Comparisson of two epidural drugs in day-case surgery

In day-case surgery, spinal anaesthesia with both rapid onset and a short duration of block is preferred. For this purpose, lidocaine has been the drug of choice for decades but has been associated with an unacceptable number (20-30%) of transient neurologic symptoms (TNSs). In recent years, chloroprocaine (CP) and prilocaine (P) have gained interest as short-acting spinal anaesthetics seemingly without the issue of urinary retention or TNSs. So far, these drugs have not been compared as to whether one would be more preferable than the other in an ambulant setting.

The null hypothesis is that there is no significant intergroup difference in time to complete recovery from motor blockade.

Concerning the sensory block, ice cubes are used at 2, 4, 6, 8, 10, 15, 20, 25 and 30 min, and then at 15-min intervals until the sensory blockade had regressed tot dermatome S2. Motor blockade is evaluated at 5, 10, 15, 20, 25, 30, 45, 60, 75 and 90 min and then every 15 min until the ‘healthy’ leg can be fully elevated.

The urinary bladder will be examined by ultra-sound 30 min postoperative.

At day 1 and 7 postoperatively

Patients receive intrathecally 40 mg plain chloroprocaine or 40 mg hyperbaric prilocaine.