Ultrasound-Guided Procedures

(a) Procedure Indications Difficult intravenous (IV) access: Risk factors for difficult IV access include: Dialysis patient Sickle cell patient Diabetic patient Chemotherapy patient Dehydration Obesity Edema IV drug abuse History of difficult access Multiple previous attempts without successful IV placement (b) Procedure Complications Infection, phlebitis, hematoma Extraluminal placement Dislodgement and infiltration (c) Transducer Selection Linear array (d) Equipment IV needle with angiocatheter: Long catheters are preferred if available. Figure 18.1—Long and short IV catheters. Ultrasound gel: Sterile surgical lubricant is recommended for deep vein access or when drawing blood cultures. Antiseptic swab: Chlorhexidine is recommended for deep vein access. Tourniquet Luer lock adapter Saline flush Adhesive dressing Gloves (e) Patient Position and Anatomical Landmarks The patient should be supine with their arm extended and externally rotated: Figure 18.2—Patient position for PIV placement Blood vessels appear anechoic: Veins are thin walled and compressible. Arteries have thicker walls, typically pulsate, and are not compressible. Figure 18.3—Ultrasound of the artery and vein. The brachial vein runs adjacent to the brachial artery and median nerve within the upper medial arm. The basilic vein runs medial to the brachial vessels. Figure 18.4—Brachial and basilic vein positions. (f) Preparation Universal precautions should be utilized at all times. Apply tourniquet. Identify the vessel with ultrasound: Success rate increases when the vein is less than 1.5 cm from the skin surface [1]. Clean transducer with antiseptic cloth. Hold transducer with nondominant hand and place over the vessel: Be careful not to apply pressure with the transducer as this will displace the vessel deeper within the arm and can compress the vein. Figure 18.5—Transducer placement. Adjust depth so that the vessel is in the center of the screen. Increase gain so that needle will show up bright on the screen. Figure 18.6—Ideal image for ultrasound-guided peripheral IV placement. (g) Technique Two approaches (in-plane or out-of-plane): Figure 18.7a—In-plane Figure 18.7b—Out-of-plane Out-of-plane: The vein will be imaged using a transverse or cross-sectional view. The transducer marker should point in the same direction on the patient as on the ultrasound monitor. Identify the vein in cross section: Make sure the vessel is compressible before attempting access. Insert the needle just distal to the transducer and enter the skin at a 15–30° angle: Figure 18.8—Needle position relative to transducer Needle tip will be visualized in the subcutaneous tissue as a small bright white dot: Figure 18.9—Needle tip As the needle is advanced closer to the vessel, the transducer should slide with the advancement to keep the needle tip visualized at all times. Once the needle tip enters the vessel, drop the angle of the needle, and advance at least 2 mm to ensure the needle and the catheter are within the vessel lumen: Figure 18.10—Needle in the vessel. Remember: catheter tip sits back slightly from needle bevel so at the initial flash, it may not be far enough into the vessel to advance the catheter. Stabilize the needle and slowly advance the catheter until it is completely within the vessel lumen. Video 18.1—Out-of-plane peripheral IV placement. In-plane: The vein will be imaged using a longitudinal view of the vessel. Place the transducer over the vessel with the marker pointed toward the needle: This can also be done with the marker pointed away from the needle. In this view, the vein will appear as an anechoic tube. Insert the needle just distal to the leading edge of the transducer and enter the skin at a 15–30° angle: Figure 18.11—Transducer and needle placement in long axis If the needle is directly under the transducer beam, it will reflect the entire needle, and you can visualize it along its course into the vessel: Figure 18.12—Long axis of needle toward the vein Once the needle tip enters the vessel, drop the angle, and advance 2 mm to ensure the needle and the catheter are within the vessel lumen: Figure 18.13—Needle in the vessel, long axis. Remember: catheter tip sits back slightly from needle bevel so at the initial flash, it may not be far enough into the vessel to advance the catheter. Stabilize the needle and slowly advance the catheter until it is completely within the vessel lumen. Video 18.2—In-plane peripheral IV placement. Completing the procedure: Remove the tourniquet. Flush the luer lock and tubing with saline to remove air bubbles, attach it to the catheter, and secure it in place with Tegaderm adhesive. Flush the catheter once inside the vessel: The IV should flush easily. If there is resistance or pain with the flush, the catheter is likely outside the lumen of the vessel and needs to be removed. (h) Key Points Ultrasound improves efficiency of IV access when blind landmark attempts have failed and decreases the number of needle sticks [2]. Tissue movement can help localize the approximate location of the needle tip prior to actually visualizing the needle tip [2].