D-dimer For Prediction Of Lower Extremity Deep Venous Thrombosis In Elderly Patients

ObjectivePart1:Find the applicable D-Dimer cut-off value to exclude low extremity deep veinthrombosis（LEDVT）in elderly patients by retrospective study.Part2:To explore the value of plasma D-dimer in prognosing lower limbs deep veinthrombosis (DVT) of cancer elderly patients within perioperative period and show themanagement and effectiveness in preventing lower limbs DVT of cancer patients withinperioperative period in our hospital.MethodsPart1:394consecutive older than60years outpatients from Jan2005to May2012withD-Dimer testing at intervals of about1-2weeks,the patients whose D-dimer valueincrease to0.5mg/l,should be carried out ultrasonic testing and reexamined at intervalsof about3-5days,at the same time D-Dimer testing turns into being executed atintervals of3-5days.Part2:A retrospective analysis was done on for187cancer patients with operationwhich concludes172male and15female between Jan2008and May2012.The averageage of them is75±10years old.Plasma D-dimer was continuous tested in preoperative、postoperative（concluding the very day、the1st day、2nd day、3rd day、the5th day、the7th day、the10th day、the15th day、the20th day、1month),Lower limbs bloodvessel ultrasonography in preoperative and postoperative(week about or the onset ofsymptoms).Then recording all patients’ detailed clinical data which included the regionand pathological type of cancer、using anticoagulant drug or not、the time usinganticoagulant、the time and region existing DVT of DVT patients.ResultsPart1: For60-79ages group, when D-Dimer cut-off value is0.5mg/l,the sensitivity、 specificity、positive predictive value(PPV)、negative predictive value(NPV) of diagnosiswith lower extremity vein thrombosis are100%、41.8%、71.7%、100%respectively.while at the cut-off value of1.0mg/l there are75.3%、56.4%、71.8%、60.8%.But for more than80years old patients,there are100%、35.6%、40.4%、100%atthe cut-off value of1.5mg/l and98.7%、50.0%、46.1%、98.9%at the cut-off value of2.0mg/l which increases specificity and holds high sensitivity.Part2:3of187patients suffered from lower limbs DVT.Plasma D-dimer of71in allpatients (71/187,38%) was more than0.5mg/l in the preoperative(The mean value is0.83±1.09mg/l);In all patients,plasma D-dimer increased obviously on the veryday of operation(The mean value is2.55±3.33mg/l),and reached the peak at the5thdayin the postoperative(The mean value is3.97±3.52mg/l),but didn’t recover topreoperative state; The plasma D-dimer has significant difference betweenadenocarcinoma and non adenocarcinoma in preoperation(The mean value respectivelywere1.0±1.25mg/l、0.48±0.54mg/l)(p=0.03<0.05),but has no significant differencebetween them in postoperation (p=0.15>0.05);In different region carcinoma,the plasmaD-dimer in the postoperative has some difference between lung and digestives y s t e m(p=0.007<0.05), w h i l e h a s n o d i ff e r e n c e i n o t h e r s (p>0.05).ConclusionPart1: For60-79years old patients,the D-Dimer cut-off value of0.5is stillapplicable for clinic diagnosis guidance of ruling out LEDVT,while for more than80-year-old patients,the D-Dimer cut-off value should be increased to1.5mg/l.Part2: Traditional plasma D-dimer value in prognosing lower limbs deep veinthrombosis (DVT) of elderly cancer patients within perioperative period has very highsensitivity and very low specificity,but it is also a very important monitoringmethod;The using of anticoagulant in the postoperative has a certain effect in preventinglower limbs DVT of elderly caner patients,but should be used carefully and at the righttime.