How Much Routine Preoperative Laboratory Testing Is Enough?

Routine preoperative laboratory testing has become dogma to many. Often, surgeons, anesthesiologists, hospital administrators, and even patients expect that there will be some "labs" on the chart prior to any operative procedure. Many have questioned the usefulness and cost-effectiveness of such a policy. There is little evidence to support the need for routine preoperative testing and much evidence against it. Preoperative testing should be based on appropriate indications. This makes the assessment of the preoperative laboratory evaluation difficult for a medical quality assurance program. The question that arises is, how much routine preoperative laboratory testing is enough? The answer to this question depends on (a) the purpose of this testing and (b) the limitations and potential misinterpretations of laboratory testing. This article will discuss the reasons for the potential misinterpretation of laboratory tests and then the data supporting selective preoperative laboratory testing.