Search results
Results from the WOW.Com Content Network
Catheter access, sometimes called a CVC (central venous catheter), consists of a plastic catheter with two lumens (or occasionally two separate catheters) which is inserted into a large vein (usually the vena cava, via the internal jugular vein or the femoral vein) to allow large flows of blood to be withdrawn from one lumen, to enter the dialysis circuit, and to be returned via the other lumen.
The instantaneous wave-free ratio (iFR, sometimes referred to as the instant wave-free ratio or instant flow reserve) is a diagnostic tool used to assess whether a stenosis is causing a limitation of blood flow in coronary arteries with subsequent ischemia. iFR is performed during cardiac catheterisation (angiography) using invasive coronary pressure wires which are placed in the coronary ...
If having thrombophlebitis or thrombosis; pain when using the access is another complication. Peripheral venous access is least prone to thrombosis, followed by midline catheters and the centrally placed catheters. Central venous access is the most common reason for venous thrombosis in children. [citation needed]
Image of a wrist with peripheral veins visible. The peripheral vascular system is the part of the circulatory system that consists of the veins and arteries not in the chest or abdomen (i.e. in the arms, hands, legs and feet).
Vascular resistance is the resistance that must be overcome for blood to flow through the circulatory system.The resistance offered by the systemic circulation is known as the systemic vascular resistance or may sometimes be called by another term total peripheral resistance, while the resistance caused by the pulmonary circulation is known as the pulmonary vascular resistance.
Normal CVP in patients can be measured from two points of reference: [citation needed] Sternum: 0–14 cm H 2 O; Midaxillary line: 8–15 cm H 2 O; CVP can be measured by connecting the patient's central venous catheter to a special infusion set which is connected to a small diameter water column.
The saturation of mixed venous blood is approximately 75% in health. Using this value in the above equation, the oxygen concentration of mixed venous blood is approximately 150 mL of O 2 per L. Therefore, using the assumed Fick determination, the approximated cardiac output for an average man (1.9 m3) is:
The catheter is inserted into the vessel under ultrasound or fluoroscopic guidance and tunneled through the skin. Tunneled catheters have multiple channels called lumens which lay exposed on the surface of the skin. These lumens are the access points when the catheter is used. Tunneled catheters can be single, double, or triple lumened.