Prilocaine theoretically could provide faster onset because of its lower pKa (7,7) compared
to bupivacaine (8,1). The primary objective of this prospective double blind randomized trial
is to determine block onset of spinal hyperbaric prilocaine compared to bupivacaine, both
with a small dose of sufentanyl as an additive.The primary hypothesis is that a significant
larger amount of patients will gain surgical readiness within 8 minutes after spinal
injection of prilocaine with sufentanyl compared to bupivacaine with sufentanyl. Surgical
readiness is defined as a sensory block level of T5 tested by loss of cold sensation.