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New Quick Question: Preoperative Screens

George has joined a Laboratory Medicine Best Practices panel whose purpose is to review patterns of preoperative coagulation screening panel usage, in particular, preoperative prothrombin times (PT) and partial thromboplastin times (PTT). We are working on the premise that screening PTs and PTTs fail to consistently predict intraoperative hemorrhage in patients who possess no known coagulopathy, and that the volume of laboratory screening could be reduced and replaced by patient history for a significant savings without sacrificing patient safety. To support the panel’s efforts, I’ve posted a new Quick Question about preoperative screens. Please look it over and give your answer.

It may be that the Quick Question doesn’t cover all situations; please provide a comment below if your institution uses a different approach. Further, the LMBP panel is soliciting unpublished data that may bear upon our goal. If you have any data on screening PT and PTT volumes and outcomes that you would like to share with the panel, please email it to me at [email protected] All such data will be treated as private and confidential. Thank you for supporting this effort.

Comments (3)
Screening Assays
Apr 10, 2013 6:31am

From Dave McGlasson: I tend to agree with D
From Dave McGlasson: I tend to agree with Dr. Favaloro’s observations. Dr. Craig Kitchens has addressed this topic in print and publicly. In Chest 1994;106:661-2 he discussed whether screening coagulation tests predict bleeding in patients undergoing fiberoptic bronchoscopy with biopsy, and that not screening everyone made good cost-effective sense. He also made a good point in J Thromb Haemost 2005 12;2607-11 with an article called “To bleed or not to bleed? Is that the question for the PTT?” He made the case that a prolonged PTT is not strongly predictive of hemorrhage nor does a normal PTT provide shelter against hemorrhagic risk. I also feel the same way about people who still use the bleeding time for pre-op screening for surgery. The prolonged bleeding time is not a good predictor of whether a patient will hemorrhage during surgery. The best option is a good history of subject and family for previous bleeding disorders.

Apr 7, 2013 1:14am

From Dr. Emmanuel Favaloro: I have several
From Dr. Emmanuel Favaloro: I have several comments. First, the situation with children and adults may be different. It is difficult to get any meaningful personal history from a young child, although one wonders if the factor VII and IX deficiencies identified above could have been elucidated from family histories. Second, it is quite common in practice to identify clinically insignificant ‘coagulopathies’ during pre-operative screening by APTT such as asymptomatic lupus anticoagulant (LA) and factor XII deficiency, and thereafter these cause much anxiety and costly follow up testing, as well as delayed surgery; all of which can be avoided by abandoning ‘routine pre-operative’ screening. In objective analysis, it is far more likely that one would identify clinically insignificant ‘coagulopathies’ far more often that clinically significant coagulopathies. In fact, the nature of the normal range is such that some 2% of test results will reflect a ‘false positive.’ Moreover, routine coagulation tests are fairly insensitive to ‘mild’ factor deficiencies, and normal coagulation test results give false reassurance to surgeons that a ‘coagulopathy’ is not present when in fact it may be. For example, PT, APTT, fibrinogen and PLT count will typically be normal in von Willebrand disease and many platelet dysfunctions. My vote is for patient and family histories every time, and to abandon ‘routine preoperative screening’ (at least in adults).

Some recommended reading:

1. Watson HG, Greaves M. Can we predict bleeding? Semin Thromb Hemost 2008;34: 97–103.
2. Hayward CPM, Moffat KA, Liu Y. Laboratory investigations for bleeding disorders. Semin Thromb Hemost 2012;38:742–52.

Apr 4, 2013 7:00am

From Brad Ertz, We recently found a mild fa
From Brad Ertz, We recently found a mild factor VII deficiency in a 8 year old preparing for a tonsillectomy. We have also found mild factor IX deficiencies in children preparing for surgery. These were discovered by our preoperative screening.

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