Abnormal Coagulation Test Results
A common problem is an unexplained increase in the PT and/or PTT. The first thing to do is get a fresh sample and repeat the test. Another consideration is heparin. It is possible that the blood sample was mistakenly drawn though a running line. Interference by heparin can be detected by absorbing the heparin with a resin (“Heparsorb”) or by using an enzyme to digest the heparin (“Hepzyme”). Also, the patient's history should be checked: Is the patient on any anticoagulants? Does the patient have liver disease? Provided that the abnormal result is reproduced on a good specimen and there is no obvious explanation from the history, the next thing to do is a mixing study. If the mixing study shows correction and no prolongation with incubation, factor assays will need to be done to look for factor deficiency, starting with VIII and IX since they are the most common deficiencies. It is useful to do a few vitamin K–dependent and a few nonvitamin K–dependent factors to be sure that the problem is not accidental or surreptitious warfarin ingestion.
Read more about this topic: Mixing Study
Famous quotes containing the words abnormal, test and/or results:
“In abnormal times like our own, when institutions are changing rapidly in several directions at once and the traditional framework of society has broken down, it becomes more and more difficult to measure any type of behavior against any other.”
—John Dos Passos (1896–1970)
“Experimental work provides the strongest evidence for scientific realism. This is not because we test hypotheses about entities. It is because entities that in principle cannot be ‘observed’ are manipulated to produce a new phenomena
[sic] and to investigate other aspects of nature.”
—Ian Hacking (b. 1936)
“A distinction of property results from that very protection which a free Government gives to unequal faculties of acquiring it.”
—James Madison (1751–1836)