Hemodynamic changes

Carotid artery disease is one of the major causes of ischemic stroke. The predominant mechanisms by which it causes stroke are (a) arterial embolism from atherosclerotic plaques (b) hemodynamic changes, leading to watershed infarcts and (c) distal propagation of thrombus originating from acute carotid occlusion. ... 

Therapeutic intravenous (TV) fluids include crystalloid solutions, colloidal solutions, and oxygen-carrying resuscitation solutions. Crystalloids are composed of water and electrolytes, all of which pass freely through semipermeable membranes and remain in the intravascular space for shorter periods of time. As such, these solutions are very useful for correcting electrolyte imbalances but result in smaller hemodynamic changes for a given unit of volume. 

Days 2 and 3 Check culture results, and assess clinical response to therapy temperature, WBCs, chest x-ray, oxygenation, purulent sputum, hemodynamic changes, and organ function. 

It has been shown that CGRP is released into the circulation during the development of human sepsis and septic shock (A8). Plasma CGRP levels correlated with the APACHE II score as well as with cardiac index and systemic vascular re-sistence index. There is also a relationship between the initial plasma CGRP levels and the severity of the disease at the time of admission to the ICU. Plasma CGRP levels are related to the hemodynamic changes seen early in septic shock. 

The usual loading dose of milrinone is 50 mcg/kg over 10 minutes. If rapid hemodynamic changes are unnecessary, the loading dose should be eliminated because of the risk of hypotension. Most patients are simply started on the maintenance continuous infusion of 0.25 mcg/kg/min (up to 0.75 mcg/kg/min). 

A. Villringer, J. Planck, C. Hock, L. Schleinkofer, and U. Dirnagl. Near infrared spectroscopy (nirs) a new tool to study hemodynamic changes during activation of brain function in human adults. Neuroscience Letters, 154 101-104, 1993. 

Galbraith, W.M., Hobson, W.C., Giclas, PC., Schechter, P.J. and Agrawal, S. (1994). Complement activation and hemodynamic changes following intravenous administration of phosphorothioate oligonucleotides in the monkey. Antisense Res. Dev. 4 201-206. 

Several studies have indicated that n-butane sensitizes the myocardium to epinephrine-induced cardiac arrhythmias. In anesthetized dogs, 5000 ppm caused hemodynamic changes such as decreases in cardiac output, left ventricular pressure, and stroke volume, myocardial contractility, and aortic pressure. Exposure of dogs to 1-20% butane for periods of 2 minutes to 2 hours hypersen-... 

Hemodynamic changes Hemodynamic changes, manifested as decreases in blood pressure and increases in pulse rate, principally at doses more than 20 meg, were observed during clinical studies, and appeared to be dose-dependent. 

Thus, it seems that the lack of sympathetic nervous system inhibition produced by the vasodilators, which is advantageous in some ways, can also be a disadvantage in that reflex increases in sympathetic nerve activity will lead to hemodynamic changes that reduce the effectiveness of the drugs. Therefore, the vasodilators are generally inadequate as the sole therapy for hypertension. However, many of the factors that limit the usefulness of the vasodilators can be obviated when they are administered in combination with a -adrenoceptor antagonist, such as propranolol, and a diuretic. Propranolol reduces the cardiac stimulation that occurs in response to increases in sympathetic nervous activity, and the... 

Most side effects associated with hydralazine administration are due to vasodilation and the reflex hemodynamic changes that occur in response to vasodilation. These side effects include headache, flushing, nasal congestion, tachycardia, and palpitations. More serious manifestations include myocardial ischemia and heart failure. These untoward effects of hydralazine are greatly attenuated when the drug is administered in conjunction with a (3-blocker. 

Cardiovascular depression may occur after the administration of barbiturates by IV bolus. The hemodynamic changes are transient in the healthy patient with good cardiovascular reserve, but they may be prolonged... 

Ochoa, J. B., Curti, B., Peitzman, A. B., Simmons, R. L., Billiar, T. R., Hoffman, R., Rault, R., Longo, D. L., Urba, W. J., and Ochoa, A. C. (1992). Increased circulation nitrogen oxides after human tumor immunotherapy Correlation with toxic hemodynamic changes. J. Nad. Cancer Inst. 84, 864-867. 

Auchampach JA, Rizvi A, Qiu Y, Tang XL, Maldonado C, Teschner S, Bolli R (1997b) Selective activation of A3 adenosine receptors with N6-(3-iodobenzyl)adenosine-5 -N-methyluronamide protects against myocardial stunning and infarction without hemodynamic changes in conscious rabbits. Circ Res 80(6) 800-809... 

The mechanisms by which tolerance develops are not completely understood. As noted above, diminished release of nitric oxide may be partly responsible for tolerance to nitroglycerin. Systemic compensation also plays a role in tolerance in the intact human. Initially, significant sympathetic discharge occurs and after one or more days of therapy with long-acting nitrates, retention of salt and water may reverse the favorable hemodynamic changes normally caused by nitroglycerin. 

Veselka J, Duchonova R, Prochazkova S, et al. Effects of varying ethanol dosing in percutaneous septal ablation for obstructive hypertrophic cardiomyopathy on early hemodynamic changes. Am J Cardiol 2005 95 675-678. 

CRITICAL ASSESSMENT OF THE METHOD Breddin (1989) described the Wessler model because of its static character as the retransformation of an in vitro experiment into a very artificial test situation. One of the major drawbacks is the relative independence of platelet function and hemodynamic changes that largely influence thrombus formation in vivo. However, the model has been shown to be very useful for evaluation of the antithrombotic effect of compounds like heparin and hirudin. 

COX-1 is constitutive, that is, always present and active it contributes to the physiological function of organs. Inhibition inevitably produces unwanted effects, such as mucosal injury, renal damage, hemodynamic changes, and disturbances of uterine function. 

The cause of cocaine-related stroke and transient ischemic attacks has been studied by transcranial Doppler sonography, a continuous measure of cerebral blood flow velocity, to monitor the course of cerebral hemodynamic changes during acute intravenous injection of placebo, and of cocaine 10, 25, and 50 mg in seven cocaine abusers (150). There was a significant increase in mean and systolic velocity (lasting about 2 minutes) with all doses of cocaine but not with placebo. Cocaine produced an immediate brief period of vasoconstriction... 

Jansen C, Ramos LMP, van Heesewijk JPM et al. (1994a). Impact of microembolism and hemodynamic changes in the brain during carotid endarterectomy. Stroke 25 992-997... 

Lin, P.W., Hemodynamic changes after hepatectomy in rats studied with radioactive microspheres, J. Formos. Med. Assoc., 89, 177, 1990. 

As demonstrated with fluorophotometry, timolol acts predominantly by decreasing the production of aqueous humor and does not significantly alter facility of outflow. Most studies support the view that both short-term and long-term administration of timolol do not alter optic nerve head circulation or produce retrobulbar hemodynamic changes. The ocular hypotensive effect of timolol is additive to most other therapies, including outflow agents (e.g., pilocarpine) and inflow agents (e.g., dorzolamide, brinzolamide, apraclonidine, and brimonidine). When added to latanoprost, timolol and most other P-blockers further reduce lOP approximately 2 mm Hg. This reduction is less than that attained by topical CAIs such as dorzolamide (Table 10-2). 

Finally, there are significant hemodynamic changes during hemodialysis that not only may affect the extent of drug removal by this procedure but also may have an important impact on patient response. 

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