Measurement by Venous Occlusion Plethysmography of Blood Flow through Surgically Created Arteriovenous Fistulae in the Human Forearm

1976 ◽  
Vol 50 (1) ◽  
pp. 43-49
Author(s):  
W. F. M. Wallace ◽  
J. P. Jamison
Keyword(s):  
Blood Flow ◽  
Arterial Occlusion ◽  
Venous Occlusion ◽  
Limited Range ◽  
Similar Amount ◽  
Absolute Value ◽  
Human Forearm ◽  
Flow Through ◽  
The Difference ◽  
Two Sides

1. Plethysmographs containing the hand plus forearm were used to measure blood flow in patients with a surgically created arteriovenous fistula in one forearm. 2. Apparent flow rate was stable over a limited range of collecting pressures; the absolute value of these pressures varied from patient to patient. 3. After arterial occlusion, blood flow increased by a similar amount on the normal side and on the side with the fistula. 4. Occlusion of fistular flow produced no significant change in heart rate. 5. Fistular flow, estimated as the difference between flow on the two sides, averaged 525 ml/min in seventeen patients.

Blood Flow through the Calf during Recovery from Fractures of the Lower Limb

1976 ◽  
Vol 51 (3) ◽  
pp. 297-302 ◽  
Author(s):  
F. J. Imms ◽  
D. A. Lorde ◽  
S. P. Prestidge ◽  
Christine Thornton
Keyword(s):  
Blood Flow ◽  
Lower Limb ◽  
Arterial Occlusion ◽  
Venous Occlusion ◽  
Relative Increase ◽  
Control Group ◽  
Muscle Fibres ◽  
Maximal Flow ◽  
Control Subjects ◽  
Flow Through

1. Venous occlusion plethysmography has been used to measure the blood flow in the calves of nineteen patients with fractures of the lower limb and in six normal control subjects. 2. The resting blood flows were significantly higher in the injured legs than in uninjured legs, irrespective of the site of injury. Flows in the uninjured limbs were similar to those of the control subjects. 3. During reactive hyperaemia after 10 min arterial occlusion, the increase of flows in both legs of the patients was significantly lower than in the control subjects. Because of the increased resting flow, the maximal flow in the injured leg was similar to that in the control subjects, whereas the maximal flow in the uninjured leg was significantly lower than in the control group. 4. The changes in resting flow cannot be accounted for by a change in the proportions of tissues in the limb but they may be explained by an increase of the flow through muscle secondary to a relative increase in the mass of slow to fast muscle fibres.

Peak calf blood flow estimates are higher with Dohn than with Whitney plethysmograph

1996 ◽  
Vol 81 (3) ◽  
pp. 1418-1422 ◽  
Author(s):  
D. N. Proctor ◽  
J. R. Halliwill ◽  
P. H. Shen ◽  
N. E. Vlahakis ◽  
M. J. Joyner
Keyword(s):  
Blood Flow ◽  
Reactive Hyperemia ◽  
Arterial Occlusion ◽  
Venous Occlusion ◽  
Calf Blood Flow ◽  
Absolute Flow ◽  
Wide Range ◽  
Before And After ◽  
The Mean ◽  
Highly Correlated

Estimates of calf blood flow with venous occlusion plethysmography vary widely between studies, perhaps due to the use of different plethysmographs. Consequently, we compared calf blood flow estimates at rest and during reactive hyperemia in eight healthy subjects (four men and four women) with two commonly used plethysmographs: the mercury-in-silastic (Whitney) strain gauge and Dohn air-filled cuff. To minimize technical variability, flow estimates were compared with a Whitney gauge and a Dohn cuff on opposite calves before and after 10 min of bilateral femoral arterial occlusion. To account for any differences between limbs, a second trial was conducted in which the plethysmographs were switched. Resting flows did not differ between the plethysmographs (P = 0.096), but a trend toward lower values with the Whitney was apparent. Peak flows averaged 37% lower with the Whitney (27.8 +/- 2.8 ml.dl-1.min-1) than with the Dohn plethysmograph (44.4 +/- 2.8 ml.dl-1.min-1; P < 0.05). Peak flow expressed as a multiple above baseline was also lower with the Whitney (10-fold) than with the Dohn plethysmograph (14.5-fold; P = 0.02). Across all flows at rest and during reactive hyperemia, estimates were highly correlated between the plethysmographs in all subjects (r2 = 0.96-0.99). However, the mean slope for the Whitney-Dohn relationship was only 60 +/- 2%, indicating that over a wide range of flows the Whitney gauge estimate was 40% lower than that for the Dohn cuff. These results demonstrate that the same qualitative results can be obtained with either plethysmograph but that absolute flow values will generally be lower with Whitney gauges.

Lumped Parameter Thermal Model for the Study of Vascular Reactivity in the Fingertip

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
O. Ley ◽  
C. Deshpande ◽  
B. Prapamcham ◽  
M. Naghavi
Keyword(s):  
Heat Flux ◽  
Blood Flow ◽  
Thermal Model ◽  
Vascular Reactivity ◽  
Arterial Occlusion ◽  
Blood Perfusion ◽  
Cost Effective ◽  
Venous Occlusion ◽  
Cardiovascular Complications ◽  
Tissue Temperature

Vascular reactivity (VR) denotes changes in volumetric blood flow in response to arterial occlusion. Current techniques to study VR rely on monitoring blood flow parameters and serve to predict the risk of future cardiovascular complications. Because tissue temperature is directly impacted by blood flow, a simplified thermal model was developed to study the alterations in fingertip temperature during arterial occlusion and subsequent reperfusion (hyperemia). This work shows that fingertip temperature variation during VR test can be used as a cost-effective alternative to blood perfusion monitoring. The model developed introduces a function to approximate the temporal alterations in blood volume during VR tests. Parametric studies are performed to analyze the effects of blood perfusion alterations, as well as any environmental contribution to fingertip temperature. Experiments were performed on eight healthy volunteers to study the thermal effect of 3min of arterial occlusion and subsequent reperfusion (hyperemia). Fingertip temperature and heat flux were measured at the occluded and control fingers, and the finger blood perfusion was determined using venous occlusion plethysmography (VOP). The model was able to phenomenologically reproduce the experimental measurements. Significant variability was observed in the starting fingertip temperature and heat flux measurements among subjects. Difficulty in achieving thermal equilibration was observed, which indicates the important effect of initial temperature and thermal trend (i.e., vasoconstriction, vasodilatation, and oscillations).

Measurement of the cutaneous circulation

1965 ◽  
Vol 20 (4) ◽  
pp. 696-702 ◽  
Author(s):  
Harry M. Wright
Keyword(s):  
Blood Flow ◽  
Skin Temperature ◽  
Circulatory Arrest ◽  
Thermal Conductance ◽  
Venous Occlusion ◽  
Indirect Methods ◽  
Blood Content ◽  
Heating And Cooling ◽  
Flow Through ◽  
Cutaneous Circulation

Relationships between four commonly used indirect methods for study of the cutaneous circulation in intact, unanesthetized man were examined. Skin temperature, thermal conductance, volume plethysmography and the light absorption of the skin (as related to hemoglobin content) were simultaneously recorded on the upper extremities of normal young men as blood flow and blood content of the skin were changed by circulatory arrest, venous occlusion, indirect heating and cooling, and changes in position. Skin temperature and thermal conductance changed along parallel courses as blood flow was changed, while finger volume and reflectance of the skin to light of wavelength 550 mμ both changed in expected directions although along different courses, following passive congestion and de-congestion and changes in level of the hand relative to the heart. The advantages, disadvantages, and limitations of each of the methods in the study of cutaneous circulation in man are discussed and compared. measurement of circulation of skin; methods for measurement of cutaneous circulation; blood flow through skin; blood content of skin; skin Submitted on March 12, 1964

Effect of active muscle mass during ischemic exercise on peak lower leg vascular conductance

2005 ◽  
Vol 98 (3) ◽  
pp. 765-771 ◽  
Author(s):  
Aaron J. Polichnowski ◽  
Ellen K. Heyer ◽  
Alexander V. Ng
Keyword(s):  
Blood Flow ◽  
Muscle Mass ◽  
Plantar Flexion ◽  
Arterial Occlusion ◽  
Venous Occlusion ◽  
Lower Leg ◽  
Isokinetic Dynamometer ◽  
Active Muscle ◽  
Vascular Conductance ◽  
The Right

Uncertainty exists as to whether a period of passive arterial occlusion (PAO) or ischemic exercise (IE) results in peak lower leg vascular conductance (LVC). This uncertainty is due to the different body positions, active muscle mass, and occlusion times used for PAO or IE. The purpose of this study was to examine whether 10 min of PAO elicits a similar LVC compared with ischemic dorsiflexion (IDF), ischemic plantar flexion (IPF), and ischemic plantar-dorsiflexion (IPDF). Ten subjects (5 women, 27 ± 9 yr, 68 ± 3 kg) were studied on 3 days over 1 wk in a semireclined position with the right foot attached to an isokinetic dynamometer. Mean arterial pressure (Finapres) and lower leg blood flow (LBF, venous occlusion plethysmography) were measured at rest and after PAO and IE. PAO was administered randomly on 1 of the 3 days and before IE. IE protocols consisted of maximal isokinetic dorsiflexion and/or plantar flexion at 120 and 60°/s, respectively. In a second experiment, an additional eight subjects (4 women, 29 ± 12 yr, 77 ± 12 kg) were studied to examine the effect of isokinetic speed during IDF on peak LBF and LVC. Peak LVC (ml·min−1·100 ml−1·mmHg−1) was similar among IPF (0.590 ± 0.16), IPDF (0.532 ± 0.17), and PAO (0.511 ± 0.18), and significantly lower after IDF (0.334 ± 0.15). No differences in peak LBF and LVC were observed after IDF using different isokinetic speeds. We conclude that 10 min of PAO, IPF, and IPDF performed in a similar posture are adequate stimuli to elicit peak LVC.

Tissue pressure as a causal factor in the autoregulation of blood flow in the isolated perfused kidney

1959 ◽  
Vol 197 (2) ◽  
pp. 309-312 ◽  
Author(s):  
Lerner B. Hinshaw ◽  
Stacey B. Day ◽  
Curtis H. Carlson
Keyword(s):  
Blood Flow ◽  
Arterial Pressure ◽  
Renal Artery ◽  
Interstitial Pressure ◽  
Tissue Pressure ◽  
Vascular Volume ◽  
Flow Through ◽  
Vascular Beds ◽  
The Difference ◽  
Bowman's Capsule

Experiments were performed on isolated perfused dog kidneys to determine relationships between tissue pressure, vascular volume, ‘over-all’ and ‘intraorgan’ vascular resistances. Results indicate that autoregulation of renal blood flow is brought about by disproportionately large increases in extravascular pressure. Since extravascular and intravascular pressures are opposing forces there is progressively less vascular distention with increases in arterial pressure as the increments in extravascular pressures approach the increments in intravascular pressures. The effective propellent force of blood flow through the kidney is thought to be the difference between the renal artery pressure and extravascular pressure. Vascular resistances calculated on this basis showed no significant changes throughout the range of autoregulation in four of the six experiments. It is proposed that the extravascular pressure within Bowmans capsule may exceed the renal interstitial pressure, and when the effects of renal extravascular pressures within and without Bowman's capsule are taken into account in the calculation of intrarenal vascular resistance, the pressure-flow relations of the kidney will be similar to those of other vascular beds.

scholarly journals Agonist-dependent variablity of contributions of nitric oxide and prostaglandins in human skeletal muscle

2005 ◽  
Vol 98 (4) ◽  
pp. 1251-1257 ◽  
Author(s):  
William G. Schrage ◽  
Niki M. Dietz ◽  
John H. Eisenach ◽  
Michael J. Joyner
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Animal Studies ◽  
Forearm Blood Flow ◽  
Feedback Inhibition ◽  
Venous Occlusion ◽  
No Synthase ◽  
Human Forearm ◽  
Independent Mechanism ◽  
Treatment Order

The relative contributions of endothelium-dependent dilators [nitric oxide (NO), prostaglandins (PGs), and endothelium-derived hyperpolarizing factor (EDHF)] in human limbs are poorly understood. We tested the hypothesis that relative contributions of NO and PGs differ between endothelial agonists acetylcholine (ACh; 1, 2, and 4 μg·dl−1·min−1) and bradykinin (BK; 6.25, 25, and 50 ng·dl−1·min−1). We measured forearm blood flow (FBF) using venous occlusion plethysmography in 50 healthy volunteers (27 ± 1 yr) in response to brachial artery infusion of ACh or BK in the absence and presence of inhibitors of NO synthase [NOS; with NG-monomethyl-l-arginine (l-NMMA)] and cyclooxygenase (COX; with ketorolac). Furthermore, we tested the idea that the NOS + COX-independent dilation (in the presence of l-NMMA + ketorolac, presumably EDHF) could be inhibited by exogenous NO administration, as reported in animal studies. FBF increased ∼10-fold in the ACh control; l-NMMA reduced baseline FBF and ACh dilation, whereas addition of ketorolac had no further effect. Ketorolac alone did not alter ACh dilation, but addition of l-NMMA reduced ACh dilation significantly. For BK infusion, FBF increased ∼10-fold in the control condition; l-NMMA tended to reduce BK dilation ( P < 0.1), and addition of ketorolac significantly reduced BK dilation. Similar to ACh, ketorolac alone did not alter BK dilation, but addition of l-NMMA reduced BK dilation. To test the idea that NO can inhibit the NOS + COX-independent portion of dilation, we infused a dose of sodium nitroprusside (NO-clamp technique) during ACh or BK that restored the reduction in baseline blood flow due to l-NMMA. Regardless of treatment order, the NO clamp restored baseline FBF but did not reduce the NOS + COX-independent dilation to ACh or BK. We conclude that the contribution of NO and PGs differs between ACh and BK, with ACh being more dependent on NO and BK being mostly dependent on a NOS + COX-independent mechanism (EDHF) in healthy young adults. The NOS + COX-independent dilation does not appear sensitive to feedback inhibition from NO in the human forearm.

Doppler Characterization of the Immediate Blood Flow Velocity Pattern after Release of Prolonged Venous Occlusion of the Forearm

1989 ◽  
Vol 77 (1) ◽  
pp. 11-12 ◽  
Author(s):  
J. N. W. West ◽  
M. S. Salih ◽  
W. A. Littler
Keyword(s):  
Blood Flow ◽  
Venous Occlusion ◽  
Short Term ◽  
Velocity Pattern ◽  
Flow Response ◽  
Resistance Vessels ◽  
Capacitance Vessels ◽  
Doppler Techniques ◽  
Flow Through

1. There is a biphasic flow response measured plethysmographically after release of prolonged venous occlusion of the forearm. 2. The response consists of an early, vasodilatory, increase in flow and is followed by a decrease in flow relative to control, thought to be mediated by myogenic contraction of resistance vessels. 3. Methodological constraints with the technique of forearm plethysmography have to date precluded an individual beat-by-beat examination of this response, in particular for resolving the question of the immediate flow pattern after release of venous occlusion. It has been suggested by Caro, Foley & Sudlow [Journal of Physiology (London) (1970), 207, 257–269] that there is a delay of up to five systolic beats before vasodilatation takes place, leading to their suggestion that the vasodilatation is passive and secondary to an increased flow through emptied capacitance vessels. 4. The introduction of peripheral Doppler techniques has led us to re-examine this response in an attempt to define short-term resistance vessel behaviour on a beat-by-beat basis. 5. Our data confirmed the hypothesis of Caro, Foley & Sudlow [Journal of Physiology (London) (1970), 207, 257–269] that there is a constant and definite latency preceding the onset of vasodilatory flow, as reflected by changes in Doppler velocities.

Inhibition of vascular ATP-sensitive K+channels does not affect reactive hyperemia in human forearm

2003 ◽  
Vol 284 (2) ◽  
pp. H711-H718 ◽  
Author(s):  
H. M. Omar Farouque ◽  
Ian T. Meredith
Keyword(s):  
Blood Flow ◽  
Adaptive Response ◽  
Healthy Subjects ◽  
Forearm Blood Flow ◽  
Reactive Hyperemia ◽  
Venous Occlusion ◽  
Channel Inhibition ◽  
Human Forearm ◽  
Hyperemic Response

The extent to which ATP-sensitive K+ channels contribute to reactive hyperemia in humans is unresolved. We examined the role of ATP-sensitive K+channels in regulating reactive hyperemia induced by 5 min of forearm ischemia. Thirty-one healthy subjects had forearm blood flow measured with venous occlusion plethysmography. Reactive hyperemia could be reproducibly induced ( n = 9). The contribution of vascular ATP-sensitive K+ channels to reactive hyperemia was determined by measuring forearm blood flow before and during brachial artery infusion of glibenclamide, an ATP-sensitive K+ channel inhibitor ( n = 12). To document ATP-sensitive K+ channel inhibition with glibenclamide, coinfusion with diazoxide, an ATP-sensitive K+ channel opener, was undertaken ( n = 10). Glibenclamide did not significantly alter resting forearm blood flow or the initial and sustained phases of reactive hyperemia. However, glibenclamide attenuated the hyperemic response induced by diazoxide. These data suggest that ATP-sensitive K+ channels do not play an important role in controlling forearm reactive hyperemia and that other mechanisms are active in this adaptive response.

Intrinsic control of colonic blood flow and oxygenation

1980 ◽  
Vol 238 (6) ◽  
pp. G478-G484
Author(s):  
P. R. Kvietys ◽  
T. Miller ◽  
D. N. Granger
Keyword(s):  
Blood Flow ◽  
Vascular Resistance ◽  
Perfusion Pressure ◽  
Reactive Hyperemia ◽  
Venous Pressure ◽  
Arterial Occlusion ◽  
Venous Occlusion ◽  
Colonic Blood Flow ◽  
O2 Extraction ◽  
O2 Delivery

In a denervated autoperfused dog colon preparation, arterial perfusion pressure, venous outflow pressure, blood flow, and arteriovenous O2 difference were measured during graded arterial pressure alterations, arterial occlusion, venous pressure elevation, venous occlusion, and local intra-arterial infusion of adenosine. As perfusion pressure was reduced from 100 to 30 mmHg, colonic blood flow decreased and arteriovenous O2 difference increased. Although blood flow was not autoregulated O2 delivery was maintained within 10% of control between 70 to 100 mmHg and then decreased with further reduction in perfusion pressure. Arterial occlusion (15, 30, and 60 s) resulted in a postocclusion reactive hyperemia; the magnitude of the hyperemia was directly related to the duration of occlusion. Venous occlusion resulted in a postocclusion reactive hypoemia. Elevation of venous pressure from 0 to 20 mmHg increased vascular resistance, O2 extraction, and the capillary filtration coefficient, but decreased O2 delivery. Infusion of adenosine decreased vascular resistance and O2 extraction, but increased O2 delivery. These data suggest that both metabolic and myogenic mechanisms are involved in the control of colonic blood flow and oxygenation.

Sign in / Sign up

Export Citation Format

Share Document