Deep Venous ThrombosisDeepvenousthrombosisoftenshortenedDVToccurswhenblood clotsinadeepveinoftheleg.Itaffectsnearly2millionpeoplein USAeveryyearandmanydiefromresultingpulmonaryembolism when the clot breaks off from the leg and moves to the lung.Normallybloodflowsfreelythroughveins.Whentheflowis interruptedeitherbyinjuryorbycompressionofthevein,the blood beyond the point of compression can clot.People at Risk of DVT:•Soon after major surgery involving the hip, knee or leg•After fractures of large bones in the leg•Patients confined to bed after any major surgery•Anyone who is bedridden for prolonged periods•Women on contraceptive Pills•Pregnancy and childbirth•Varicose veins•Airline passengers confined to their seats on long haul flights GenerallytheolderyouarethegreaterthechancesofdevelopingDVT.Itissaidthatthechancesdoublewitheachdecade of life after 40. Symptoms:•Swollen leg compared to opposite leg•Leg may be warm and red•Pain in the calf muscle particularly when pressure is applied•Chest pain or difficulty to breathe if the clot moves to the lungTests for DVT:Clinical examination may suggest a possible DVT. This should be confirmed by one or two tests. •Ultrasound: US will usually confirm a blocked vein from a clot.•D-dimer blood test: If the level of D-Dimer is raised, it is probable that you have DVT.•Venography is sometimes done if the ultra sound is not very clear.•Sometimes MRI or CT scan may be requested.•If pulmonary embolism is suspected a Ventilation/Perfusion scan is done.Preventing DVT:Steps should always be taken to prevent a DVT rather than worry about it when it happens. Inahospitalsettingmostofthepatientswhoaresubjectedtomajorlowerlimbsurgerywillbeprescribedbloodthinning medication and maintained on it until they start walking normally. Inmanycountriesallpatientsadmittedtohospitalarealsogivenantiembolismstockingstowear.Theseareelasticstockings that provide uniform compression for the leg preventing pooling of blood in the veins when they are in bed. Ingoodoperatingtheatresapumpwillbeusedon anaesthetisedpatients,tosqueezethecalfmuscles intermittentlytokeepthebloodcirculatinginthelegwhenthe patient remains still.Olderagegrouppeopleshouldbeencouragedtoexercise regularlyandadvisedtoavoidsittingorlyinginbedfor prolonged periods. Longdistancetravelers,beitonaplane,trainorbusmustbe encouragedtoexercisethelegmuscleseveryhour.They shouldbeadvisedifpossibletogetoutoftheirseatandwalk intheaislefromtimetotime.Iftheyareunabletodothat,the leasttheycandoismovethefootupanddownatregular intervals during the flight. AllthesemeasuresareparticularlyimportantforindividualswhohavehadaDVTinthepastorhaveahigherriskof developing DVT.Treating DVTThe main goal of treating a DVT is to stop a clot from increasing in size and stop it getting to the lung.MedicationusedinDVTarecollectivelycalledanticoagulants.Theyactbyturningoffordelayingtheclottingmechanismin the body. Heparin and Warfarin are the two main drugs used in DVT. Heparin is given by the needle and warfarin as a pill. OnceDVTissuspectedanddiagnosed,treatmentisstartedpromptlywithheparin.ActionofHeparinisimmediate.Warfarin whichisalsostartedwithheparintakesalongertimetoact(3to5days).Oncewarfarinbecomeseffectiveheparincanbe discontinued.Thetimetodiscontinueheparinisdeterminedbybloodtests.Whilethepatientisonwarfarinregularblood testswillbenecessarytomakesurethatthecorrectamountofwarfarinisbeinggiven.Toomuchwarfarincancauseinternal bleeding.ThelengthoftimethatapatientwillneedwarfarinwilldependonthecauseofDVT.Itcanbeanythingbetween 6 weeks to a year.Anyonewhosuddenlydevelopslegpainandswellingorbreathingproblemswithinaweekafterbeinginahospitalorbeen on a long haul flight should seek medical advice immediately.K. BadrinathThis topic was discussed in greater detail on 4th May in the “Forum” - under “General Topics