Percentage of patients, regardless of age, who undergo placement of a peripheral intra-arterial catheter for whom the arterial line was inserted with all indicated elements of sterile barrier technique, hand hygiene, skin preparation and, if ultrasound is used, sterile ultrasound techniques followed. This measure will consist of two performance rates: a. Percentage of patients, regardless of age, who undergo placement of a peripheral intra-arterial line in the brachial, radial, posterior tibial or dorsalis pedis artery for whom the arterial line was inserted with all indicated elements of sterile barrier technique, hand hygiene, skin preparation and, if ultrasound is used, sterile ultrasound techniques followed b. Percentage of patients, regardless of age, who undergo placement of a peripheral intra-arterial line in the femoral or axillary artery for whom the arterial line was inserted with all indicated elements of maximal sterile barrier technique, hand hygiene, skin preparation and, if ultrasound is used, sterile ultrasound technique is followed The overall measure score will be calculated as an average of the performance rates of part A and part B.