Indwelling central venous lines are an essential part of the care of acute and chronically ill patients (Figure 65-1). These patients may require implanted venous access devices due to their poor peripheral venous access or for long-term intravenous therapies (Figures 65-2, 65-3, 65-4). The Emergency Physician must act quickly and thoughtfully to diagnose and correct the malfunctioning indwelling central venous line without further damaging the device or exposing the patient to increased risk. Understanding the various etiologies and a thorough assessment are critical to the successful management of a central venous catheter malfunction.
A variety of indwelling access devices. (Courtesy of Smiths Medical, St. Paul, MN.)
A Mahurkar short-term vascular access catheter. (Courtesy of Medtronic, Minneapolis, MN.)
Long-term vascular access catheters. A. The Eschelon. (Courtesy of Medical Components, Harleysville, PA.) B. The Groshong. (Courtesy of C.R. Bard, Murray Hill, NJ.)
Subcutaneous buried ports. A. Examples. B. Access using the Huber needle. (Courtesy of Smiths Medical, St. Paul, MN.)
ANATOMY AND PATHOPHYSIOLOGY
Indwelling central venous catheters allow access to the central venous circulation from a peripheral site. This access to the central circulation is via the end of a partially implanted catheter that protrudes from the body or through the skin into a subcutaneous reservoir of a fully implanted catheter (Figure 65-1).1,2 The proximal tip of the central venous line resides in the inferior vena cava, the right atrium, or the superior vena cava. Distance from the right atrium is an important risk factor for catheter occlusion, with the incidence of occlusion increasing the more distal the catheter tip.3
Indwelling central venous access devices can malfunction for a variety of reasons. The two most common types of vascular catheter complications are thrombotic occlusions and infections.4 The etiology of the malfunction can be divided into external to the catheter and internal to the catheter. External malfunctions are, for the most part, mechanical malfunctions (e.g., catheter migration, the catheter tip abutting a vessel wall, a mural thrombus, and kinked catheters). Internal malfunctions can be divided into thrombotic (e.g., intraluminal thrombus, fibrin sheath, and fibrin tail) and nonthrombotic (e.g., drug-drug precipitate, drug-solution precipitate, insoluble salts, and lipid precipitate).4-6 Phenytoin and diazepam cannot be given through silicone indwelling lines as they can crystallize and permanently obstruct the catheter lumen.5 Calcium and phosphate can form an insoluble precipitate within ...