scholarly journals Effect of Selected Manual Therapy Interventions for Mechanical Neck Pain on Vertebral and Internal Carotid Arterial Blood Flow and Cerebral Inflow

2013 ◽  
Vol 93 (11) ◽  
pp. 1563-1574 ◽  
Author(s):  
Lucy C. Thomas ◽  
Darren A. Rivett ◽  
Grant Bateman ◽  
Peter Stanwell ◽  
Christopher R. Levi
Keyword(s):  
Blood Flow ◽  
Magnetic Resonance ◽  
Manual Therapy ◽  
Therapeutic Interventions ◽  
Arterial Blood Flow ◽  
Large Individual ◽  
Serious Adverse Events ◽  
Arterial Blood ◽  
Significant Difference ◽  
The Brain

Background Manual therapy of the cervical spine has occasionally been associated with serious adverse events involving compromise of the craniocervical arteries. Ultrasound studies have shown certain neck positions can alter craniocervical arterial blood flow velocities; however, findings are conflicting. Knowledge about the effects of neck position on blood flow may assist clinicians in avoiding potentially hazardous practices. Objective The purpose of this study was to examine the effects of selected manual therapeutic interventions on blood flow in the craniocervical arteries and blood supply to the brain using magnetic resonance angiography (MRA). Design This was an experimental, observational magnetic resonance imaging study. Method Twenty adult participants who were healthy and had a mean age of 33 years were imaged using MRA in the following neck positions: neutral, rotation, rotation/distraction (similar to a Cyriax manipulation), C1–C2 rotation (similar to a Maitland or osteopathic manipulation), and distraction. Results The participants were imaged using 3T MRA. All participants had normal vascular anatomy. Average inflow to the brain in neutral was 6.98 mL/s and was not significantly changed by any of the test positions. There was no significant difference in flow in any of the 4 arteries in any position from neutral, despite large individual variations. Limitations Only individuals who were asymptomatic were investigated, and a short section of the arteries only were imaged. Conclusions Blood flow to the brain does not appear to be compromised by positions commonly used in manual therapy. Positions using end-range neck rotation and distraction do not appear to be more hazardous to cerebral circulation than more segmentally localized techniques.

Abstract 67: Vasopressin impairs Brain, Heart and Kidney Perfusion in Acute Heart Failure

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Stig Müller ◽  
Ole-Jakob How ◽  
Stig E Hermansen ◽  
Truls Myrmel
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Heart Function ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Arterial Blood Flow ◽  
Organ Blood Flow ◽  
Arterial Blood ◽  
Time Flow ◽  
The Brain

Arginin Vasopressin (AVP) is increasingly used to restore mean arterial pressure (MAP) in various circulatory shock states including cardiogenic shock. This is potentially deleterious since AVP is also known to reduce cardiac output by increasing vascular resistance. Aim: We hypothesized that restoring MAP by AVP improves vital organ blood flow in experimental acute cardiac failure. Methods: Cardiac output (CO) and arterial blood flow to the brain, heart, kidney and liver were measured in nine pigs by transit-time flow probes. Heart function and contractility were measured using left ventricular Pressure-Volume catheters. Catheters in central arteries and veins were used for pressure recordings and blood sampling. Left ventricular dysfunction was induced by intermittent coronary occlusions, inducing an 18 % reduction in cardiac output and a drop in MAP from 87 ± 3 to 67 ± 4 mmHg. Results: A low-dose therapeutic infusion of AVP (0.005 u/kg/min) restored MAP but further impaired systemic perfusion (CO and blood flow to the brain, heart and kidney reduced by 29, 18, 23 and 34 %, respectively). The reduced blood flow was due to a 2.0, 2.2, 1.9 and 2.1 fold increase in systemic, brain, heart and kidney specific vascular resistances, respectively. Contractility remained unaffected by AVP. The hypoperfusion induced by AVP was most likely responsible for observed elevated plasma lactate levels and an increased systemic oxygen extraction. Oxygen saturation in blood drawn from the great cardiac vein fell from 31 ± 1 to 22 ± 3 % dropping as low as 10 % in one pig. Finally, these effects were reversed forty minutes after weaning the pigs form the drug. Conclusion: The pronounced reduction in coronary blood flow point to a potentially deleterious effect in postoperative cardiac surgical patients and in patients with coronary heart disease. Also, this is the first study to report a reduced cerebral perfusion by AVP.

Cardiovascular Magnetic Resonance Measurement of Coronary Arterial Blood Flow at Rest and After Submaximal Exercise

2006 ◽  
Vol 30 (3) ◽  
pp. 421-425 ◽  
Author(s):  
Erica Dall'Armellina ◽  
Miranda B. Baugh ◽  
Timothy M. Morgan ◽  
Craig A. Hamilton ◽  
Ping Tan ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
Submaximal Exercise ◽  
Arterial Blood Flow ◽  
Resonance Measurement ◽  
Arterial Blood

scholarly journals Autoregulation assessment by direct visualisation of pial arterial blood flow in the piglet brain

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
S. P. Klein ◽  
V. De Sloovere ◽  
G. Meyfroidt ◽  
B. Depreitere
Keyword(s):  
Blood Flow ◽  
Brain Injury ◽  
Therapeutic Interventions ◽  
Arterial Blood Flow ◽  
Large Animal Model ◽  
Large Animal ◽  
Main Site ◽  
Cranial Window ◽  
Arterial Blood ◽  
The Impact

Abstract Impairment of cerebrovascular autoregulation (CAR) is common after brain injury, although the pathophysiology remains elusive. The mechanisms of vascular dysregulation, their impact on brain function, and potential therapeutic implications are still incompletely understood. Clinical assessment of CAR remains challenging. Observational studies suggest that CAR impairment is associated with worse outcomes, and that optimization of cerebral blood flow (CBF) by individual arterial blood pressure (ABP) targets could potentially improve outcome. We present a porcine closed cranial window model that measures the hemodynamic response of pial arterioles, the main site of CBF control, based on changes in their diameter and red blood cell velocity. This quantitative direct CAR assessment is compared to laser Doppler flow (LDF). CAR breakpoints are determined by segmented regression analysis and validated using LDF and brain tissue oxygen pressure. Using a standardized cortical impact, CAR impairment in traumatic brain injury can be studied using our method of combining pial arteriolar diameter and RBC velocity to quantify RBC flux in a large animal model. The model has numerous potential applications to investigate CAR physiology and pathophysiology of CAR impairment after brain injury, the impact of therapeutic interventions, drugs, and other confounders, or to develop personalized ABP management strategies.

Cardiac output distribution and regional blood flow during hypocarbia in monkeys

1985 ◽  
Vol 58 (4) ◽  
pp. 1225-1230 ◽  
Author(s):  
S. Gelman ◽  
K. C. Fowler ◽  
S. P. Bishop ◽  
L. R. Smith
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Regional Blood Flow ◽  
Arterial Blood Flow ◽  
Tissue Blood Flow ◽  
Base Line ◽  
Output Distribution ◽  
Arterial Blood ◽  
Cardiac Output Distribution ◽  
The Brain

Cardiac output distribution and regional blood flow were studied during hypocarbia independent of changes in ventilatory parameters. Fifteen cynomolgus monkeys were anesthetized with methohexital sodium (8 mg/kg im) and hyperventilated through an endotracheal tube. Hypocarbia at two levels, 28 +/- 1.8 and 17 +/- 0.6 Torr, was achieved by a stepwise decreasing CO2 flow into the semiclosed system. Regional blood flow was determined with labeled microspheres. At each stage of experiments two sets of microspheres (9 and 15 microns diam) were used simultaneously. The use of two microsphere sizes allowed evaluation of the relationship between total (nutritive and nonnutritive) tissue blood flow, determined with 15-microns spheres, and nutritive blood flow, determined with 9-microns spheres. There was no change in cardiac output or arterial pressure during both degrees of studied hypocarbia. Hypocarbia was accompanied by a decrease in myocardial blood flow determined with 15-microns spheres and preservation of the flow determined with 9-microns spheres. Splenic blood flow was decreased, whereas hepatic arterial blood flow was increased during both levels of hypocarbia. Blood flow through the brain, renal cortex, and gut showed a biphasic response to hypocarbia: during hypocarbia at 28 +/- 1.8 Torr, blood flow determined with 15-microns spheres was unchanged (in the gut) or decreased (in the brain and kidneys), whereas blood flow determined with 9-microns spheres was decreased. During hypocarbia at 17 +/- 0.6 Torr, blood flow determined with 9-microns spheres had a tendency to restore to base-line values.

Arterial Blood Flow to the Brain in Patients with Vascular Disease: The SMART Study

Radiology ◽  
2006 ◽  
Vol 240 (2) ◽  
pp. 515-521 ◽  
Author(s):  
A. Fleur van Raamt ◽  
Auke P. A. Appelman ◽  
Willem P. T. M. Mali ◽  
Yolanda van der Graaf
Keyword(s):  
Blood Flow ◽  
Vascular Disease ◽  
Arterial Blood Flow ◽  
Arterial Blood ◽  
Smart Study ◽  
The Brain

Cerebral arterial blood flow and aneurysm surgery

1977 ◽  
Vol 47 (6) ◽  
pp. 819-827 ◽  
Author(s):  
Helge Nornes ◽  
Hanna Berit Knutzen ◽  
Per Wikeby
Keyword(s):  
Blood Flow ◽  
Systematic Investigation ◽  
Arterial Blood Flow ◽  
Surprising Result ◽  
Induced Hypotension ◽  
Content Type ◽  
Intracranial Surgery ◽  
Arterial Blood ◽  
Upper Limit ◽  
Significant Difference

✓ A study of 21 patients was conducted to clarify the autoregulatory capacity in patients subjected to induced hypotension during intracranial surgery for saccular aneurysms. Trimethaphan camsylate (Arfonad) was used for induced hypotension and arterial blood flow was measured with an electromagnetic flow probe on the internal carotid artery or one of its main intracranial branches. In Grade I and II patients the control arterial blood pressure (ABP) ranged from a mean of 90 to 135 mm Hg (average 110 mm Hg), with a lower level of autoregulation (LLAR) from 35 to 85 mm Hg (average 62 mm Hg). Grade III patients had a control ABP of between 105 and 145 mm Hg (average 124 mm Hg) and the LLAR was found to be between 60 and 95 mm Hg (average 76 mm Hg). There was a significant difference between the two groups with regard to both the control ABP and the LLAR. A surprising result obtained from these data was that the average lower autoregulatory range (the difference between control ABP and LLAR) is practically the same in the two groups. A systematic investigation of the upper limit of autoregulation was not possible for ethical reasons. In those few patients in whom spontaneous increase in the ABP made such observations possible, upper limits up to 150 mm Hg with a total autoregulatory capacity of about 75 mm Hg were observed. In some patients, however, lower limits and corresponding “breakthroughs” of cerebral blood flow were seen, demonstrating that the upper limit of autoregulation is markedly influenced by several factors.

scholarly journals A magnetic resonance imaging-compatible small animal model under extracorporeal circulation

2019 ◽  
Vol 29 (4) ◽  
pp. 612-614
Author(s):  
Anna Kathrin Assmann ◽  
Payam Akhyari ◽  
Florian Demler ◽  
Artur Lichtenberg ◽  
Alexander Assmann
Keyword(s):  
Magnetic Resonance Imaging ◽  
Animal Model ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Extracorporeal Circulation ◽  
Arterial Blood Flow ◽  
Flow Profile ◽  
Resonance Imaging ◽  
Arterial Blood ◽  
The Impact

Abstract The impact of different extracorporeal circulation (ECC) scenarios on arterial blood flow profiles has not yet been revealed. To allow for exact measurements, magnetic resonance imaging (MRI) during ECC is required. Therefore, the present study addressed the feasibility of a high-resolution MRI-compatible animal model of ECC. For usage in New Zealand White rabbits, we developed an ECC device, the tubes of which were long enough to eliminate impacts of the magnetic field on the blood pump and heart–lung control machine. The miniaturized ECC system via thoracic access comprised an infant oxygenator, a pulsatile centrifugal pump, 1/8″ tubes, a 10-Fr aortic cannula and a 12-Fr venous cannula for vacuum-assisted drainage. This miniaturized ECC system has very low priming volume (230–255 ml) to reduce the system-inherent haemodilution to 50%. Consequently, haemoglobin rates remained high enough to guarantee adequate oxygenation (arterial pressure of oxygen >200 mmHg). Optimized venous drainage by an additionally inserted pulmonary artery vent catheter resulted in sufficient blood flow (31.6–65.8 ml/min/kg) that was maintained for 60 min with pulsatility. The current study demonstrates the feasibility of MRI-compatible ECC in rabbits, and this model allows for real-time blood flow profile measurements during different ECC scenarios in future projects.

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