In examples described herein, a system includes an elongate member configured to be introduced into vasculature of a patient. The elongate member includes a pressure sensor configured to generate a pressure signal indicative of pressure in the vasculature adjacent the needle. The system includes processing circuitry configured to receive the pressure signal from the pressure sensor, detect, based on the pressure signal, dislodgment of the elongate member from the vasculature, and generate an output in response to detecting the dislodgment of the elongate member from the vasculature.