Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.095
Filtrar
1.
Adv Exp Med Biol ; 1232: 331-337, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31893428

RESUMO

Obesity, a risk factor of coronary artery disease, is known to cause peripheral microcirculatory disturbances. This study evaluated the relationship between the degree of obesity and peripheral microcirculatory disturbances, using peripheral near infrared spectroscopy (NIRS) with a vascular occlusion test (VOT). We compared correlations between the NIRS parameter changes induced by VOT and body mass index (BMI) in patients with and without statin therapy. A NIRS probe was set on the right thenar eminence, brachial artery blood flow was blocked for 3 min, and then released. Although total hemoglobin (ΔcHb), deoxyhemoglobin (ΔHHb) and tissue oxygenation index (ΔTOI) were not correlated with BMI, a significant negative correlation was found between oxyhemoglobin (ΔO2Hb) and BMI in the overall study population (r = -0.255, p-value 0.02). In addition, a significant negative correlation was found between ΔO2Hb and BMI in patients without statin therapy (r = -0.353, p-value 0.02) but not in patients with statin therapy (r = -0.181, p-value 0.27). These findings suggest that ΔO2Hb may be a useful indicator to assess peripheral microcirculation.


Assuntos
Índice de Massa Corporal , Doença da Artéria Coronariana , Espectroscopia de Luz Próxima ao Infravermelho , Idoso , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Masculino , Microcirculação/fisiologia , Oxigênio , Consumo de Oxigênio , Oxiemoglobinas/metabolismo , Fatores de Risco , Espectroscopia de Luz Próxima ao Infravermelho/normas
2.
Curr Cardiol Rep ; 22(2): 9, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31993834

RESUMO

PURPOSE OF REVIEW: The aim of this review is to provide an update on the use of positron emission tomography (PET) with myocardial blood flow (MBF) quantification for the diagnosis and management of patients with microvascular disease. RECENT FINDINGS: It is now recognized that a large proportion of patients with classical angina and non-obstructive epicardial disease are suffering from microvascular angina. Microvascular angina shares several key features with epicardial coronary disease, including many risk factors. Clinical criteria for the diagnosis of microvascular angina were recently proposed and PET imaging is called to play a central role in evaluation of these patients. Indeed, PET allows non-invasive measurements of MBF and flow reserve, which are altered in microvascular dysfunction. Furthermore, PET with flow quantification provides independent prognostic information and has the potential to monitor response to therapy in microvascular disease. PET with MBF quantification allows detection of microvascular dysfunction and plays a key role in the investigation of patients with suspected microvascular angina.


Assuntos
Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Reserva Fracionada de Fluxo Miocárdico/fisiologia , Angina Microvascular/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Circulação Coronária , Humanos , Microcirculação/fisiologia , Imagem de Perfusão do Miocárdio/métodos
3.
Acta Odontol Scand ; 78(1): 31-37, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31349769

RESUMO

Objectives: To determine the baseline perfusion parameters of the alveolar mucosa using laser Doppler flowmetry and tissue spectrophotometry (LDF-TS) in healthy adults.Material and methods: Forty-two healthy adult subjects of either sex were tested. The perfusion of the alveolar mucosa was evaluated using a laser Doppler flowmetry and tissue spectrophotometry using O2C 'oxygen to see' device. The measurements encompassed the maxillary and mandibular mucosa at 20 different points.Results: The O2C device is a reliable method for noninvasive measurement of different perfusion parameters of the oral mucosa. The hemoglobin saturation values (So2 in %), as well as relative amount of hemoglobin in arbitrary units (AU) of the maxillary mucosa demonstrated lower values of that in the mandible. The flow value (AU) exhibited a significant difference in the posterior molar region only, while the velocity value (AU) showed a significant difference across all points except for the anterior region.Conclusion: the present study provides a set of brand-new perfusion parameters of the microcirculation of the alveolar mucosa using LDF-TS. The study suggests a variation of the perfusion parameters between the maxilla and the mandible. Differences in the anatomy of the blood supply, the thickness of the mucosa and the cortical bone, may be attributed to this variation. Further studies using different probes and a combination of ultrasonic measurements and SDF imaging will aid in giving a better overview of the perfusion in the oral mucosa.


Assuntos
Fluxometria por Laser-Doppler/métodos , Mandíbula/irrigação sanguínea , Maxila/irrigação sanguínea , Microcirculação/fisiologia , Mucosa Bucal/irrigação sanguínea , Oxigênio/fisiologia , Espectrofotometria/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Perfusão
4.
Phys Rev Lett ; 123(22): 228103, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31868401

RESUMO

Neuronal activity induces changes in blood flow by locally dilating vessels in the brain microvasculature. How can the local dilation of a single vessel increase flow-based metabolite supply, given that flows are globally coupled within microvasculature? Solving the supply dynamics for rat brain microvasculature, we find one parameter regime to dominate physiologically. This regime allows for robust increase in supply independent of the position in the network, which we explain analytically. We show that local coupling of vessels promotes spatially correlated increased supply by dilation.


Assuntos
Encéfalo/irrigação sanguínea , Microvasos/fisiologia , Modelos Cardiovasculares , Animais , Encéfalo/metabolismo , Microcirculação/fisiologia , Microvasos/inervação , Microvasos/metabolismo , Neurônios/fisiologia , Ratos
5.
Artigo em Russo | MEDLINE | ID: mdl-31626154

RESUMO

AIM: To study the impact of external counterpulsation (ECP) on endothelial function and microcirculation in patients after myocardial revascularization (stenting and coronary artery bypass grafting) for functional class (FC) II-III chronic heart failure (CHF). SUBJECTS AND METHODS: Sixty patients aged 50 to 75 years after myocardial revascularization for FC II-III CHF were examined. All the patients received one-hour ECP sessions 5 times per week. The treatment cycle consisted of 35 sessions. To evaluate the microcirculatory bed, capillary blood flow was studied by laser Doppler flowmetry. RESULTS: The cycle of ECP in patients with FC II-III CHF after myocardial revascularization had a corrective effect on the microhemodynamic system. Microcirculatory changes were due to the normalized myogenic and neurogenic tone of arterioles and to increased oscillations in the endothelial range. The pronounced beneficial effect of ECP on the cardiovascular system in the examined patients was confirmed by a significant increase in exercise tolerance and by a statistically significant improvement in the results of 6-minute walk test. There was a decrease in FC heart failure. CONCLUSION: ECP is an effective, non-invasive treatment in patients with heart failure.


Assuntos
Doença das Coronárias/cirurgia , Contrapulsação , Insuficiência Cardíaca/complicações , Microcirculação/fisiologia , Idoso , Doença das Coronárias/fisiopatologia , Insuficiência Cardíaca/cirurgia , Humanos , Pessoa de Meia-Idade , Resultado do Tratamento
6.
Clin Exp Rheumatol ; 37 Suppl 119(4): 97-101, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31573479

RESUMO

OBJECTIVES: The fingers, toes, and tips of the nose and ears have specialised structural and functional features for thermoregulation, and are the most common areas of Raynaud's phenomenon in systemic sclerosis. Digital thermal monitoring (DTM) of vascular reactivity assesses Doppler ultrasound hyperemic, low frequency, blood velocity of radial artery and fingertip vascular function. Flow mediated dilation (FMD) is an indirect measure of endothelial function, perfusion, and vasodilator ability. In this study, we investigated the cross-sectional correlation of FMD and DTM variables to inform an optimised noninvasive study of SSc endothelial function. A student's T-test was used to compare means of DTM across binary variables. METHODS: Consented SSc registry patients were included in this analysis. The subjects were prepared for FMD and DTM per standardised guidelines. The SSc clinical features were recorded. Spearman's Rank Correlation was used to assess the strength of a relationship FMD and DTM variables. RESULTS: Thirty-four SSc subjects had FMD and DTM performed on the same day. Relative (0.42, p=<0.02), absolute FMD (0.41, p<0.02), and shear rate (0.32, p<0.07) were weakly, but significantly correlated with the DTM. Reactive hyperemia (-0.44, p=0.000) was weakly inversely, but significantly related with DTM. Baseline diameter and flow were not significantly related to the DTM. CONCLUSIONS: This non-invasive study of SSc endothelial function suggests that macrocirculation (including relative and absolute FMD, shear rate, and peak hyperemia) and microcirculatory thermoregulation (characterised by DTM) are significantly correlated, thus warrants further prospective study.


Assuntos
Microcirculação/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Escleroderma Sistêmico , Pele/irrigação sanguínea , Artéria Braquial , Estudos Transversais , Dilatação , Endotélio Vascular , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Escleroderma Sistêmico/fisiopatologia , Vasodilatação
8.
Anaesthesia ; 74(11): 1389-1396, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31389614

RESUMO

We evaluated the effect of adrenaline on human skin microcirculation (nutritive and sub-papillary) and systemic cardiovascular variables after it was added to lidocaine in infraclavicular brachial plexus blocks. Twelve healthy, non-smoking male volunteers were included, each attending two study sessions 2 weeks apart, and they were studied using a crossover design. In both sessions, they received an ultrasound-guided infraclavicular brachial plexus block in the non-dominant arm with 0.4 ml.kg-1 lidocaine, 15 mg.ml-1 with or without adrenaline 5 µg.ml-1 . Microcirculation was assessed by laser Doppler fluxmetry (sub-papillary blood flow), capillary video microscopy (nutritive blood flow) and continuous temperature measurements. Heart rate and arterial pressure were recorded continuously and non-invasively. Median (IQR [range]) sub-papillary blood flow increased substantially 30 min after the brachial plexus block, from 8.5 (4.4-13.5 [2.9-28.2]) to 162.7 (111.0-197.8 [9.5-206.7]) arbitrary units with adrenaline (p = 0.017), and from 6.9 (5.3-28.5 [1.8-42.1] to 133.7 (16.5-216.7 [1.0-445.0] arbitrary units without adrenaline (p = 0.036). Nutritive blood flow (functional capillary density, capillaries.mm-2 , measured at the dorsal side of the hand) decreased in the blocked extremity when adrenaline was used as adjuvant, from median (IQR [range]) 45 (36-52 [26-59]) to 38 (29-41 [26-42]), p = 0.028, whereas no significant change occurred without adrenaline. Median finger skin temperature (°C) increased by 44% (data pooled) with no significant differences between the groups. No significant changes were found in the systemic cardiovascular variables with or without adrenaline. We conclude that lidocaine infraclavicular brachial plexus blocks caused an increase in skin sub-papillary blood flow. The addition of adrenaline produced stronger and longer lasting blocks, but decreased the nutritive blood flow.


Assuntos
Anestésicos Locais/farmacologia , Bloqueio do Plexo Braquial/métodos , Epinefrina/farmacologia , Hemodinâmica/efeitos dos fármacos , Lidocaína/farmacologia , Microcirculação/efeitos dos fármacos , Agonistas alfa-Adrenérgicos/farmacologia , Adulto , Estudos Cross-Over , Método Duplo-Cego , Quimioterapia Combinada , Hemodinâmica/fisiologia , Humanos , Masculino , Microcirculação/fisiologia , Pessoa de Meia-Idade , Estudos Prospectivos , Valores de Referência , Ultrassonografia de Intervenção/métodos , Adulto Jovem
9.
Invest Ophthalmol Vis Sci ; 60(8): 3110-3118, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31323681

RESUMO

Purpose: Blood flow in the optic nerve head (ONH) is known to be reduced in eyes with advanced glaucoma. However, experimental results from non-human primates suggest an initial increase in ONH blood flow at the earliest stages of damage. This study assesses flow and pulsatile hemodynamics across a range of severities to test the hypothesis that this also occurs in human glaucoma. Methods: Laser speckle flowgraphy was used to measure average mean blur rate (MBRave) within ONH tissue (a correlate of capillary blood flow) and the pulsatile waveform in 93 eyes with functional loss and 74 glaucoma suspect/fellow eyes without functional loss. These were compared against results from 92 healthy control eyes. Parameters produced by the instrument's software were age-corrected, then compared between groups using generalized estimating equation models. Results: The mean MBRave in the control eyes was 12.5 units. In glaucoma suspect/fellow eyes, the mean was 16.4 units, higher with P < 0.0001. In eyes with functional loss, the mean was 13.8 units, lower than eyes without functional loss with P < 0.0001, although still higher than control eyes with P = 0.0096. Analysis of the pulsatile waveform suggested that the deceleration in flow as it approaches its maximum across the cardiac cycle was delayed in glaucoma. Conclusions: Blood flow within ONH capillaries was higher in glaucoma suspect eyes than in healthy controls. It was less elevated in eyes that had developed functional loss. The mechanisms causing these changes and their relation to concurrent changes in pulsatile hemodynamics remain under investigation.


Assuntos
Velocidade do Fluxo Sanguíneo/fisiologia , Capilares/fisiopatologia , Glaucoma de Ângulo Aberto/fisiopatologia , Microcirculação/fisiologia , Disco Óptico/irrigação sanguínea , Fluxo Sanguíneo Regional/fisiologia , Adulto , Idoso , Capilares/diagnóstico por imagem , Feminino , Angiofluoresceinografia , Fundo de Olho , Glaucoma de Ângulo Aberto/diagnóstico , Humanos , Pressão Intraocular , Fluxometria por Laser-Doppler/métodos , Masculino , Pessoa de Meia-Idade , Prognóstico , Tomografia de Coerência Óptica/métodos
11.
Medicine (Baltimore) ; 98(27): e15990, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31277090

RESUMO

BACKGROUND: Recent studies have demonstrated that coronary microcirculation dysfunction (CMVD) is closely correlated with adverse clinical outcomes. In this study, quantitative stress myocardial contrast echocardiography (MCE) was used to evaluate the CMVD and to investigate its association with the prognosis of patients with nonobstructive coronary artery disease (CAD). MATERIAL AND METHODS: From 2006 to 2014, 227 consecutive patients with chest pain and a diagnostic coronary angiography without significant coronary artery stenosis (<50%) who underwent adenosine triphosphate disodium (ATP) stress MCE were enrolled. Quantitative MCE measurements were analyzed using replenishment curves. RESULTS: Median follow-up time of this study was 5.3 years. Predictors of impaired coronary flow reserve (CFR) were smoking, diabetes, high apolipoprotein B, high low-density lipoprotein, serum uric acid, and low apolipoprotein A. During follow-up, 22 patients were reported to have 30 cardiac events (21 unstable angina, 3 nonfatal myocardial infarctions, 6 percutaneous coronary interventions). Using multivariate analysis, abnormal ß reserve (≤1.6), impaired CFR (≤2.0), and diabetes were independent predictors of primary endpoint events in patients with nonobstructive CAD (P < .05). Multivariate analysis showed that CFR ≤2.0 (odds ratio [OR] =  25.21, 95% confidence interval [CI]: 3.01-182.32; P = .003), ß reserve ≤1.6 (OR = 29.96, 95% CI: 3.5-241.27; P = .002), and diabetic (OR = 33.11, 95% CI: 3.65-300.02; P = .002) significantly increased the risk of the primary endpoint events. CONCLUSIONS: ATP stress quantitative MCE is a feasible and effective method to evaluate microcirculation abnormalities in human coronary arteries and it can be used for the clinical analysis, risk stratification, and treatment of early CAD.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Estenose Coronária/diagnóstico por imagem , Ecocardiografia sob Estresse/métodos , Ecocardiografia/métodos , Microcirculação/fisiologia , Trifosfato de Adenosina/administração & dosagem , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Fatores de Risco
12.
Artigo em Russo | MEDLINE | ID: mdl-31329184

RESUMO

AIM: To study the impact of comprehensive anti-edematous therapy (CAET) on the microcirculatory indicators of patients with lower limb lymphedema. MATERIAL AND METHODS: The investigation enrolled 60 patients with stages I-III lower limb lymphedema (according to its classification (T.V. Savchenko and A.V. Pokrovsky, 2004). All the patients were randomly divided into two groups: 1) 30 patients received CAET; 2) 30 patients had basic therapy with a conventional lymphovenous tonic and elastic compression. The time course of microcirculatory changes were evaluated in all the patients, by using laser Doppler flowmetry. RESULTS: Analysis of the findings revealed that all the patients had spastic and stagnant microcirculation prior to treatment. After a treatment cycle, group 1 showed positive changes in the clinical manifestations of the disease and in the microcirculation, while group 2 displayed slight reductions in sensation of heaviness, leg swelling, as well as positive changes at the level of the venules of the microcirculatory bed. CONCLUSION: This investigation of microcirculatory indicators in patients with lower limb lymphedema revealed a considerable improvement at the level of all microcirculatory components (arterioles, precapillaries, and venules) after CAET.


Assuntos
Extremidade Inferior/irrigação sanguínea , Linfedema/terapia , Microcirculação/fisiologia , Humanos , Fluxometria por Laser-Doppler , Resultado do Tratamento
13.
Int J Nanomedicine ; 14: 4767-4780, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31308657

RESUMO

Background: Magnetic nanoparticles (MNPs) can be localized against hemodynamic forces in blood vessels with the application of an external magnetic field. In addition, PEGylation of nanoparticles may increase the half-life of nanocomposites in circulation. In this work, we examined the effect of PEGylation on the magnetic capture of MNPs in vivo. Methods: Laser speckle contrast imaging and capillaroscopy were used to assess the magnetic capture of dextran-coated MNPs and red blood cell (RBC) flow in cremaster microvessels of anesthetized rats. Magnetic capture of MNPs in serum flow was visualized with an in vitro circulating system. The effect of PEGylation on MNP-endothelial cell interaction was studied in cultured cells using an iron assay. Results: In microcirculation through cremaster muscle, magnet-induced retention of 250 nm MNPs was associated with a variable reduction in RBC flow, suggesting a dynamic coupling of hemodynamic and magnetic forces. After magnet removal, faster restoration of flow was observed in PEG(+) than PEG(-) group, which may be attributed to a reduced interaction with vascular endothelium. However, PEGylation appears to be required for magnetic capture of 50 nm MNPs in microvessels, which was associated with increased hydrodynamic diameter to 130±6 nm in serum, but independent of the ς-potential. Conclusion: These results suggest that PEGylation may enhance magnetic capture of smaller MNPs and dispersion of larger MNPs after magnet removal, which may potentially affect the targeting, pharmacokinetics and therapeutic efficacy.


Assuntos
Dextranos/química , Nanopartículas de Magnetita/química , Microcirculação/fisiologia , Polietilenoglicóis/química , Animais , Hemodinâmica , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Campos Magnéticos , Microvasos/fisiologia , Ratos Sprague-Dawley , Eletricidade Estática
14.
Wounds ; 31(7): 173-178, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31184593

RESUMO

INTRODUCTION: Maintaining adequate skin hydration is crucial in the feet of patients with diabetes because xerotic skin may crack and develop fissures, thereby increasing vulnerability to ulceration and infection. The nervous system is considered the powerhouse for maintaining adequate skin hydration; however, no clinical study has assessed the effect of the nervous system on skin hydration. In addition, it is hypothesized that microcirculation may play an important role in maintaining adequate hydration in patients with diabetes. OBJECTIVE: This study aims to evaluate the influence of peripheral nerve function and microvascularity on skin hydration in the feet of patients with diabetes mellitus and compare the effects of these 2 functions on skin hydration. MATERIALS AND METHODS: This study included 266 patients with diabetic foot disease. Skin hydration was evaluated using corneometry and microvascularity by measuring the transcutaneous oximetry (TcpO2) of the foot. The Semmes-Weinstein 5.07/10-g monofilament test, electromyography, and nerve conduction velocity test were conducted to evaluate peripheral neuropathy. Patient data were divided into 3 subgroups according to test values, and statistical comparisons were performed using the linear-by-linear association trend and Pearson's chi-square tests. RESULTS: There was a significant correlation between skin hydration and TcpO2. However, there was no significant correlation between skin hydration and peripheral nerve function (P = .338). CONCLUSIONS: The results of this study demonstrated that skin hydration in the feet of patients with diabetes mellitus mainly is influenced by microcirculation rather than peripheral nerve function.


Assuntos
Pé Diabético/diagnóstico , Pé Diabético/terapia , Neuropatias Diabéticas/terapia , Hipodermóclise/métodos , Microcirculação/fisiologia , Adulto , Idoso , Monitorização Transcutânea dos Gases Sanguíneos , Estudos de Coortes , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Neuropatias Diabéticas/diagnóstico , Feminino , Hospitais Universitários , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
15.
Semin Ophthalmol ; 34(4): 279-286, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31158045

RESUMO

There is growing evidence that vascular dysfunction plays a role in the pathogenesis of glaucoma. The details of this relationship have remained elusive partially due to limitations in our ability to assess blood flow in the optic nerve. Optical coherence tomography angiography (OCTA) has emerged as a promising new technology well positioned to become the first clinically suitable test of optic nerve perfusion. OCTA uses the motion of red blood cells as an intrinsic contrast agent to create reproducible images of microvascular networks rapidly and non-invasively. A significant body of research regarding the use of OCTA in glaucoma has emerged in recent years. This review aims to provide an overview of the basic principles underlying OCTA technology, summarize the current literature regarding the application of OCTA in the management of glaucoma, and address the role of OCTA in explicating the vascular pathogenesis of glaucoma.


Assuntos
Técnicas de Diagnóstico Oftalmológico , Angiofluoresceinografia/métodos , Glaucoma/diagnóstico por imagem , Retina/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Glaucoma/fisiopatologia , Humanos , Microcirculação/fisiologia , Fibras Nervosas/patologia , Disco Óptico/fisiopatologia , Fluxo Sanguíneo Regional/fisiologia , Células Ganglionares da Retina/patologia , Vasos Retinianos/fisiologia
16.
BMC Ophthalmol ; 19(1): 127, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31182069

RESUMO

BACKGROUND: To evaluate the efficacy of swept -source optical coherence tomography angiography (SS-OCTA) in grading macular perfusion in retinal vein occlusion. METHODS: Retrospective observational case series including patients with different types of retinal vein occlusion (RVO). SS-OCTA utilizes OCTARA algorithm to examine the retinal vascular plexuses for the presence of morphological signs of ischemia according to a predetermined grading scheme. The findings were compared with fundus fluorescein angiography (FFA), and swept-source optical coherence tomography (SS-OCT) features. Bivariate correlation, coefficient of determination, and crosstabs procedures were used to calculate inter-variable linear correlation, relative contribution of the tested variables, and multivariate association, respectively. RESULTS: The study included 144 eyes of 138 patients. The most common type of RVO was branch retinal vein occlusion (BRVO) (53%). The superficial capillary plexus (SCP) and the deep capillary plexus (DCP) did not correlate with each other in all parameters tested. Increased central macular thickness (CMT) and disrupted retinal outer layers (DROL) were associated with increased severity of ischemia in DCP. Disorganized retinal inner layers (DRIL) correlated significantly with the presence of perifoveal capillary ischemia in the SCP and the DCP. Macular ischemia on FFA correlated with ischemia in the SCP layer only. Increased CMT, DROL and DRIL on SS-OCT, and SCP and DCP ischemia on SS-OCTA contributed significantly to diminished best-corrected visual acuity (BCVA). CONCLUSION: SS-OCTA is more precise in defining the extent and location of maximum ischemic insult following RVO compared to FFA, hence represents a more efficient grader for ischemic damage in the posterior pole. Increased CMT, DRIL, and DROL on SS-OCT, and SCP and DCP ischemia on SS-OCTA are significant predictors of poor visual outcome.


Assuntos
Angiofluoresceinografia/métodos , Macula Lutea/fisiopatologia , Microcirculação/fisiologia , Oclusão da Veia Retiniana/diagnóstico por imagem , Vasos Retinianos/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Adulto , Idoso , Idoso de 80 Anos ou mais , Capilares/patologia , Capilares/fisiopatologia , Feminino , Fundo de Olho , Humanos , Macula Lutea/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Oclusão da Veia Retiniana/fisiopatologia , Vasos Retinianos/fisiopatologia , Estudos Retrospectivos , Fatores de Tempo , Adulto Jovem
17.
Crit Care ; 23(1): 211, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31182133

RESUMO

BACKGROUND: Mottling score, a tissue perfusion parameter, is correlated with outcome in septic shock patients. However, its predictive value on mortality according to prognostic covariates such as vasopressor dose and other tissue perfusion parameters remains unknown. METHODS: Mottling score and tissue perfusion parameters were recorded at ICU admission (H0), H-6, H 12, and H-24 and used to assess the predictive value of mottling score on 14-day mortality in a development cohort. Results were then validated in an independent cohort of septic shock patients in Brazil. RESULTS: Overall, 259 patients with sepsis or septic shock were included, 14-day mortality was 37%. Factors associated with death were mottling score (OR 2.26 [95% CI, 1.72-2.97]), arterial lactate level (OR 1.29 [1.11-1.5]), and urine output < 0.5 ml/Kg/h (OR 3.03 [1.37-6.69]). The C statistic for the model was 0.90 in the development cohort and 0.76 in the validation cohort. The predictive value of mottling score was not affected by vasopressor doses (p for interaction = 0.33): OR for mottling score ranged from 2.34 [1.10-3.15] in patients without vasopressor to 3.84 [1.98-7.43] in patients infused with high doses of vasopressor (> 0.8 µg/kg/min). There was no difference in the effect of mottling score on mortality according to mean arterial pressure, heart rate, cardiac index, and urine output, but we found a significant interaction between arterial lactate level and mottling score (p = 0.04). The predictive value of the mottling score remains significant when using the recent SEPSIS-3 definition of septic shock. Finally, a decrease of mottling score during resuscitation was significantly associated with better outcome after adjustment on SOFA score (p = 0.001). CONCLUSIONS: Our results support the high prognostic value of mottling score for 14-day mortality in septic patients, whatever vasopressor dosage and other perfusion parameters. Mottling score variations during resuscitation are also predictive of mortality.


Assuntos
Microcirculação/fisiologia , Sepse/tratamento farmacológico , Índice de Gravidade de Doença , Vasoconstritores/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Brasil , Feminino , Hidratação/métodos , Humanos , Unidades de Terapia Intensiva/organização & administração , Unidades de Terapia Intensiva/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Prognóstico , Sepse/mortalidade , Resultado do Tratamento , Vasoconstritores/uso terapêutico
18.
J Reconstr Microsurg ; 35(7): 522-528, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31039587

RESUMO

BACKGROUND: Free tissue transfer has become a common and safe reconstructive procedure. However, total or partial flap losses remain a looming threat, especially for lower extremity free flaps due to the gravitational challenge associated with dependency. Thus, the majority of microsurgical centers apply some kind of structured flap training. However, due to the lack of evidence, these differ greatly, for example, in the application of an elastic wrapping during dangling. Therefore, the aim of this study was to assess the impact of an elastic wrapping on free flap microcirculation, edema, and pain during dangling. METHODS: Standardized dangling was performed from postoperative day (POD) 6 to 9 in 30 patients with microvascular reconstruction of the lower extremity. The first dangling per day was performed without elastic wrapping, followed by another session with 30 mm Hg of elastic wrapping. Tissue oxygen saturation (StO2), regional hemoglobin content (rHb), and blood flow (BF) were continuously measured in the free flap; the circumference of the flap as well as pain was assessed. RESULTS: During wrapped dangling, BF as well as StO2 was significantly increased, while rHb was significantly lower on all PODs. Wrapped dangling was rated significantly more comfortable and the girth of the free flaps was significantly less after wrapped dependency when compared with unwrapped dangling. CONCLUSION: Dangling with an elastic wrapping with 30 mm Hg pressure improved flap microcirculation and reduced pain and edema formation.


Assuntos
Bandagens Compressivas , Edema/prevenção & controle , Retalhos de Tecido Biológico/irrigação sanguínea , Extremidade Inferior/cirurgia , Dor/prevenção & controle , Velocidade do Fluxo Sanguíneo , Feminino , Sobrevivência de Enxerto , Humanos , Masculino , Microcirculação/fisiologia , Pessoa de Meia-Idade , Oxigênio/sangue , Medição da Dor , Cicatrização
19.
Pediatr Cardiol ; 40(6): 1151-1158, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31098675

RESUMO

Heart failure (HF) is associated with microcirculatory changes secondary to neuro-humoral imbalance, vascular stiffness and increased sympathetic tone. Near Infra-Red Spectroscopy (NIRS) derived Thenar muscle tissue oxygenation levels (StO2) can provide an estimate of the functional status of microcirculation. There is a paucity of literature regarding evaluation of microcirculation in pediatric subjects with HF. We hypothesized that microcirculation and oxygen saturation dynamics as assessed by Thenar StO2 levels using vascular occlusion test (VOT) would be altered in HF subjects and that these changes may correlate with the severity of heart failure. We prospectively enrolled 60 pediatric subjects (29 healthy control, 31 HF). Baseline StO2 levels were measured using InSpectra™ StO2 probe placed over the Thenar eminence of right hand, followed by a VOT for 3 min, during which the changes in StO2 levels during the occlusion phase and post occlusion phase were recorded. Baseline Thenar StO2 levels (72 ± 8 vs 76 ± 5, p = 0.02) and time to baseline StO2 in seconds (150 ± 70 vs 200 ± 70, p = 0.007) were significantly lower in HF group compared to healthy control (HC). In addition, HF patients had a significantly lower trough StO2 (37 ± 9 vs 42 ± 11%, p = 0.04) and peak StO2 compared to HC (87 ± 8 vs 91 ± 5%, p = 0.01). However, there was no difference in the rate of desaturation, rate of resaturation or time to peak StO2 levels in between the 2 groups. Significant correlation was present between baseline Thenar StO2 levels and NYU Pediatric Heart Failure Index Score (NYU-PHFI) (p = 0.003). This study is the first to report an objective assessment of microcirculation and Thenar tissue oxygen dynamics in pediatric subjects with HF in comparison with HC. Our study suggests altered microcirculation and oxygenation patterns in these subjects as well as correlation with a validated pediatric heart failure clinical score. Large-scale prospective studies are needed to further study the utility of this novel technology in HF subjects.


Assuntos
Insuficiência Cardíaca/fisiopatologia , Microcirculação/fisiologia , Músculo Esquelético/fisiologia , Consumo de Oxigênio/fisiologia , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Adolescente , Estudos de Casos e Controles , Criança , Feminino , Humanos , Masculino , Estudos Prospectivos , Índice de Gravidade de Doença
20.
Echocardiography ; 36(6): 1103-1109, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31116460

RESUMO

OBJECTIVE: The correlation between the echocardiographic Doppler flow parameters of microvascular obstruction (MVO) and coronary wedge pressure (CWP) measured as a marker of severe compressive microvascular dysfunction and a predictor of adverse left ventricular remodeling was evaluated in a group of high-risk acute anterior myocardial infarction survivors. METHODS: Twenty-four patients with mechanically reperfused anterior STEMI were divided into two groups based on the 38 mm Hg CWP cutoff for adverse left ventricular remodeling. Diastolic deceleration time (DDT), coronary flow reserve (CFR), systolic retrograde flow, peak systolic and peak diastolic velocities in the infarct-related artery were determined 3-5 days after revascularization. An echocardiographic 20% increase in left ventricular volumes defined adverse remodeling. RESULTS: No significant differences were recorded between groups with regard to the echocardiographic parameters of MVO. No significant correlation was identified between CWP on one side and DDT (P = 0.30) and CFR (P = 0.39) on the other, irrespective of total ischemic time and extracted thrombus length. No difference in 5 years of follow-up left ventricular remodeling was detected in patients with DDT<900 msec as compared to those with DDT≥900 msec. The medium increase in left ventricular end-systolic volume in patients with low CWP was 24.78%, while it reached 127.27% (P = 0.03) in patients with CWP>38 mm Hg. CONCLUSIONS: Coronary wedge pressure did not correlate with the surrogate parameters for MVO, but it was a predictor of left ventricular remodeling. None of the echocardiographic MVO parameters was associated with adverse remodeling at 5 years of follow-up.


Assuntos
Circulação Coronária/fisiologia , Trombose Coronária/diagnóstico por imagem , Ecocardiografia Doppler/métodos , Microcirculação/fisiologia , Infarto do Miocárdio com Supradesnível do Segmento ST/fisiopatologia , Remodelação Ventricular/fisiologia , Trombose Coronária/complicações , Trombose Coronária/fisiopatologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Pressão Propulsora Pulmonar , Infarto do Miocárdio com Supradesnível do Segmento ST/complicações
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA