Frequent arterial blood sampling is required and an umbilical arterial catheter cannot be placed or has been removed.
Intra-arterial blood pressure monitoring.
Measure preductal PaO2. Requires right upper extremity catheterization.
Exchange transfusions (removal of blood only). Used in peripheral vessel exchange transfusion (PVET) when drawing blood from a peripheral artery and infusing through a peripheral vein.
Safety-engineered catheter over needle access device based on local practices (22 or 24 gauge; 24 gauge preferred for infants <1500 g), arm board (or 2 tongue blades taped together), adhesive tape, cap, mask, sterile fenestrated drape, povidone-iodine or skin disinfectant, sterile gloves, suture material (optional; needle holder, suture scissors, 4–0 or 5–0 silk sutures) or Steri-Strips or Tegaderm, 0.5% or 0.25% normal saline flush solution (0.25% preferred in premature infants to decrease hypernatremia risk) with heparin (0.5–2 units of heparin/mL saline), pressure bag (to prevent backflow and keep the line free of clots), connecting tubing, pressure transducer for continuous blood pressure monitoring, fiberoptic light for transillumination, a Doppler device or a portable ultrasound to locate the artery.
The radial, dorsalis pedis, and posterior tibial sites are the preferred sites. Two methods are described here using the radial artery, which is the most common access site because of low complication rates. Methods can be adapted to other arteries. Another common site is the posterior tibial artery, as both the radial and posterior tibial arteries have good collateral circulation. The dorsalis pedis artery can be used as an alternative site but is often too small. The temporal, brachial, and femoral arteries are not recommended. Temporal artery catheterization may have adverse neurologic sequelae. The brachial artery is not recommended because it does not have good collateral flow and the median nerve can be damaged. The ulnar artery should also not be used because of poor collateral circulation or potential for damage to the ulnar nerve.
Locate the artery by palpation, transillumination Doppler auditory assistance, or point-of-care ultrasound (POCUS). Palpation of the artery can be done at the following sites: radial artery (lateral wrist), ulnar artery (medial wrist), posterior tibial artery (posterior to the medial malleolus), and dorsalis pedis artery (on top of the foot). For technique in transillumination see Chapter 44. Doppler device can identify the artery by a characteristic high sound. Using POCUS, one can find the artery which will be pulsatile and will not collapse like the vein when compressed.
Point-of-care ultrasound during cannulation. The use of ultrasound during radial arterial cannulation is considered standard of care in adults and pediatrics. Use in neonates depends upon the clinician’s training and experience and availability of equipment. It can help guide the catheter during the procedure, can lead to a shorter procedure time, a higher first and second attempt success rate, and a decrease in complications (hematoma or ischemia) as compared to palpation or Doppler auditory assistance as noted in a 2016 Cochrane review. The procedure involves using a linear probe transverse to the artery to first find the vessel. The artery will appear pulsatile and will not collapse with compression. Place the small linear probe over the vessel, insert the needle near the probe, and advance the needle until the vessel wall is punctured. The advantage is that one can directly visualize the needle passing into the vessel on the image.
Verify adequate collateral circulation in the hand using the modified Allen test or Doppler evaluation. (See Chapter 26...