By
Dr Pankaj Handa, Senior Consultant, Department of General Medicine, Tan Tock Seng Hospital
Deep Vein Thrombosis (DVT) is a
common cause of morbidity and
mortality. Timely diagnosis and
prompt treatment can be lifesaving,
as death may result from Pulmonary
Embolism (PE).
Patients presenting at a primary care
setting with unilateral swelling, pain
and erythema of a lower limb should
be viewed with high suspicion of DVT.
However, the diagnosis of DVT can be
very challenging as many skin and
musculoskeletal disorders can mimic
such presentation. The diagnosis of
DVT rests on 3 pillars of (i) clinical
suspicion, (ii) a blood test called
d-dimer and (iii) compression
ultrasound (CUS). While a clinical
diagnosis can be difficult, an astute
physician can judge the patient to be
at low, moderate or high risk of DVT,
based on Well’s score of pre-test
probability. D-dimer is often
considered unreliable as a raised level
can be seen in many other conditions
and a normal value does not rule out
DVT reliably. CUS has become the
diagnostic modality of choice for the
diagnosis of DVT.
Anticoagulation remains the
cornerstone of DVT management. The
anticoagulant agents available for use
include (i) Heparin — unfractionated
heparin (UFH) and low molecular
weight heparin (LMWH), (ii) Vitamin K
antagonists (VKA) — the all too familiar
warfarin and (iii) Non-vitamin K
antagonists (NOACs) which include
direct thrombin inhibitors like
dabigatran and factor Xa inhibitors like
rivaroxaban and apixaban. Over the
years there has been a shift in
management of DVT in selected
patients from inpatient to outpatient
departments (OPD). The patients
suitable for OPD treatment should be haemodynamically stable, have low
bleeding risk and have normal renal
function.
Traditional approach of treating DVT
with warfarin, overlapped with a short
course of LMWH till INR stabilises in
target range of 2-3 is marred with
difficulties in keeping INR in stable
range over a longer period often due
to various food and drug interactions.
NOACs have revolutionised the
management of DVT and there is now
the possibility for the complete
management of selected patients with
DVT to be undertaken by primary care.
NOACs (rivaroxaban and apixaban) can
be given in a fixed dose, without initial
treatment with heparin. Rivaroxaban
is given as 15 mg x twice a day for 3
weeks and 20 mg x once a day for the
next 9 weeks. These drugs additionally
enjoy minimal drug and food
interactions and require no
monitoring. However, NOACs are
expensive, not safe in patients with
compromised renal function and
cannot be easily reversed in case of
bleeding or at the time of urgent
surgery.
Other therapies of DVT including
thrombolysis (usually catheter
directed) and throbectomy (surgical or
percutaneous mechanical) are rarely
employed in cases of massive
illeofemoral thrombosis (Phlegmasia
Cerulea Dolens) with risk of venous
gangrene.
