Indwelling vascular catheters

If tuberculin syringes are used to measure very small doses, one must be aware of the problem of inadvertent overadministration of digoxin. Do not flush the syringe with the parenteral solution after its contents are expelled into an indwelling vascular catheter. 

Heparin is used as an anticoagulant for prophylaxis and treatment of various thromboembolic disease processes. It is used to maintain relatively anticoagulated states in patients on extracorporeal circulation or hemodialysis and to help maintain patency of indwelling vascular catheters. 

Catheter device selection is based on a number of factors, including the plarmed application and placement site, duration of implantation, composition of fluids infused, and frequency of access (Namyslowski and Patel, 1999). Vascular catheters can be divided into two genei groups shortterm, temporary catheters that are placed percutaneously, and long-term, indwelling vascular catheters that usually require a surgical insertion. Temporary catheters include short peripheral venous and arterial catheters, nontunneled central venous and arterial catheters, and peripherally inserted central catheters (Pearson, 1996). Tunneled central venous catheters and totally implantable intra-... 

Raad I, Costerton W, Sabharwal U, et al. Ultrastructural analysis of indwelling vascular catheters a quantitative relationship between luminal colonization and duration of placement. J Infect Dis August 1993 168(2) 400-7. 

Placement of vascular access ports is similar to that of a long-term indwelling arterial catheter. A small incision is made over the selected vein and a second incision is made lower in the anterior chest to create a pocket to house the port. The catheter is tuimeled subcutaneously from its entry point into the vein with the tip inside the right atrium. The final position of the catheter is verified by fluoroscopy, secured with sutures, and the subcutaneous pocket is closed. The port septum is easily palpable transcutaneously, and the system may be used immediately. A surgeon typically inserts the vascular access port in an outpatient setting. 

Vascular inujury Major orthopedic surgery (e.g., knee and hip replacement) Trauma (esp. fractures of the pelvis, hip, or leg) Indwelling venous catheters... 

Lazar et al., 1999 Mueller et al., 1999). Hydrophilic coatings have also been placed on balloon catheters, with recent results showing a 72 percent reduction in ischemic vascular complications when modified devices are used (Winters et al., 1999). Antibiotic coatings for indwelling catheters could be used to coat intra-aortic balloons if such treatment is proven to be efficacious. 

A peripheral venous catheter or indwelling venous cannula (see Fig. 13.7) is the most commonly used vascular access. Often these infusion devices are named by their brand name such as Venflon marketed by BD or Brauniile marketed by B.Braun Melsungen. The cannula or peripheral venous catheter is inserted into a peripheral vein at the hand or the arm to administer infusion solutions... 

It is now well identified that bacteria connect to solid supports to shape structured communities called biofilms, also known as biopolymer matrix-enclosed microbial populations adhering to each other and/or surfaces [111]. Biofihns occur on both living and inert supports in all environments [112]. They influence various industrial and domestic areas [113] and are accountable for a broad range of human diseases [111], In view of the ever growing number of implanted patients, biofilm-linked infections of indwelling medical devices are more predominantly a foremost public health issue. Various examples of implants that can be inflated by biofilm formation are mechanical heart valves, catheters, pacemakers/defibriUators, ventricular assist devices, vascular prostheses, coronary stents, neurosurgical ventricular shunts, cerebrospinal fluid shunts, neurological stimulation implants, ocular prostheses, inflatable penile, cochlear, joint prostheses, fracture-fixation devices, breast, and dental implants and contact lenses, intrauterine contraceptive devices [114-116]. 

Biomaterials have played a vital role in the treatment of cardiovascular diseases, examples of applications including heart valve prostheses, vascular grafts, stents, indwelling catheters, ventricular assist devices, total implantable artificial heart, pacemakers, automatic internal cardioverter defibrillator, intraaortic balloon pump, and more. A key requirement for materials in cardiovascular applications, particularly blood-contacting devices, is blood compatibility, that is, nonthrombogenic. Additional requirements include mechanical and surface properties that are application specific. Surveying the field of polymers used in cardiovascular applications reveals that PUs, polyethylene terephthalate (PET), and expanded PTFE (ePTFE) are the most commonly used. This section will review each of the three polymers followed by a brief introduction of other emerging polymers for use in the cardiovascular area. 

Biocompatible and lubricous coatings Crosslinked or grafted coatings have been used on contact lenses to enhance wetting, on silicone rubber indwelling catheters to prevent occlusion, and on prosthetic devices, such as artificial valves, intraocular lenses, vascular grafts, and pacemakers to improve device biocompatibility. [66-71 ]... 

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