or the following questions, a time unit will be 15-minutes. Base unit value for each case is provided within the question. Refer to the resources in "Program resources" for the conversion factors, Qualifying circumstances and Physical Status Modifiers. A cesarean section was conducted in Alfred, NY, on a patient with preeclampsia (1 modifying unit). The base unit value for the service is 7. Calculate the anesthesia rates for procedures lasting 45 minutes.