What preoperative laboratory studies should be obtained before surgery?
For an ambulatory surgery unit that is affiliated with or attached to a hospital, clinical laboratory testing guidelines should be identical to those required by the related institution. It has been well established that shotgun, nonselective screening batteries of both laboratory, radiographic, and other studies yield an extraordinarily low rate of abnormal findings, few of which may have a significant impact on patient management. Patients scheduled for surgery should have preoperative testing ordered with selectivity and based only on a screening including a careful history and physical examination. In fact, indiscriminate ordering of tests can have potentially serious and deleterious conse-quences. To explain abnormal results, additional series of tests may be obtained. Some invasive studies have inherent dangers. Often, abnormalities are simply ignored, creating a potential medicolegal liability. Indiscriminate screening often reveals abnormalities that fail to have any relevance to either the surgery or the choice of anesthetic agent or technique. Some centers use handheld computers to obtain the patient history. Branching lines of questioning depend-ent on previous answers allow extensive information to be gathered. At the conclusion of the interactive interview, the computer can provide a detailed printout of significant findings in the history and recommend the preoperative testing to be obtained. Many facilities do not require any preoperative testing for superficial surgical procedures on otherwise healthy men and women below the age of 40–50 years.