An arterial catheter is a thin, flexible tube inserted into an artery to monitor blood pressure and obtain blood samples. It allows for continuous blood pressure monitoring, which is crucial in critically ill patients or during major surgeries. The catheter is typically placed in the radial artery in the wrist or the femoral artery in the groin. These catheters are often used in intensive care units and operating rooms. They help healthcare providers make informed decisions about a patient's condition and treatment. Proper placement and maintenance are essential to prevent complications, such as infection or blood clots.