Common complications of NS are infections, acute
renal failure, electrolyte imbalance, bone mineral
loss, stunted growth, hypertension and thromboembolism
[1]. The incidence of thromboembolism in children
is 1.8–5% which can be asymptomatic [1,2].
The common thromboembolic features are renal vein thrombosis, deep vein thrombosis more in association
with use of central venous access, pulmonary embolism,
mesenteric vein thrombosis, cerebral venous
thrombosis and even arterial thrombosis. The direct
mechanisms proposed are increased platelet aggregation,
hypercoagulation, increased urinary losses of natural
anticoagulants, decreased fibrinolytic activity and
endothelial cell injury [3]. The indirect mechanisms are
hyperviscosity, hyperlipidemia and erythrocyte hyper
aggregation [4]. In our child, there was cerebral sinovenous
thrombosis, which has only 1–2% incidence in
patients with steroid sensitive NS in remission.
The common conditions associated with aseptic
cerebral sinovenous thrombosis in children including
NS is listed in Table 1 [5]. There was no significant
severe dehydration in our child and there was no usage
of diuretics in the recent past. In general, the statistical
significant association between NS and venous
thrombosis are, age of the child > 12 yr, severe proteinuria
> 10 g/day, hypoalbuminemia < 2 g/dL, previous
episodes of thrombosis, central line access, congenital
NS and secondary glomerulonephritis like systemic
lupus erythematosus or membranous histology [4].
There is even an extreme view that anti-coagulation
therapy should be given during the first 6 mo of diagnosis
of NS as the incidence of thromboembolism
is highest during this period or as long as the patient
is nephrotic. This has been proved by Markov based
decision analysis studied in adult patients with NS [6–
9]. Prophylactic use of warfarin is recommended in
children with serum albumin < 2 g/dL, fibrinogen levFig.
5. Magnetic resonance imaging showing absence of parenchymal
abnormality.
el > 6 g/L or anti-thrombin III level < 70% of normal.
Higher dose of heparin is required to maintain
therapeutic response due to decreased anti-thrombin
III levels. Low dose aspirin and dipyridamole are not
proven to be effective in prevention of thrombosis in
controlled trials [10]. Prevention includes early mobilization,
avoidance of hemoconcentration and treating
early sepsis and volume depletion [10]. In our child
who was having steroid sensitive NS and was under
remission following steroid therapy, cerebral sinovenous
thrombosis had occurred. The child had no proteinuria
of NS to account for the thrombosis directly.
Whether venous thrombosis would have started during
the time of relapse and progressed to symptomatic
cerebral sinovenous thrombosis at the time of remission
can also be considered. Common associated
dysfunctions like presence of procoagulant factors and
hematological factors are ruled out with the available
investigations. Idiopathic nature of thrombosis should
also be remembered [5]. One should always consider
that prolonged use of steroids in NS and occurrence of
significant hypovolemia during the phase of induction
of remission are co-factors for the occurrence of thrombosis.
Disappearance of proteinuria taken as a pointer
for remission occurs early even before normalization
of serum albumin in NS which of course can take few
more days beyond disappearance of proteinuria [11].
Whether this stage of hypovolemia or hypovolemia induced
by indiscriminate usage of diuretics combined
with salt and water restriction during the phase of severe
edema in nephrotic children in general can lead to
venous thrombosis should be accounted.