Comparing Palpation Guided and Ultrasound Guided Arterial Line Placement

When surgery is performed under general anesthesia, a catheter is placed in a vein to administer drugs and saline. During major operations, an additional catheter is placed in an artery in order to measure the blood pressure closely and withdraw blood samples at frequent intervals for various laboratory tests. This arterial catheter is usually placed by feeling the patient's artery at the wrist and inserting the guide-needle in a blind fashion. This procedure, at times, leads to delays and failures due to an inability to feel the arterial pulsation well either due to the patients' anatomy or the anesthetic effect. This study will determine whether training Anesthesiology Residents in the use of ultrasound technology and its application in identifying an artery can prevent the problems associated with the conventional palpation technique. Our finding will lead to better and safer anesthetic management of patients presenting for a major surgical procedure. Furthermore, the finding will help us in introducing the education and training of ultrasound-guided arterial catheter placement in our Residency Program. The investigators propose to follow anesthesia residents over a course of 3 years assessing their skill level for both palpation and ultrasound technique.