Colloid Pre-Loading on D-Dimer During Cesarean Section Under Spinal Anesthesia

preloaded prior to spinal anesthesia with 500 mL hydroxyethyl starch (6%130/0.4) (Voluven).

Sub arachnoid 10-12 mg hyperbaric bupivacaine

Sub arachnoid 200 meg morphine

10 ml/kg of isotonic 0.9 sodium chloride (NaCl) solutions will be used as co loading during the duration of the operation

If severe hypotension (fall of \> 20% of mean arterial pressure from baseline) occurred, vasopressors, 6 mg ephedrine (per dose) will be used.

Bradycardia (fall of \>30% of heart rate from baseline or \<50 beats /minute and when associated with hypotension) will treated with 0.5 mg of atropine intravenous.