Group IVA patients received a bolus dose of i.v. alfentanil 10 microg/kg , followed by a continuous infusion of alfentanil 0.25 microg/kg/min starting 2 min before the spinal block , and group FIC patients received a FIC block with 30 ml of ropivacaine 3.75 mg/ml ( 112.5 mg ) 20 min before the spinal block .
