A former president of the Maryland State Medical Society, Dr. Ronald Sroka has practiced family medicine for 32 years in a small, red-brick building just six miles from his childhood home, treating fishing buddies, neighbors and even his elementary school principal much the way doctors have practiced medicine for centuries. He likes to chat, but with costs going up and reimbursements down, that extra time has hurt his income. So Dr. Sroka, 62, thought about retiring. He tried to sell his once highly profitable practice. No luck. He tried giving it away. No luck. Dr. Sroka's fate is emblematic of a transformation in American medicine. He once provided for nearly all of his patients' medical needs' stitching up the injured, directing care for the hospitalized and keeping vigil for the dying. But doctors like him are increasingly being replaced by teams of rotating doctors and nurses who do not know their patients nearly as well.