Patients with excessive clotting tendency despite receiving low molecular weight heparin will be subjected for evaluation of platelet activation. If the bleeding time is reduced by >50% of the baseline of the particular GBS patient, investigators will introduce anti-platelet medication. A loading oral dose of aspirin (500 mg) and clopidogrel (600 mg) will be given at least two hours before the next session of SVPE. Thereafter daily maintenance dose of oral aspirin (150 mg) and clopidogrel (75 mg) along with subcutaneous low molecular weight heparin (1.5 mg/kg) will be continued for eight days or until SVPE completed.