To be effective in screening for any condition, an understanding of the areas in which risk can arise is important. In the preoperative patient, risks stem from the patient's medical status, the nature of the surgical procedure, and anesthesia. Although the primary care physician is well suited to assessing medical conditions and suggesting management of these problems in the perioperative period to avoid unfavorable outcomes or medical complications, a working understanding of the risks conveyed by surgery and anesthesia has great value. One of the most compelling reasons for acquiring such knowledge is that it permits a more thorough medical evaluation of potential sources of risk and should enhance the overall preoperative preparation of patients from both the medical and the anesthetic management perspectives.

Effective screening in the preoperative patient requires that specific sources of risk be quantified and modified when possible. A secondary objective of this process is to highlight sources of risk, once identified, for members of the surgical and anesthetic team, who will be directly responsible for the patient's perioperative care. It is critically important that information from the preoperative evaluation be communicated to members of the perioperative team well in advance of the procedure so that informed decisions about anesthetic management and surgical approach can be made. Such discussions can also benefit those performing the medical evaluation through a process of feedback and education, further enhancing the quality of subsequent preoperative evaluations they perform. Unless communication takes place, the management implications of specific observations (e.g., decreased range of motion of the neck in a patient with rheumatoid arthritis or the chronic use of nonselective monoamine oxidase–inhibiting agents) may not be apparent to the physician performing the screening examination and may lead to considerable harm to the patient.