A RTERIAL C ATHETER I NSERTION Mahdieh Alkony An-Najah National University College of Nursing

C ONDITIONS THAT WARRANT THE USE OF ARTERIAL PRESSURE MONITORING INCLUDE PATIENTS WITH THE FOLLOWING : ❖ Acute hypotension or hypertension (hypertensive crisis) ❖ Hemodynamic instability or circulatory collapse ❖ Cardiac arrest ❖ Hemorrhage ❖ Shock from any cause ❖ Continuous infusion of vasoactive medications ❖ Frequent arterial blood gas measurements ❖ Nonpulsatile blood flow (i.e., those using nonpulsatile ventricular assist devices or receiving extracorporeal membrane oxygenation) ❖ Intraaortic balloon pump therapy ❖ Neurologic injury ❖ Coronary interventional procedures ❖ Major surgical procedures

❖ Multiple trauma ❖ Respiratory failure ❖ Sepsis ❖ Obstetric emergencies

Noninvasive, indirect blood pressure measurements determined by auscultation of Korotkoff sounds distal to an occluding cuff consistently average 10 to 20 mm Hg lower than simultaneous direct measurement. Arterial waveform inspection can help rapidly diagnose the presence of valvular disorders, the effects of dysrhythmias on perfusion, the effects of the respiratory cycle on blood pressure, and the effects of intraaortic balloon pumping or ventricular assist devices on blood pressure

The preferred artery for arterial catheter insertion is the radial artery (see Fig. 79-1). Though this artery is smaller than the ulnar artery, it is more superficial and can be more easily stabilized during the procedure. Some research has found that the brachial artery is a safe and reliable alternative site for arterial puncture and line placement.9 At times, the femoral artery may be used for arterial catheter insertion. The use of this artery can be technically difficult because of the proximity of the femoral artery to the femoral vein (see Fig. 79-2).

S ITE SELECTION Use the radial artery as the first choice. Perform a modified Allen test to determine the patency of the radial and ulnar arteries before performing the arterial puncture (see Fig. 79-3). Normal palmar blushing is complete before 7 seconds, indicating a positive result; 8 to 14 seconds is considered equivocal; and 15 ormore seconds indicates a negative test. Doppler flow studies or plethysmography can also be performed to ensure the presence of collateral flow. Research shows these studies to be more reliable than the Allen test.11 Thrombosis of the arterial cannula is a common complication. Ensuring collateral flow distal to the puncture site is important for preventing ischemia.

S ITE SELECTION Use the brachial artery as the second choice, except in the presence of poor pulsation caused by shock, obesity, or a sclerotic vessel (e.g., because of previous cardiac catheterization). The brachial artery is larger than the radial artery. Hemostasis after arterial cannulation is enhanced by its proximity to the bone if the entry point is approximately 1.5 inches above the antecubital fossa

S ITE SELECTION Use the femoral artery in the case of cardiopulmonary arrest or altered perfusion to the upper extremities. The femoral artery is a large superficial artery located in the groin. It is easily palpated and punctured. Complications related to femoral artery puncture include hemorrhage and hematoma formation (because bleeding can be difficult to control), inadvertent puncture of the femoral vein (because of its close proximity to the artery), infection (because aseptic technique is difficult to maintain in the groin area), and limb ischemia (if the femoral artery is damaged).

EQUIPMENT 2-in, 20-G, nontapered Teflon cannula-over-needle Single-pressure transducer system (see Procedure 75) Monitoring equipment consisting of a connecting cable, monitor, oscilloscope display screen, and recorder Nonsterile gloves and goggles Sterile gloves Antiseptic solution (e.g., 2% chlorhexidine-based preparation) Sterile 4 × 4 gauze pads Suture material 1% lidocaine without epinephrine, 1 ml to 2 ml 3-ml syringe with 25-G needle Sheet protector Sterile towels 2-in tape

PATIENT ASSESSMENT Obtain the patient’s medical history of diabetes, hypertension, peripheral vascular disease, vascular grafts, arterial vasospasm, thrombosis, or embolism. Obtain the patient’s history of prior coronary artery bypass graft surgery in which radial arteries were removed for use or presence of A-V fistulas or shunts. ➸ Rationale: Extremities with any of the above problems should be avoided as sites for cannulation Patients with diabetes mellitus or hypertension are at higher risk for arterial or venous insufficiency. Previously removed radial arteries are a contraindication for ulnar artery cannulation.

Assess the patient’s medical history of coagulopathies, use of anticoagulants, vascular abnormalities, or peripheral neuropathies. ➸ Rationale: Assists in determining safety of the procedure and aids in site selection. Assess the patient’s allergy history (e.g., allergy to lidocaine, topical anesthetic cream, antiseptic solutions, or tape). ➸ Rationale: Decreases the risk for allergic reactions. Assess the patient’s current anticoagulation therapy, known blood dyscrasias, and pertinent laboratory values (e.g., platelets, PTT, PT/INR) prior to the procedure. ➸ Rationale: Anticoagulation therapy, blood dyscrasias, or alterations in coagulation studies could increase the risk for hematoma formation or hemorrhage.

Presence of collateral flow to the area distal to the arterial catheter should be evaluated before cannulating the artery. For radial or ulnar arterial lines, a modified Allen test should be performed. ➸ Rationale: Ensures presence of collateral flow to the hand to reduce vascular complications. Assess the intended insertion site for the presence of a strong pulse. ➸ Rationale: Identification and localization of the pulse increases the chance of a successful arterial cannulation.

Patient Preparation Ensure that the patient and family understand preprocedural teaching. Answer questions as they arise and reinforce information as needed. ➸ Rationale: Evaluates and reinforces understanding of previously taught information. Obtain informed consent. ➸ Rationale: Protects the rights of the patient and makes a competent decision possible for the patient; however, under emergency circumstances, time may not allow form to be signed.

Place the patient supine with the head of the bed at a comfortable position. The limb that the arterial catheter will be inserted into should be resting comfortably on the bed. ➸ Rationale: Provides patient comfort and facilitates insertion. Place a towel under the back of the wrist to hyperextend the wrist and tape it in place or have someone hold it (if the radial artery is being used). ➸ Rationale: Positions the arm and brings the artery closer to the surface.

Elevate and hyperextend the patient’s arm. Support the arm with a pillow (when using the brachial artery). ➸ Rationale: Increases accessibility of the artery. When using the femoral artery, position the patient supine with the head of the bed at a comfortable angle. The patient’s leg should be straight with the femoral area easily accessible. ➸ Rationale: Provides the best position for localizing the femoral artery pulse.

1. Wash hands. 2. Prepare a single pressure transducer system 3. If the radial artery is to be used, it is recommended to perform Allen test before arterial catheter insertion (see Fig. 79-3).

A. With the patient’s hand held overhead, instruct the patient to open and close his or her hand several times. B. With the patient’s fist clenched, apply direct pressure on both the radial and ulnar arteries. C. Instruct the patient to lower and open his or her hand. D. While maintaining pressure on the radial artery, release the pressure over the ulnar artery and observe the hand for return of color Return of color within 7 seconds indicates patency of the ulnar artery If it takes 15 or more seconds for color to return, the test is considered abnormal and another site should be considered.

Prepare the site with the antiseptic solution (e.g., 2% chlorhexidine- based preparation). Starting at the insertion site, cleanse back and forth for 3 seconds. Wash hands and change to sterile gloves. Drape the area around the site with sterile towels Locally anesthetize the puncture site. A. Use a 1-ml syringe with a 25-G needle to draw up 0.5 ml of 1% lidocaine without epinephrine.

B. Aspirate before injecting the local anesthetic. C. Inject intradermally and then with full infiltration around the intended arterial insertion site. Use approximately 0.2 to 0.3 ml for an adult. Perform the percutaneous puncture of the selected artery. A. Palpate and stabilize the artery with the index and middle fingers of the nondominant hand. B. With the needle bevel-up and the syringe at a 30- to 60-degree angle to the radial or brachial artery, puncture the skin slowly. Adjust the angle to a 60- to 90-degree angle to the femoral artery.

Advance the needle and the cannula until a blood return is noted in the hub; then slowly advance the catheter about 1/4 to 1/2 inch farther to ensure that the cannula is in the artery. If, on initial insertion, a blood return is not noted, a 3-ml syringe may be placed at the end of the cannula. While advancing the a syringe on the catheter, gentle withdrawing of the syringe plunger may be performed in an effort to determine proper placement in the artery.

Level the catheter to the skin; then continue to advance the cannula to its hub with a firm, steady rotary action. 13. Correct positioning is confirmed by the presence of pulsatile blood return on the removal of the stylet 14. Once positioning is confirmed, remove the stylet and connect the prepares the catheter to the single- pressure blood pressure monitoring transducer system and flush the system.

15. Level the air-fluid interfac (zeroing stopcock) to the phlebostatic axis, zero the monitoring system, verify the arterial waveform, and activate the alarm system (see Procedure 59). 16. Suture the arterial catheter Maintains arterial catheter in place. 17. Apply a dry, occlusive sterile dressing and label the insertion information. 18. Discard used supplies; needles and other sharp objects in appropriate containers; remove gloves and wash hands.

P ATIENT M ONITORING AND C ARE 1. Observe the insertion site for signs of hemostasis after the procedure. 2. Assess the arterial catheter insertion site and involved extremity for signs of postinsertion complications. 3. Monitor the arterial catheter insertion site for signs of local infection