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1.
Ann Palliat Med ; 10(10): 10904-10912, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34763452

RESUMO

BACKGROUND: A monitoring method is needed to further guide fluid resuscitation in severe burn injury. This study was performed to investigate the effects of pulse contour cardiac output (PCCO) monitoring on the prognosis of adult severe burns patients. METHODS: We conducted a retrospective study enrolling patients from January 2015 to December 2020, who were divided into a control group receiving conventional monitoring and a study group receiving PCCO monitoring. The primary outcomes were 28-day mortality and total mortality, and the secondary outcomes included burn-related complications and the length of hospital stay and ICU stay. Multivariable logistic regression analysis and linear regression analysis were performed to determine the risk factors of burns-related complications and length of hospital stay in enrolled patients. RESULTS: A total of 109 patients in the control group and 82 patients in the study group were enrolled. While the area of full thickness burn was much higher in the control group than in the study group (P=0.021), no significant difference was found in other characteristics between the two groups. During fluid resuscitation, the fluid volume ratio of the study group was significantly different from that of the control group, and both in the first 24 hours and the second 24 hours, the resuscitation fluid volume ratio and colloid volume ratio was significantly higher in the control group than in the study group (all P<0.001). Eight patients died during treatment, and there were more patients experiencing AKI and ARDS in the control group than in the study group (P=0.029 and 0.016). The lengths of hospital stay and ICU stay in the study group was much shorter than in the control group (P<0.001 and 0.005). In addition, TBSA was an important risk factor for both AKI and ARDS, and the existence of inhalation injury and older age increased the incidence of ARDS. Higher TBSA, inhalation injury, and burn-related complications were related to longer hospital stay in enrolled patients. CONCLUSIONS: Fluid resuscitation according to PCCO monitoring can effectively reduce the volume of colloid and overall fluid volume and reduce the incidence of burns-related complications and shorten the length of hospital stay.


Assuntos
Queimaduras , Hidratação , Adulto , Idoso , Queimaduras/terapia , Débito Cardíaco , Humanos , Prognóstico , Estudos Retrospectivos
2.
Best Pract Res Clin Anaesthesiol ; 35(4): 543-549, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34801216

RESUMO

Oxygen delivery is dependent on pulmonary gas exchange, cardiac output, blood oxygen-carrying capacity, and tissue oxygen extraction. Reduction in oxygen delivery or higher oxygen consumption can initiate complex protective cellular processes precipitating oxygen debt. In critically ill and potentially surgical patients, stress and consequent hormonal or metabolic changes can trigger oxygen debt which is associated with worse morbidity and mortality. Increase in oxygen delivery by augmenting cardiac output or by increasing fraction of inspired oxygen (FiO2) can help reduce oxygen debt. However, the extent of oxygen debt in an individual patient is poorly defined and difficult to measure. Furthermore, large heterogeneity in clinical trials assessing outcomes benefit of increasing oxygen delivery limits our ability to recommend goal directed fluid therapy aimed at increasing cardiac ouput or higher FiO2. To understand and prevent oxygen debt in critically ill and surgical patients, we need to develop continuous monitoring techniques to assess the balance of oxygen delivery and consumption. Furthermore, methods of increasing oxygen delivery like goal-directed fluid therapy, higher FiO2 and anemia prevention should be rigorously evaluated with focus on establishing outcomes benefit.


Assuntos
Consumo de Oxigênio , Troca Gasosa Pulmonar , Débito Cardíaco , Estado Terminal , Humanos , Oxigênio
3.
PLoS One ; 16(10): e0258225, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34653194

RESUMO

BACKGROUND: Right (R) or left (L) ventricular outflow tract (VOT) obstruction can be either a dynamic phenomenon or a congenital anatomic lesion, which requires a prompt and optimal timing of treatment to avoid a pathological ventricular remodelling. OBJECTIVE: To develop a simple and reliable numerical tool able to relate the R/L obstruction size with the pressure gradient and the cardiac output. To provide indication of the obstruction severity and be of help in the clinical management of patients and designing the surgical treatment for obstruction mitigation. METHODS: Blood flow across the obstruction is described according to the classical theory of one-dimensional flow, with the obstruction uniquely characterized by its size. Hemodynamics of complete circulation is simulated according to the lumped parameter approach. The case of a 2 years-old baby is reproduced, with the occlusion placed in either the R/ or the L/VOT. Conditions from wide open to almost complete obstruction are reproduced. RESULTS: Both R/LVOT obstruction in the in-silico model resulted in an increased pressure gradient and a decreased cardiac output, proportional to the severity of the VOT obstruction and dependent on the R/L location of the obstruction itself, as it is clinically observed. CONCLUSION: The in-silico model of ventricular obstruction which simulates pressure gradient and/or cardiac output agrees with clinical data, and is a first step towards the creation of a tool that can support the clinical management of patients from diagnosis to surgical treatments.


Assuntos
Simulação por Computador , Hemodinâmica/fisiologia , Modelos Cardiovasculares , Obstrução do Fluxo Ventricular Externo/fisiopatologia , Débito Cardíaco/fisiologia , Criança , Ventrículos do Coração/fisiopatologia , Humanos , Pressão , Artéria Pulmonar/fisiopatologia
5.
Medicine (Baltimore) ; 100(35): e27099, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34477146

RESUMO

ABSTRACT: Transcatheter occlusion and surgical ligation are the treatments of choice for most patent ductus arteriosus (PDA) in children. Fifty-five children who had PDA completed a pulmonary function test and a symptom-limited treadmill exercise test from 2016 to 2018 at 1 medical center in southern Taiwan. The study group was divided into surgical ligation and catheterization groups, which were compared to a healthy control group matched for age, sex, and body mass index. Data about the performance on the exercise test, including metabolic equivalent at anaerobic threshold and peak, were analyzed. No differences in the pulmonary function and ventilatory parameters were observed between the surgery, catheterization, and control groups. Heart rate at peak and at anaerobic threshold significantly differed in the investigated groups. The post hoc analysis showed that the surgery group had a lower heart rate at peak and threshold compared to the catheterization and control groups (P = .02, P < .001, respectively). No significant difference was found between the catheterization group and the control group. A larger and younger group of patients were recruited, allowing for newer data about the cardiopulmonary function to be obtained. The findings suggest that patients with PDA could undergo physical training after intervention. The imposition of restrictions to limit sports activities should be avoided.


Assuntos
Débito Cardíaco/fisiologia , Permeabilidade do Canal Arterial/complicações , Testes de Função Cardíaca/estatística & dados numéricos , Cateterismo Cardíaco/métodos , Cateterismo Cardíaco/estatística & dados numéricos , Criança , Permeabilidade do Canal Arterial/fisiopatologia , Feminino , Testes de Função Cardíaca/métodos , Humanos , Masculino , Pediatria/métodos , Resultado do Tratamento
6.
Resuscitation ; 168: 1-5, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34506875

RESUMO

PURPOSE: Fluid boluses (FB) are often used in post-cardiac arrest (CA) patients with haemodynamic instability. Although FB may improve cardiac output (CO) and mean arterial pressure (MAP), FB may also increase central venous pressure (CVP), reduce arterial PaO2, dilute haemoglobin and cause interstitial oedema. The aim of the present study was to investigate the net effect of FB administration on cerebral tissue oxygenation saturation (SctO2) in post-CA patients. METHODS: Pre-planned sub-study of the Neuroprotect post-CA trial (NCT02541591). Patients with anticipated fluid responsiveness based on stroke volume variation (SVV) or passive leg raising test were administered a FB of 500 ml plasma-lyte A (Baxter Healthcare) and underwent pre- and post-FB assessments of stroke volume, CO, MAP, CVP, haemoglobin, PaO2 and SctO2. RESULTS: 52 patients (mean age 64 ±â€¯12 years, 75% male) received a total of 115 FB. Although administration of a FB resulted in a significant increase of stroke volume (63 ±â€¯22 vs 67 ±â€¯23 mL, p = 0.001), CO (4,2 ±â€¯1,6 vs 4,4 ±â€¯1,7 L/min, p = 0.001) and MAP (74,8 ±â€¯13,2 vs 79,2 ±â€¯12,9 mmHg, p = 0.004), it did not improve SctO2 (68.54 ±â€¯6.99 vs 68.70 ±â€¯6.80%, p = 0.49). Fluid bolus administration also resulted in a significant increase of CVP (10,0 ±â€¯4,5 vs 10,7 ±â€¯4,9 mmHg, p = 0.02), but did not affect PaO2 (99 ±â€¯31 vs 94 ±â€¯31 mmHg, p = 0.15) or haemoglobin concentrations (12,9 ±â€¯2,1 vs 12,8 ±â€¯2,2 g/dL, p = 0.10). In a multivariate model, FB-induced changes in CO (beta 0,77; p = 0.004) and in CVP (beta -0,23; p = 0.02) but not in MAP (beta 0,02; p = 0.18) predicted post-FB ΔSctO2. CONCLUSIONS: Despite improvements in CO and MAP, FB administration did not improve SctO2 in post-cardiac arrest patients.


Assuntos
Hidratação , Parada Cardíaca , Idoso , Pressão Arterial , Débito Cardíaco , Pressão Venosa Central , Feminino , Parada Cardíaca/terapia , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade
7.
Medicine (Baltimore) ; 100(38): e27235, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34559119

RESUMO

ABSTRACT: To investigate the usefulness of afterload-related cardiac performance (ACP) for assessing cardiac impairment and predicting prognosis in septic patients.Adult patients with sepsis in the intensive care unit were included. Cardiac output, cardiac index, cardiac power index, and ACP were calculated at the time of admission (D0) and 48-72 h after admission (D3). They were correlated with Acute Physiology and Chronic Health Evaluation II and sequential organ failure assessment scores, then the prognostic values were analyzed.A total of 41 patients with sepsis were selected. ACP showed a stronger negative correlation with Acute Physiology and Chronic Health Evaluation II and sequential organ failure assessment scores than cardiac output, cardiac index, and cardiac power index. ACP predicted 28-day mortality with an area under the curve of 0.775 and 0.976 on D0 and D3, respectively. In addition, most non-survivors had emergent cardiac impairment (ACP ≤ 80%) on D0, and cardiac function was deteriorated on D3. Survival analysis showed that the patients with a decreased ACP from D0 to D3 had the highest mortality. The decrease of ACP on D3 was an independent risk factor for mortality (hazard ratio, 11.89; P = .0028).ACP can be used to assess the severity of cardiac impairment in sepsis. Continued decline of ACP during the first 3 days strongly suggests a poor prognosis.


Assuntos
Débito Cardíaco/fisiologia , Prognóstico , Sepse/fisiopatologia , Idoso , Área Sob a Curva , Estado Terminal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escores de Disfunção Orgânica , Projetos Piloto , Estudos Prospectivos , Curva ROC , Sepse/complicações , Análise de Sobrevida
8.
Medicine (Baltimore) ; 100(36): e27020, 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34516492

RESUMO

INTRODUCTION: The study aimed to reveal how the fraction of inspired oxygen (FIO2) affected the value of mixed venous oxygen saturation (SvO2) and the accuracy of Fick-equation-based cardiac output (Fick-CO). METHODS: Forty two adult patients who underwent elective cardiac surgery were enrolled and randomly divided into 2 groups: FIO2 < 0.7 or >0.85. Under stable general anesthesia, thermodilution-derived cardiac output (TD-CO), SvO2, venous partial pressure of oxygen, hemoglobin, arterial oxygen saturation, arterial partial pressure of oxygen, and blood pH levels were recorded before surgical incision. RESULTS: Significant differences in FIO2 values were observed between the 2 groups (0.56 ±â€Š0.08 in the <70% group and 0.92 ±â€Š0.03 in the >0.85 group; P < .001). The increasing FIO2 values lead to increases in SvO2, venous partial pressure of oxygen, and arterial partial pressure of oxygen, with little effects on cardiac output and hemoglobin levels. When comparing to TD-CO, the calculated Fick-CO in both groups had moderate Pearson correlations and similar linear regression results. Although the FIO2 <0.7 group presented a less mean bias and a smaller limits of agreement, neither group met the percentage error criteria of <30% in Bland-Altman analysis. CONCLUSION: Increased FIO2 may influence the interpretation of SvO2 and the exacerbation of Fick-CO estimation, which could affect clinical management. TRIAL REGISTRATION: ClinicalTrials.gov ID number: NCT04265924, retrospectively registered (Date of registration: February 9, 2020).


Assuntos
Débito Cardíaco , Procedimentos Cirúrgicos Cardíacos , Oxigênio/sangue , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Período Pós-Operatório , Estudos Prospectivos , Troca Gasosa Pulmonar , Adulto Jovem
9.
Am J Vet Res ; 82(10): 818-822, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34554871

RESUMO

OBJECTIVE: To compare the accuracy and precision of cardiac output (CO) measurements derived from 4 thermodilution protocols that used different injectate temperatures and volumes in healthy adult horses. ANIMALS: 8 healthy adult horses. PROCEDURES: Horses were anesthetized and instrumented with Swan-Ganz catheters. The CO was derived from each of 4 thermodilution protocols (IV injection of physiologic saline [0.9% NaCl] solution chilled to < 5 °C at volumes of 1 mL/15 kg of body weight [protocol A; control], 1 mL/25 kg [protocol B], and 1 mL/35 kg [protocol C] or maintained at 17 °C at a volume of 1 mL/15 kg [protocol D]) 3 times during each of 5 measurement cycles, with a 30-minute interval between cycles. During each measurement cycle, protocol A was performed first, and protocols B, C, and D were performed in a randomized order. Mean CO and within-subject variance in CO were compared among the 4 protocols. RESULTS: Mean CO did not differ significantly among the 4 protocols. The within-subject variance for CO measurements derived from protocols C and D, but not protocol B, was significantly greater than that for protocol A (control). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that, in healthy adult horses, decreasing the thermodilution injectate volume to 1 mL/25 kg from the recommended volume of 1 mL/15 kg did not adversely affect the accuracy or precision of CO measurements. However, use of smaller injectate volumes or use of injectate at approximately room temperature is not recommended owing to a clinically unacceptable increase in CO measurement variability.


Assuntos
Temperatura Corporal , Termodiluição , Animais , Débito Cardíaco , Cavalos , Temperatura , Termodiluição/veterinária
10.
Neonatology ; 118(5): 600-608, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34518489

RESUMO

INTRODUCTION: It is unknown whether bioreactance (BR) can accurately track cardiac output (CO) changes in preterm neonates. METHODS: A prospective observational longitudinal study was performed in stable preterm infants (<37 weeks) during the first 72 h of life. Stroke volume (SV) and CO, as measured by BR and transthoracic echocardiography, were compared. RESULTS: The mean gestational age (GA) was 31.3 weeks and mean birth weight (BW) was 1,563 g. Overall, 690 measurements were analysed for trending ability by 4-quadrant and polar plots. For non-weight-indexed measurements, 377 (54.6%) lay outside the 5% exclusion zone, the concordance rate was poor (77.2%) with a high mean angular bias (28.6°), wide limits of agreement and a poor angular concordance rate (17.4%). Neither GA, BW nor respiratory support mode affected trending data. Patent ductus arteriosus, postnatal age, and CO level had variable effects on trending data. Trending data for 5 and 10% exclusion zones were also compared. CONCLUSION: The ability of BR to track changes in CO is not interchangeable with CO changes as measured by echocardiography. BR, as a trend monitor for changes in CO or SV to determine clinical decisions around interventions in neonatology, should be used with caution.


Assuntos
Ecocardiografia , Recém-Nascido Prematuro , Débito Cardíaco , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Volume Sistólico
11.
Physiol Meas ; 42(10)2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34547725

RESUMO

Objective.Breast cancer treatment can negatively impact cardiac function in some breast cancer patients. Current methods (MUGA, echocardiography) used in clinical practice to detect abnormal cardiac changes as a result of treatment suffer from important limitations. Use of alternative techniques that would offer safe, inexpensive and non-invasive cardiac function assessment in this population would be highly advantageous. The aim of this study was to examine the agreement between impedance cardiography (ICG) and cardiac magnetic resonance imaging (CMR) in quantifying stroke volume (SV), cardiac output (CO) and end-diastolic volume (EDV) in this population.Approach.Sixteen breast cancer patients underwent ICG and CMR assessments at three time-points (before treatment, immediately after chemotherapy, and four months after chemotherapy). Bland-Altman analysis was used to quantify the accuracy and precision of ICG (relative to CMR) in estimating absolute values of SV, CO and EDV. Four methods (concordance rate, polar concordance rate, clinical concordance rate and trend interchangeability rate) were also used to assess ICG performance in tracking changes in these variables.Main results.Bland-Altman analysis showed that the accuracy of ICG relative to CMR was -3.1 ml (SV), 0.2 l·min-1(CO) and -26.0 ml (EDV) and precision was 13.2 ml (SV), 1.1 l·min-1(CO) and 20.1 ml (EDV), respectively. Trending ability assessment showed that (1) the concordance rate was 87% (SV), 73% (CO) and 73% (EDV), (2) the polar concordance rate was 67% (SV), 53% (CO) and 33% (EDV), (3) the clinical concordance rate was 33% (SV), 40% (CO) and 20% (EDV) and (4) the trend interchangeability rate was 29% (SV), 43% (CO) and 17% (EDV), respectively.Significance.Our findings show that, although ICG showed good accuracy for absolute SV and CO measurements and for CO and EDV changes, precision was poor for all variables in terms of both absolute measurements and trend tracking performance. This suggests that ICG cannot be used interchangeably with CMR in breast cancer patients.


Assuntos
Neoplasias da Mama , Cardiografia de Impedância , Neoplasias da Mama/diagnóstico por imagem , Débito Cardíaco , Feminino , Humanos , Imageamento por Ressonância Magnética , Volume Sistólico
12.
Sci Rep ; 11(1): 17862, 2021 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-34504252

RESUMO

When hemoglobin (Hb) is fully saturated with oxygen, the additional gain in oxygen delivery (DO2) achieved by increasing the fraction of inspired oxygen (FiO2) is often considered clinically insignificant. In this study, we evaluated the change in DO2, interrogated by mixed venous oxygen saturation (SvO2), in response to a change in FiO2 of 0.5 during cardiac surgery. When patients were hemodynamically stable, FiO2 was alternated between 0.5 and 1.0 in on-pump cardiac surgery patients (pilot study), and between 0.3 and 0.8 in off-pump coronary artery bypass grafting patients (substudy of the CARROT trial). After the patient had stabilized, a blood gas analysis was performed to measure SvO2. The observed change in SvO2 (ΔSvO2) was compared to the expected ΔSvO2 calculated using Fick's equation. A total 106 changes in FiO2 (two changes per patient; total 53 patients; on-pump, n = 36; off-pump, n = 17) were finally analyzed. While Hb saturation remained near 100% (on-pump, 100%; off-pump, mean [SD] = 98.1% [1.5] when FiO2 was 0.3 and 99.9% [0.2] when FiO2 was 0.8), SvO2 changed significantly as FiO2 was changed (the first and second changes in on-pump, 7.7%p [3.8] and 7.6%p [3.5], respectively; off-pump, 7.9%p [4.9] and 6.2%p [3.9]; all P < 0.001). As a total, regardless of the surgery type, the observed ΔSvO2 after the FiO2 change of 0.5 was ≥ 5%p in 82 (77.4%) changes and ≥ 10%p in 31 (29.2%) changes (mean [SD], 7.5%p [3.9]). Hb concentration was not correlated with the observed ΔSvO2 (the first changes, r = - 0.06, P = 0.677; the second changes, r = - 0.21, P = 0.138). The mean (SD) residual ΔSvO2 (observed - expected ΔSvO2) was 0%p (4). Residual ΔSvO2 was more than 5%p in 14 (13.2%) changes and exceeded 10%p in 2 (1.9%) changes. Residual ΔSvO2 was greater in patients with chronic kidney disease than in those without (median [IQR], 5%p [0 to 7] vs. 0%p [- 3 to 2]; P = 0.049). DO2, interrogated by SvO2, may increase to a clinically significant degree as FiO2 is increased during cardiac surgery, and the increase of SvO2 is not related to Hb concentration. SvO2 increases more than expected in patients with chronic kidney disease. Increasing FiO2 can be used to increase DO2 during cardiac surgery.


Assuntos
Débito Cardíaco/fisiologia , Consumo de Oxigênio/fisiologia , Oxigênio/sangue , Troca Gasosa Pulmonar/fisiologia , Cirurgia Torácica , Idoso , Gasometria/métodos , Ponte de Artéria Coronária sem Circulação Extracorpórea/métodos , Daucus carota/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oximetria/métodos
13.
Environ Toxicol Pharmacol ; 87: 103723, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34391906

RESUMO

Living organisms are commonly exposed to cadmium and other toxic metals. A vast body of research has shown the significant effects of these toxic metals on developmental processes. In order to study the role of toxic metals on early developmental stages of eukaryotes, we explored the effect of cadmium (Cd2+) contaminant on zebrafish. Thus, zebrafish embryos were exposed to 3 mg/L (16.7 µM) Cd2+ for 96 h and imaged every 24 h from the exposure onwards. Hatching rates of the eggs were determined at 72 h, followed by analyses at 96 h for: survival rate, morphometrical factors, and functional parameters of the cardiovascular system. Interestingly enough, significant hatching delays along with smaller cephalic region and some morphological abnormalities were observed in the treatment group. Moreover, substantial changes were noticed in the length of notochord and embryo, absorption of yolk sac with shorter extension, area of swimming bladder, as well as pericardium sac after Cd2+ treatment. Cadmium also caused significant abnormalities in heart physiology which could be the leading cause of mentioned morphological deformities. Herein, our results shine light on systematic acute embryological effects of cadmium in the early development of zebrafish for the first time.


Assuntos
Anormalidades Induzidas por Medicamentos , Anormalidades Múltiplas/induzido quimicamente , Cádmio/toxicidade , Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Teratógenos/toxicidade , Poluentes Químicos da Água/toxicidade , Anormalidades Induzidas por Medicamentos/fisiopatologia , Animais , Débito Cardíaco/efeitos dos fármacos , Embrião não Mamífero/anormalidades , Embrião não Mamífero/fisiologia , Frequência Cardíaca/efeitos dos fármacos , Volume Sistólico/efeitos dos fármacos , Peixe-Zebra/anormalidades , Peixe-Zebra/fisiologia
14.
Am J Physiol Heart Circ Physiol ; 321(4): H738-H747, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34448634

RESUMO

Hemoconcentration can influence hypoxic pulmonary vasoconstriction (HPV) via increased frictional force and vasoactive signaling from erythrocytes, but whether the balance of these mechanism is modified by the duration of hypoxia remains to be determined. We performed three sequential studies: 1) at sea level, in normoxia and isocapnic hypoxia with and without isovolumic hemodilution (n = 10, aged 29 ± 7 yr); 2) at altitude (6 ± 2 days acclimatization at 5,050 m), before and during hypervolumic hemodilution (n = 11, aged 27 ± 5 yr) with room air and additional hypoxia [fraction of inspired oxygen ([Formula: see text])= 0.15]; and 3) at altitude (4,340 m) in Andean high-altitude natives with excessive erythrocytosis (EE; n = 6, aged 39 ± 17 yr), before and during isovolumic hemodilution with room air and hyperoxia (end-tidal Po2 = 100 mmHg). At sea level, hemodilution mildly increased pulmonary artery systolic pressure (PASP; +1.6 ± 1.5 mmHg, P = 0.01) and pulmonary vascular resistance (PVR; +0.7 ± 0.8 wu, P = 0.04). In contrast, after acclimation to 5,050 m, hemodilution did not significantly alter PASP (22.7 ± 5.2 vs. 24.5 ± 5.2 mmHg, P = 0.14) or PVR (2.2 ± 0.9 vs. 2.3 ± 1.2 wu, P = 0.77), although both remained sensitive to additional acute hypoxia. In Andeans with EE at 4,340 m, hemodilution lowered PVR in room air (2.9 ± 0.9 vs. 2.3 ± 0.8 wu, P = 0.03), but PASP remained unchanged (31.3 ± 6.7 vs. 30.9 ± 6.9 mmHg, P = 0.80) due to an increase in cardiac output. Collectively, our series of studies reveal that HPV is modified by the duration of exposure and the prevailing hematocrit level. In application, these findings emphasize the importance of accounting for hematocrit and duration of exposure when interpreting the pulmonary vascular responses to hypoxemia.NEW & NOTEWORTHY Red blood cell concentration influences the pulmonary vasculature via direct frictional force and vasoactive signaling, but whether the magnitude of the response is modified with duration of exposure is not known. By assessing the pulmonary vascular response to hemodilution in acute normobaric and prolonged hypobaric hypoxia in lowlanders and lifelong hypobaric hypoxemia in Andean natives, we demonstrated that a reduction in red cell concentration augments the vasoconstrictive effects of hypoxia in lowlanders. In high-altitude natives, hemodilution lowered pulmonary vascular resistance, but a compensatory increase in cardiac output following hemodilution rendered PASP unchanged.


Assuntos
Aclimatação , Altitude , Pressão Arterial , Eritrócitos/metabolismo , Hemodiluição , Hipóxia/sangue , Policitemia/sangue , Artéria Pulmonar/fisiopatologia , Vasoconstrição , Adulto , Viscosidade Sanguínea , Débito Cardíaco , Frequência Cardíaca , Hematócrito , Humanos , Hipóxia/diagnóstico , Hipóxia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Policitemia/diagnóstico , Policitemia/fisiopatologia , Fatores de Tempo , Resistência Vascular , Adulto Jovem
15.
Vet Anaesth Analg ; 48(5): 654-662, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34332897

RESUMO

OBJECTIVE: To evaluate the systemic cardiovascular effects of dose escalating administration of norepinephrine in healthy dogs anesthetized with isoflurane. STUDY DESIGN: Experimental study. ANIMALS: A total of six adult laboratory Beagle dogs, 10.5 (9.2-12.0) kg [median (range)]. METHODS: Each dog was anesthetized with isoflurane at an end-tidal concentration of 1.7%, mechanically ventilated and administered a continuous rate infusion of rocuronium (0.5 mg kg-1 hour-1). Each dog was administered incremental dose rates of norepinephrine (0.05, 0.125, 0.25, 0.5, 1.0 and 2.0 µg kg-1 minute-1), and each dose was infused for 15 minutes. Cardiovascular variables were recorded before administration and at the end of each infusion period. RESULTS: Norepinephrine infusion increased mean arterial pressure (MAP), cardiac output (CO) and oxygen delivery in a dose-dependent manner. Systemic vascular resistance did not significantly change during the experiment. Stroke volume increased at the lower dose rates and heart rate increased at the higher dose rates. Oxygen consumption and lactate concentrations did not significantly change during infusions. CONCLUSIONS: In dogs anesthetized with isoflurane, norepinephrine increased MAP by increasing the CO. CO increased with a change in stroke volume at lower dose rates of norepinephrine. At higher dosage, heart rate also contributed to an increase in CO. Norepinephrine did not cause excessive vasoconstriction that interfered with the CO during this study. CLINICAL RELEVANCE: Norepinephrine can be useful for treating hypotension in dogs anesthetized with isoflurane.


Assuntos
Anestésicos Inalatórios , Isoflurano , Norepinefrina , Anestésicos Inalatórios/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Débito Cardíaco/efeitos dos fármacos , Cães , Frequência Cardíaca/efeitos dos fármacos , Isoflurano/farmacologia , Norepinefrina/farmacologia
16.
Crit Care ; 25(1): 302, 2021 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-34419120

RESUMO

BACKGROUND: Through venous contraction, norepinephrine (NE) increases stressed blood volume and mean systemic pressure (Pms) and exerts a "fluid-like" effect. When both fluid and NE are administered, Pms may not only result from the sum of the effects of both drugs. Indeed, norepinephrine may enhance the effects of volume expansion: because fluid dilutes into a more constricted, smaller, venous network, fluid may increase Pms to a larger extent at a higher than at a lower dose of NE. We tested this hypothesis, by mimicking the effects of fluid by passive leg raising (PLR). METHODS: In 30 septic shock patients, norepinephrine was decreased to reach a predefined target of mean arterial pressure (65-70 mmHg by default, 80-85 mmHg in previously hypertensive patients). We measured the PLR-induced increase in Pms (heart-lung interactions method) under high and low doses of norepinephrine. Preload responsiveness was defined by a PLR-induced increase in cardiac index ≥ 10%. RESULTS: Norepinephrine was decreased from 0.32 [0.18-0.62] to 0.26 [0.13-0.50] µg/kg/min (p < 0.0001). This significantly decreased the mean arterial pressure by 10 [7-20]% and Pms by 9 [4-19]%. The increase in Pms (∆Pms) induced by PLR was 13 [9-19]% at the higher dose of norepinephrine and 11 [6-16]% at the lower dose (p < 0.0001). Pms reached during PLR at the high dose of NE was higher than expected by the sum of Pms at baseline at low dose, ∆Pms induced by changing the norepinephrine dose and ∆Pms induced by PLR at low dose of NE (35.6 [11.2] mmHg vs. 33.6 [10.9] mmHg, respectively, p < 0.01). The number of preload responders was 8 (27%) at the high dose of NE and 15 (50%) at the low dose. CONCLUSIONS: Norepinephrine enhances the Pms increase induced by PLR. These results suggest that a bolus of fluid of the same volume has a greater haemodynamic effect at a high dose than at a low dose of norepinephrine during septic shock.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Norepinefrina/farmacologia , Choque Séptico/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea/fisiologia , Débito Cardíaco/efeitos dos fármacos , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Norepinefrina/administração & dosagem , Norepinefrina/farmacocinética , Substitutos do Plasma/administração & dosagem , Substitutos do Plasma/farmacocinética , Substitutos do Plasma/farmacologia , Choque Séptico/fisiopatologia , Resultado do Tratamento , Vasoconstritores/administração & dosagem , Vasoconstritores/farmacocinética , Vasoconstritores/farmacologia
17.
Sci Rep ; 11(1): 17141, 2021 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-34433865

RESUMO

We investigated hemodynamic, cardiac morphofunctional, and cardiovascular autonomic adaptations in spontaneously hypertensive rats (SHRs) after aerobic physical training associated with chronic cholinergic stimulation. Fifty-four SHRs were divided into two groups: trained and untrained. Each group was further subdivided into three smaller groups: vehicle, treated with pyridostigmine bromide at 5 mg/kg/day, and treated with pyridostigmine bromide at 15 mg/kg/day. The following protocols were assessed: echocardiography, autonomic double pharmacological blockade, heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS). Physical training and pyridostigmine bromide reduced BP and HR and increased vagal participation in cardiac autonomic tonic balance. The associated responses were then potentialized. Treatment with pyridostigmine bromide increased HRV oscillation of both low frequency (LF: 0.2-0.75 Hz) and high frequency (HF: 0.75-3 Hz). However, the association with physical training attenuated HF oscillations. Additionally, treatment with pyridostigmine bromide also increased LF oscillations of BPV. Both treatment groups promoted morphofunctional adaptations, and associated increased ejection volume, ejection fraction, cardiac output, and cardiac index. In conclusion, the association of pyridostigmine bromide and physical training promoted greater benefits in hemodynamic parameters and increased vagal influence on cardiac autonomic tonic balance. Nonetheless, treatment with pyridostigmine bromide alone seems to negatively affect BPV and the association of treatment negatively influences HRV.


Assuntos
Inibidores da Colinesterase/farmacologia , Coração/efeitos dos fármacos , Hipertensão/terapia , Condicionamento Físico Animal/métodos , Brometo de Piridostigmina/farmacologia , Nervo Vago/efeitos dos fármacos , Animais , Pressão Sanguínea , Débito Cardíaco , Inibidores da Colinesterase/administração & dosagem , Inibidores da Colinesterase/uso terapêutico , Coração/fisiopatologia , Hipertensão/tratamento farmacológico , Brometo de Piridostigmina/administração & dosagem , Brometo de Piridostigmina/uso terapêutico , Ratos , Ratos Endogâmicos SHR , Nervo Vago/fisiopatologia
18.
Biol Psychol ; 165: 108165, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34416348

RESUMO

We know surprisingly little on how heartbeat-evoked responses (HERs) vary with cardiac parameters. Here, we measured both stroke volume, or volume of blood ejected at each heartbeat, with impedance cardiography, and HER amplitude with magneto-encephalography, in 21 male and female participants at rest with eyes open. We observed that HER co-fluctuates with stroke volume on a beat-to-beat basis, but only when no correction for cardiac artifact was performed. This highlights the importance of an ICA correction tailored to the cardiac artifact. We also observed that easy-to-measure cardiac parameters (interbeat intervals, ECG amplitude) are sensitive to stroke volume fluctuations and can be used as proxies when stroke volume measurements are not available. Finally, interindividual differences in stroke volume were reflected in MEG data, but whether this effect is locked to heartbeats is unclear. Altogether, our results question assumptions on the link between stroke volume and HERs.


Assuntos
Cardiografia de Impedância , Coração , Débito Cardíaco , Feminino , Coração/diagnóstico por imagem , Frequência Cardíaca , Humanos , Masculino , Volume Sistólico
19.
Sci Rep ; 11(1): 15849, 2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34349162

RESUMO

Extracorporeal membrane oxygenation (ECMO) is a life-saving intervention for patients suffering from respiratory or cardiac failure. The ECMO-associated morbidity and mortality depends to a large extent on the underlying disease and is often related to systemic inflammation, consecutive immune paralysis and sepsis. Here we tested the hypothesis that human α1-antitrypsin (SERPINA1) due to its anti-protease and anti-inflammatory functions may attenuate ECMO-induced inflammation. We specifically aimed to test whether intravenous treatment with α1-antitrypsin reduces the release of cytokines in response to 2 h of experimental ECMO. Adult rats were intravenously infused with α1-antitrypsin immediately before starting veno-arterial ECMO. We measured selected pro- and anti-inflammatory cytokines and found, that systemic levels of tumor necrosis factor-α, interleukin-6 and interleukin-10 increase during experimental ECMO. As tachycardia and hypertension developed in response to α1-antitrypsin, a single additional bolus of fentanyl and midazolam was given. Treatment with α1-antitrypsin and higher sedative doses reduced all cytokine levels investigated. We suggest that α1-antitrypsin might have the potential to protect against both ECMO-induced systemic inflammation and immune paralysis. More studies are needed to corroborate our findings, to clarify the mechanisms by which α1-antitrypsin inhibits cytokine release in vivo and to explore the potential application of α1-antitrypsin in clinical ECMO.


Assuntos
Débito Cardíaco/efeitos dos fármacos , Citocinas/metabolismo , Oxigenação por Membrana Extracorpórea/métodos , Hemodinâmica , Inibidores da Tripsina/farmacologia , alfa 1-Antitripsina/farmacologia , Animais , Masculino , Ratos , Ratos Endogâmicos Lew
20.
Am J Physiol Regul Integr Comp Physiol ; 321(3): R454-R468, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34346723

RESUMO

We evaluated maternal pregnancy adaptations and their relationships with circulating hormones in women who conceived with or without in vitro fertilization (IVF). Pregnancies were grouped by corpus luteum (CL) number: 1 CL with physiological plasma relaxin concentration (PRLN; spontaneous pregnancies); 0 CL without circulating RLN (programmed cycles); >1 CL with elevated PRLN (ovarian stimulation). Major findings were that declines in plasma osmolality (Posm) and plasma sodium concentration ([Formula: see text]) were comparable in the 1 CL and 0 CL cohorts, correlated with plasma estradiol and progesterone concentrations but not PRLN; gestational declines in plasma uric acid (UA) concentration (PUA) were attenuated after IVF, especially programmed cycles, partly because of subdued increases of renal UA clearance; and PRLN and cardiac output (CO) were inversely correlated when plasma estradiol concentration was below ∼2.5 ng/mL but positively correlated above ∼2.5 ng/mL. Unexpectedly, PRLN and plasma sFLT1 (PsFLT1) were directly correlated. Although PsFLT1 and CO were not significantly associated, CO was positively correlated with plasma placental growth factor (PLGF) concentration after the first trimester, particularly in women who conceived with 0 CL. Major conclusions are that 1) circulating RLN was unnecessary for gestational falls in Posm and [Formula: see text]; 2) PRLN and CO were inversely correlated during early gestation, suggesting that PRLN in the lower range may have contributed to systemic vasodilation, whereas at higher PRLN RLN influence became self-limiting; 3) evidence for cooperativity between RLN and estradiol on gestational changes in CO was observed; and 4) after the first trimester in women who conceived without a CL, plasma PLGF concentration was associated with recovery of CO, which was impaired during the first trimester in this cohort.


Assuntos
Fertilização In Vitro , Hormônios Gonadais/sangue , Hemodinâmica , Infertilidade/terapia , Adaptação Fisiológica , Adulto , Biomarcadores/sangue , Débito Cardíaco , Estradiol/sangue , Feminino , Humanos , Infertilidade/sangue , Infertilidade/fisiopatologia , Pessoa de Meia-Idade , Concentração Osmolar , Fator de Crescimento Placentário/sangue , Gravidez , Primeiro Trimestre da Gravidez/sangue , Relaxina/sangue , Sódio/sangue , Ácido Úrico/sangue , Vasodilatação , Adulto Jovem
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