant hemodynamic fluctuations during cesarean delivery under spinal anesthesia, despite attempts to maintain blood pressure at baseline levels with intermittent boluses of phenylephrine.
JUSTIFICATIVA Y OBJETIVOS: La monitorización de la presión arterial ofrece una comprensión limitada de las consecuencias hemodinámicas de la raquianestesia para la cesárea. El objetivo de este estudio fue evaluar, con la ayuda del monitor de débito cardíaco no invasivo y con base en la biorreactancia, las alteraciones hemodinámicas durante la cesárea electiva bajo raquianestesia, en la cual bolos intermitentes de fenilefrina fueron utilizados para prevenir y tratar la hipotensión. MÉTODOS: Este estudio observacional fue realizado posterior a la aprobación de la comisión de ética en investigación y de la firma del consentimiento informado. Se evaluaron los pacientes sanos con cesárea electiva programada bajo raquianestesia. Bolos intermitentes de fenilefrina fueron administrados para mantener la presión arterial sistólica en los niveles basales, y las pacientes fueron evaluadas con la ayuda del monitor de débito cardíaco no invasivo con base en la biorreactancia. Los datos hemodinámicos se recopilaron continuamente en el momento basal y durante los períodos postraquianestesia y después del nacimiento del feto. Los datos se analizaron usando ANOVA para modelos mixtos, y un p < 0,05 fue considerado significativo. RESULTADOS: La presión arterial sistólica se mantuvo entre 79,2 (14,2) y 105,9 (10,0) por ciento de los valores basales durante el período postraquianestesia, y 78,4 (11,13) y 100,9 (10,7) por ciento de los valores basales en el período postparto promedio ± de. Las fluctuaciones significativas se observaron en la presión arterial sistólica, en la frecuencia cardíaca y en el débito cardíaco en el período postparto. CONCLUSIONES: Un nuevo monitor no invasivo, con base en la biorreactancia, reveló fluctuaciones hemodinámicas significativas durante la cesárea bajo la raquianestesia, pese a los intentos de mantener la presión arterial a niveles basales con bolos intermitentes de fenilefrina.