Shah et al listed the different ways to identify misplacement of an intravenous catheter into an adjacent artery. The presence of one or more of the findings indicate the need to reposition the catheter and to correct the arterial injury. The authors are from Westcheter Medical Center in Valhalla, New York.


Arterial blood from a misplaced catheter will:

(1) have a redder color than venous blood

(2) have pulsatile flow

(3) have a PaO2 similar to arterial blood (arterial blood should 80-100 mm Hg while the venous blood has a value of around 40 mm Hg); PaCO2 will also be lower than in venous blood

(4) have a higher pressure as measured by a transducer (venous pressure < 20 mm Hg while systolic blood pressure would be > 90 mm Hg unless the patient is in shock)


In addition, a post-insertion X-ray will show the catheter to be in an artery (such as the aorta) rather than a vein.


To read more or access our algorithms and calculators, please log in or register.