Peripheral arterial lines may be placed by a physician or neonatal nurse practitioner. The most frequently used sites in neonates are the radial and dorsalis pedis arteries. The transilluminator may be used as a light source to locate the artery. Never use a head lamp or other hot light as it may burn the infant.

The site of insertion should be prepped with betadine or chlorhexidine. A 22 or 24 gauge catheter is used. The arterial line is usually secured in place with a transparent dressing and an armboard.

Fluids that may be run through a peripheral arterial line in the NICU include ½ NS or NS with ½ unit/mL heparin at 0.5 – 1 mL/hr. 4mg/dL lidocaine may or may not be included in art-line fluids to decrease vasospasm. Never infuse any other medications or fluids through a peripheral arterial line. Arterial line fluids should be changed every 72 hours.

The transducer should be positioned at the level of the right atrium in the midaxillary line. The transducer should be zeroed every 12 hours and prn. Transducers and tubing should be changed every 72 hours. If the waveform becomes dampened, a peripheral blood pressure should be obtained and recorded once a shift to confirm accuracy. The pulse alarm of the cardiac monitor should be set for any infant with an arterial line.

To sample blood from a peripheral arterial line, the port should be cleaned with betadine and allowed to dry for 30-60 seconds, then wiped with alcohol before withdrawing the sample. The fluids should be clamped off at the T-connector, as near to the port as possible to prevent backflow of blood into the line. Insert a sterile 22 or 25 gauge needle and allow at least 3 drops of blood to escape to clear the line of fluid. Then attach a sterile syringe and withdraw the sample. To minimize arterial vasospasm, aspirate blood very slowly. Allowing the sample to drip freely may be preferable to using suction. Afterwards remove the needle and release the clamp. Gently flush the line with a small amount of fluid to clear the hub of blood and prevent clotting.

Arterial vascular access plays an important role in monitoring premature and sick infants in the NICU.  A potential complication of arterial vascular access is arterial occlusion.   Clinical presentations may include sudden limb pallor and loss of distal pulses.  Severe ischemic injury may lead to necrosis, gangrene, and loss of affected limb.  It may be possible is some circumstances to decrease severity of occlusion by using topical nitroglycerin ointment but this may or may not help. A physician should be notified promptly of any bleeding from the arterial line site or compromise in distal circulation.

 

Nitroglycerin ointment, a direct arterial and venous vasodilator, applied to ischemic extremities may prove beneficial and has been shown to restore blood flow to ischemic areas.  Apply a thin layer of 2% nitroglycerin ointment to affected areas (which may include catheter site and surrounding area) as often as every 4-6 hours and wrapped with Bioclusive® (approximately 4 mm/kg applied topically is equivalent to 0.2-0.5 mcg/kg/min continuous IV infusion nitroglycerin).  Blood pressure and heart rate should continue to be monitored.  Nursing staff should apply ointment using gloves. Topical nitroglycerin ointment is absorbed readily and may cause severe headache and/or hypotension secondary to systemic absorption and vasodilation.  If skin should come in contact with the ointment wash area with soap and water immediately. 

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