scholarly journals Assessment of small pulmonary blood vessels in COVID-19 patients using HRCT

2020 ◽  
Author(s):  
Muriel Lins ◽  
Jan Vandevenne ◽  
Muhunthan Thillai ◽  
Ben R. Lavon ◽  
Maarten Lanclus ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Blood Vessels ◽  
Blood Volume ◽  
Vascular Dysfunction ◽  
Pulmonary Vasculature ◽  
Vascular Density ◽  
Small Blood Vessel ◽  
Pulmonary Blood Volume ◽  
Pulmonary Hemodynamic ◽  
Blood Volumes

AbstractBackgroundMounting evidence supports the role of pulmonary hemodynamic alternations in the pathogenesis of COVID-19. Previous studies have demonstrated that changes in pulmonary blood volumes measured on CT are associated with histopathological markers of pulmonary vascular pruning, suggesting that quantitative HRCT analysis may eventually be useful in the assessment pulmonary vascular dysfunction more broadly.MethodsBuilding upon previous work, automated HRCT measures of small blood vessel volume and pulmonary vascular density were developed. Scans from 103 COVID-19 patients and 108 healthy volunteers were analyzed and their results compared, with comparisons made both on lobar and global levels.ResultsCompared to healthy volunteers, COVID-19 patients showed significant reduction in BV5 (pulmonary blood volume contained in blood vessels of <5 mm2) expressed as BV5/(Total pulmonary blood volume) (p<0.0001), and significant increases in BV5_10 and BV 10 (pulmonary blood volumes contained in vessels between 5 and 10 mm2 and above 10 mm2, respectively) (p<0.0001). These changes were consistent across lobes.ConclusionsCOVID-19 patients display striking anomalies in the distribution of blood volume within the pulmonary vascular tree, consistent with increased pulmonary vasculature resistance in the pulmonary vessels below the resolution of HRCT.

Systemic and pulmonary hemodynamic responses to intracranial hypertension

1984 ◽  
Vol 247 (5) ◽  
pp. H715-H721 ◽  
Author(s):  
H. I. Chen ◽  
D. J. Wang
Keyword(s):  
Intracranial Hypertension ◽  
Blood Volume ◽  
Vascular Resistance ◽  
Venous Pressure ◽  
Resistance Response ◽  
Pulmonary Blood Volume ◽  
Control Value ◽  
Pulmonary Hemodynamic ◽  
Arterial Inflow ◽  
Capacitance Vessels

Experiments were conducted in anesthetized, vagotomized, and open-chest dogs. Total heart bypass was performed to perfuse the systemic and pulmonary circulations with constant flow. The venous outflows were diverted into reservoirs. We studied the simultaneous changes in systemic vascular resistance (SVR) and capacity (SVC) as well as pulmonary vascular resistance (PVR) and capacity (PVC) during a period of intracranial hypertension (ICH). In 20 dogs with an intracranial pressure of 164 +/- 12 mmHg, SVR increased by 110% and SVC decreased by 8.4 +/- 1.2 ml/kg. The increase in PVR reached 69%, and the decrease in PVC amounted to 1.24 +/- 0.40 ml/kg body wt or 9.7 +/- 3.9 ml/100 g lung wt. The results indicate that ICH exerts profound effects on both systemic and pulmonary resistance and capacitance vessels. An analysis from the pulmonary blood volume change suggested that the pulmonary vascular compliance was significantly reduced by ICH from a control value of 0.33 +/- 0.06 to 0.26 +/- 0.05 ml X mmHg-1 X kg-1. In the pulmonary circulation, an elevation of left atrial pressure with lung volume expansion attenuated the resistance response, while it increased the capacity reduction. When pulmonary blood volume was kept constant by a constant venous outflow equal to the arterial inflow, the response of capacitance vessels to ICH increased both pulmonary arterial and venous pressures associated with a slight change in PVR. These findings suggest that an increase in pulmonary venous pressure with a constant or increased blood volume reduced the ICH-induced change in resistance.

Observations on Cardiac Output and ”Pulmonary Blood Volume” in Normal Man by External Recording of the Intracardiac Flow of 131I Labelled Albumin

1961 ◽  
Vol 1 (04) ◽  
pp. 353-379
Author(s):  
Jacques Lammerant ◽  
Norman Veall ◽  
Michel De Visscher
Keyword(s):  
Cardiac Output ◽  
Blood Volume ◽  
Normal Subjects ◽  
Published Data ◽  
Total Blood Volume ◽  
Total Blood ◽  
Pulmonary Blood Volume ◽  
Intracardiac Flow ◽  
Normal Man ◽  
Mean Circulation

Summary1. The technique for the measurement of cardiac output by external recording of the intracardiac flow of 131I labelled human serum albumin has been extended to provide a measure of the mean circulation time from right to left heart and hence a new approach to the estimation of the pulmonary blood volume.2. Values for the basal cardiac output in normal subjects and its variations with age are in good agreement with the previously published data of other workers.3. The pulmonary blood volume in normal man in the basal state was found to be 28.2 ± 0.6% of the total blood volume.4. There was no correlation between cardiac output and pulmonary blood volume in a series of normal subjects in the basal state.5. The increase in cardiac output during digestion was associated with a decrease in pulmonary blood volume equal to 6.3 ± 1.2% of the total blood volume, that is, about 280 ml.6. The increase in cardiac output during exercise was associated with a decrease in pulmonary blood volume equal to 4.5 ± 1.0% of the total blood volume, that is, about 200 ml.7. The increase in cardiac output attributed to alarm is not associated with a decrease in pulmonary blood volume, the latter may in fact be increased.8. The total blood volume is advocated as a standard of reference for studies of this type in normal subjects in preference to body weight or surface area.9. The significance of these results and the validity of the method are discussed.

scholarly journals PATH-04. THE BLOOD-BRAIN BARRIER IN DIFFUSE MIDLINE GLIOMA AND ITS IMPLICATIONS FOR DRUG DELIVERY

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii164-ii164
Author(s):  
Rianne Haumann ◽  
Fatma El-Khouly ◽  
Marjolein Breur ◽  
Sophie Veldhuijzen van Zanten ◽  
Gertjan Kaspers ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Blood Vessels ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Vascular Density ◽  
Zonula Occludens ◽  
Blood Brain ◽  
Zonula Occludens 1 ◽  
End Stage ◽  
Diffuse Midline Glioma

Abstract INTRODUCTION Chemotherapy has been unsuccessful for pediatric diffuse midline glioma (DMG) most likely due to an intact blood-brain barrier (BBB). However, the BBB has not been characterized in DMG and therefore its implications for drug delivery are unknown. In this study we characterized the BBB in DMG patients and compared this to healthy controls. METHODS End-stage DMG pontine samples (n=5) were obtained from the VUmc diffuse intrinsic pontine glioma (DIPG) autopsy study and age-matched healthy pontine samples (n=22) were obtained from the NIH NeuroBioBank. Tissues were stained for BBB markers claudin-5, zonula occludens-1, laminin, and PDGFRβ. Claudin-5 stains were used to determine vascular density and diameter. RESULTS In DMG, expression of claudin-5 was reduced and dislocated to the abluminal side of endothelial cells. In addition, the expression of zonula occludens-1 was reduced. The basement membrane protein laminin expression was reduced at the glia limitans in both pre-existent vessels and neovascular proliferation. PDGFRβ expression was not observed in DMG but was present in healthy pons. Furthermore, the number of blood vessels in DMG was significantly (P&lt; 0.01) reduced (13.9 ± 11.8/mm2) compared to healthy pons (26.3 ± 14.2/mm2). Markedly, the number of small blood vessels (&lt; 10µm) was significantly lower (P&lt; 0.01) while larger blood vessels (&gt; 10µm) were not significantly different (P= 0.223). The mean vascular diameter was larger for DMG 9.3 ± 9.9µm compared to 7.7 ± 9.0µm for healthy pons (P= 0.016). CONCLUSION Both the BBB and the vasculature are altered at end-stage DMG. The reduced vascular density might have implications for several drug delivery methods such as focused ultrasound and convection enhanced delivery that are being explored for the treatment of DMG. The functional effects of the structurally altered BBB remain unknown and further research is needed to evaluate the BBB integrity at end-stage DMG

scholarly journals Combination of µCT and light microscopy for generation-specific stereological analysis of pulmonary arterial branches: a proof-of-concept study

2020 ◽  
Author(s):  
Roman Grothausmann ◽  
Jonas Labode ◽  
Pablo Hernandez-Cerdan ◽  
David Haberthür ◽  
Ruslan Hlushchuk ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Volume Fraction ◽  
Pulmonary Vasculature ◽  
Chronic Obstructive ◽  
Micro Computed Tomography ◽  
Vascular Perfusion ◽  
Arterial Tree ◽  
Color Code ◽  
Rabbit Lung ◽  
Stereological Analysis

AbstractVarious lung diseases, including pulmonary hypertension, chronic obstructive pulmonary disease or bronchopulmonary dysplasia, are associated with structural and architectural alterations of the pulmonary vasculature. The light microscopic (LM) analysis of the blood vessels is limited by the fact that it is impossible to identify which generation of the arterial tree an arterial profile within a LM microscopic section belongs to. Therefore, we established a workflow that allows for the generation-specific quantitative (stereological) analysis of pulmonary blood vessels. A whole left rabbit lung was fixed by vascular perfusion, embedded in glycol methacrylate and imaged by micro-computed tomography (µCT). The lung was then exhaustively sectioned and 20 consecutive sections were collected every 100 µm to obtain a systematic uniform random sample of the whole lung. The digital processing involved segmentation of the arterial tree, generation analysis, registration of LM sections with the µCT data as well as registration of the segmentation and the LM images. The present study demonstrates that it is feasible to identify arterial profiles according to their generation based on a generation-specific color code. Stereological analysis for the first three arterial generations of the monopodial branching of the vasculature included volume fraction, total volume, lumen-to-wall ratio and wall thickness for each arterial generation. In conclusion, the correlative image analysis of µCT and LM-based datasets is an innovative method to assess the pulmonary vasculature quantitatively.

P4129cMR-Pulmonary transit time and pulmonary blood volume have an additional prognostic value over cMR-right ventricular ejection fraction in predicting mortality in HF-rEF patients

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
L Houard ◽  
H Langet ◽  
S Militaru ◽  
M F Rousseau ◽  
A C Pouleur ◽  
...  
Keyword(s):  
Blood Volume ◽  
Transit Time ◽  
Primary Endpoint ◽  
Prognostic Value ◽  
Beta Blockers ◽  
Class Iii ◽  
Baseline Model ◽  
Pulmonary Blood Volume ◽  
Pulmonary Transit Time ◽  
Overall Mortality

Abstract Background Assessment of congestion and cardiac function has been shown to have both therapeutic and prognostic implication for the management of patient with CHF. Pulmonary transit time (PTT) assessed by cMR is a novel parameter, which reflects not only hemodynamic congestion but also LV and RV function. Purpose We sought to explore the prognostic value of the pulmonary transit time assessed in seconds (PTT) and in beats (PTB) and the pulmonary blood volume indexed (PBVi) above conventional well-known risk factors including cMR-RVEF and estimated pulmonary artery pressure (eSPAP) in predicting outcomes. PBVi is defined by the product of PTB and the stroke volume indexed to body surface area. Methods 401 patients in sinus rhythm with a LVEF <35% (age 61±13 years; 25% female) underwent a cMR and an echocardiography. Patients were followed for a primary endpoint of overall mortality. Results Average cMR-LVEF was 23±7%, cMR-RVEF was 43±15%, average estimated systolic pulmonary pressure (eSPAP) was 33±12mmH, average PTT was 11±6s, PTB 8.9±5.6 bpm and average PBVi 305.5±254.9ml/m2. After a median follow-up of 6 years, 182 reached the primary endpoint. In univariate cox regression, age, ischemic cardiomyopathy, hypertension, diabetes, NYHA class III-IV, eSPAP >40mmHg, E/A ratio, e/e'ratio, cMR-RVEF, LV scar, PTT, PTB, PBVi, GFR, beta blockers and diuretics were associated with overall mortality. For the multivariate analysis, a baseline model was created where age, ischemic etiology, NYHA functional class III-IV, eSPAP >40 mmHg, beta-blockers and cMR-RVEF were found to be significantly and independently associated with the primary endpoint. PTT (X2 to improve = 5.3, HR: 1.03; 95% CI: [1.01; 1.06]; P=0.015), PTB (X2 to improve = 11.8, HR: 1.06; 95% CI: [1.03; 1.09]; P<0.001) and PBVi (X2 to improve = 7.7, HR: 1.08; 95% CI: [1.03; 1.14]; P=0.002) showed a significantly additional prognostic value over the baseline model (p<0.001). Conclusion Pulmonary transit time and pulmonary blood volume provide higher prognostic information over well-known risk factors including cMR-RVEF and eSPAP with high power to stratify prognosis in HF-rEF and might be promising tools to identify patients at higher risk among HF patients. Acknowledgement/Funding Fond National de recherche scientifique (FNRS)

Effects of hemorrhage and hepatic nerve stimulation on venous compliance and unstressed volume in cat liver

1987 ◽  
Vol 65 (11) ◽  
pp. 2168-2174 ◽  
Author(s):  
C. V. Greenway
Keyword(s):  
Blood Flow ◽  
Blood Volume ◽  
Nerve Stimulation ◽  
Marked Decrease ◽  
Venous Compliance ◽  
Remarkable Feature ◽  
Unstressed Volume ◽  
Passive Response ◽  
The Relationship ◽  
Blood Volumes

Intrahepatic blood volume–pressure relationships were studied using plethysmography to measure hepatic blood volume and a hepatic venous long-circuit to control intrahepatic pressure. In cats anesthetized with pentobarbital or with ketamine–chloralose, hemorrhage (to reduce hepatic blood flow to 60% of control) caused marked reductions in hepatic blood volume and intrahepatic pressure but did not significantly change hepatic blood volume–pressure relationships. We were unable to demonstrate an active reflex venous response to hemorrhage in these preparations, although a large passive response occurred. The volume–pressure relationships in innervated livers were different from those in denervated livers: apparent venous compliance was much greater and apparent unstressed volume was zero or negative. Hepatic nerve stimulation in denervated livers caused a marked decrease in hepatic blood volume at low intrahepatic pressures but failed to alter hepatic blood volumes at high intrahepatic pressures (15 mmHg) (1 mmHg = 133.3 Pa). This resulted in large apparent compliances and apparently negative unstressed volumes, as seen in the innervated livers. Thus blood volume–pressure relationships in innervated livers may not give valid measurements of compliance and unstressed volume. A remarkable feature in all these experiments was the linearity of the relationship between hepatic blood volume and intrahepatic pressure. Exudation of fluid begins at higher intrahepatic pressures in innervated compared with denervated livers.

Pulmonary Hypertension Associated With Myocardial Amyloid Degeneration: a Case Report

2021 ◽  
Author(s):  
Lu Yan ◽  
Qixian Zeng ◽  
Changming Xiong ◽  
Zhihui Zhao ◽  
Qing Zhao ◽  
...  
Keyword(s):  
Heart Failure ◽  
Pulmonary Hypertension ◽  
Blood Vessels ◽  
Amyloid Fibrils ◽  
Right Heart Failure ◽  
Pulmonary Artery Hypertension ◽  
Pulmonary Vasculature ◽  
Vascular Involvement ◽  
Right Heart ◽  
Protein Deposits

Abstract Background: There is very little literature on Pulmonary hypertension associated with myocardial amyloid degeneration. At present, only 10 cases pulmonary hypertension cased by amyloid protein deposits in the pulmonary blood vessels have been reported by Eder et al. We reported a case that the patient was pulmonary artery hypertension combined with myocardial amyloid change. It’s aim to claims that pulmonary hypertension is most likely caused by amyloid fibrin deposition in pulmonary blood vessels.Case presentation: We report a case of a 65-year-old male patient with with AL and ATTR combined type amyloidosis who developed right heart failure because of severe pulmonary hypertension. Pulmonary hypertension due to deposition of amyloid in the pulmonary vasculature is an uncommon finding; however, it should be considered in cases of unexplained pulmonary hypertension in patients with amyloidosis.Conclusion: we present a men with amyloidosis who developed dyspnea and right heart failure and was diagnosed with pulmonary hypertension, most probably secondary to pulmonary vascular involvement by amyloid fibrils.

Effect of nitroglycerin on splanchnic and pulmonary blood volume

2021 ◽  
Author(s):  
Luis E. Okamoto ◽  
William D. Dupont ◽  
Italo Biaggioni ◽  
Marvin W. Kronenberg ◽  
Amy K. Wright
Keyword(s):  
Blood Volume ◽  
Pulmonary Blood Volume

Effect of lung inflation on lung blood volume and pulmonary venous flow

1985 ◽  
Vol 58 (3) ◽  
pp. 954-963 ◽  
Author(s):  
R. Brower ◽  
R. A. Wise ◽  
C. Hassapoyannes ◽  
B. Bromberger-Barnea ◽  
S. Permutt
Keyword(s):  
Blood Volume ◽  
Transpulmonary Pressure ◽  
Left Ventricular ◽  
Respiratory Cycle ◽  
Pulmonary Vasculature ◽  
Venous Flow ◽  
Lung Inflation ◽  
Pulmonary Venous Flow ◽  
Respiratory Wave ◽  
Left Ventricular Preload

Phasic changes in lung blood volume (LBV) during the respiratory cycle may play an important role in the genesis of the respiratory wave in arterial pressure, or pulsus paradoxus. To better understand the effects of lung inflation on LBV, we studied the effect of changes in transpulmonary pressure (delta Ptp) on pulmonary venous flow (Qv) in eight isolated canine lungs with constant inflow. Inflation when the zone 2 condition was predominant resulted in transient decreases in Qv associated with increases in LBV. In contrast, inflation when the zone 3 condition was predominant resulted in transient increases in Qv associated with decreases in LBV. These findings are consistent with a model of the pulmonary vasculature that consists of alveolar and extra-alveolar vessels. Blood may be expelled from alveolar vessels but is retained in extra-alveolar vessels with each inflation. The net effect on LBV and thus on Qv is dependent on the zone conditions that predominate during inflation, with alveolar or extra-alveolar effects being greater when the zone 3 or zone 2 conditions predominate, respectively. Lung inflation may therefore result in either transiently augmented or diminished Qv. Phasic changes in left ventricular preload may therefore depend on the zone conditions of the lungs during the respiratory cycle. This may be an important modulator of respiratory variations in cardiac output and blood pressure.

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