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1.
Arq Bras Cir Dig ; 33(1): e1484, 2020.
Artigo em Inglês, Português | MEDLINE | ID: mdl-32236290

RESUMO

BACKGROUND: Hepatectomies promote considerable amount of blood loss and the need to administrate blood products, which are directly linked to higher morbimortality rates. The blood-conserving hepatectomy (BCH) is a modification of the selective vascular occlusion technique. It could be a surgical maneuver in order to avoid or to reduce the blood products utilization in the perioperative period. AIM: To evaluate in rats the BCH effects on the hematocrit (HT) variation, hemoglobin serum concentration (HB), and on liver regeneration. METHODS: Twelve Wistar rats were divided into two groups: control (n=6) and intervention (n=6). The ones in the control group had their livers partially removed according to the Higgins and Anderson technique, while the rats in the treatment group were submitted to BCH technique. HT and HB levels were measured at day D0, D1 and D7. The rate between the liver and rat weights was calculated in D0 and D7. Liver regeneration was quantitatively and qualitatively evaluated. RESULTS: The HT and HB levels were lower in the control group as of D1 onwards, reaching an 18% gap at D7 (p=0.01 and p=0.008, respectively); BCH resulted in the preservation of HT and HB levels to the intervention group rats. BCH did not alter liver regeneration in rats. CONCLUSION: The BCH led to beneficial effects over the postoperative HT and serum HB levels with no setbacks to liver regeneration. These data are the necessary proof of evidence for translational research into the surgical practice. A) Unresected liver; B) liver appearance after the partial hepatectomy (1=vena cava; 2=portal vein; 3=hepatic vein; 4=biliary drainage; 5=hepatic artery).


Assuntos
Hepatectomia/métodos , Regeneração Hepática , Fígado/irrigação sanguínea , Fígado/cirurgia , Veias/fisiologia , Animais , Volume Sanguíneo/fisiologia , Hematócrito , Hemoglobinas/análise , Hepatopatia Veno-Oclusiva/fisiopatologia , Masculino , Veia Porta/cirurgia , Período Pós-Operatório , Ratos , Ratos Wistar
3.
Bioelectromagnetics ; 41(1): 21-33, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31755122

RESUMO

The present study is part of an ongoing effort to develop a simple diagnostic technology for detecting internal bleeding in the brain, which can be used in lieu or in support of medical imaging and thereby reduce the cost of diagnostics in general, and in particular, would make diagnostics accessible to economically disadvantaged populations. The study deals with a single coil inductive device to be used for detecting cerebral hemorrhage. It presents a first-order experimental study that examines the predictions of our recently published theoretical study. The experimental model employs a homogeneous cylindrical phantom in which internal head bleeding was simulated by way of a fluid inclusion. We measured the changes in amplitude and phase across the coil with a network vector analyzer as a function of frequency (100-1,000 MHz), volume of blood simulating fluid, and the site of the fluid injection. We have developed a new mathematical model to statistically analyze the complex data produced in this experiment. We determined that the resolution for the fluid volume increase following fluid injection is strongly dependent on frequency as well as the location of liquid accumulation. The experimental data obtained in this study supports the predictions of our previous theoretical study, and the statistical analysis shows that the simple single coil device is sensitive enough to detect changes due to fluid volume alteration of two milliliters. Bioelectromagnetics. 2020;41:21-33 © 2019 Bioelectromagnetics Society.


Assuntos
Determinação do Volume Sanguíneo/métodos , Simulação por Computador , Imagens de Fantasmas , Acidente Vascular Cerebral/diagnóstico , Volume Sanguíneo , Condutividade Elétrica , Campos Eletromagnéticos , Desenho de Equipamento , Transdutores
4.
J Glob Health ; 9(2): 020432, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31788230

RESUMO

Background: Postpartum hemorrhage (PPH) is the leading cause of maternal mortality worldwide, but it mainly affects women from low- and middle-income countries. Despite being a treatable condition, the high number of maternal deaths resulting from PPH is outstanding for at least 25 years. Late diagnosis and difficulties in identifying women who will develop severe postpartum bleeding can, in part, explain the high incidence of PPH. Over the past few years, researchers have focused on identifying a simple, accessible and low-cost diagnostic tool that could be applied to avoid maternal deaths. In particular, it has been suggested that vital signs and shock index (SI) could be useful. The objective of this study was to evaluate whether vital signs are correlated with the percentage of body blood volume (BBVp) lost after vaginal delivery. Methods: A prospective cohort study was performed at the Women's Hospital of UNICAMP, Brazil. The inclusion criteria were women delivering vaginally who did not suffer from hypertension, hyper- or hypothyroidism, cardiac disease, infections or coagulopathy. Blood loss was measured over 24 hours using a calibrated drape and by weighing compresses, gauzes and pads. Vital signs were measured up to 24 hours after delivery. We evaluated the BBVp lost, and generated a Receiver operating characteristics (ROC) curve with area under the curve (AUC) analysis to determine the cut-off values for vital signs to determine the likelihood of postpartum bleeding above the 90th percentile within 24 hours of delivery. Results: A total of 270 women were included. The mean blood loss within 24 hours of vaginal delivery was 570.66 ± 360.04 mL. In the first 40 minutes, 73% of the total blood loss over the 24-hour period had occurred, and within 2 hours, 91% of women had bled 90% of the total blood loss. Changes in SI and heart rate (HR) were statistically significant in predicting postpartum bleeding (P ≤ 0.05). Higher values for likelihood ratio (LR) to identify BBVp loss above the 90th percentile within 2 hours were a SI above 1.04 at 41-60 minutes after birth (LR = +11.84) and a HR above 105.2 bpm at 21-40 minutes after birth (LR = +4.96). Both measures showed high specificity but low sensitivity. Conclusion: Values of SI and HR are statistically significant in predicting postpartum bleeding with high specificity but low sensitivity. The cut-off points were 1.04 for SI and 105 bpm for HR.


Assuntos
Perda Sanguínea Cirúrgica/fisiopatologia , Parto Obstétrico/efeitos adversos , Frequência Cardíaca/fisiologia , Hemorragia Pós-Parto/epidemiologia , Índices de Gravidade do Trauma , Adulto , Volume Sanguíneo , Brasil/epidemiologia , Feminino , Humanos , Incidência , Mortalidade Materna , Valor Preditivo dos Testes , Gravidez , Estudos Prospectivos , Índice de Gravidade de Doença , Sinais Vitais
5.
Heart Surg Forum ; 22(5): E352-E356, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31596710

RESUMO

BACKGROUND: The association of obesity with postoperative bleeding volume and transfusions after coronary artery bypass grafting (CABG) is not clear. We evaluated the effects of body mass index (BMI) on bleeding volume and transfusions in patients undergoing on-pump CABG. METHODS: We investigated 1,050 patients, aged 24 years to 83 years, who underwent isolated, primary CABG with cardiopulmonary bypass (CPB) at Fuwai Hospital, Chinese Academy of Medical Sciences, from September 2017 to July 2018. We recorded preoperative medical and laboratory coagulation parameters, intraoperative data, and postoperative bleeding volume for 24 hours following surgery. Primary endpoint was bleeding volume within 24 hours and transfusions after surgery. We analyzed the correlation between bleeding volume within 24 hours and transfusions after surgery and preoperative data with univariate and multivariate linear regression and logistic regression. RESULTS: Old age significantly increased postoperative transfusions (OR = 1.035 95% CI 1.013-1.058, P = .002), whereas higher BMI (OR = 0.897 95% CI 0.848-0.949, P < .001) and higher hemoglobin (HGB) (OR = 0.966 95% CI 0.954-0.978, P < 0.001) decreased postoperative transfusions. And, BMI independently was correlated with bleeding volume after multivariate regression analysis (B = -0.257, P < .001). CONCLUSIONS: Our findings suggest higher BMI may reduce postoperative bleeding volume and transfusion rate, thus such patients may save blood products during on-pump CABG.


Assuntos
Perda Sanguínea Cirúrgica/estatística & dados numéricos , Transfusão de Sangue/estatística & dados numéricos , Índice de Massa Corporal , Ponte Cardiopulmonar , Ponte de Artéria Coronária/métodos , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Coagulação Sanguínea , Volume Sanguíneo , Tubos Torácicos , Drenagem , Feminino , Hemoglobina A/análise , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
6.
Radiology ; 293(2): 469-470, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31577176

Assuntos
Volume Sanguíneo , Rim
7.
Best Pract Res Clin Anaesthesiol ; 33(2): 155-163, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31582095

RESUMO

The clinical usefulness of the so-called "static" cardiac filling pressures - central (CVP) and pulmonary-artery-occlusion-pressure (PAOP) - has come into question for guiding hemodynamic therapy due to their poor ability to predict fluid responsiveness in comparison with other monitoring modalities such as transpulmonary thermodilution-derived volumetric measurements, dynamic variables for assessing fluid responsiveness, and the potential risks associated with pulmonary artery catheterization. This contrasts with observations in multiple patient populations showing a clear association between increased CVP and PAOP levels and poor outcomes, probably due to a reduction in effective perfusion pressure (mean arterial pressure minus CVP) and their role as effectiveness parameters of the cardiovascular system. Furthermore, clinical studies have revealed beneficial effects when interpreting CVP and PAOP dynamically and combining them with flow-related hemodynamic variables. Taking into account the additional information derived from bedside CVP and PAOP pulse curve interpretation, cardiac filling pressures remain an important hemodynamic monitoring tool.


Assuntos
Pressão Sanguínea/fisiologia , Monitorização Hemodinâmica/métodos , Assistência Perioperatória/métodos , Volume Sistólico/fisiologia , Volume Sanguíneo/fisiologia , Débito Cardíaco/fisiologia , Humanos
8.
J Nippon Med Sch ; 86(4): 192-200, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31484880

RESUMO

Twin to twin transfusion syndrome (TTTS) is a major complication of monochorionic diamniotic (MD) twins, and its onset is known to be associated with placental vascular anastomoses and blood flow imbalance. In a typical case of TTTS, the recipient develops polyhydramnios, weight gain, cardiomegaly and hydrops fetalis in the uterus. In contrast, the donor develops oligohydramnios and intrauterine growth restriction. Recently, the significance of the renin-angiotensin-aldosterone system (RAAS) that transfers from the donor to the recipient has attracted interest in the fetal circulation of TTTS. The donor has decreased renal blood flow due to decreased circulating blood volume. For this reason, the secretion of RAAS hormones is augmented in the fetal kidneys of the donor. In TTTS, these RAAS hormones from the donor transfer to the recipient through the anastomosed vessels. In addition to excess preload, the recipient heart is exposed to excess afterload due to systemic vasoconstriction through RAAS hormones. Commonly occurring complications in the recipient include myocardial hypertrophy, atrioventricular valve regurgitation, and pulmonary valve stenosis or pulmonary atresia. Fetoscopic laser photocoagulation (FLP) has been introduced recently because neither mortality nor neurological morbidity have been satisfactorily improved with conventional treatment. FLP is a curative method that may improve the prognosis of TTTS. In Japan, this procedure has been performed frequently, and positive neurological outcomes have been achieved.


Assuntos
Transfusão Feto-Fetal , Feto/irrigação sanguínea , Volume Sanguíneo , Cardiomegalia/embriologia , Cardiomegalia/etiologia , Feminino , Doenças Fetais/etiologia , Doenças Fetais/fisiopatologia , Retardo do Crescimento Fetal/etiologia , Transfusão Feto-Fetal/diagnóstico por imagem , Transfusão Feto-Fetal/etiologia , Transfusão Feto-Fetal/patologia , Transfusão Feto-Fetal/terapia , Fetoscopia , Humanos , Terapia com Luz de Baixa Intensidade , Poli-Hidrâmnios/etiologia , Gravidez , Prognóstico , Estenose da Valva Pulmonar/embriologia , Estenose da Valva Pulmonar/etiologia , Circulação Renal , Sistema Renina-Angiotensina/fisiologia
9.
PLoS Comput Biol ; 15(9): e1007346, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31513566

RESUMO

We performed a mathematical analysis of the dynamic control loops regulating the vasomotor tone of vascular smooth muscle, blood volume, and mean arterial pressure, which involve the arginine vasopressin (AVP) system, the atrial natriuretic peptide system (ANP), and the renin-angiotensin-aldosterone system (RAAS). Our loop analysis of the AVP-ANP-RAAS system revealed the concurrent presence of two different regulatory mechanisms, which perform the same qualitative function: one affects blood pressure by regulating vasoconstriction, the other by regulating blood volume. Both the systems are candidate oscillators consisting of the negative-feedback loop of a monotone system: they admit a single equilibrium that can either be stable or give rise to oscillatory instability. Also a subsystem, which includes ANP and AVP stimulation of vascular smooth muscle cells, turns out to be a candidate oscillator composed of a monotone system with multiple negative feedback loops, and we show that its oscillatory potential is higher when the delays along all feedback loops are comparable. Our results give insight into the physiological mechanisms ruling long-term homeostasis of blood hydraulic parameters, which operate based on dynamical loops of interactions.


Assuntos
Pressão Sanguínea/fisiologia , Volume Sanguíneo/fisiologia , Homeostase/fisiologia , Modelos Biológicos , Arginina Vasopressina/metabolismo , Fator Natriurético Atrial/metabolismo , Cálcio/metabolismo , Biologia Computacional , Retroalimentação Fisiológica/fisiologia , Humanos , Músculo Liso Vascular/citologia , Sistema Renina-Angiotensina/fisiologia
10.
Sex Reprod Healthc ; 21: 21-25, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31395229

RESUMO

INTRODUCTION: Retained placenta can be defined as lack of expulsion of the placenta within 30 min of delivery of the infant. It is a significant cause of maternal mortality and morbidity throughout the developing world. AIM OF THE WORK: The aim of this study was to compare the efficacy of intra-umbilical vein injection of carbetocin versus oxytocin in the management of retained placenta. PATIENTS AND METHODS: A total of 200 women were included in this study. They were divided into two groups; each 100 women. The first group received intra-umbilical vein injection of 1 mL carbetocin (containing 100 µg carbetocin) diluted in 20 mL normal saline 0.9% and the second group received intra-umbilical vein injection of 20 IU oxytocin diluted in 20 mL normal saline 0.9%. RESULTS: Total blood loss (ml) and duration of the third stage of labor (minutes) were significantly lower in carbetocin group when compared to oxytocin group. Postoperative Hb concentration (g/dl) was significantly higher in carbetocin group. Also there was a highly significant difference between both groups as regard change in Hb concentration (g/dl) with less change in the carbetocin group. The need for additional uterotonic drugs following placental delivery and the occurrence of postpartum hemorrhage and the need for blood transfusion were significantly lower in the carbetocin group. CONCLUSION: Intra-umbilical carbetocin is more effective than intra-umbilical oytocin as a method for management of retained placenta. Intra-umbilical carbetocin seems to have more acceptable hemodynamic safety profile when compared to intra-umbilical oxytocin in the management of retained placenta.


Assuntos
Ocitócicos/uso terapêutico , Ocitocina/análogos & derivados , Ocitocina/uso terapêutico , Placenta Retida/tratamento farmacológico , Hemorragia Pós-Parto/prevenção & controle , Adulto , Transfusão de Sangue , Volume Sanguíneo , Método Duplo-Cego , Feminino , Hemoglobinas/metabolismo , Humanos , Injeções Intravenosas , Ocitócicos/administração & dosagem , Ocitocina/administração & dosagem , Ocitocina/efeitos adversos , Gravidez , Estudos Prospectivos , Veias Umbilicais , Adulto Jovem
12.
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
13.
Respir Res ; 20(1): 137, 2019 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-31272464

RESUMO

BACKGROUND: The severity of Hereditary Hemorrhagic Telangiectasia (HHT) disease is generally related to vascular visceral involvement represented by arteriovenous malformations (AVMs). Pulmonary function tests (PFTs) remain normal in HHT patients without Pulmonary AVMs (PAVMs) and respiratory comorbidity. The aim of our study was to compare the diffusing capacity of the lung for carbon monoxide (DLCO) and nitric oxide (DLNO) and its 2 components: the pulmonary capillary blood volume (Vc) and the alveolar-capillary membrane conductance (Dm), in HHT patients with PAVMs, PAVMs and liver AVMs (LAVMs), LAVMs without PAVM, no PAVM and LAVM, and controls. METHODS: Sixty one consecutive adult patients (HHT without PAVM and LAVM: n = 7; HHT with PAVMs: n = 8; HHT with PAVMs and LAVMs: n = 25; HHT with LAVMs: n = 21) and controls matched for age and sex ratio without respiratory, heart and liver pathology (n = 15) were non-invasively evaluated using PFTs, combined DLCO/DLNO, arterial blood gas at rest, contrast echocardiography and enhanced computed tomography scan of the liver and chest the day of pulmonary function testing. RESULTS: We found that patients with LAVMs but without PAVMs exhibited increased Vc/Dm ratio. Interestingly, HHT patients with hepatic artery enlargement showed higher Vc/Dm ratio than HHT patients with normal hepatic artery diameter. CONCLUSION: Vc/Dm ratio may have practical impact in HHT patients' management to detect precociously the occurrence of LVAMs. However, further studies are needed to assess the accuracy and potential prognostic value of pulmonary gas exchange measurements in HHT patients with LVAMs.


Assuntos
Malformações Arteriovenosas/fisiopatologia , Volume Sanguíneo/fisiologia , Hepatopatias/fisiopatologia , Troca Gasosa Pulmonar/fisiologia , Telangiectasia Hemorrágica Hereditária/fisiopatologia , Adolescente , Adulto , Idoso , Malformações Arteriovenosas/diagnóstico , Malformações Arteriovenosas/epidemiologia , Feminino , Humanos , Hepatopatias/diagnóstico , Hepatopatias/epidemiologia , Masculino , Pessoa de Meia-Idade , Telangiectasia Hemorrágica Hereditária/diagnóstico , Telangiectasia Hemorrágica Hereditária/epidemiologia , Adulto Jovem
14.
J Neurooncol ; 144(2): 409-417, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31321614

RESUMO

PURPOSE: Dynamic susceptibility contrast (DSC) MR-perfusion is becoming a standard of care for the monitoring of glioblastoma. Yet, technical standards are lacking and measurements without leakage correction are still common. Also, data on leakage corrected measurements during stable disease is scarce. In this study we hypothesized that basic leakage correction would significantly enhance data quality during stable disease and improve progress detection. We furthermore investigated whether longitudinal data could increase diagnostic performance. METHODS: Patients with histologically proven glioblastoma undergoing first-line therapy were prospectively recruited. We conducted DSC perfusion measurements without prebolus administration in 6-week intervals from the end of radiotherapy until progression. Maximum relative cerebral volume values (rCBVmax) with and without leakage correction were calculated using Philips IntelliSpace®. RESULTS: We recruited 16 patients and conducted 82 MRI scans with a mean follow up of 7.2 month. During stable disease, corrected rCBVmax was significantly more stable than uncorrected rCBVmax. Detection of progression with a rCBVmax cutoff was better for corrected (specificity 86%) than for uncorrected rCBVmax (specificity 41%). Interestingly, the increase of corrected rCBVmax upon progression also had a good diagnostic performance with a combination of both cutoffs delivering the best result (sensitivity/specificity 89%/93%). CONCLUSION: Corrected rCBVmax supports the imaging finding of a stable disease and large increases during longitudinal observation support the diagnosis of tumor progression. rCBV values without prebolus or leakage correction are not reliable to monitor glioblastomas. Further studies to investigate the value of longitudinal rCBV dynamics for the differentiation of real tumor progression from pseudoprogression are warranted.


Assuntos
Volume Sanguíneo , Neoplasias Encefálicas/patologia , Circulação Cerebrovascular , Meios de Contraste , Glioblastoma/patologia , Imagem por Ressonância Magnética/métodos , Adulto , Idoso , Algoritmos , Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/radioterapia , Feminino , Seguimentos , Glioblastoma/irrigação sanguínea , Glioblastoma/radioterapia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos
15.
World Neurosurg ; 130: e613-e619, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31260850

RESUMO

BACKGROUND: The amount of blood detected on brain computed tomography scan is frequently used in prediction models for delayed cerebral ischemia (DCI) in patients with aneurysmal subarachnoid hemorrhage (aSAH). These models, which include coarse grading scales to assess the amount of blood, have only moderate predictive value. Therefore, we aimed to develop a predictive model for DCI including automatically quantified total blood volume (TBV). METHODS: We included patients from a prospective aSAH registry. TBV was assessed with an automatic hemorrhage quantification algorithm. The outcome measure was clinical deterioration due to DCI. Clinical and radiologic variables were included in a logistic regression model. The final model was selected by bootstrapped backward selection and internally validated by assessing the optimism-corrected R2 value, c-statistic, and calibration plot. The c-statistic of the TBV model was compared with models that used the (modified) Fisher scale instead. RESULTS: We included 369 patients. After backward selection, only TBV was included in the final model. The internally validated R2 value was 6%, and the c-statistic was 0.64. The c-statistic of the TBV model was higher than both the Fisher scale model (0.56; P < 0.001) and the modified Fisher scale model (0.58; P < 0.05). CONCLUSIONS: In our registry, only TBV independently predicted DCI. TBV discriminated better than the (modified) Fisher scale, but still had only moderate value for predicting DCI. Our findings suggest that other factors need to be identified to achieve better accuracy for predicting DCI.


Assuntos
Volume Sanguíneo/fisiologia , Isquemia Encefálica/etiologia , Hemorragia Subaracnóidea/complicações , Adulto , Idoso , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Índice de Gravidade de Doença , Hemorragia Subaracnóidea/diagnóstico por imagem , Hemorragia Subaracnóidea/fisiopatologia , Fatores de Tempo , Tomografia Computadorizada por Raios X
16.
Turk J Med Sci ; 49(4): 1170-1178, 2019 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-31340632

RESUMO

Background/aim: To compare the inferior vena cava (IVC) indices, identify their variation rates at positive pressure values and accurate predictive values for the volume status in patients with spontaneous respiration receiving different positive pressure support. Materials and methods: The study included 100 patients who were divided into 4 pressure support groups, according to the different pressure supports received, and 3 volume groups according to their CVP values. Ultrasonography was applied to all of the patients to define their IVC diameters at different pressure supports. Dynamic parameters were derived from the ultrasonographic assessment of the IVC diameter [collapsibility (CI-IVC), distensibility (dIVC), and delta (ΔIVC) indices]. Results: There were significant differences between the 3 indices (CI-IVC, dIVC, and ΔIVC) according to the pressure groups [(10/5), (10/0), (0/5), (t tube 0/0)]. The median value for the dIVC percentages was ≤18% for all of the positive pressure support hypervolemic groups, apart from the hypervolemic t tube group (19%). For the hypervolemic groups, the best estimation according to the cut-off value appeared to be for the dIVC. Values with the highest sensitivity for differentiation of the hypovolemic individuals were calculated with the dIVC. Conclusion: The dIVC had a more accurate predictive role in predicting the volume status when compared with the CI-IVC and ΔIVC, and may be used reliably with positive pressure supports.


Assuntos
Volume Sanguíneo/fisiologia , Respiração com Pressão Positiva , Veia Cava Inferior , Idoso , Pressão Venosa Central/fisiologia , Cuidados Críticos , Feminino , Humanos , Hipovolemia/diagnóstico por imagem , Hipovolemia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Ultrassonografia , Veia Cava Inferior/diagnóstico por imagem , Veia Cava Inferior/fisiopatologia
17.
Cardiol Young ; 29(8): 1016-1019, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31221238

RESUMO

Splanchnic circulation constitutes a major portion of the vasculature capacitance and plays an important role in maintaining blood perfusion. Because patients with asplenia syndrome lack this vascular bed as a blood reservoir, they may have a unique blood volume and distribution, which may be related to their vulnerability to the haemodynamic changes often observed in clinical practice. During cardiac catheterisation, the mean circulatory filling pressure was calculated with the Valsalva manoeuvre in 19 patients with Fontan circulation, including 5 patients with asplenia syndrome. We also measured the cardiac output index and circulatory blood volume by using a dye dilution technique. The blood volume and the mean circulatory filling pressure and the venous capacitance in patients with asplenia syndrome were similar to those in the remaining patients with Fontan circulation (85 ± 14 versus 77 ± 18 ml/kg, p = 0.43, 31 ± 8 versus 27 ± 5 mmHg, p = 0.19, 2.8 ± 0.6 versus 2.9 ± 0.9 ml/kg/mmHg, p = 0.86). Unexpectedly, our data indicated that patients with asplenia syndrome, who lack splanchnic capacitance circulation, have blood volume and venous capacitance comparable to those in patients with splanchnic circulation. These data suggest that (1) there is a blood reservoir other than the spleen even in patients with asplenia; (2) considering the large blood pool of the spleen, the presence of a symmetrical liver may represent the possible organ functioning as a blood reservoir in asplenia syndrome; and (3) if this is indeed the case, there may be a higher risk of hepatic congestion in patients with Fontan circulation with asplenia syndrome than in those without.


Assuntos
Vasos Sanguíneos/fisiologia , Técnica de Fontan , Síndrome de Heterotaxia/cirurgia , Circulação Esplâncnica , Adaptação Fisiológica , Volume Sanguíneo , Cateterismo Cardíaco , Débito Cardíaco , Criança , Pré-Escolar , Hemodinâmica , Humanos
18.
Int J Sports Med ; 40(7): 434-439, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31189188

RESUMO

This study investigated aerobic metabolism responses in trunk muscles during a prolonged trunk extension exercise in athletes and untrained young men. The aim was to analyze the adaptations induced by 2 types of sports: one involving intensive use of trunk muscles (i. e., judo), and one known to induce high aerobic capacity in the whole body (i. e., cycling). Eleven judokas, 10 cyclists and 9 healthy untrained young men performed trunk extension exercises on an isokinetic dynamometer. During the first session, muscle strength was assessed during maximal trunk extension. During a second session, a 5-min exercise was performed to investigate aerobic responses with regard to trunk muscles. The near infrared spectroscopy technique and a gas exchange analyzer were used continuously to evaluate mechanical efficiency, V̇O2 on-set kinetics, trunk muscle deoxygenation and blood volume. Judokas showed greater trunk strength and mechanical efficiency (p<0.05). Cyclists presented faster V̇O2 on-set kinetics (p<0.05) and greater muscle deoxygenation and blood volume compared to untrained men (p<0.001). These results suggest that practicing judo improves trunk extension efficiency whereas cycling accelerates aerobic pathways and enhances microvascular responses to trunk extension exercise. Sport practice improves aerobic metabolism responses in trunk extensor muscles differently, according to the training specificities.


Assuntos
Ciclismo/fisiologia , Artes Marciais/fisiologia , Músculo Esquelético/metabolismo , Resistência Física/fisiologia , Aptidão Física/fisiologia , Adolescente , Adulto , Volume Sanguíneo , Humanos , Masculino , Microcirculação , Força Muscular , Músculo Esquelético/irrigação sanguínea , Consumo de Oxigênio , Condicionamento Físico Humano , Troca Gasosa Pulmonar , Espectroscopia de Luz Próxima ao Infravermelho , Torque , Tronco/fisiologia , Adulto Jovem
19.
J Extra Corpor Technol ; 51(2): 67-72, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31239578

RESUMO

Optimal oxygen delivery during cardiopulmonary bypass (CPB) for open heart surgery is crucial to protect organ function, improve outcomes, and reduce hospital stay. Effective preparation for optimal oxygen delivery during CPB is dependent on a reliable estimation of total blood volume (TBV) to accurately predict dilutional hematocrit (Hct) and calculate indexed oxygen delivery (iDO2). Unreliable estimation of TBV is a major reason for inaccurate prediction of dilutional Hct and iDO2. We performed a retrospective study of 113 patients who underwent cardiac surgery to compare the accuracy of predicted versus measured Hct and iDO2. We used four conventional methods of TBV estimation: 1) weight based A; 70 mL/kg for all patients, 2) weight based B; 70 mL/kg for males and 65 mL/kg for females, 3) Allen's formula, and 4) Nadler's formula. We found that TBV estimated by Allen's formula predicted dilutional Hct better than the other three. However, all four methods overestimate TBV when Hct is low and underestimate when Hct is high, suggesting that TBV is dependent on Hct in addition to body size and gender. Our analysis indicates that two individuals with the same body size and gender can have different TBV depending on Hct. We revised Allen's formula by adding a component that adjusts TBV depending on Hct to provide a more accurate prediction of dilutional Hct and iDO2.


Assuntos
Volume Sanguíneo , Ponte Cardiopulmonar , Feminino , Hematócrito , Humanos , Masculino , Oxigênio , Estudos Retrospectivos
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