Central lines are something we routinely do but can and do lead to complications. Complications include pneumothorax, dysrhythmias, guidewire loss, and of course arterial cannulation. We will focus mostly on talking about arterial cannulation and arterial dilation/insertion of a catheter. Arterial injury occurs in less than 1% of catheter placements, but arterial puncture occurs in 4.2–9.3% of line placements. Most of the time it is often easily recognized secondary to pulsatile flow, the artery is not dilated, and pressure is held with no complications. Hematoma formation has been reported in up to 4.7% of all catheter placements. Hematoma formation is often not life-threatening.
Complications from arterial puncture, and especially arterial dilation & catheter insertion include AV fistula, arterial thrombosis & subsequent stroke, arterial pseudoaneurysm, & arterial dissection. Immediate removal of an accidental arterial catheter can result in uncontrolled hemorrhage so the catheter should be left in place for removal by interventional radiology or vascular surgery (direct suture repair, percutaneous closure device, stent-graft insertion). Studies have demonstrated that leaving the arterial catheter in place with prompt repair carries less morbidity and mortality than catheter removal with pressure.
Discerning if you are in the artery or vein
Ultrasound can be used to confirm appropriate guidewire placement in the venous system prior to dilation
Venous pressure waveform on CVP monitor (applies more for ICU)
Watch for pulsatile flow, but recognition may be difficult in a hypotensive patient, which are a significant portion of patients who are getting central access
Send off blood gas and decide if it is a VBG or ABG (but VBG may resemble ABG in a hyperoxic patient on high FiO2)
Confirmation using angiocath in the central line kit in conjunction with the extension tubing and evaluating the column of blood in the extension tube. Dr. Strayer has a complete description here. https://emupdates.com/catheter-in-artery-vs-vein/
CxR showing catheter going towards RA (venous) vs LV (arterial). However, with this method, confirmation is achieved only after dilation.
If inadvertent arterial insertion fails to be recognized, further complications can arise from infusion of vasopressors into arterial circulation, such as ischemic stroke.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4613416/
https://www.reliasmedia.com/articles/131944-complications-of-tubes-and-lines-part-i
https://emupdates.com/catheter-in-artery-vs-vein/