A catheter system may include a catheter lumen, first and second electrodes, and a sensor in communication with the first and second electrodes. The sensor may be configured to detect at least one of: a bulk volume of blood within a blood vessel and extravasation of a drug from the blood vessel into soft tissue adjacent the blood vessel. Other catheter systems may include a catheter lumen and a sensing chip coupled to the catheter lumen. The sensing chip may be configured to detect at least one of: a bulk volume of blood within a blood vessel and extravasation of a drug from the blood vessel into soft tissue adjacent the blood vessel.