Search results for "Flow velocity"
showing 10 items of 227 documents
Relationship between kidney findings and systemic vascular damage in elderly hypertensive patients without overt cardiovascular disease
2017
Few studies have investigated the influence of age on the relationships between systemic vascular damage, kidney dysfunction, and intrarenal hemodynamic changes in patients with hypertension without overt cardiovascular disease. The authors enrolled 126 elderly patients with hypertension (aged ≥65 years) and 350 nonelderly patients with hypertension (aged <65 years). Carotid intima‐media thickness, renal resistive index, and aortic pulse wave velocity were performed in all patients. Elderly patients with hypertension had lower estimated glomerular filtration rates and higher albuminuria, renal resistive index, carotid intima‐media thickness, and aortic pulse wave velocity compared with none…
Shunting of the Microcirculation After Mesenteric Ischemia and Reperfusion Is a Function of Ischemia Time and Increases Mortality
2006
Shunting of the microcirculation contributes to the pathology of sepsis and septic shock. The authors address the hypothesis that shunting of the microcirculation occurs after superior mesenteric artery occlusion (SMAO) and reperfusion, and explore functional consequences.Spontaneously breathing animals (rats) (n = 30) underwent SMAO for 0 (controls), 30 (SMAO_30) or 60 min (SMAO_60) followed by reperfusion (4 h) with normal saline. Leukocyte-endothelial interactions in mesenteric venules were quantified in an exteriorized ileal loop using intravital microscopy. Abdominal blood flow was recorded continuously, and arterial blood gases were analyzed at intervals. The above groups were matched…
Cerebral haemodynamic changes during propofol-remifentanil or sevoflurane anaesthesia: transcranial Doppler study under bispectral index monitoring
2006
Background. Sevoflurane or propofol–remifentanil-based anaesthetic regimens represent modern techniques for neurosurgical anaesthesia. Nevertheless, there are potential differences related to their activity on the cerebrovascular system. The magnitude of such difference is not completely known. Methods. In total 40 patients, treated for spinal or maxillo-facial disorders, were randomly allocated to either i.v. propofol–remifentanil or inhalational sevoflurane anaesthesia. Transcranial Doppler was used to assess changes in cerebral blood flow velocity, carbon dioxide reactivity, cerebral autoregulation and the bispectral index to assess the depth of anaesthesia. Results. Time-averaged mean f…
Acute normovolaemic anaemia prevents ethanol-induced gastric damage in rats through a blood flow related mechanism.
1994
The aim of the study was to assess whether changes in gastric mucosal blood flow induced by acute normovolaemic anaemia influence the susceptibility of the gastric mucosa to ethanol-induced damage, and the relationship of these changes with nitric oxide biosynthesis. Acute normovolaemic anaemia, promoted by exchanging 3 ml of blood by a plasma expander, induced a significant increase in gastric mucosal blood flow measured by hydrogen gas clearance, without changes in arterial blood pressure. After intragastric 60% ethanol administration, gastric blood flow was still significantly higher in anaemic than in control rats, and this was associated with a lower macroscopic and microscopic gastric…
Blood pressure and pulse wave velocity values in the institutionalized elderly aged 80 and over: baseline of the PARTAGE study.
2009
The aim of the longitudinal study PARTAGE (predictive values of blood pressure and arterial stiffness in institutionalized very aged population) was to determine the predictive value of blood pressure (BP) and arterial stiffness for overall mortality, major cardiovascular events and cognitive decline in a large population of institutionalized patients aged 80 and over. In the study herein, we present the baseline data values of this study.A total of 1130 patients were recruited (878 women), living in French and Italian nursing homes. Clinical and 3-day self-measurements of BP were conducted. Aortic and upper limb pulse wave velocity were obtained using a PulsePen tonometer.Of this populatio…
Extracranial internal carotid artery occlusion: the role of common carotid artery volume flow.
2002
BACKGROUND AND PURPOSE Quantitative measurement of blood flow volume in the common carotid artery (CCA) is now possible using the color velocity imaging quantification (CVI-Q) ultrasound technique. The aim of this study was to evaluate the cerebral hemodynamic effects of unilateral internal carotid artery (ICA) occlusion on CCA blood flow volumes (FVs) using CVI-Q. METHODS Records of ultrasound studies in our neurosonology laboratory were retrospectively reviewed to identify patients with unilateral ICA occlusions who at a minimum received both a routine color duplex carotid ultrasound examination and quantitative measurement of FV in the CCA, bilaterally, using the CVI-Q method. A total of…
Optic Nerve Decompression Improves Hemodynamic Parameters in Papilledema
1993
Purpose: The purpose of this study is to examine changes in color Doppler imaging parameters before and after optic nerve sheath decompression (ONSD) for chronic papilledema caused by pseudotumor cerebri (PTC). Methods: Color Doppler imaging was performed within 48 hours before surgery and within 48 hours after the procedure using a color Doppler unit with a 7.5-MHz phased linear transducer. Pulsed Doppler spectrum analyses were recorded digitally on videotape from the ophthalmic, central retinal, and short posterior ciliary arteries, using a 0.4 × 0.6-mm sample volume. Results: Blood flow velocities in the ophthalmic, short posterior ciliary, and central retinal arteries of 24 eyes were si…
Color Doppler Imaging of Arterial Blood Flow in Central Retinal Vein Occlusion
1994
Purpose: The hemodynamics of the retrobulbar arterial circulation of patients with central retinal vein occlusion were evaluated in order to better understand the pathophysiology of this disease. Methods: Color Doppler imaging was used to measure the peak systolic velocity and vascular resistance (pulsatility index) in the retrobulbar arteries of involved eyes and clinically healthy fellow eyes of patients with central retinal vein occlusion and in the control eyes of age- and sex-matched healthy volunteers. Results: Average peak systolic velocity was significantly lower and average vascular resistance was significantly higher in the central retinal artery of involved eyes of patients with …
Double-blind, crossover study of the clinical efficacy and the hemorheological effects of pentoxifylline in patients with occlusive arterial disease …
1984
The effect of a 3 month daily administration of 800 mg pentoxifylline (Trental 400 bds) or placebo was assessed under double blind crossover design in 18 patients (12 males and 6 females) with peripheral occlusive arterial disease in respect of painfree walking distance and various hemorheological and hemostasiological variables, platelet aggregation, serum cholesterol and triglycerides. In first treatment period walking distance significantly increased with pentoxifylline by 46% from baseline 121 ± 15 m and by 4% with placebo from baseline 134 ± 18 m. Pentoxifylline administration furthermore yielded significant decrease in whole blood and plasma viscosity and significant increase in eryt…
Nail fold capillary diameter changes in acute systemic hypoxia.
2013
The present study was undertaken to determine the effect of arterial blood hypoxemia induced by acute systemic hypoxia (pO2=12%) on capillary recruitment and diameter, and red blood cell (RBC) velocity in human nail fold capillaries during rest, arterial post-occlusive reactive hyperemia (PRH), and venous occlusion (VO) using intravital video-capillaroscopy. Capillary recruitment was unchanged in acute systemic hypoxia (H) versus normoxia (N). There was no difference in RBC velocity measurements between normoxia and hypoxia (P<0.63). However, a statistically significant increase in nail fold capillary total width (N, 39.9±9.1 vs. H, 42.7±10.3 μm; P<0.05), apical diameter (N, 15.5±4.3 vs. H,…