TEMPORARY VASCULAR ACCESS FOR EXTRACORPOREAL RENAL REPLACEMENT THERAPIES IN ACUTE-RENAL-FAILURE PATIENTS

Temporary vascular access is an essential component to perform any ext racorporeal renal replacement therapy (RRT) in the acute renal failure patient. RRT used in the acute setting may be categorized in two grou ps: intermittent (IRRT) and continuous (CRRT). Therapeutic indications are based on clinical and technical considerations. Continuous modali ties are mainly utilized in intensive care units for hemodynamically c ompromised patient. Initially performed spontaneously via an arteriove nous circuit, CRRT modalities have progressively become venovenous wit h the circulatory assistance of a blood pump. Since both intermittent and continuous RRT modalities are now performed almost exclusively by venovenous modalities, this article deals exclusively with temporary v enous catheters. At present, double-lumen catheters represent the most common vascular access for RRT modalities. Semi-rigid polyurethane ca theters currently used in case of emergency are limited to short term use. Hemocompatible, flexible silicone catheters, less aggressive for the vessels, seem better suited for the medium end long term run. The tunneled silicone cathers (DualCath type) meet the short and long term needs, and allows for blood flow rates up to 400 ml/min. The internal jugular vein, particularly the right one, stems to warrant the proper functioning of catheters while reducing the risk of stenotic complica tions. Subclavian access should be limited in time and reserved fur si licons catheters in order to limit the risk of stenosis and/or thrombo sis. Femoral access, very useful in eases of emergency and respiratory problems, greatly impairs the patient's mobility and should be limite d by time to prevent thrombosis and/or infection. Late and!or delayed dysfunctioning of catheters are indicative of a thrombosis. Performanc e standards of catheters are less of a limiting factor in continuous l ow flow RRT modalities than in the intermittent ones. Finally, careful handling of the catheter essential to prevent infectious complication s.