Arteries are the large vessels that carry oxygenated blood away from the heart (except for the pulmonary circuit, in which the arterial blood is deoxygenated). The distribution of the systemic arteries is like a ramified tree, the common trunk of which, formed by the aorta, commences at the left ventricle, while the smallest ramifications extend to the peripheral parts of the body and the contained organs.
The arteries, in their distribution, communicate with one another (forming what are called anastomoses) and end in minute vessels, called arterioles, which in their turn open into a close-meshed network of microscopic vessels, termed capillaries, the true deliverers of oxygen and nutrients to the cells.
Arteries are found in all parts of the body, except in the hairs, nails, epidermis, cartilages, and cornea.
Anatomy of Upper Limb Arteries
On the right side, the subclavian artery arises from the brachiocephalic trunk behind the right sternoclavicular articulation; on the left side, it springs from the arch of the aorta, behind the left common carotid. The branches of the subclavian artery are the vertebral artery (entering the skull through the foramen magnum, uniting with the vessel of the opposite side to form the basilar artery), the thyrocervical trunk, the internal thoracic artery (dividing at the level of the sixth intercostal space into the musculophrenic and superior epigastric arteries), the costocervical trunk, and the dorsal scapular artery.
The axillary artery is the continuation of the subclavian, which commences at the outer border of the first rib. The branches of these vessels are, from the first part, the highest thoracic; from the second part, the thoracoacromial and lateral thoracic; and from the third part, the subscapular, posterior humeral circumflex, and anterior humeral circumflex.
The brachial artery commences at the lower margin of the tendon of the teres major. Passing down the arm, it ends about 1 cm below the bend of the elbow, where it branches into the radial and ulnar arteries. At first, the brachial artery lies medial to the humerus, but as it runs down the arm, it gradually gets in front of the bone; at the bend of the elbow, it lies midway between its 2 epicondyles. The branches of this artery are the deep brachial (profunda brachii), the superior ulnar collateral, the nutrient, the inferior ulnar collateral, and the muscular branches.
The radial artery commences at the bifurcation of the brachial, just below the bend of the elbow, and passes along the radial side of the forearm to the wrist. The branches of the radial artery may be divided into 3 groups, corresponding with the 3 regions in which the vessel is situated: a forearm group (radial recurrent, muscular, palmar carpal, and superficial palmar), a wrist group (dorsal carpal and first dorsal metacarpal), and a hand group (princeps pollicis, radialis indicis, and deep palmar arch).
The ulnar artery is the larger of the 2 terminal branches of the brachial and begins a little below the bend of the elbow. The branches may be arranged in the following groups: a forearm group (anterior ulnar recurrent, posterior ulnar recurrent, common interosseous, and muscular), a wrist group (palmar carpal and dorsal carpal), and a hand group (superficial palmar arch and a contribution to the deep palmar arch).
The process of puncturing an artery, with a needle aseptic technique. A peripheral arterial line (PAL) is a small, short, plastic catheter that is put through the skin into an artery of the arm or leg. Sometimes it can call ‘Art Line’ or ‘A Line’.
An arterial line is usually inserted into the radial artery in the wrist, but can also be inserted into the brachial artery at the elbow, into the femoral artery in the groin, into the dorsalis pedis artery in the foot, or into the ulnar artery in the wrist. A golden rule is that there has to be collateral circulation to the area affected by the chosen artery,
Importance of Insertion of Arterial Line
To measure central venous pressure. Placement of an arterial line is indicated for continuous monitoring of arterial pressure and direct arterial blood sampling. The radial pulse is palpated between the distal radius and the flexor carpi radialis tendon. Prior to line placement, perfusion of the extremity should be checked. For radial arterial catheters.
Radial arterial lines are important tools in the treatment of critically ill patients. Continuous monitoring of blood pressure is indicated for patients with hemodynamic instability that requires inotropic or vasopressor medication. An arterial line allows for consistent and continuous monitoring of blood pressure to facilitate the reliable titration of supportive medications.
There are several techniques for the placement of a radial arterial line; two of the more common are known as “over the wire” and “over the needle.”
Preparation for both techniques is identical. The equipment needed includes a sterile preparation solution and a sterile field, a board and tape to secure and position the wrist
Requirements / Equipments
- Bivalve x 1
- 500 ml. Normal Saline with 5000 IU Heparin.
- Pressure Bag.
- Transducer with CVP cable.
- Arteriofix / Insyte – no. 18/20 / Jelco/Vein flow.
- Betadine Lotion
- Sterile Towel
- Disinfectant for Hand Hygiene
- Xylocaine 2%
- 5 ml. Syringe
- Suture Materials
- Betadine Ointment
- Dynaplast Dressing
- Kidney Tray and Mackintosh
Placement of the Line
- The radial artery is palpated 1 to 2 cm from the wrist, between the bony head of the distal radius and the flexor carpi radialis tendon.
- In a conscious patient, lidocaine may be infused at the insertion site to help minimize pain on insertion of the line.
- For the over-the-wire technique, the artery should be palpated gently with the non-dominant hand proximal to the insertion site.
- The needle should enter at a 30-to-45-degree angle to the skin directly over the point at which the pulse is palpated.
- The catheter should be advanced slowly through the artery; once a flash of blood is seen in the hub of the catheter, the needle should be advanced a few millimeters farther through the vessel.
- The wire should be prepared and the needle slowly withdrawn until pulsatile blood flow is observed.
- At this point, the wire is advanced into the vessel. The wire should thread easily and without resistance.
- Once the wire is in the vessel, the needle can be removed; the catheter is then advanced over the wire.
- Pressure should be placed over the artery proximal to the catheter, the wire removed, and the catheter connected to a transduction system.
- For the over-the-needle technique, the initial approach is the same. The pulse should be palpated proximal to the insertion site; the needle should penetrate the skin at a 30-to-45-degree angle directly over the palpated pulse and then be advanced slowly toward the pulse.
- Once pulsatile blood return is seen in the catheter, the catheter should be advanced slightly farther to ensure that the catheter itself is within the vessel.
- The catheter angle should then be lowered to 10 to 15 degrees and the catheter advanced over the needle into the vessel.
- Regardless of technique, the catheter should be secured in place. Suturing is the preferred method, but many practitioners choose to tape the catheter securely in place.
- It is important to ensure that the catheter is not subject to tension from the tubing or at risk of being removed by the patient.
- Perfusion to the hand should be reassessed after placement of the arterial line and at frequent intervals while the line is in use.
- Any sign of vascular compromise at any time should prompt the removal of the line. The line should be removed as early as possible after it is no longer needed.
- Collect all equipment.
- Explain Procedure to patient.
- Prepare pressure transducer system.
- Support the insertion site as necessary. If Radial Artery – Dorsifix the wrist.
- Provide disinfectant and gloves for the physician.
- Provide gauze and spirit or Betadine Lotion as requested by Physician.
- Provide Sterile Hole Towel for draping the area.
- Clean top of Xylocaine vial with spirit and allow drying.
- Provide syringe and needles – 5 ml.
- Provide Heparin and water for injection.
- Provide Arterio fix 18/ 20 and Bivalve.
- Connect transducer system + zero transducer.
- Provide suture material – Ethilon 3-0.
- Apply Betadine Ointment and Gauze + Dynaplast.
- Splint Arterial line necessary.
- Label Arterial Line clearly.
- Tidy and Restock all equipment used.
- Segregate generated Bio-Medical Waste as per HIC policy.
- Maintain transducer position at a constrain level.
- Level with right atrium.
Arterial spasm and an inability on the part of the clinician to pass the wire or catheter through the artery are the most common difficulties in catheterization. If spasm is suspected, attempts at catheterizing that artery should be abandoned and an alternative site selected.
If the wire or catheter cannot be passed despite the return of pulsatile blood, this is either because the angle of the needle in relation to the vessel is too acute or because the needle tip is not completely within the artery. With adjustment of the angle, a slight advance, or withdrawal of the needle, placement may yet be successful.