Embolus

Deficiency of Factor VII is relatively rare and inherited as an autosomal recessive disorder. Deficiency of Factor VII has been reported to be associated with bond abnormal bleeding and thrombotic tendencies. Deep vein thrombosis and pulmonary emboli have been reported in affected individuals. There is a very high frequency of Factor VII deficiency in people with the Dubin-Johnson syndrome, which is a congenital disorder of Hver function. 

An episode of acute regional ischemia in the brain leading to neuronal death. It is usually caused by thrombi or emboli from atherosclerotic plaques. 

Reduction of the risk of transient ischemic attacks or strokes in men who have had transient ischemia of the brain due to fibrin platelet emboli (aspirin only). This use has been found to be effective only in men (not women). 

The therapeutic effect achieved lysis of thrombi or emboli occurs and the catheter or cannula is patent. 

AM I NO ACIDS A microscopic filter is attached to the IV line when amino acid solutions are administered. The filter prevents microscopic aggregates (particles that may form in the IV bag) from entering the bloodstream where they could cause massive emboli. 

Occasionally, the diagnosis of acute ischemia can be established by NCCT because embohc material can be visualized directly, usually in the MCA or its branches. Emboli are often more radiodense than normal brain tissue, and therefore an affected proximal MCA may appear as a linear hyperdensity ( hyperdense middle cerebral artery sign or HMCA sign, Fig. 2.1c). One study found that the HMCA sign was 100% specific for MCA occlusion, but only 27% sensitive, probably because the density of embohc material is often indistinguishable from that of the normal MCA. ... 

Lyden PD, Zivin JA, Clark WA, Madden K, Sasse KC, Mazzarella VA, Terry RD, Press GA. Tissue plasminogen activator-mediated thrombolysis of cerebral emboli and its effect on hemorrhagic infarction in rabbits. Neurology. 1989 39 703-708. 

Cardioembolic strokes may also have poor outcome, especially with large emboli as in AF. In the Rochester population, patients with cardioembolic stroke were the most impaired during the hospitalization only 14% were independent as compared to 38% with lacunar stroke, 24% with atherosclerotic stroke, and 27% with ischemic stroke of unknown cause. " The latter group probably included patients with emboli of unknown origin. As evidence of the proportion of patients with devastating strokes, patients classified as cardioembolic subtype were also least likely to be independent at 1 year (27%). 

Cardioembolism Cardioembolism accounts for approximately 30% of all stroke and 25-30% of strokes in the young (age <45 years)." AF accounts for a large proportion of these strokes (15-25%). Symptoms may be suggestive, but they are not diagnostic. Repetitive, stereotyped, transient ischemic attacks (TIAs) are unusual in embolic stroke. The classic presentation for cardioembolism is the sudden onset of maximal symptoms. The size of the embolic material determines, in part, the course of the embolic material. Small emboli can cause retinal ischemic or lacunar symptoms. Posterior cerebral artery territory infarcts, in particular, are often due to cardiac embolism. This predilection is not completely consistent across the various cardiac structural abnormalities that predispose to stroke, and may be due to patterns of blood flow associated with specific cardiac pathologies. 

Markus HS, Droste DW, Kaps M, Larrue V, Lees KR, Siebler M, Ringelstein EB. Dual antiplatelet therapy with clopidogrel and aspirin in s3miptomatic carotid stenosis evaluated using doppler embolic signal detection the Clopidogrel and Aspirin for Reduction of Emboli in Symptomatic Carotid Stenosis (CARESS) trial. Circulation 2005 lll(17) 2233-2240. 

Evidence of active pericarditis, endocarditis, septic emboli, current or recent pregnancy, and lactating women... 

Creatinine clearance < 60 mL/min/1.73 m2 (stages III-V chronic kidney disease), diabetes mellitus (with renal insufficiency), hypertension, chronic heart failure, cirrhosis, nephrosis, age >75 yr, cholesterol emboli syndrome, multiple myeloma (questionable)... 

V/Q scan and CT scans are the most commonly used tests to diagnose PE. A V/Q scan measures the distribution of blood and air flow in the lungs. When there is a large mismatch between blood and air flow in one area of the lung, there is a high probability that the patient has a PE. Spiral CT scans can detect emboli in the pulmonary arteries. 

A transthoracic echocardiogram will identify whether there are heart valve abnormalities or problems with wall motion resulting in emboli to the brain. 

Osier nodes are small (usually 2-15 mm), painful, tender subcutaneous nodules located on the pads of the fingers and toes (Fig. 71-3/i) caused primarily by either septic emboli or vasculitis. These nodes are rare in acute disease but are also nonspecific for IE despite occurring in 10% to 25% of all patients.1... 

Janeway lesions are small, painless hemorrhagic macular plaques on the palms of the hands or soles of the feet due to septic emboli and more commonly associated with acute S. aureus IE (Fig. 71-3F). 

Embolic phenomena (emboli affect the heart, lungs, abdomen, or extremities)... 

Vascular phenomena, major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhages, and Janeway s lesions... 

These complications primarily are due to the presence of large, friable vegetations and numerous emboli and the development of acute congestive heart failure that often requires valve replacement.31,32 It is important to allow cultures sufficient incubation time (often 2-3 weeks) in order to isolate these organisms. Often these organisms may not be isolated on culture and thus present as culture-negative IE. 

Review any additional diagnostic tests to determine if treatment may be needed to prevent/minimize complications (e.g., emboli, congestive heart failure). 

Autologous hematopoietic stem cells are obtained (or harvested ) from bone marrow or peripheral blood. The technique for harvesting autologous hematopoietic cells depends on the anatomic source (i.e., bone marrow or peripheral blood). A surgical procedure is necessary for obtaining bone marrow. Multiple aspirations of marrow are obtained from the anterior and posterior iliac crests until a volume with a sufficient number of hematopoietic cells is collected (i.e., 600-1200 mL of bone marrow). The bone marrow then is processed to remove fat or marrow emboli and usually is infused intravenously into the patient like a blood transfusion. 

The Food and Drug Administration (FDA) published a safety alert in 1994 in response to two deaths associated with calcium-phosphate precipitation in PN.16 Autopsy reports from these patients revealed diffuse micro vascular pulmonary emboli containing calcium-phosphate precipitates. Because calcium and phosphate can bind and precipitate in solution, caution must be exercised when mixing these two electrolytes in PN admixtures. Several factors can affect calcium-phosphate solubility, including... 

Micro vascular pulmonary emboli An obstruction in the small blood vessels in the lung caused by material (e.g., blood clot, fat, air, and foreign body) that is carried through the circulation until it lodges in another small vessel. 

For parenteral emulsions, the formulation scientist must be particularly aware of changes in particle size distribution of the oil phase. Droplet coalescence results in increased droplet size. As a general rule, average droplet size should be less than 1 pm. Droplet sizes of more than 6 pm can cause blockage of capillaries (capillary emboli). 

Such clots—also known as emboli—present a serious hazard by their potential for blocking circulation of blood to vital organs. The considerable research devoted to agents that will lyse the fibrin in clots has led to the development of the clinically useful agent, uj-okinase. This drug is a fibrinolytic proteinaceous enzyme isolated from human urine. The difficulty involved in isolation of significant amounts and the antigenicity of urokinase and a related... 

Anticoagulant drugs include heparin and warfarin (Coumadin ) —agents used to prevent deep vein thrombosis. They are also used to prevent formation of emboli due to atrial fibrillation, valvular heart disease, and other cardiac disorders. Heparin, which is not absorbed by the gastrointestinal tract, is available only by injection its effect is immediate. 

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