The modified Seldinger technique, used with a QuickFlash radial artery catheterization set (Arrow International, Bloomington, IN), is very useful for the catheterization of deep brachial and external jugular veins. The unit is commonly available in Emergency Departments and Intensive Care Units. It consists of a one-piece unit that incorporates a catheter-over-the-needle, a guide-wire in a feed tube, and a lever to advance the guidewire (Figure 48-15). The black mark on the feed tube is a reference mark. The tip of the guidewire is positioned at the tip of the needle when the advancement lever is at the reference mark. The unit is also available without the catheter-over-the-needle as the Positive placement Spring-Wire Guide (Arrow International, Bloomington, IN). It can be attached to a standard stock catheter-over-the-needle. A similar device is The WAND (Access Scientific, San Diego, CA).
The Arrow QuickFlash radial artery catheterization set. Note the different positions of the guidewire. The guidewire is within the feed tube (top). The tip of the guidewire is at the tip of the needle when the advancement lever is at the reference mark (middle). The guidewire is advanced through the catheter-over-the-needle (bottom).
The integral guidewire and soft, 2 in. long, 20 gauge catheter found in the QuickFlash set can ease the process of catheterization considerably. The depth of the deep brachial vein combined with the overlying skin (which is often scarred from previous venipunctures) makes catheterization with the usual 1¼ in catheter difficult. The external jugular vein is quite mobile, and the overlying tissues are fairly tough. This can make it quite difficult to thread an over-the-needle catheter into the vein without pushing the vein off the end of the needle.
Select a vein to cannulate. Clean and prep the skin overlying the puncture site. Place a tourniquet on the extremity. Open the package and remove the unit. Advance the guidewire through the needle and then retract it. Do not use the catheterization unit if the guidewire does not advance and retract smoothly. Ensure that the guidewire advancement lever is retracted as far as possible so that the guidewire is not within the needle. The flashback of blood will not be seen if the guidewire is not fully retracted and out of the needle.
Stabilize the vein with the nondominant hand. Insert the catheter-over-the-needle through the skin and into the vein (Figure 48-16A). A flash of blood in the hub of the needle indicates that the tip of the needle is within the vein. Hold the needle hub securely. Advance the guidewire, using the advancement lever, into the vein (Figure 48-16B). Continue to advance the guidewire as far as possible into the vein. The advancement lever must be distal to the reference mark to ensure that the guidewire is past the tip of the needle. Stop advancing the guidewire if resistance is encountered. Do not force the guidewire against resistance. Do not retract the guidewire if resistance to advancement is encountered. Doing so may damage the vein or shear off a piece of the guidewire. Withdraw the entire unit and repeat the procedure with a new unit.
The Arrow QuickFlash radial artery catheterization set. A. The vein is punctured and blood returns into the hub of the needle. B. The guidewire is advanced into the vein. C. The catheter is advanced over the needle and guidewire with a back-and-forth rotating motion. The needle and guidewire are then removed as a unit.
Advance the guidewire as far as possible into the vein. Advance the catheter-over-the-needle an additional 1 to 2 mm into the vein. This will ensure that the tip of the catheter is within the vein. Hold the hub of the needle securely. Advance the catheter over the needle and guidewire until its hub is against the skin (Figure 48-16C). A twisting motion may help to advance the catheter against resistance. Release the tourniquet. Hold the catheter hub firmly against the skin. Remove the needle and guidewire, through the catheter, as a unit. Attach a syringe, vacuum blood collection system, intravenous line, or saline (heparin) lock onto the catheter hub. Secure the catheter with adhesive tape.
External Jugular Vein Cannulation
Place the patient in the Trendelenburg position to distend the external jugular vein. Turn the patient's head to the opposite side. This will gently stretch the vein and prevent it from rolling. Clean and prep the skin of the neck. Place the nondominant thumb or index finger above the midportion of the clavicle to obstruct outflow and distend the external jugular vein. Align the catheter-over-the-needle parallel to the vein with the bevel of the needle upward and the tip of the needle pointing toward the clavicle. Enter the vein midway between the angle of the mandible and the midclavicle. Insert the catheter-over-the-needle during inspiration, when the valves of the external jugular vein are open. Be sure to cover the open hub of the needle and/or catheter with a finger at all times to prevent an air embolism. If the vein rolls, attempt to insert the catheter-over-the-needle obliquely into the vein. Another option is to cannulate the vein in the area where a tributary joins it. These areas are often anchored in the subcutaneous tissue. The remainder of the technique is similar to that described previously.
Deep Brachial Vein Cannulation
Extend the patient's arm. By palpation, identify the brachial artery pulse in the antecubital fossa. Clean and prep the skin of the antecubital fossa. Place a tourniquet on the upper arm. Reidentify the brachial artery pulse. Place a 2 to 3 in. long catheter-over-the-needle onto a 5 mL syringe and insert it just medial or lateral to the brachial artery pulse and at a 30° to 45° angle to the skin with the tip of the needle pointing cephalad. Advance the catheter-over-the-needle while applying negative pressure to the syringe. A flash of blood in the syringe indicates that the vein has been entered. If a flash is not seen, slowly withdraw the catheter-over-the-needle. It may have gone “through-and-through”. A flash will be seen as the catheter-over-the-needle is withdrawn and the tip of the needle reenters the vein. The remainder of the technique is similar to that described previously. The use of ultrasonography can significantly improve the success rate of deep brachial vein cannulation. Complications include brachial artery puncture, hematoma formation, loss of vascular access, and transient paresthesias.20,21
Ultrasound-Guided Peripheral Vein Cannulation
A deep peripheral vein, often the brachial or basilic vein, may be cannulated under direct visualization using ultrasonography.9 Ultrasound may also be used to identify a superficial vein when one is not palpable or visible. Place a tourniquet on the upper arm. Identify the vein by placing the ultrasound probe perpendicular to the vein. Identify the vein as a thin-walled, nonpulsatile, vascular structure. Move the probe along the vein to identify its most superficial and easiest accessed point. A catheter-over-the-needle can then be inserted in the vein under direct visualization.10,11
The easiest way to determine the depth of the vein is to note its depth on the ultrasound screen. Move the ultrasound probe distally this same distance while still maintaining visualization of the vein. Insert the catheter-over-the-needle at a 45° angle and advance it until the tip of the needle is seen on the ultrasound screen. Puncture the vein wall using a quick and short jabbing motion. Take care to not puncture through the posterior wall of the vein. Once the tip of the needle is seen within the vein, advance the catheter over the needle and into the vein. Refer to Chapter 50 for the complete details of ultrasound-guided vascular access.