Part of the case evaluation process is a review of appropriate literature. A literature review is not enough – you still need as expert to testify that the protocols set forth in any given piece of literature represent the standard of care. But the existence of literature on point can help you persuade experts to testify and, indeed, can even help you identity experts (by contacting the authors).
The American College of Emergency Physicians (ACEC) has issued a list of documents which "describe the College’s policies on the clinical management of presenting symptoms, specific illnesses or injuries." The ACEC’s Clinical Policies Committee drafts each protocol and and each protocol is approved by the ACEP Board.
Here is the list: