Blood Flow in Expanded Tissue Treated with an Anticontractile Agent

1991 ◽  
Vol 100 (12) ◽  
pp. 962-965 ◽  
Author(s):  
John W. Canady ◽  
Kevin M. Kelly ◽  
Christopher A. Squier ◽  
Janusz Bardach
Keyword(s):  
Blood Flow ◽  
Guinea Pigs ◽  
Laser Doppler Velocimetry ◽  
Tissue Expansion ◽  
Blood Perfusion ◽  
Doppler Velocimetry ◽  
Expansion Process ◽  
Ischemic Complications ◽  
Group 2 ◽  
Group 1

The present study investigates blood flow at several stages of expansion with and without enhancement by anticontractile agents (papaverine). Twelve 1-kg guinea pigs were divided into two groups. In group 1 were six animals undergoing tissue expansion without anticontractile agents, and in group 2 were six animals treated with a saturated solution of papaverine prior to expansion. Laser-Doppler velocimetry was used to monitor the changes in blood perfusion that occurred with each expansion. Animals pretreated with papaverine (group 2) maintained higher blood flow following inflation of the expander than untreated animals (group 1). This study provides physiologic evidence of the benefits of pharmacologic enhancement of the expansion process. Agents of this type may have a future role in the prevention of ischemic complications.

Dopamine-1 receptor stimulation impairs intestinal oxygen utilization during critical hypoperfusion

2003 ◽  
Vol 284 (2) ◽  
pp. H668-H675 ◽  
Author(s):  
Jorge A. Guzman ◽  
Ariosto E. Rosado ◽  
James A. Kruse
Keyword(s):  
Blood Flow ◽  
Mucosal Blood Flow ◽  
Control Group ◽  
Oxygen Utilization ◽  
Hemorrhage Control ◽  
Receptor Stimulation ◽  
Anesthetized Dogs ◽  
Group 2 ◽  
Increased Susceptibility ◽  
Group 1

Effects of a dopamine-1 (DA-1) receptor agonist on systemic and intestinal oxygen delivery (D˙o 2)-uptake relationships were studied in anesthetized dogs during sequential hemorrhage. Control ( group 1) and experimental animals ( group 2) were treated similarly except for the addition of fenoldopam (1.0 μg · kg−1 · min−1) in group 2. Both groups had comparable systemic criticalD˙o 2(D˙o 2crit), but animals in group 2 had a higher gut D˙o 2crit(1.12 ± 1.13 vs. 0.80 ± 0.09 ml · kg−1 · min−1, P < 0.05). At the mucosal level, a clear biphasic delivery-uptake relationship was not observed in group 1; thus oxygen consumption by the mucosa may be supply dependent under physiological conditions. Group 2 demonstrated higher peak mucosal blood flow and lack of supply dependency at higher mucosalD˙o 2 levels. Fenoldopam resulted in a more conspicuous biphasic relationship at the mucosa and a rightward shift of overall splanchnic D˙o 2crit despite increased splanchnic blood flow. These findings suggest that DA-1 receptor stimulation results in increased gut perfusion heterogeneity and maldistribution of perfusion, resulting in increased susceptibility to ischemia.

Laser Doppler velocimetry: a new technique for the measurement of intestinal mucosal blood flow

1984 ◽  
Vol 30 (4) ◽  
pp. 225-230 ◽  
Author(s):  
Andrew D. Feld ◽  
Joseph D. Fondacaro ◽  
G. Allen Holloway ◽  
Eugene D. Jacobson
Keyword(s):  
Blood Flow ◽  
Laser Doppler Velocimetry ◽  
Mucosal Blood Flow ◽  
Laser Doppler ◽  
New Technique ◽  
Doppler Velocimetry ◽  
A New Technique

Hybrid blood flow probe for simultaneous H2 clearance and laser-Doppler velocimetry

1987 ◽  
Vol 253 (4) ◽  
pp. G573-G581 ◽  
Author(s):  
G. R. DiResta ◽  
J. W. Kiel ◽  
G. L. Riedel ◽  
P. Kaplan ◽  
A. P. Shepherd
Keyword(s):  
Blood Flow ◽  
Laser Doppler Velocimetry ◽  
Regional Blood Flow ◽  
Laser Doppler ◽  
Doppler Velocimetry ◽  
Flow Probe ◽  
Flow Measurements ◽  
Blood Flow Measurements ◽  
Light Guides ◽  
The Relationship

To perform two independent regional blood flow measurements in tissue volumes of similar dimensions, we designed a hybrid blood flow probe capable of measuring regional perfusion by both laser-Doppler velocimetry (LDV) and H2 clearance. The probe consisted of two fiber-optic light guides to conduct light between the surface of tissue of interest and a laser-Doppler blood flowmeter. Also contained within the probe were a platinum 25-microns H2-sensing electrode and a 125-microns H2-generating electrode. The probe can thus be used to measure local perfusion with H2 clearance. The H2 can either be inhaled or can be generated electrochemically at the locus of interest. Evaluation of the probe in the canine gastric mucosa indicated 1) that the relationship between mucosal flow measurements made simultaneously with H2 clearance and LDV was highly significant and linear and 2) that H2 clearance could potentially be used to calibrate the laser-Doppler blood flowmeter in absolute units. The methods of constructing the flow probes are discussed in detail.

Regulation of local oxygen tension and blood flow in the inner retina during hyperoxia

1986 ◽  
Vol 61 (2) ◽  
pp. 592-598 ◽  
Author(s):  
C. E. Riva ◽  
C. J. Pournaras ◽  
M. Tsacopoulos
Keyword(s):  
Blood Flow ◽  
Laser Doppler Velocimetry ◽  
Time Course ◽  
Retinal Blood Flow ◽  
Doppler Velocimetry ◽  
Outer Retina ◽  
Retinal Arterioles ◽  
Arteriolar Wall ◽  
Local Oxygen ◽  
Venous O2 Saturation

A study has been undertaken to determine whether local changes in PO2 could be a factor in the regulation of retinal blood flow during 100% O2 breathing. For this purpose we have measured simultaneously in eyes of anesthetized and artificially ventilated miniature pigs the change in local preretinal PO2 and retinal blood flow using O2-sensitive microelectrodes and laser Doppler velocimetry. Although preretinal intervascular PO2 changed little, periarteriolar PO2 increased markedly during 100% O2 breathing. When measured less than 50 microns from the arteriolar wall, the time course of this increase preceded that of the decrease in retinal blood flow. The results indicate that O2 diffusing through the wall of the large retinal arterioles represents the most important component of periarteriolar PO2. This diffusion coupled with the decrease in retinal blood flow could play a major role in the regulation of inner retinal PO2. The data also suggest that diffusional shunting of O2 between retinal arterioles and veins could explain the unexpected increase in venous O2 saturation during 100% O2 breathing that has been previously reported by others. The finding that retinal periarteriolar PO2 is always higher than the PO2 in the outer retina does not support the previously formulated hypothesis that O2 from the choroid is responsible for the constriction of the arterioles during hyperoxia.

scholarly journals THE ROLE OF MYOCARDIAL REVASCULARIZATION IN THE SURVIVAL OF PATIENTS WITH ALTERED CORONARY BLOOD FLOW DETECTED BY TRANSTHORACIC ULTRASOUND

2019 ◽  
Vol 34 (1) ◽  
pp. 54-60
Author(s):  
M. S. Kamenskikh ◽  
A. V. Zagatina ◽  
N. T. Zhuravskaya ◽  
Yu. N. Fedotov ◽  
D. V. Shmatov
Keyword(s):  
Blood Flow ◽  
Coronary Blood Flow ◽  
Myocardial Revascularization ◽  
Control Group ◽  
P Value ◽  
Coronary Events ◽  
Group 2 ◽  
Group 1 ◽  
Flow Velocities

Aim of the study was to identify the effects of myocardial revascularization on the prognosis in patients with altered coronary blood flow detected by transthoracic ultrasound.Material and Methods. Four hundred and twelve (412) patients were included in the study. The inclusion criterion was coronary velocity more than 70 cm/s during echocardiography. The study population was divided into three groups: Group 1 comprised patients with high velocities in the coronary arteries detected by ultrasound, in whom myocardial revascularization was performed; Group 2 comprised patients with high velocities in the coronary arteries, in whom myocardial revascularization was not performed and; the Control Group comprised patients with normal coronary blood flow according to ultrasound. The follow-up period was 10–11 months.Results. Seventeen (17) deaths (4.7%) occurred during follow-up. Death rates were 1.6 vs. 8.1 vs. 0% in Group 1, Group 2 and the Control Group, respectively, with a p-value for the difference between Group 1 and Group 2 (p1) of <0.009; and a p-value for the differences compared with the Control group (р2) of <0.03. Death, myocardial infarction, pulmonary edema, and acute coronary syndrome were observed in 27 patients (7.7% of the study group with accelerated blood flow). The rates of these outcomes were 4.9 vs. 11.0 vs. 0% in Group 1, Group 2, and the Control Group, respectively (p1<0.05; p2<0.006). Discussion. The study showed high rates of mortality or acute coronary events in the group of patients with pathologically high coronary flow velocities. The positive effects of revascularization on survival in this group were verified.Conclusions: 1. Left artery coronary flow velocities over 70 cm/s indicate a high probability of death or acute coronary events within 10.5 months.2. Myocardial revascularization has a significant positive effect on the survival rate and incidence of acute coronary events in patients with coronary artery flow velocities greater than 70 cm/s.3. Patients with high coronary blood flow velocities should be referred to coronary angiography or other diagnostic tests without waiting for clinical manifestations and specific symptoms for coronary artery disease.

Differences in reactive hyperemia between the intestinal mucosa and muscularis

1984 ◽  
Vol 247 (6) ◽  
pp. G617-G622
Author(s):  
A. P. Shepherd ◽  
G. L. Riedel
Keyword(s):  
Blood Flow ◽  
Metabolic Rate ◽  
Laser Doppler Velocimetry ◽  
Reactive Hyperemia ◽  
Arterial Occlusion ◽  
Oxygen Demand ◽  
Laser Doppler ◽  
Doppler Velocimetry ◽  
Total Blood ◽  
Total Blood Flow

In a previous study of regional intestinal blood flow by laser-Doppler velocimetry, we noted that the mucosa displayed reactive hyperemia following arterial occlusion but that the muscularis did not. Therefore, to determine whether this observation is generally valid, we compared responses of the mucosa and muscularis externa to arterial occlusion. We measured total blood flow to isolated loops of canine small bowel with an electromagnetic flow probe on the supply artery; blood flow either in the mucosa or in the muscularis was measured by laser-Doppler velocimetry. Mucosal and total blood flow consistently showed reactive hyperemia in response to a 60-s occlusion, but the muscularis did not. To determine whether metabolic rate influenced reactive hyperemia, we increased enteric oxygen uptake by placing 5% bile and transportable solutes in the lumen; these agents increased oxygen consumption by 36%. After a 60-s occlusion, the durations of both total and mucosal reactive hyperemia were significantly prolonged by increased metabolic rate. Similarly, the payback-to-debt ratios in both total and mucosal blood flows were significantly increased at elevated metabolic rate. These data support the conclusions that reactive hyperemia occurs more frequently and has a greater magnitude in the mucosa compared with the muscularis and both total and mucosal reactive hyperemia are strongly influenced by the preocclusive oxygen demand. These findings therefore constitute further evidence that metabolic factors contribute to reactive hyperemia in the intestinal circulation.

Effects of Sufentanil on Cerebral Hemodynamics and Intracranial Pressure in Patients with Brain Injury

1995 ◽  
Vol 83 (4) ◽  
pp. 721-726. ◽  
Author(s):  
Christian Werner ◽  
Eberhard Kochs ◽  
Hanswerner Bause ◽  
William E. Hoffman ◽  
Jochen Schulte am Esch
Keyword(s):  
Blood Flow ◽  
Middle Cerebral Artery ◽  
Flow Velocity ◽  
Cerebral Artery ◽  
Blood Flow Velocity ◽  
Artery Blood Flow ◽  
Arterial Blood ◽  
Norepinephrine Infusion ◽  
Group 2 ◽  
Group 1

Background The current study investigates the effects of sufentanil on cerebral blood flow velocity and intracranial pressure (ICP) in 30 patients with intracranial hypertension after severe brain trauma (Glasgow coma scale &lt; 6). Methods Mechanical ventilation (FIO2 0.25-0.4) was adjusted to maintain arterial carbon dioxide tensions of 28-30 mmHg. Continuous infusion of midazolam (200 micrograms/kg/h intravenous) and fentanyl (2 micrograms/kg/h intravenous) was used for sedation. Mean arterial blood pressure (MAP, mmHg) was adjusted using norepinephrine infusion (1-5 micrograms/min). Mean blood flow velocity (Vmean, cm/s) was measured in the middle cerebral artery using a 2-MHz transcranial Doppler sonography system. ICP (mmHg) was measured using an epidural probe. After baseline measurements, a bolus of 3 micrograms/kg sufentanil was injected, and all parameters were continuously recorded for 30 min. The patients were assigned retrospectively to the following groups according to their blood pressure responses to sufentanil: group 1, MAP decrease of less than 10 mmHg, and group 2, MAP decrease of more than 10 mmHg. Results Heart rate, arterial blood gases, and esophageal temperature did not change over time in all patients. In 18 patients, MAP did not decrease after sufentanil (group 1). In 12 patients, sufentanil decreased MAP &gt; 10 mmHg from baseline despite norepinephrine infusion (group 2). ICP was constant in patients with maintained MAP (group 1) but was significantly increased in patients with decreased MAP. Vmean did not change with sufentanil injection regardless of changes in MAP. Conclusions The current data show that sufentanil (3 micrograms/kg intravenous) has no significant effect on middle cerebral artery blood flow velocity and ICP in patients with brain injury, intracranial hypertension, and controlled MAP. However, transient increases in ICP without changes in middle cerebral artery blood flow velocity may occur concomitant with decreases in MAP. This suggests that increases in ICP seen with sufentanil may be due to autoregulatory decreases in cerebral vascular resistance secondary to systemic hypotension.

315 USE OF PERIFOLLICULAR BLOOD FLOW TO PREDICT THE DEVELOPMENTAL COMPETENCE OF BOVINE CUMULUS-OOCYTE COMPLEXES COLLECTED DURING REPEATED OVUM PICKUP SESSIONS ONCE OR TWICE WEEKLY

2009 ◽  
Vol 21 (1) ◽  
pp. 254 ◽  
Author(s):  
A. Hanstedt ◽  
K. Höffmann ◽  
Ä Honnens ◽  
H. Bollwein ◽  
C. Wrenzycki
Keyword(s):  
Blood Flow ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Small Individual ◽  
Color Flow ◽  
Color Flow Imaging ◽  
Significant Difference ◽  
Developmental Rates ◽  
Group 2 ◽  
Group 1

On average, only 20% of the cumulus–oocyte complexes (COC) develop to the blastocyst stage (Merton et al. 2003 Theriogenology 59, 651–674). An increase in the blood supply to individual follicles appears to be associated with follicular growth rates, whereas a reduction seems to be closely related to follicular atresia (Acosta et al. 2003 Reproduction 125, 759–767). The purpose of this study was to determine whether qualitative perifollicular blood flow changes can be used to predict the developmental competence of COC collected during repeated ovum pickup (OPU) sessions once or twice weekly. Lactating Holstein cows (n = 20) were used as oocyte donors. After dominant follicle removal, OPU was performed twice (group 1, for 3 weeks) or once (group 2, for six weeks) weekly employing a 7.5-MHz transducer (GE 8C-RS) of an ultrasound scanner (GE Logiq Book). Follicle size and Doppler characteristics were recorded by transvaginal ultrasonography just before COC collection using color flow imaging. Owing for technical limitations for measurement of blood flow in small individual follicles, only the presence or absence of blood flow was assessed for each follicle. When a clearly visible blue or red spot (blood flow) was detected in the follicle wall, it was considered as a follicle with detectable blood flow. Follicles with or without detectable blood flow from each individual cow were aspirated separately. After morphological classification of COC, standard protocols for IVP were used for embryo production (Wrenzycki et al. 2001 Biol. Reprod. 65, 323–331). Cleavage and blastocyst rates were recorded at Day 3 and Day 8, respectively. In total, 464 (246 with and 218 without detectable blood flow) and 243 (125 with and 118 without detectable blood flow) follicles ≥3 mm were aspirated in group 1 and group 2, respectively. Morphology of the COC was similar in all groups. Developmental rates for COC stemming from follicles with or without detectable blood flow in group 1 did not show differences for cleavage rates, 54.0% (34/63) and 56.7% (45/81), and for blastocyst rates, 25.4% (16/63) and 22.2% (18/83), respectively. In group 2, the cleavage rates were also similar for COC originating from follicles with and without detectable blood flow, 54.3% (25/46) and 51.5% (34/66). However, developmental rates up to the blastocyst stage did show a significant difference, 23.9% (11/46) and 15.2% (10/66) for COC aspirated from follicles with or without detectable blood flow (P ≤ 0.05). These results show that using COC originating from follicles with detectable perifollicular blood flow collected once weekly may have a higher developmental competence compared to those from follicle without detectable blood flow. Within the detection limits of this study, differences in perifollicular blood flow during repeated OPU sessions once weekly were predictive of oocyte competence. Ruthe Research Farm, Germany, for providing the animals; Masterrind GmbH, Germany, for donation of the semen; and the HW Schaumann Stiftung for financial support.

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