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1.
Nonlinear Dynamics Psychol Life Sci ; 23(4): 415-432, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31586496

RESUMO

This paper introduces a new measure to evaluate heart output from a dynamical systems approach. The measure is based on the time delay technique for two-dimensional state space reconstruction from time series of interbeat intervals. The system's trajectories within this space are depicted and the mean distance, as well as the total and maximum distances travelled by the system, are calculated in pixels. Preliminary data from adolescents with highly positive emotional regulation (HPER) style (n=10) and adolescents with highly negative (HNER) style (n=10) who underwent a protocol of stress induction show the usefulness of the new metrics to distinguish the dynamical behavior of the heart systems from these groups. Repeated measures ANOVAs revealed that changes in all three distances across conditions (baseline, anticipation of stress, exposure to stress, and recovery) were significant in the HPER group but not in the HNER group. As to the physiological meaning of the new measure a correlational analysis revealed that associations with time-domain HRV measures were stronger than associations with frequency-domain HRV measures in both groups. Because of the small sample size, bootstrap resampling was used to obtain confidence intervals. Distances calculated with the new measure are sensitive to the ER-related cardiac flexibility under acute stress conditions. However, the physiological meaning of the new indices remains unclear.


Assuntos
Débito Cardíaco/fisiologia , Coração/fisiologia , Estresse Psicológico/fisiopatologia , Adolescente , Emoções , Humanos
2.
Adv Physiol Educ ; 43(3): 423-429, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31408386

RESUMO

An understanding of the complexity of the cardiovascular system is incomplete without a knowledge of the venous system. It is important for students to understand that, in a closed system, like the circulatory system, changes to the venous side of the circulation have a knock-on effect on heart function and the arterial system and vice versa. Veins are capacitance vessels feeding blood to the right side of the heart. Changes in venous compliance have large effects on the volume of blood entering the heart and hence cardiac output by the Frank-Starling Law. In healthy steady-state conditions, venous return has to equal cardiac output, i.e., the heart cannot pump more blood than is delivered to it. A sound understanding of the venous system is essential in understanding how changes in cardiac output occur with changes in right atrial pressure or central venous pressure, and the effect these changes have on arterial blood pressure regulation. The aim of this paper is to detail simple hands-on physiological assessments that can be easily undertaken in the practical laboratory setting and that illustrate some key functions of veins. Specifically, we illustrate that venous valves prevent the backflow of blood, that venous blood pressure increases from the heart to the feet, that the skeletal muscle pump facilitates venous return, and we investigate the physiological and clinical significance of central venous pressure and how it may be assessed.


Assuntos
Compreensão , Modelos Cardiovasculares , Fisiologia/educação , Veias/fisiologia , Pressão Venosa/fisiologia , Volume Sanguíneo/fisiologia , Débito Cardíaco/fisiologia , Humanos
3.
Hypertension ; 74(3): 705-715, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31352818

RESUMO

Commonly used in vitro fertilization protocols produce pregnancies without a corpus luteum (CL), a major source of reproductive hormones. In vitro fertilization pregnancies without a CL showed deficient gestational increases of central (aortic) arterial compliance during the first trimester and were at increased risk for developing preeclampsia. Here, we investigated whether there was generalized impairment of cardiovascular adaptation in in vitro fertilization pregnancies without a CL compared with pregnancies conceived spontaneously or through ovarian stimulation, which lead to 1 and >1 CL, respectively (n=19-26 participants per cohort). Prototypical maternal cardiovascular adaptations of gestation were serially evaluated noninvasively, initially during the follicular phase before conception, 6× in pregnancy, and then, on average, 1.6 years post-partum. The expected increases of cardiac output, left atrial dimension, peak left ventricular filling velocity in early diastole (E wave velocity), peripheral/central arterial pulse pressure ratio, and global AC, as well as decrease in augmentation index were significantly attenuated or absent during the first trimester in women who conceived without a CL, when compared with the 1 and >1 CL cohorts, which were comparable. Thereafter, these cardiovascular measures showed recovery in the 0 CL group except for E wave velocity, which remained depressed. These results provided strong support for a critical role of CL factor(s) in the transformation of the maternal cardiovascular system in early gestation. Regimens that lead to the development of a CL or replacement of missing CL factor(s) may be indicated to improve cardiovascular function and reduce preeclampsia risk in in vitro fertilization pregnancies.


Assuntos
Doenças Cardiovasculares/etiologia , Sistema Cardiovascular/fisiopatologia , Corpo Lúteo/patologia , Fertilização In Vitro/efeitos adversos , Saúde Materna , Adulto , Análise de Variância , Débito Cardíaco/fisiologia , Doenças Cardiovasculares/diagnóstico por imagem , Doenças Cardiovasculares/epidemiologia , Estudos de Coortes , Feminino , Testes de Função Cardíaca , Humanos , Modelos Lineares , Gravidez , Primeiro Trimestre da Gravidez , Estudos Prospectivos , Análise de Onda de Pulso
4.
Aerosp Med Hum Perform ; 90(8): 688-695, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31331418

RESUMO

INTRODUCTION: Changes in gravity or body position provoke changes in hydrostatic pressure in the arterial system and in venous return. Potential asymmetries between left (QLV) and right ventricular (QRV) cardiac output during transient gravity changes were investigated. It was hypothesized that blood volume is temporarily stored in the pulmonary vessels, with amount and duration depending on the level and directions of gravity.METHODS: Eight healthy, male subjects (32 ± 3 yr, 182 ± 7 cm, 82 ± 6 kg) were tested on a tilt seat (TS), in a long arm human centrifuge (laHC), and during parabolic flights (PF). The gravitational changes during PF were reconstructed by changing gravity in a laHC and different body positions on a TS. All participants were tested in the seated, resting position. Heart rate and blood pressure were recorded continuously and QLV was calculated, applying the Modelflow Algorithm. Gas exchange was measured breath-by-breath. QRV was calculated from these data according to the Fick Principle. Four sequences were superimposed and analyzed by ANOVA with the factors Time, Ventricle (QRV, QLV), and Mode (TS, PF, laHC).RESULTS: After reductions in gravity QRV and QLV were transiently desynchronized. ANOVA showed no main effect for Mode, but significant changes were found for Time and Ventricle and all interactions.DISCUSSION: Phases of reduced gravity seem to lead to transiently increased storage of blood volume inside the pulmonary vascular system. A more detailed understanding of these mechanisms might help to describe the compliance of the pulmonary vascular system in diseases of the pulmonary circulation.Hoffmann U, Koschate J, Appell Coriolano H-J, Drescher U, Thieschäfer L, Dumitrescu D, Werner A. Adaptation of systemic and pulmonary circulation to acute changes in gravity and body position. Aerosp Med Hum Perform. 2019; 90(8):688-695.


Assuntos
Adaptação Fisiológica , Hipergravidade/efeitos adversos , Postura/fisiologia , Voo Espacial , Adulto , Pressão Sanguínea/fisiologia , Débito Cardíaco/fisiologia , Centrifugação , Voluntários Saudáveis , Frequência Cardíaca/fisiologia , Humanos , Masculino , Circulação Pulmonar/fisiologia
5.
Complement Ther Med ; 45: 211-214, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31331563

RESUMO

BACKGROUND: Individuals diagnosed with congestive heart failure (CHF) have a 50% five-year mortality rate and approximately 650,000 new cases of CHF are diagnosed annually. Plant-based diets are known to improve plasma lipid concentrations, reduce blood pressure, and as part of a lifestyle intervention, lead to the regression of atherosclerotic lesions. However, a paucity of data exists with regards to plant-based diets in the treatment of CHF. METHODS: Three patients diagnosed with CHF opted to undergo a dietary intervention consisting of a defined plant-based diet as an adjunct to standard medical treatment for CHF. Cardiac magnetic resonance imaging was performed. Patients' consumed the defined plant-based diet for an average of ˜79 days. RESULTS: Follow-up cardiac magnetic resonance images revealed a 92% increase in ejection fraction [mean ±â€¯standard deviation for all data] (22.0 ±â€¯6.9% vs 42.2 ±â€¯18.4%), 21% reduction in left ventricular mass (214 ±â€¯90 g vs 170 ±â€¯102 g), 62% increase in stroke volume (55.8 ±â€¯24.3 cc vs 90.3 ±â€¯30.6 cc) and a 17% increase in cardiac output (3.6 ±â€¯1.2 L/min vs 4.2 ±â€¯1.6 L/min). In patient 1, 90-95% ostial stenosis of the left anterior descending artery nearly completely regressed following the dietary intervention. All patients subjectively reported significant clinical improvements, including less angina, shortness of breath and fatigue. CONCLUSION: As an adjunct treatment, a defined plant-based diet may contribute to the reversal of cardiac morphological and functional abnormalities in the setting of CHF.


Assuntos
Insuficiência Cardíaca/dietoterapia , Idoso , Aterosclerose/fisiopatologia , Pressão Sanguínea/fisiologia , Débito Cardíaco/fisiologia , Dieta Vegetariana , Feminino , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Volume Sistólico/fisiologia
6.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 31(6): 731-736, 2019 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-31315732

RESUMO

OBJECTIVE: To explore the effect of goal-directed therapy bundle based on pulse-indicated continuous cardiac output (PiCCO) parameters to the prevention and treatment of acute kidney injury (AKI) in patients after cardiopulmonary bypass cardiac operation. METHODS: A prospective observational study was conducted. The adult patients with selective cardiopulmonary bypass cardiac operation admitted to the Third People's Hospital of Chengdu from December 2015 to January 2018 were enrolled. All patients were divided into two groups based on informed consent for PiCCO monitor at the time of admission to the intensive care unit (ICU): regular monitoring and treatment group (group A) and goal-directed therapy group based on PiCCO parameters (group B). In group A, the restrictive capacity management strategy was implemented to maintain the mean arterial pressure (MAP) > 65 mmHg (1 mmHg = 0.133 kPa) and the central venous pressure (CVP) between 8 mmHg and 10 mmHg. In group B, volume and hemodynamic status were optimized depending on PiCCO parameters to a goal of cardiac index (CI) > 41.68 mL×s-1×m-2, global end diastolic volume index (GEDVI) > 700 mL/m2 or intrathoracic blood volume index (ITBVI) > 850 mL/m2, extravascular lung water index (EVLWI) < 10 mL/kg, and MAP > 65 mmHg. Then the changes in hemodynamics and different prognosis of the patients in two groups were observed. Risk factors affecting the AKI were analyzed by Logistic regression. RESULTS: 171 cases were included, with 68 in group A and 103 in group B. There were no significant differences in gender, age, pre-operative scores by European system for cardiac operative risk evaluation (EuroScore), operation ways, operation time, cardiopulmonary bypass time, intraoperative dominant liquid equilibrium quantity, the use of intra-aortic balloon counterpulsation (IABP) during operation, and serum creatinine (SCr) level at the time of admission to ICU between the two groups. There were no significant differences in CVP within 24 hours after admission to ICU between the two groups. MAP in group B was significantly higher than that in group A at 8 hours and 16 hours after ICU admission (mmHg: 68.9±6.3 vs. 66.7±5.1, 69.0±4.9 vs. 67.0±5.3, both P < 0.05). Sequential organ failure assessment (SOFA) score in group B was significantly lower than that in group A at 24 hours after ICU admission (5.7±2.2 vs. 6.9±2.8, P < 0.05). Dominant liquid equilibrium quantity in group B was significant higher than that in group A at 24 hours after ICU admission (mL/kg: 7.1±6.2 vs. -0.1±8.2, P < 0.01), but there was no significant difference of that between groups at 48 hours and 72 hours after ICU admission. Compared with group A, incidence of combination with AKI during 72 hours after ICU admission was significantly decreased in group B [48.5% vs. 69.1%; odds ratio (OR) = 0.422, 95% confidence interval (95%CI) = 0.222-0.802, P < 0.05], and incidence of moderate to severe AKI was also significantly decreased in group B (19.4% vs. 35.3%; OR = 0.442, 95%CI = 0.220-0.887, P < 0.05). There was no significant difference in usage of continuous renal replacement therapy (CRRT) after ICU admission between both groups (group A was 4.4%, group B was 4.9%, P > 0.05). It was shown by correlation analysis that only MAP and CI at 8 hours after ICU admission were significantly negatively correlated with AKI (MAP and AKI: r = -0.697, P = 0.000; CI and AKI: r = -0.664, P = 0.000). It was shown by Logistic regressive analysis that the MAP and CI at 8 hours after ICU admission were independent risk factors that influence the incidence of AKI at 72 hours after ICU admission (MAP: OR = 0.736, 95%CI = 0.636-0.851, P = 0.000; CI: OR = 0.006, 95%CI = 0.001-0.063, P = 0.000). There were no significant differences in the duration of mechanical ventilation, the length of ICU stay, the post-operation complications (except AKI), 7-day and 28-day mortality between the two groups. CONCLUSIONS: Goal-directed therapy bundle based on PiCCO parameters reduced the incidence of AKI in patients after cardiopulmonary bypass cardiac operation and improved the severity of systemic disease. However, it did not reduce the duration of mechanical ventilation, length of ICU stay, the incidence of complications (except AKI), short-term mortality. The MAP and CI at 8 hours after ICU admission were independent risk factors that influence the incidence of AKI in patients after cardiopulmonary bypass cardiac operation.


Assuntos
Lesão Renal Aguda/prevenção & controle , Débito Cardíaco/fisiologia , Ponte Cardiopulmonar , Lesão Renal Aguda/epidemiologia , Adulto , Metas , Humanos , Incidência , Unidades de Terapia Intensiva , Estudos Prospectivos , Resultado do Tratamento
7.
Zhonghua Shao Shang Za Zhi ; 35(6): 434-440, 2019 Jun 20.
Artigo em Chinês | MEDLINE | ID: mdl-31280536

RESUMO

Objective: To explore the guiding significance of pulse contour cardiac output (PiCCO) monitoring technology in the treatment of fluid replacement during shock stage of extensive burn in clinic. Methods: Sixty-five patients with extensive burn hospitalized in our unit from January 2014 to December 2018, conforming to the inclusion criteria, were recruited to conduct a prospective controlled research. According to the order of admission, 35 odd-numbered patients and 30 even-numbered patients were enrolled in routine rehydration group (25 males and 10 females) and PiCCO monitoring rehydration group (21 males and 9 females) respectively, with the age of (48±9) and (44±8) years respectively. All patients of the two groups were rehydrated according to the rehydration formula of the Third Military Medical University during shock stage. The rehydration speed was adjusted in routine rehydration group according to the general indexes of shock such as central venous pressure, mean arterial pressure, heart rate, respiratory rate, urine volume, and clinical symptoms of patients. PiCCO monitoring was performed in patients of PiCCO monitoring rehydration group, and the global end-diastolic volume index combined with the other relevant indicators of PiCCO were used to guide rehydration on the basis of the monitoring indicators of routine rehydration group. The heart rates and positive fluid balance volumes at post injury hour (PIH) 8, 16, 24, 32, 40, 48, 56, 64, and 72, the diuretic dosage at PIH 48 and 72, the total fluid replacement volumes, urine volumes, blood lactic acid, platelet count, and hematocrit at PIH 24, 48, and 72, the length of intensive care unit (ICU) stay, and the incidence of complications and death within 28 days after injury were compared between patients in the two groups. Data were processed with analysis of variance for repeated measurement, t test, Bonferroni correction, Mann-Whitney U test, chi-square test, and Fisher's exact probability test. Results: The heart rates of patients in the two groups were similar at PIH 8, 16, 24, 32, 40, 48, and 56 (t=0.775, 1.388, 2.511, 2.203, 1.654, 2.303, 1.808, P>0.05), and the heart rates of patients in PiCCO monitoring rehydration group at PIH 64 and 72 were obviously lower than those of routine rehydration group (t=3.229, 3.357, P<0.05 or P<0.01). The positive fluid balance volumes of patients in the two groups were similar at PIH 8, 16, 40, and 56 (t=0.768, 1.670, 2.134, 2.791, P>0.05), and the positive fluid balance volumes of patients in PiCCO monitoring rehydration group at PIH 24, 32, 48, 64, and 72 were obviously less than those of routine rehydration group (t=3.364, 4.047, 2.930, 2.950, 2.976, P<0.05 or P<0.01). The amount of diuretics used by patients in the two groups was similar at PIH 48 and 72 (Z=-0.697, -1.239, P>0.05). The total fluid replacement volumes of patients in PiCCO monitoring rehydration group at PIH 24, 48, and 72 were (13 864±4 241), (9 532±2 272), and (8 480±2 180) mL, respectively, obviously more than those in routine rehydration group [(10 388±2 445), (8 095±1 720), and (7 059±1 297) mL, respectively, t=-3.970, -2.848, -3.137, P<0.05 or P<0.01]. The urine volumes of patients in the two groups at PIH 24 were close (t=-1.027, P>0.05). The urine volumes of patients in PiCCO monitoring rehydration group at PIH 48 and 72 were (3 051±702) and (3 202±624) mL respectively, obviously more than those in routine rehydration group [(2 401±588) and (2 582±624) mL respectively, t=-4.062, -4.001, P<0.01]. The levels of blood lactate acid of patients in PiCCO monitoring rehydration group at PIH 24, 48, and 72 were obviously lower than those in routine rehydration group (t=4.758, 6.101, 3.938, P<0.01). At PIH 24 and 48, the values of the platelet count of patients in PiCCO monitoring rehydration group were obviously higher than those in routine rehydration group (t=-2.853, -2.499, P<0.05), and the values of hematocrit of patients in PiCCO monitoring rehydration group were obviously lower than those in routine rehydration group (t=2.698, 4.167, P<0.05 or P<0.01). Both the platelet count and hematocrit of patients in the two groups were similar at PIH 72 (t=-1.363, 0.476, P>0.05). The length of ICU stay of patients in PiCCO monitoring rehydration group was obviously shorter than that of routine rehydration group (t=2.184, P<0.05). Within 28 days after injury, the incidence of complications of patients in routine rehydration group was obviously higher than that in PiCCO monitoring rehydration group (P<0.05), while the mortality rate of patients in routine rehydration group was similar to that in PiCCO monitoring rehydration group (P>0.05). Conclusions: The application of PiCCO monitoring technology in monitoring fluid replacement in patients with extensive burn can quickly correct shock, reduce the occurrence of organ complications caused by improper fluid replacement, and shorten the length of ICU stay, which is of great significance in guiding the treatment of burn shock.


Assuntos
Queimaduras/terapia , Débito Cardíaco/fisiologia , Hidratação , Frequência Cardíaca/fisiologia , Monitorização Fisiológica/métodos , Choque/terapia , Feminino , Humanos , Unidades de Terapia Intensiva , Tempo de Internação , Masculino , Estudos Prospectivos , Resultado do Tratamento
8.
Emerg Med Clin North Am ; 37(3): 395-408, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31262411

RESUMO

Patients in shock present frequently to the emergency department. The emergency physician must be skilled in the resuscitation of both differentiated and undifferentiated shock. Early, aggressive resuscitation of patients in shock is essential, using macrocirculatory, microcirculatory, and clinical end points to guide interventions. Therapy should focus on the restoration of oxygen delivery to match tissue demand. This article reviews the evidence supporting common end points of resuscitation for common etiologies of shock and limitations to their use.


Assuntos
Ressuscitação , Choque/terapia , Lesão Renal Aguda/diagnóstico , Lesão Renal Aguda/prevenção & controle , Pressão Arterial/fisiologia , Biomarcadores , Circulação Sanguínea/fisiologia , Dióxido de Carbono/sangue , Débito Cardíaco/fisiologia , Medicina de Emergência , Homeostase/fisiologia , Humanos , Hipotensão/prevenção & controle , Ácido Láctico/sangue , Oxigênio/sangue , Sepse/fisiopatologia , Choque/sangue , Urina
9.
EuroIntervention ; 15(7): 586-593, 2019 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-31147306

RESUMO

AIMS: The haemodynamic effects of primary implantation of an intra-aortic balloon pump (IABP) versus inotropes in decompensated heart failure and low output (DHF-LO), but without an acute coronary syndrome, have not been investigated. We therefore aimed to investigate the effect of primary IABP implantation as compared to inotropes on haemodynamics in DHF-LO with no acute ischaemia. METHODS AND RESULTS: Patients (n=32) with DHF-LO despite IV diuretics were randomised to primary 50 mL IABP or inotropes (INO: enoximone or dobutamine). The primary endpoint was the improvement of organ perfusion assessed by ∆ mixed-venous oxygen saturation (SvO2) at 3 hours; secondary endpoints included ∆ cardiac power output (CPO), NT-proBNP proportional change, cumulative fluid balance and ∆ dyspnoea severity score, all at 48 hours. Data are presented as median (IQR). Patients were 60 (48-69) years old and 72% were male. Baseline SvO2 was 44 (39-53)%. ∆SvO2 was higher in the IABP group (+17 [+9; +24] vs. +5 [+2; +9]%, p<0.05). IABP patients had a higher ∆CPO, a greater relative reduction in NT-proBNP, a more negative cumulative fluid balance, and a greater reduction in dyspnoea severity score. There were no IABP-related serious adverse events (SAEs). Thirty-day mortality was 23% (IABP) vs. 44% (INO). CONCLUSIONS: Primary circulatory support by IABP showed a significant increase in improved organ perfusion assessed by SvO2.


Assuntos
Débito Cardíaco/fisiologia , Cardiotônicos/uso terapêutico , Dobutamina/uso terapêutico , Enoximona/uso terapêutico , Insuficiência Cardíaca/cirurgia , Hemodinâmica/fisiologia , Balão Intra-Aórtico/métodos , Idoso , Débito Cardíaco/efeitos dos fármacos , Feminino , Coração Auxiliar , Hemodinâmica/efeitos dos fármacos , Humanos , Balão Intra-Aórtico/efeitos adversos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
10.
Medicina (Kaunas) ; 55(7)2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31248012

RESUMO

Background and objectives: Physical load causes structural changes in the heart that vary depending on the type of training and may affect the function of the heart. Aim of the study: To determine, using the applied co-integration method on algebraic data, the impact of sprinting and of endurance adaptation on the dynamic interactions of cardiovascular functional indices while participants were performing under an increasing workload, up to their inability to continue. Materials and Methods: Healthy athletes were chosen to take part in this study and were separated into two groups: Sprinters (n = 11) and endurance athletes (n = 13). The bicycle ergometric method of incremental increase in a provocative workload (graded stress) was used. The heart rate, stroke volume, and cardiac output were determined using the tetrapolar rheography method. Results: Individuals who are adapted to endurance while carrying physical loads, in contrast to well adapted sprinters, are characterized with a lower rate of changing the pace of interactions between stroke volume and cardiac output while performing at an increasing workload up to their inability to continue. Also, endurance athletes displayed a long and relatively stable phase as well as a greater decrease of interaction between indices at the end of the workload. At the beginning of the exercise, the interaction between the stroke volume and the cardiac output was reduced. However, as the physical load continued, this interaction became significantly stronger. The comparison of the stroke volume and the cardiac output's dynamic interaction revealed that the endurance group had a greater working capacity. Conclusions: Typical dynamics of interactions during the testing with an increasing physical load can be differentiated into separate phases: The decrease of interaction at the onset of the load, the increase during the continuation of an increased workload, and the decrease at the last stages of the load.


Assuntos
Adaptação Biológica/fisiologia , Exercício/fisiologia , Testes de Função Cardíaca/estatística & dados numéricos , Adulto , Análise de Variância , Atletas , Pressão Sanguínea/fisiologia , Débito Cardíaco/fisiologia , Teste de Esforço/métodos , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Volume Sistólico/fisiologia
11.
Crit Care ; 23(1): 179, 2019 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-31097012

RESUMO

BACKGROUND: Fluid challenge (FC) is one of the most common practices in Intensive Care Unit (ICU). The present study aimed to evaluate whether echocardiographic assessment of the response to FC at the end of the infusion or 20 min later could affect the results of the FC. METHODS: This is a prospective, observational, multicenter study including all ICU patients in septic shock requiring a FC of 500 mL crystalloids over 10 min. Fluid responsiveness was defined as a > 15% increase in stroke volume (SV) assessed by velocity-time integral (VTI) measurements at baseline (T0), at the end of FC (T10), then 10 (T20) and 20 min (T30) after the end of FC. RESULTS: From May 20, 2014, to January 7, 2016, a total of 143 patients were enrolled in 11 French ICUs (mean age 64 ± 14 years, median IGS II 53 [43-63], median SOFA score 10 [8-12]). Among the 76/143 (53%) patient responders to FC at T10, 37 patients were transient responders (TR), i.e., became non-responders (NR) at T30 (49%, 95%CI = [37-60]), and 39 (51%, 95%CI = [38-62]) patients were persistent responders (PR), i.e., remained responders at T30. Among the 67 NR at T10, 4 became responders at T30, (6%, 95%CI = [1.9-15.3]). In the subgroup analysis, no statistical difference in hemodynamic and echocardiographic parameters was found between groups. CONCLUSIONS: This study shows that 51.3% of initial responders have a persistent response to fluid 30 min after the beginning of fluid infusion and only 41.3% have a transient response highlighting that fluid responsiveness is time dependent. TRIAL REGISTRATION: ClinicalTrials.gov , NCT02116413 . Registered on April 16, 2014.


Assuntos
Hidratação/métodos , Sepse/terapia , Fatores de Tempo , Idoso , Pressão Arterial/efeitos dos fármacos , Pressão Arterial/fisiologia , Débito Cardíaco/efeitos dos fármacos , Débito Cardíaco/fisiologia , Soluções Cristaloides/uso terapêutico , Ecocardiografia/métodos , Feminino , França , Humanos , Unidades de Terapia Intensiva/organização & administração , Unidades de Terapia Intensiva/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sepse/fisiopatologia
12.
Int J Artif Organs ; 42(9): 490-499, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31104554

RESUMO

Current left ventricular assist devices are designed to reestablish patient's hemodynamics at rest but they lack the suitability to sustain the heart adequately during physical exercise. Aim of this work is to assess the performance during exercise of a left ventricular assist device with flatter pump pressure-flow characteristic and increased pressure sensitivity (left ventricular assist device 1) and to compare it to the performance of a left ventricular assist device with a steeper characteristic (left ventricular assist device 2). The two left ventricular assist devices were tested at constant rotational speed with a verified computational cardiorespiratory simulator reproducing an average left ventricular assist device patient response to exercise (EXE↑) and a left ventricular assist device patient with no chronotropic and inotropic response (EXE→). According to the results, left ventricular assist device 1 pumps a higher flow than left ventricular assist device 2 both at EXE↑ (6.3 vs 5.6 L/min) and at EXE→ (6.7 vs 6.1 L/min), thus it better unloads the left ventricle. Left ventricular assist device 1 increases the power delivered to the circulation from 0.63 W at rest to 0.67 W at EXE↑ and 0.82 W at EXE→, while left ventricular assist device 2 power shows even a minimal decrease. Left ventricular assist device 1 better sustains exercise hemodynamics and can provide benefits in terms of exercise performance, especially for patients with a poor residual left ventricular function, for whom the heart can hardly accommodate an increase of cardiac output.


Assuntos
Exercício/fisiologia , Coração Auxiliar , Modelos Cardiovasculares , Função Ventricular Esquerda/fisiologia , Débito Cardíaco/fisiologia , Tolerância ao Exercício/fisiologia , Insuficiência Cardíaca/fisiopatologia , Frequência Cardíaca/fisiologia , Humanos , Descanso/fisiologia
13.
Cardiovasc Ultrasound ; 17(1): 5, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30944001

RESUMO

BACKGROUND: Three-dimensional color flow Doppler (3DCF) is a new convenient technique for cardiac output (CO) measurement. However, to date, no one has evaluated the accuracy of 3DCF echocardiography for CO measurement after cardiac surgery. Therefore, this single-center, prospective study was designed to evaluate the reliability of three-dimensional color flow and two-dimensional pulse wave Doppler (2D-PWD) transthoracic echocardiography for estimating cardiac output after cardiac surgery. METHODS: Post-cardiac surgical patients with a good acoustic window and a low dose or no dose of vasoactive drugs (norepinephrine < 0.05 µg/kg/min) were enrolled for CO estimation. Three different methods (third generation FloTrac/Vigileo™ [FT/V] system as the reference method, 3DCF, and 2D-PWD) were used to estimate CO before and after interventions (baseline, after volume expansion, and after a dobutamine test). RESULTS: A total of 20 patients were enrolled in this study, and 59 pairs of CO measurements were collected (one pair was not included because of increasing drainage after the dobutamine test). Pearson's coefficients were 0.260 between the CO-FT/V and CO-PWD measurements and 0.729 between the CO-FT/V and CO-3DCF measurements. Bland-Altman analysis showed the bias between the absolute values of CO-FT/V and CO-PWD measurements was - 0.6 L/min with limits of agreement between - 3.3 L/min and 2.2 L/min, with a percentage error (PE) of 61.3%. The bias between CO-FT/V and CO-3DCF was - 0.14 L/min with limits of agreement between - 1.42 L /min and 1.14 L/min, with a PE of 29.9%. Four-quadrant plot analysis showed the concordance rate between ΔCO-PWD and ΔCO-3FT/V was 93.3%. CONCLUSIONS: In a comparison with the FT/V system, 3DCF transthoracic echocardiography could accurately estimate CO in post-cardiac surgical patients, and the two methods could be considered interchangeable. Although 2D-PWD echocardiography was not as accurate as the 3D technique, its ability to track directional changes was reliable.


Assuntos
Débito Cardíaco/fisiologia , Procedimentos Cirúrgicos Cardíacos , Ecocardiografia Doppler em Cores/métodos , Ecocardiografia Tridimensional/métodos , Cardiopatias/diagnóstico , Ventrículos do Coração/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Cardiopatias/fisiopatologia , Cardiopatias/cirurgia , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Estudos Prospectivos , Reprodutibilidade dos Testes , Adulto Jovem
14.
Eur J Radiol ; 114: 137-145, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31005164

RESUMO

PURPOSE: Cardiac magnetic resonance (CMR) is a substitute technique for noninvasively assessing pulmonary hemodynamics. Some preliminary studies have shown that CMR has the potential to quantify pulmonary vascular resistance (PVR). However, the evaluative value has not been well established. The purpose of the systematic review is to assess the feasibility of CMR in the measurement of PVR in patients with pulmonary hypertension (PH). METHODS: Studies were retrieved from multiple databases. Methodological evaluation of CMR and right heart catheterization (RHC) in estimating PVR were obtained from included studies. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool was used to assess the quality of studies. The results of comparisons of continuous variables are reported as weighted mean difference (WMD), together with the corresponding 95% confidence intervals (CIs). Summary correlation coefficient (r) values were extracted from each study, and 95% CIs were calculated after Fisher's z transformation. Sensitivity analysis was conducted to investigate potential heterogeneity. RESULTS: A total of 15 studies were included in the systematic review, and 6 of these studies were included in the meta-analysis. The pooled WMD with fixed-effects analysis revealed no statistical significance between PVR-CMR and PVR-RHC in patients with PH (WMD = 0.278 WU; 95% CI: -0.415 to 0.972; p = 0.431). The pooled r value for all studies was 0.85 (95% CI: 0.81, 0.89), and notable heterogeneity was evident. The pooled r value after the exclusion of one heterogeneous article was 0.81 (95% CI: 0.74, 0.87) and was not significantly heterogeneous. CONCLUSIONS: CMR and RHC have good consistency in the testing of PVR in the meta-analysis. The systematic review shows that completely noninvasive evaluation of PVR with CMR in patients with pH is feasible.


Assuntos
Hipertensão Pulmonar/diagnóstico por imagem , Hipertensão Pulmonar/fisiopatologia , Espectroscopia de Ressonância Magnética , Artéria Pulmonar/diagnóstico por imagem , Artéria Pulmonar/fisiopatologia , Resistência Vascular/fisiologia , Cateterismo Cardíaco , Débito Cardíaco/fisiologia , Estudos de Viabilidade , Humanos , Monitorização Fisiológica
15.
Crit Care ; 23(1): 118, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30987647

RESUMO

BACKGROUND: We hypothesized that the cardiovascular responses to Surviving Sepsis Guidelines (SSG)-defined resuscitation are predictable based on the cardiovascular state. METHODS: Fifty-five septic patients treated by SSG were studied before and after volume expansion (VE), and if needed norepinephrine (NE) and dobutamine. We measured mean arterial pressure (MAP), cardiac index (CI), and right atrial pressure (Pra) and calculated pulse pressure and stroke volume variation (PPV and SVV), dynamic arterial elastance (Eadyn), arterial elastance (Ea) and left ventricular (LV) end-systolic elastance (Ees), Ees/Ea (VAC), LV ejection efficiency (LVeff), mean systemic pressure analogue (Pmsa), venous return pressure gradient (Pvr), and cardiac performance (Eh), using standard formulae. RESULTS: All patients were hypotensive (MAP 56.8 ± 3.1 mmHg) and tachycardic (113.1 ± 7.5 beat min-1), with increased lactate levels (lactate = 5.0 ± 4.2 mmol L-1) with a worsened VAC. CI was variable but > 2 L min-1 M-2 in 74%. Twenty-eight-day mortality was 48% and associated with admission lactate, blood urea nitrogen (BUN), and creatinine levels but not cardiovascular state. In all patients, both MAP and CI improved following VE, as well as cardiac contractility (Ees). Fluid administration improved Pra, Pmsa, and Pvr in all patients, whereas both HR and Ea decreased after VE, thus normalizing VAC. CI increases were proportional to baseline PPV and SVV. CI increases proportionally decreased PPV and SVV. VE increased MAP > 65 mmHg in 35/55 patients. MAP responders had higher PPV, SVV, and Eadyn than non-responders. NE was given to 20/55 patients in septic shock, but increased MAP > 65 mmHg in only 12. NE increased Ea, Eadyn, Pra, Pmsa, and VAC while decreasing HR, PPV, SVV, and LVeff. MAP responders had higher pre-NE Ees and lower VAC. Dobutamine was given to 6/8 patients who remained hypotensive following NE. It increased Ees, MAP, CI, and LVeff, while decreasing HR, Pra, and VAC. At all times and all steps of the protocol, CI changes were proportional to Pvr changes independent of treatment. CONCLUSIONS: The cardiovascular response to SSG-based resuscitation is highly heterogeneous but predictable from pre-treatment measures of cardiovascular state.


Assuntos
Fenômenos Fisiológicos Cardiovasculares , Ressuscitação/normas , Sepse/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Débito Cardíaco/fisiologia , Cardiotônicos/uso terapêutico , Dobutamina/uso terapêutico , Feminino , Frequência Cardíaca/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Humanos , Hipotensão/tratamento farmacológico , Hipotensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Norepinefrina/uso terapêutico , Ressuscitação/métodos , Ressuscitação/estatística & dados numéricos , Sepse/tratamento farmacológico , Choque Séptico/tratamento farmacológico , Choque Séptico/fisiopatologia , Estatísticas não Paramétricas , Volume Sistólico/fisiologia , Vasoconstritores/uso terapêutico
16.
Crit Care ; 23(1): 116, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30971307

RESUMO

BACKGROUND: In critically ill patients, changes in the velocity-time integral (VTI) of the left ventricular outflow tract, measured by transthoracic echocardiography (TTE), are often used to non-invasively assess the response to fluid administration or for performing tests assessing fluid responsiveness. However, the precision of TTE measurements has not yet been investigated in such patients. First, we aimed at assessing how many measurements should be averaged within one TTE examination to reach a sufficient precision for various variables. Second, we aimed at identifying the least significant change (LSC) of these variables between successive TTE examinations. METHODS: We prospectively included 100 haemodynamically stable patients in whom TTE examination was planned. Three TTE examinations were performed, the first and the third by one operator and the second by another one. We calculated the precision and LSC (1) within one examination depending on the number of averaged measurements and (2) between measurements performed in two successive examinations. RESULTS: In patients in sinus rhythm, averaging three measurements within an examination was enough for obtaining an acceptable precision (interquartile range highest value < 10%) for VTI. In patients with atrial fibrillation, averaging five measurements was necessary. The precision of some other common TTE variables depending on the number of measurements is provided. Between two successive examinations performed by the same operator, the LSC was 11 [5-18]% for VTI. If two operators performed the examinations, the LSC for VTI significantly increased to 14 [8-26]%. The LSC between two examinations for other TTE variables is also provided. CONCLUSIONS: Averaging three measurements within one TTE examination is enough for obtaining precise measurements for VTI in patients in sinus rhythm but not in patients with atrial fibrillation. Between two TTE examinations performed by the same operator, the LSC of VTI is compatible with the assessment of the effects of a 500-mL fluid infusion but is not precise enough for assessing the effects of some tests predicting preload responsiveness.


Assuntos
Débito Cardíaco/fisiologia , Ecocardiografia/normas , Volume Sistólico/efeitos dos fármacos , Pesos e Medidas/instrumentação , Idoso , Idoso de 80 Anos ou mais , Estado Terminal/terapia , Ecocardiografia/métodos , Feminino , Hidratação/instrumentação , Hidratação/métodos , França , Humanos , Unidades de Terapia Intensiva/organização & administração , Unidades de Terapia Intensiva/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Volume Sistólico/fisiologia , Pesos e Medidas/normas
17.
Cardiol Rev ; 27(3): 138-144, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30946701

RESUMO

The need to quantify blood flow through the heart has led to the development of different techniques for its measurement. The 3 main approaches are the Fick method, dye dilution, and thermodilution techniques. The latter 2 are based on the use of indicators that indirectly quantify blood flow. These have slowly been developed over centuries, from the concept of measuring blood flow, to a technique, and its clinical utility. Thermodilution is the most popular dilution method used for measuring cardiac output (CO) in the clinical setting. The information obtained during this procedure is relevant in the process of clinical decision making in patients with critical illness, valvular heart disease, and congestive heart failure. The technique increased in popularity in the early 1970's after Swan and Ganz invented the pulmonary artery catheter that simplified thermodilution enough to utilize it as a bedside procedure. This was only possible with simple yet clever engineering methods that are not commonly known in the medical community. Despite these advancements, the concept of measuring CO by dilution techniques is one where its optimal use in the clinical setting continues to be an area of investigation. The thermodilution concept and the mechanism of measuring CO will be discussed in the following review.


Assuntos
Débito Cardíaco/fisiologia , Monitorização Fisiológica/história , Termodiluição/história , História do Século XIX , História do Século XX , História do Século XXI , Humanos , Monitorização Fisiológica/métodos
18.
Anaesthesia ; 74(6): 735-740, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30888055

RESUMO

Intravenous fluid boluses guided by changes in stroke volume improve some outcomes after major surgery, but invasive measurments may limit use. From October 2016 to May 2018, we compared the agreement and trending ability of a photoplethysmographic device (Clearsight) with a PiCCO, calibrated by thermodilution, for haemodynamic variables in 20 adults undergoing major elective surgery. We analysed 4519 measurement pairs, including before and after 68 boluses of 250 ml crystalloid. The bias and precision of stroke volume measurement by Clearsight were -0.89 ± 4.78 ml compared with the invasive pulse-contour cardiac output device. The coefficient of agreement for stroke volume variation after fluid boluses between the two devices was 0.79 ('strong'). Fluid boluses that increased stroke volume by ≥ 10% increased mean absolute volume (SD) and mean percentage (SD) stroke volume measurements similarly for the invasive pulse-contour cardiac output and Clearsight devices: 9 (4) ml vs. 8 (4) ml and 16% (8%) vs. 15% (10%), respectively, p > 0.05. The non-invasive Clearsight pulse-contour analysis was similar to an invasive pulse-contour device in measuring absolute and changing stroke volumes during major surgery.


Assuntos
Débito Cardíaco/fisiologia , Monitorização Intraoperatória/métodos , Adulto , Idoso , Feminino , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Volume Sistólico/fisiologia , Termodiluição/métodos
19.
Chin Med J (Engl) ; 132(10): 1139-1146, 2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-30882456

RESUMO

BACKGROUND: Increased extravascular lung water (EVLW) in shock is common in the critically ill patients. This study aimed to explore the effect of cardiac output (CO) on EVLW and its relevant influence on prognosis. METHODS: The hemodynamic data of 428 patients with pulse-indicated continuous CO catheterization from Department of Critical Care Medicine, Peking Union Medical College Hospital were retrospectively collected and analyzed. The patients were assigned to acute respiratory distress syndrome group, cardiogenic shock group, septic shock group, and combined shock (cardiogenic and septic) group according to their symptoms. Information on 28-day mortality and renal function was also collected. RESULTS: The CO and EVLW index (EVLWI) in the cardiogenic and combined shock groups were lower than those in the other groups (acute respiratory distress syndrome group vs. cardiogenic shock group vs. septic shock group vs. combined shock group: CO, 5.1 [4.0, 6.2] vs. 4.7 [4.0, 5.7] vs. 5.5 [4.3, 6.7] vs. 4.6 [3.5, 5.7] at 0 to 24 h, P = 0.009; 4.6 [3.8, 5.6] vs. 4.8 [4.1, 5.7] vs. 5.3 [4.4, 6.5] vs. 4.5 [3.8, 5.3] at 24 to 48 h, P = 0.048; 4.5 [4.1, 5.4] vs. 4.8 [3.8, 5.5] vs. 5.3 [4.0, 6.4] vs. 4.0 [3.2, 5.4] at 48 to 72 h, P = 0.006; EVLWI, 11.4 [8.7, 19.1] vs. 7.9 [6.6, 10.0] vs. 8.8 [7.4, 11.0] vs. 8.2 [6.7, 11.3] at 0 to 24 h, P < 0.001; 11.8 [7.7, 17.2] vs. 7.8 [6.3, 10.2] vs. 8.7 [6.6, 12.2] vs. 8.0 [6.6, 11.1] at 24 to 48 h, P < 0.001; and 11.3 [7.7, 18.7] vs. 7.5 [6.3, 10.0] vs. 8.8 [6.3, 12.2] vs. 8.4 [6.4, 11.2] at 48 to 72 h, P < 0.001. The trend of the EVLWI in the septic shock group was higher than that in the cardiogenic shock group (P < 0.05). Moreover, there existed some difference in the pulmonary vascular permeability index among the cardiogenic shock group, the septic shock group, and the combined shock group, without statistical significance (P > 0.05). In addition, there was no significant difference in tissue perfusion or renal function among the four groups during the observation period (P > 0.05). However, the cardiogenic shock group had a higher 28-day survival rate than the other three groups [log rank (Mantel-Cox) = 31.169, P < 0.001]. CONCLUSION: Tissue-aimed lower CO could reduce the EVLWI and achieve a better prognosis.


Assuntos
Débito Cardíaco/fisiologia , Água Extravascular Pulmonar/fisiologia , Choque Séptico/terapia , Adulto , Idoso , Feminino , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos
20.
Scand J Trauma Resusc Emerg Med ; 27(1): 30, 2019 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-30867006

RESUMO

BACKGROUND: There is little published data investigating non-invasive cardiac output monitoring in the emergency department (ED). We assessed six non-invasive fluid responsiveness monitoring methods which measure cardiac output directly or indirectly for their feasibility and repeatability of measurements in the ED: (1) left ventricular outflow tract echocardiography derived velocity time integral, (2) common carotid artery blood flow, (3) suprasternal aortic Doppler, (4) bioreactance, (5) plethysmography with digital vascular unloading method, and (6) inferior vena cava collapsibility index. METHODS: This is a prospective observational study of non-invasive methods of assessing fluid responsiveness in the ED. Participants were non-ventilated ED adult patients requiring intravenous fluid resuscitation. Feasibility of each method was determined by the proportion of clinically interpretable measurements from the number of measurement attempts. Repeatability was determined by comparing the mean difference of two paired measurements in a fluid steady state (after participants received an intravenous fluid bolus). RESULTS: 76 patients were recruited in the study. A total of 207 fluid responsiveness measurement sets were analysed. Feasibility rates were 97.6% for bioreactance, 91.3% for vascular unloading method with plethysmography, 87.4% for common carotid artery blood flow, 84.1% for inferior vena cava collapsibility index, 78.7% for LVOT VTI, and 76.8% for suprasternal aortic Doppler. The feasibility rates difference between bioreactance and all other methods was statistically significant. CONCLUSION: Our study shows that non-invasive fluid responsiveness monitoring in the emergency department may be feasible with selected methods. Higher repeatability of measurements were observed in non-ultrasound methods. These findings have implications for further studies specifically assessing the accuracy of such non-invasive cardiac output methods and their effect on patient outcome in the ED in fluid depleted states such as sepsis.


Assuntos
Débito Cardíaco/fisiologia , Serviço Hospitalar de Emergência , Hidratação/métodos , Monitorização Fisiológica/métodos , Ressuscitação/métodos , Sepse/terapia , Ecocardiografia , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sepse/diagnóstico , Sepse/fisiopatologia
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