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Preoperative Hemostasis Testing

There has recently been a reevaluation of the need for preoperative testing of hemostasis, driven by a desire to reduce the expense of unnecessary laboratory tests that are of no clinical value. There is no doubt that the most important part of a preoperative screen of hemostasis is a carefully documented clinical history. Emphasis should be placed on a history of excessive bleeding associated with dental extractions, tonsillectomies, other surgery, childbirth or injury. Other important information to elicit in the history includes any underlying medical problems, medications and family history of a bleeding tendency.

The hemostatic tests available to screen for a wide variety of coagulation and platelet abnormalities include the PT, APTT, platelet count and bleeding time. The extent of preoperative laboratory testing in each case depends entirely on the screening history (see Table). If the history is entirely negative, no screening tests at all are recommended. If the screening history raises the likelihood of defective hemostasis (liver disease, use of anticoagulant drugs or leukemia) a PT and APTT are indicated - a platelet count should be added for patients with leukemia. For patients with a personal or family history of a bleeding disorder a full screening panel is recommended (PT, APTT, platelet count and bleeding time).

Several recent studies have shown no benefit in obtaining routine preoperative screening coagulation tests in patients with a negative clinical history related to hemostasis. In one study of 750 preoperative patients, only 13 of 480 patients (2.7%) with a negative history had an abnormal PT or APTT, and in 12 of these 13 patients repeat testing was normal or surgery was uneventful without repeat testing. In another study, 3,242 surgery patients had routine preoperative PT, APTT, platelet count and bleeding time. Of those with an abnormality of the screening tests, specific treatment to correct a hemostatic defect was required in 26 of 172 patients (15%) with a positive clinical history, and in only 1 of 340 patients (0.3%) with a negative history.

The bleeding time has become obsolete. It has been replaced by Platelet Function testing with an instrument such as the PFA100.  Platelet function testing can be helpful if used in a focused patient population, namely those with a positive personal or family history of a bleeding disorder. In addition, a preoperative bleeding time may be warranted in patients with chronic renal failure, which is commonly associated with platelet dysfunction.

Recommended Preoperative Hemostasis Tests

Clinical History

Preoperative Tests



Liver disease, Anticoagulants



PT, APTT, Platelet count

History of bleeding disorder (personal or family)

PT, APTT, Platelet count, platelet function

Chronic renal failure

Platelet function test

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