The nurse is responsible for assessing the arterial waveform and addressing inaccuracies that can be identified by comparing the a-line blood pressure reading to a manual blood pressure reading. The nurse is responsible for zeroing the a-line every 4 hours, at change of shift, and after blood draws, in addition to any time an inaccuracy is suspected. The nurse must also continuously assess the site for signs of bleeding, dislodgement, hematoma formation, and infection, and must assess the patient for the 5 P’s: pain, pallor, pulses, paresthesia, and paralysis.