Question: A non-medically directed CRNA took the patient into the operating room. He placed the patient on monitors, intubated, and induced the patient. Then the anesthesiologist came into the room and placed an arterial line and CVP before the case started. How do we calculate the time the physician took to place the lines? North Carolina Subscriber Answer: Since the lines were placed by a different provider and AFTER induction of anesthesia, you do not need to deduct the time spent placing the arterial line and CVP from the total anesthesia time. However, you will bill the lines under the physician’s provider number. For example, you might submit 36620 (Arterial catheterization or cannulation for sampling, monitoring or transfusion [separate procedure]; percutaneous) for the arterial line and 36556 (Insertion of non-tunneled centrally inserted central venous catheter; age 5 years or older) for the CVP on the anesthesiologist’s claim. Bill the other services under the CRNA. Include modifier QZ (CRNA service: without medical direction by a physician) to indicate he or she was not medically directed during the case.