Deep vein thrombosis: a study in clinical diagnosis.
Recently, three patients presented with deep vein thrombosis-like symptoms and signs but were negative on venogram. Three questions arose: Was the clinical diagnosis accurate? What is the accuracy of the diagnostic test used? What is the time taken for the clot to lyse? To answer the first question, a retrospective clinical study was done. For the other two I did a literature search. For the clinical study, I analysed thirty patients with venogram proven deep vein thrombosis (DVT) and five patients with DVT-like clinical findings but four were venogram negative and one was ultrasound negative. The results showed that symptoms and almost all the clinical signs were useless in differentiating these two sets of patients. Swelling was very sensitive but not specific and the Homan's sign was very specific for DVT but not very sensitive and would be of use only in a case by case basis. Other significant findings were that DVT was more common in the Chinese than the other races and more common in females. The incidence of DVT is also particularly marked in the 30-39 and 70-79 age groups. It was also found that venograms were very accurate in diagnosing DVT but need to be read by two experienced radiologist. Also it was found that clot lysis can take place as early as 35 hours after starting heparin but vessel changes remain for at least 11 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)
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Department of General Medicine, Tan Tock Seng Hospital, Singapore.
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D005342:Fibrinolysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010690:Phlebography; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012737:Sex Factors; D012846:Singapore; D013924:Thrombophlebitis / Q000000981:diagnostic imaging*; D013997:Time Factors; D018608:Ultrasonography, Doppler