Venous stasis

Venous stasis Major medical illness (e.g., congestive heart failure) Major surgery (e.g., general anesthesia for greater than 30 minutes) Paralysis (e.g., due to stroke or spinal cord injury) Polycythemia vera Obesity Varicose veins... 

The ACCP Conference on Antithrombotic Therapy recommended against the use of aspirin as the primary method of VTE prophylaxis.2 Antiplatelet drugs clearly reduce the risk of coronary artery and cerebrovascular events in patients with arterial disease, but aspirin produces a very modest reduction in VTE following orthopedic surgeries of the lower extremities. The relative contribution of venous stasis in the pathogenesis of venous thrombosis compared with that of platelets in arterial thrombosis likely explains the reason for this difference. 

Pulmonary hypertension develops late in the course of COPD, usually after the development of severe hypoxemia. It is the most common cardiovascular complication of COPD and can result in cor pulmonale, or right-sided heart failure. Hypoxemia plays the primary role in the development of pulmonary hypertension by causing vasoconstriction of the pulmonary arteries and by promoting vessel wall remodeling. Destruction of the pulmonary capillary bed by emphysema further contributes by increasing the pressure required to perfuse the pulmonary vascular bed. Cor pulmonale is associated with venous stasis and thrombosis that may result in pulmonary embolism. Another important systemic effect is the progressive loss of skeletal muscle mass, which contributes to exercise limitations and declining health status. 

Venous stasis is slowed blood flow in the deep veins of the legs resulting from damage to venous valves, vessel obstruction, prolonged periods of immobility, or increased blood viscosity. Conditions associated with venous stasis include major medical illness (e.g., heart failure, myocardial infarction), major surgery, paralysis (e.g., stroke, spinal cord injury), polycythemia vera, obesity, or varicose veins. 

Venous stasis resulting from prolonged bed rest, cardiac failure, or pelvic, abdominal, or hip surgery may precipitate thrombus formation in the deep veins of the leg or calf and may lead to fatal pulmonary embolism. Heparin may also be used prophylactically following surgery. 

Shifts in the cutaneous microbiome have also been noted in chronic ulcer disease, such as those caused by venous stasis or diabetes (175). Patients with chronic ulcers treated with antibiotics have been shown to have an increased abundance of Pseudomonadaceae while an increase in Streptococcaceae has been noted in diabetic ulcers (175). A longitudinal shift in wound microbiota has also been shown to coincide with impaired healing in diabetic mice, and may interact with aberrantly expressed host cutaneous defense response genes leading to ulcerogenesis (176). When compared to controls, the feet of diabetic men has also been noted to have decreased populations of Staphylococcus species, a relative increase in the population of S. aureus and increased bacterial diversity, which may increase the risk for wound infections in diabetic patients (177). 

It was found that rivaroxaban competitively inhibits human FXa and prothrombinase activity (/C50 = 2.1 nM). It inhibits endogenous FXa more potently in human and rabbit plasma (/C50 = 21 nM) than in rat plasma (/C50 = 290 nM). Rivaroxaban has demonstrated anticoagulant effects in human plasma, doubling the prothrombin time (PT) and activated partial thromboplastin time (APTT) at 0.23 and 0.69 pM, respectively. In vivo, rivaroxaban reduced venous thrombosis dose dependency (EDS0 = 0.1 mg/kg i.v.) in a rat venous stasis model. The pharmacological actions of rivaroxaban have been described in more detail by Perzbom et al.12... 

Q10 Venous stasis and embolism can be a problem in hospitalized patients. Which drugs may be useful to reduce the risks of embolization in such patients ... 

Q6 A thrombus is a blood clot which is fixed to the blood vessel wall. When it detaches and is carried in the blood, it is known as an embolus. Both thrombi and emboli can block blood vessels and deprive tissues of oxygen. In arteries blood clots usually form because the inner surface has been altered by deposition of atheroma. In contrast venous thrombosis results from slow or stagnant blood flow in veins, or defects in mechanisms which normally oppose inappropriate coagulation. Three major risk factors for pulmonary embolism are (i) venous stasis, (ii) hypercoagulability ofblood and (iii) injury to vascular endothelium following trauma or plaque rupture. 

Extrahepatic causes of increased transaminases include (1.) cardiac infarction, (2.) severe tachycardia, (3.) muscular diseases, (4.) pulmonary embolism, (5.) hypo-/ hyperthyreosis, 6.) coeliac disease, (7.) heatstroke, (8.) hyperthermia, (9.) excessive physical exercise, (10.) longterm fasting, (11.) above-average protein intake, (12.) haemolysis, (13.) postprandial and (14.) long-term venous stasis. 

Ethacridine (6,9-diamino-2-ethoxyacridine) is widely used in the local treatment of inflammatory or ulcerative conditions of the skin, particularly crural eczema due to venous stasis. Many publications point to the high frequency of exacerbation involving local allergic reactions and also generalized eczematous reactions (SEDA-11, 474). 

Snir M, Axer-Siegel R, Buckman G, Yassur Y. Central venous stasis retinopathy following the use of tranexamic acid. Retina 1990 10(3) 181. ... 

The composition of blood drawn first—that is, the blood closest to the tourniquet—is most representative of the composition of circulating blood. The first-drawn specimen should therefore be used for those analytes such as calcium that are pertinent to critical medical decisions. Blood drawn later shows a greater effect from venous stasis. Thus the first tube may show a 5% increase of protein, whereas the third... 

A common and important source of preanalytical error in the measurement of calcium is the increase in total, but not free, calcium concentration associated with tourniquet use and venous occlusion during sampling. Errors of 0.5 to 1.0 mg/dL (0.12 to 0.25 mmol/L) in total calcium may result because of the increase in protein-bound calcium caused by the efflux of water from the vascular compartment during stasis. Only small and clinically insignificant increases in free calcium have been reported with venous stasis. If a tourniquet is required, it should be applied just before sampling and released as soon as possible. 

Leu HJ, Wenner A, Spycher MA. Erythrocyte diapedesis in venous stasis syndrome. (Electron microscopic examinations). VASA 1981 10 17-23. 

The risks of cor pulmonale include venous stasis with the potential for thrombosis and pulmonary embolism. Another important systemic consequence of COPD is a loss of skeletal muscle mass and general decline in the overall health status. 

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