E

Figure 18-7 Seldinger technique of vascular cannulation. (A) Vessel cannula-tion with needle. (B) Guidewire advancement. (C) Needle removal and puncture wound enlargement. (D) Subcutaneous tissue dilation. (E) Dilator removal and catheter advancement. (Source: Adapted from Deitch EA. Tools of the Trade and Rules of the Road. Philadelphia, PA: Lippincott-Raven, 1997.)

antimicrobial or antiseptic agents (minocycline/ rifampin or chlorhexidine/sil-ver-sulfadiazine), but nothing replaces sterile technique during CVC placement and subsequent dressing changes. The most common therapy for suspected catheter infection is removal of the catheter.

CVCs can deliver medications directly to the heart for immediate distribution to the body. This also avoids potential venous irritation or infiltration of substances, such as dopamine. In cases of poor PIV access or chronic IV needs, CVCs are an only option.

There are several types of CVCs, which are based on the intended lifespan, pathway from skin to vessel (tunneled versus nontunneled), and lumen number. Long-term CVCs consist of (1) Dacron cuffed, tunneled Silastic catheters (Fig. 18-8) and (2) implantable ports (Fig. 18-9). The subcutaneous tunnel isolates the venous puncture site from the skin and decreases the potential for bacterial contamination. The Dacron cuffs (one near the venous entrance site and one near the skin exit site) anchor the catheter and are also believed to inhibit colonization of the CVC by skin organisms. Hickman (single or double lumen), Broviac (small internal diameter), and Groshong (one-way valve preventing reflux) are cuffed, tunneled catheters. Cuffed, tunneled catheters can be removed at the bedside by bluntly dissecting the fibrous

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