W2 Arterial Puncture Flashcards
Indications for an ABG
—To confirm a clinically suspected acute problem with CO2 or O2, OR an acid-base balance
—To monitor a clinical intervention such as oxygen supplementation, hyperventilation, or CPR
—To confirm the need for home oxygen therapy
—To obtain a blood sample in emergent situations when phlebotomy cannot be performed or when venous sites are inaccessible
Contraindications
—Inability to palpate an arterial pulsation
—Known or suspected severe arterial disease of aneurysmal, atherosclerotic, inflammatory, or vasospastic nature
—Poor perfusion from the ulnar artery when the radial artery is the intended puncture site (and vice versa)
—Active bleeding from thrombolytic therapy
Arterial site selection
Due to the proximity to the skin surface, the RADIAL ARTERY is preferred; typically on the nondominant hand. THere has to be adequate ulnar artery collateral circulation.
—In severely hypotensive patients or during CPR/code, the FEMORAL ARTERY is usually the most palpable
—Alternative sites:
Brachial
Superficial Temporal
Dorsalis Pedis
ALLEN TEST - Assessment of Ulnar Collateral Circulation
Why? Because radial artery puncture (or cannulation) can result in thrombosis of the distal radial artery.
Considering up to 10-15% of hands have poor collateral flow or an incomplete palmar arch with no collateral circulation, the collateral flow should be evaluated before the procedure to reduce the risk of ischemic damage to the hand.
First described in 1929 however has been modified.
Modified Allen test
1.Have the patient hold the hand above heart level. They then open and close the hand several times to exsanguinate it (about a minute). Have them make a fist and clench it tightly. If the patient is comatose, the hand will need to be moved by the provider.
2.Compress the radial and ulnar arteries
3.Lower the fist below heart level and the patient should unclench it
4.Release pressure from the ulnar artery (hyperextension of the wrist or fingers can produce a falsely abnormal test)
5.With pressure off the ulnar artery, the cadaveric/exsanguinated color of the PALM should return to normal color within 6 seconds, and color throughout the entire HAND in less than 15 seconds.
7. If any area of the hand does not rapidly return to normal color, this is a (+) test for abnormal collateral flow. Further tests (doppler) or an alternative location should be considered.
8. The thumb, index finger, and thenar eminence are the most frequent sites involved in a (+) test because of their dependence on radial artery perfusion.
ABG Technique
1.Clean the radial artery site with alcohol gauze for 30 seconds and allow to dry
2.Local anesthetic (lidocaine, remember this is an anti arrhythmic!) can be administered subcutaneously (make sure to aspirate to ensure you are not within a blood vessel prior to administration, draw back). ABG kit contains a heparinized syringe.
3.Sterile gloves
4.Hold the barrel of the syringe like a pencil with the bevel up
5.Extend the wrist of the nondominant hand and support it with a firm surface
6.Insert needle at 45 degrees to the area where the pulse is most prominent (½ to 1 inch proximal to the wrist crease),
Brachial Artery Puncture:
-Extend and supinate the arm
-Insert needle 45-60 degrees
toward the pulsation in the
median aspect of the AC fossa
(slightly above the elbow
crease
FEMORAL ARTERY:
FEMORAL ARTERY:
-Patient is supine
-Insert needle 2-3 cm distal
to the inguinal ligament
(inguinal crease) at a
60-90 degree angle toward
The pulsation
Technique
- Puncture is detected when blood enters the syringe. It should enter SPONTANEOUSLY without withdrawing the plunger. With hypotensive patients, slight aspiration is sometimes necessary.
- If no blood is obtained, withdraw the needle to just beneath the skin and advance again without changing the angle of approach but with the needle directed 1 mm to either side of the previous attempt.
- COllect 3 cc of blood and remove the needle from the artery smoothly while applying pressure to the site. Steady pressure should be maintained for 5-10 minutes (might be longer in patients on anticoagulation).
- While applying pressure with one hand, use the other hand to hold the syringe with the needle tip upright and expel any air bubbles.
- Impale the syringe in a rubber stopper and remove the needle after it is securely capped.
- Roll the syringe in your hand 4-5x to mix the blood uniformly with the heparin.
- Label with patient’s information and immediately transport to the lab on ice.
- Examine the patient for a hematoma. Instruct the patient to inform you if the extremity becomes numb, painful, cold, or blue.
Complications
Hemorrhage/Hematoma (most common)
Thrombosis
Nerve Damage
Infection
Venous Blood
PERCUTANEOUS ARTERIAL LINE PLACEMENT
Indications
Contraindications
—Continuous monitoring of arterial blood pressure; patients in shock and with the need for vasopressor or vasodilator therapy
—Continuous access to arterial blood is desired to avoid repeated punctures
Contraindications:
Inadequate collateral blood flow; (+) Allen test
Severe atherosclerotic or vasospastic arterial disease
Hypercoagulable state
Thrombolytic therapy
Local skin compromise from a burn or infection
Percutaneous arterial line placement
TECHNIQUE:
1.Palpate the radial artery
2.Preferably on the nondominant hand, extend and immobilize the wrist by taping a gauze roll between the supinated extended wrist and a dorsally applied arm board. Tape the fingers (excluding the thumb) around the armboard. Tape the forearm to the armboard.
3.Prep the skin in an aseptic manner
4.Local anesthetic can be administered (lidocaine)
5.Drape the area with sterile towels
6.Don sterile gloves and hold the catheter needle hub like a pencil with the needle bevel up
7.Insert the needle ½ to 1 inch proximal to the wrist crease at about a 30 degree angle. Direct is slowly toward the pulsati
- Puncture is detected when blood appears in the needle hub
- While holding the needle fixed, advance the catheter-over-needle into the artery.
- If the artery cannot be cannulated after the flash of blood, the posterior artery wall has likely been penetrated. Remove the needle entirely, slowly withdraw the catheter until blood flows into it, and readvance the catheter.
- While advancing, make sure the catheter advances without ANY resistance to reduce the risk of dissection.
If failed 3x, then try the artery on the other side. - The catheter should advance until the hub is in contact with the skin. Attach the connector tubing. Flush the catheter and observe for the arterial tracin
