Effect of hypothermia and HTK on the microcirculation in the rat cremaster muscle after ischaemia

2005 ◽  
Vol 109 (1) ◽  
pp. 117-123 ◽  
Author(s):  
Jacqueline BASTIAANSE ◽  
Dick W. SLAAF ◽  
Mirjam G. A. oude EGBRINK ◽  
Gary L. ANDERSON ◽  
Hans VINK ◽  
...  
Keyword(s):  
Blood Flow ◽  
Vessel Wall ◽  
Tissue Perfusion ◽  
Cremaster Muscle ◽  
Capillary Perfusion ◽  
Combined Application ◽  
Warm Ischaemia ◽  
Preservation Method ◽  
Flow Restoration ◽  
Wall Interactions

Hypothermia is an important preservation method for tissues and solid organs. The aim of the present study was to assess in rat cremaster muscle the effect of hypothermia, without or with pre-ischaemic HTK (histidine-tryptophan-ketoglutarate–Bretschneider solution) perfusion, on microvascular consequences of 4 or 6 h ischaemia and 2 h of reperfusion. Intravital microscopy was applied to examine capillary perfusion and leucocyte–endothelium interactions. The cremaster muscle was subjected to 4 or 6 h of cold (4 °C) or warm (33–34 °C) ischaemia and 2 h of reperfusion. Measurements were performed at baseline, prior to HTK perfusion and ischaemia, and at 0, 1 and 2 h after blood flow restoration. Hypothermia completely prevented the 50% reduction in capillary perfusion that was observed previously at start of reperfusion after 4 h warm ischaemia. After 6 h of warm ischaemia, perfusion resumed in only 45% of capillaries and remained at this low level during reperfusion. In contrast, only a slight decrease (<10%) in capillary perfusion was observed after 6 h of cold ischaemia. Pre-ischaemic HTK perfusion had no beneficial effect on tissue perfusion. Both hypothermia and HTK attenuated the significant increase in venular leucocyte–vessel wall interactions, which was observed after 4 h of warm ischaemia in a previous study. Combined application of both interventions had no additional effects. After 6 h of warm ischaemia, no increase in leucocyte–vessel wall interactions was observed, possibly due to venular flow reduction. In conclusion, hypothermia preserves capillary perfusion and prevents an increase in leucocyte–vessel wall interactions during reperfusion after muscle tissue ischaemia. Preischaemic perfusion of the vasculature with HTK does not improve the effects of cold storage on tissue perfusion, but attenuates the inflammatory response independently of temperature effect.

Abolition of arteriolar dilation but not constriction to histamine in cremaster muscle of eNOS–/– mice

2003 ◽  
Vol 285 (2) ◽  
pp. H493-H498 ◽  
Author(s):  
Geoffrey W. Payne ◽  
Joseph A. Madri ◽  
William C. Sessa ◽  
Steven S. Segal
Keyword(s):  
Blood Flow ◽  
Receptor Antagonist ◽  
Muscle Blood Flow ◽  
Tissue Perfusion ◽  
No Production ◽  
Local Concentration ◽  
Cremaster Muscle ◽  
Microvascular Endothelium ◽  
Peak Response ◽  
Vasomotor Responses

Histamine increases the permeability of capillaries and venules but little is known of its precapillary actions on the control of tissue perfusion. Using gene ablation and pharmacological interventions, we tested whether histamine could increase muscle blood flow through stimulating nitric oxide (NO) release from microvascular endothelium. Vasomotor responses to topical histamine were investigated in second-order arterioles in the superfused cremaster muscle of anesthetized C57BL6 mice and null platelet endothelial cell adhesion molecule-1 (PECAM-1–/–) and null endothelial NO synthase (eNOS–/–) mice aged 8–12 wk. Neither resting (17 ± 1 μm) nor maximum diameters (36 ± 2 μm) were different between groups, nor was the constrictor response (∼5 ± 1 μm) to elevating superfusate oxygen from 0 to 21%. For arterioles of C57BL6 and PECAM-1–/– mice, cumulative addition of histamine to the superfusate produced vasodilation (1 nM–1 μM; peak response, 9 ± 1 μm) and then vasoconstriction (10–100 μM; peak response, 12 ± 2 μm). In eNOS–/– mice, histamine produced only vasoconstriction. In C57BL6 and PECAM-1–/– mice, vasodilation was abolished with Nω-nitro-l-arginine (30 μM); in all mice, vasoconstriction was abolished with nifedipine (1 μM). Vasomotor responses were eliminated with pyrilamine (1 μM; H1 receptor antagonist) yet remained intact with cimetidine (1 μM; H2 receptor antagonist). These findings illustrate that the biphasic vasomotor response of mouse cremaster arterioles to histamine is mediated through H1 receptors on endothelium (NO-dependent vasodilation) as well as smooth muscle (Ca2+ entry and constriction). Thus histamine can increase as well as decrease muscle blood flow, according to local concentration. However, when NO production is compromised, only vasoconstriction and flow reduction occur.

scholarly journals The endothelial glycocalyx promotes homogenous blood flow distribution within the microvasculature

2016 ◽  
Vol 311 (1) ◽  
pp. H168-H176 ◽  
Author(s):  
P. Mason McClatchey ◽  
Michal Schafer ◽  
Kendall S. Hunter ◽  
Jane E. B. Reusch
Keyword(s):  
Blood Flow ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Vessel Wall ◽  
Tissue Perfusion ◽  
Cell Interactions ◽  
Microvascular Perfusion ◽  
Endothelial Glycocalyx ◽  
Heterogeneous Distribution

Many common diseases involve impaired tissue perfusion, and heterogeneous distribution of blood flow in the microvasculature contributes to this pathology. The physiological mechanisms regulating homogeneity/heterogeneity of microvascular perfusion are presently unknown. Using established empirical formulations for blood viscosity modeling in vivo (blood vessels) and in vitro (glass tubes), we showed that the in vivo formulation predicts more homogenous perfusion of microvascular networks at the arteriolar and capillary levels. Next, we showed that the more homogeneous blood flow under simulated in vivo conditions can be explained by changes in red blood cell interactions with the vessel wall. Finally, we demonstrated that the presence of a space-filling, semipermeable layer (such as the endothelial glycocalyx) at the vessel wall can account for the changes of red blood cell interactions with the vessel wall that promote homogenous microvascular perfusion. Collectively, our results indicate that the mechanical properties of the endothelial glycocalyx promote homogeneous microvascular perfusion. Preservation or restoration of normal glycocalyx properties may be a viable strategy for improving tissue perfusion in a variety of diseases.

Blood Flow Pattern and Anastomotic Compliance for Interrupted versus Continuous Coronary Bypass Grafts

2005 ◽  
Vol 6 (2) ◽  
pp. 65 ◽  
Author(s):  
Marc Gerdisch ◽  
Thomas Hinkamp ◽  
Stephen D. Ainsworth
Keyword(s):  
Blood Flow ◽  
Vessel Wall ◽  
Coronary Bypass ◽  
Bypass Grafts ◽  
Cross Sectional ◽  
Coronary Bypass Grafts ◽  
Geometric Consistency ◽  
Suturing Technique ◽  
Suturing Techniques ◽  
Key Indicators

<P>Background: Use of the interrupted coronary anastomosis has largely been abandoned in favor of the more rapid continuous suturing technique. The Coalescent U-CLIP anastomotic device allows the surgeon to create an interrupted distal anastomosis in the same amount of time that it would take to create a continuous anastomosis. This acute bovine study examined the effect of the anastomotic technique on blood flow and vessel wall function. </P><P>Methods: End-to-side coronary anastomoses were created in an open chest bovine model using the left and right internal thoracic arteries and the left anterior descending coronary artery. All other variables except suturing technique were carefully controlled. In each animal, one anastomosis was completed using a continuous suturing technique and the other was performed in an interrupted fashion using the Coalescent U-CLIP anastomotic device. Volumetric flow curves through each graft were analyzed using key indicators of anastomotic quality, and anastomotic compliance was evaluated using intravascular ultrasound. Luminal castings were created of each vessel to examine the interior surface of each anastomosis for constrictions and deformities. </P><P>Results: The interrupted anastomoses created with the Coalescent U-CLIP anastomotic device showed significant differences with respect to anastomotic compliance, pulsatility index, peak flow, and percentage of diastolic flow. The cross-sectional area and degree of luminal deformity were also different for the two suturing techniques. </P><P>Conclusions: In this acute bovine model, interrupted coronary anastomoses demonstrated superior geometric consistency and greater physiologic compliance than did continuously sutured anastomoses. The interrupted anastomosis also caused fewer disturbances to the flow waveform, behaving similarly to a normal vessel wall. The combination of these effects may influence both acute and long-term patency of the coronary bypass grafts.</P>

Blood flow and high-energy phosphates in microregions of left ventricular subendocardium

1981 ◽  
Vol 240 (5) ◽  
pp. H804-H810 ◽  
Author(s):  
H. D. Kleinert ◽  
H. R. Weiss
Keyword(s):  
Blood Flow ◽  
Linear Relationship ◽  
Tissue Perfusion ◽  
High Energy ◽  
Left Ventricular ◽  
Significant Loss ◽  
Tissue Blood Flow ◽  
High Energy Phosphates ◽  
Tissue Samples ◽  
Heterogeneous Distribution

Blood flow and high-energy phosphate (HEP) content were determined simultaneously in multiple microregions of left ventricular subendocardium in 29 normal anesthetized open-chest rabbits by use of a new micromethod to determine whether a direct linear relationship existed between these parameters. Tissue samples weighed 1-2 mg. ATP and creatine phosphate (CP) content were quantitated in quick-frozen hearts by fluorometry at sites where tissue perfusion was measured by H2 clearance by use of bare-tipped platinum electrodes. A series of validation studies were conducted to ensure that 1) no significant damage to the tissue surrounding the electrode occurred during the period of experimentation and 2) no significant loss of biochemical constituents had occurred due to labile processes during freezing or storage of the tissue. Blood flow, ATP, and CP values averaged 79.1 +/- 24.1 (SD) ml.min-1.100 g-1, 4.9 +/- 1.3 mumol/g tissue, and 8.0 +/- 3.0 mumol/g tissue, respectively, and are similar to those reported in studies using larger tissue samples. Correlation between the heterogeneous distribution of tissue perfusion and HEP revealed no direct linear relationship between these parameters in the normal unstressed rabbit subendocardium.

scholarly journals WALANT–Epinephrine injection may lead to short term, reversible episodes of critical oxygen saturation in the fingertips

2021 ◽  
Vol 141 (3) ◽  
pp. 527-533
Author(s):  
P. Moog ◽  
M. Dozan ◽  
J. Betzl ◽  
I. Sukhova ◽  
H. Kükrek ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oxygen Saturation ◽  
Substantial Reduction ◽  
Tissue Perfusion ◽  
Critical Levels ◽  
Short Term ◽  
Doppler Flowmetry ◽  
Epinephrine Injection ◽  
Venous Oxygen Saturation

Abstract Introduction Although the WALANT technique’s long-term safeness has been demonstrated in many studies, there are only few data investigating its short-term effects on tissue perfusion and oxygen levels. It was hypothesized that, temporarily, critical levels of tissue perfusion may occur. Methods Seventeen patients, who were scheduled for different procedures in WALANT technique, were injected with 5–7 ml of 1% Articain containing 1:200,000 epinephrine at the finger base. Capillary-venous oxygen saturation, hemoglobin volume in the capillaries, and relative blood flow in the fingertips were recorded once per second by white light spectrometry and laser Doppler flowmetry before, during and after injection for an average of 32 min. Results Clinically, no persistent tissue malperfusion was observed, and there were no postoperative complications. Capillary-venous oxygen saturation was reduced by ≥ 30% in seven patients. Critical levels of oxygen saturation were detected in four patients during 13 intervals, each lasting for 132.5 s on average. Oxygen saturation returned to noncritical values in all patients by the end of the observation period. Blood flow in the fingertips was reduced by more than 30% in nine patients, but no critical levels were observed, as with the hemoglobin. Three patients demonstrated a reactive increase in blood flow of more than 30% after injection. Conclusions Injection of tumescent local anesthesia containing epinephrine into finger base may temporarily cause a substantial reduction in blood flow and lead to critical levels of oxygen saturation in the fingertips. However, this was fully reversible within minutes and does not cause long-term complications.

Platelet-vessel wall interactions: Implication of 5-hydroxytryptamine. A review

1984 ◽  
Vol 15 (5-6) ◽  
pp. 612-626 ◽  
Author(s):  
F. Clerck ◽  
J. M. Nueten ◽  
R. S. Reneman
Keyword(s):  
Vessel Wall ◽  
Wall Interactions

scholarly journals Monitoring skin blood flow to rapidly identify alterations in tissue perfusion during fluid removal using continuous veno-venous hemofiltration in patients with circulatory shock

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wasineenart Mongkolpun ◽  
Péter Bakos ◽  
Jean-Louis Vincent ◽  
Jacques Creteur
Keyword(s):  
Blood Flow ◽  
Blood Lactate ◽  
Skin Blood Flow ◽  
Removal Rate ◽  
Lactate Concentration ◽  
Tissue Perfusion ◽  
Fluid Removal ◽  
Hemodynamic Variables ◽  
Group A ◽  
Group B

Abstract Background Continuous veno-venous hemofiltration (CVVH) can be used to reduce fluid overload and tissue edema, but excessive fluid removal may impair tissue perfusion. Skin blood flow (SBF) alters rapidly in shock, so its measurement may be useful to help monitor tissue perfusion. Methods In a prospective, observational study in a 35-bed department of intensive care, all patients with shock who required fluid removal with CVVH were considered for inclusion. SBF was measured on the index finger using skin laser Doppler (Periflux 5000, Perimed, Järfälla, Sweden) for 3 min at baseline (before starting fluid removal, T0), and 1, 3 and 6 h after starting fluid removal. The same fluid removal rate was maintained throughout the study period. Patients were grouped according to absence (Group A) or presence (Group B) of altered tissue perfusion, defined as a 10% increase in blood lactate from T0 to T6 with the T6 lactate ≥ 1.5 mmol/l. Receiver operating characteristic curves were constructed and areas under the curve (AUROC) calculated to identify variables predictive of altered tissue perfusion. Data are reported as medians [25th–75th percentiles]. Results We studied 42 patients (31 septic shock, 11 cardiogenic shock); median SOFA score at inclusion was 9 [8–12]. At T0, there were no significant differences in hemodynamic variables, norepinephrine dose, lactate concentration, ScvO2 or ultrafiltration rate between groups A and B. Cardiac index and MAP did not change over time, but SBF decreased in both groups (p < 0.05) throughout the study period. The baseline SBF was lower (58[35–118] vs 119[57–178] perfusion units [PU], p = 0.03) and the decrease in SBF from T0 to T1 (ΔSBF%) higher (53[39–63] vs 21[12–24]%, p = 0.01) in group B than in group A. Baseline SBF and ΔSBF% predicted altered tissue perfusion with AUROCs of 0.83 and 0.96, respectively, with cut-offs for SBF of ≤ 57 PU (sensitivity 78%, specificity 87%) and ∆SBF% of ≥ 45% (sensitivity 92%, specificity 99%). Conclusion Baseline SBF and its early reduction after initiation of fluid removal using CVVH can predict worsened tissue perfusion, reflected by an increase in blood lactate levels.

scholarly journals Preliminary Evaluation of a Cycling Cleat Designed for Diabetic Foot Ulcers

2017 ◽  
Vol 107 (6) ◽  
pp. 475-482 ◽  
Author(s):  
Ryan T. Crews ◽  
Steven R. Smith ◽  
Ramin Ghazizadeh ◽  
Sai V. Yalla ◽  
Stephanie C. Wu
Keyword(s):  
Blood Flow ◽  
Diabetic Foot ◽  
Plantar Pressure ◽  
Tissue Perfusion ◽  
Foot Ulcers ◽  
Preliminary Evaluation ◽  
Diabetic Foot Ulcers ◽  
Time Integral ◽  
Traditional Health ◽  
Before And After

Background: Offloading devices for diabetic foot ulcers (DFU) generally restrict exercise. In addition to traditional health benefits, exercise could benefit DFU by increasing blood flow and acting as thermotherapy. This study functionally evaluated a cycling cleat designed for forefoot DFU. Methods: Fifteen individuals at risk of developing a DFU used a recumbent stationary bicycle to complete one 5-minute cycling bout with the DFU cleat on their study foot and one 5-minute bout without it. Foot stress was evaluated by plantar pressure insoles during cycling. Laser Doppler perfusion monitored blood flow to the hallux. Infrared photographs measured foot temperature before and after each cycling bout. Results: The specialized cleat significantly reduced forefoot plantar pressure (9.9 kPa versus 62.6 kPa, P &lt; .05) and pressure time integral (15.4 versus 76.4 kPa*sec, P &lt; .05). Irrespective of footwear condition, perfusion to the hallux increased (3.97 ± 1.2 versus 6.9 ± 1.4 tissue perfusion units, P &lt; .05) after exercise. Infrared images revealed no changes in foot temperature. Conclusions: The specialized cleat allowed participants to exercise with minimal forefoot stress. The observed increase in perfusion suggests that healing might improve if patients with active DFU were to use the cleat. Potential thermotherapy for DFU was not supported by this study. Evaluation of the device among individuals with active DFU is now warranted.

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