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Multiple factors determine the route and site for vascular access, and knowing the basic anatomy, techniques, indications, and contraindications is essential to emergency care.
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Infusion rate is key in the resuscitation of those with severe hypovolemia or hemorrhage.1 Infusion rates through a medical catheter behave according to Poiseuille's law:
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The rate of flow is directly proportional to the catheter radius and the pressure gradient, and inversely proportional to the dynamic fluid viscosity and catheter length. Flow rates increase with larger catheter radius, use of more pressure (gravity, manual push-pull devices, pressure bag application, or commercial rapid infusing devices), decreasing viscosity (co-administration of crystalloid with viscous blood products), or decreasing catheter length (peripheral angiocatheter vs triple-lumen catheter). Flow rates are maximized by using the largest internal diameter catheter possible.
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PERIPHERAL VENOUS ACCESS SITES
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PERIPHERAL VENOUS ANATOMY OF THE UPPER EXTREMITY
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The most commonly accessed veins for peripheral catheterization of the upper extremity are the dorsal hand veins and the veins of the antecubital fossa (Figure 31-1).
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Peripheral catheterization of the superficial veins of the lower extremity can require cutdown of the great and small saphenous veins. The femoral vein is the primary deep vein of the lower extremity. It is located medial to the femoral artery.
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TECHNIQUE FOR PERIPHERAL VENOUS ACCESS
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Gather all equipment before beginning the procedure (Table 31-1). Observe universal precautions. The procedure for peripheral IV line insertion is summarized in Table 31-2.
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