Multiple factors determine the route and site for vascular access, and knowing the basic anatomy, techniques, indications, and contraindications is essential to emergency care.
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:
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.
PERIPHERAL VENOUS ACCESS SITES
PERIPHERAL VENOUS ANATOMY OF THE UPPER EXTREMITY
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).
Venous anatomy of the upper extremity.
Catheter-over-needle technique for venous access. A. Catheter needle is inserted into skin and vessel until blood flash. B. Catheter is advanced. C. Needle is withdrawn. D. Catheter is attached to IV tubing and secured.
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.
TECHNIQUE FOR PERIPHERAL VENOUS ACCESS
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.
TABLE 31-1Materials for Peripheral IV Line Placement |Favorite Table|Download (.pdf) TABLE 31-1 Materials for Peripheral IV Line Placement
Personal protective equipment (gloves, face shield)
Alcohol swabs or povidone iodine
Appropriate-sized venous catheter
IV solution and tubing (if indicated)
2 × 2 gauze
Sterile transparent dressing
TABLE 31-2Peripheral IV Line Insertion |Favorite Table|Download (.pdf) TABLE 31-2 Peripheral IV Line Insertion
|Step ||Comment |
|1. Apply tourniquet. ||Apply tourniquet tightly enough to facilitate adequate venous filling and distention without causing patient discomfort or ischemia. |
|2. Locate vein. || |
Inspect and palpate the vein.
Warm the skin, tap the vein, or apply topical nitroglycerin ointment to ease identification.
|3. Clean area with either an alcohol swab or povidone iodine solution. ||— |
|4. Apply gentle ...|