SPINAL-ANESTHESIA WITH ROPIVACAINE - A DOUBLE-BLIND-STUDY ON THE EFFICACY AND SAFETY OF 0.5-PERCENT AND 0.75-PERCENT SOLUTIONS IN PATIENTS UNDERGOING MINOR LOWER-LIMB SURGERY

The purpose of this study was to determine the clinical efficacy and s afety of ropivacaine as a local anesthetic for spinal anesthesia. Fort y patients between the ages of 18 and 75 yr,scheduled for minor lower limb surgery, were studied. They were randomly allocated to receive ei ther 3 mL glucose-free 0.5% (15 mg) or 0.75% (22.5 mg) ropivacaine in a double-blind fashion. The subarachnoid puncture was performed with a 26-gauge Quincke-point needle at the L3-4 interspace with the patient s in the sitting position. The onset of analgesia to pinprick was simi lar with both concentrations. The median (range) upper level of analge sia obtained with the 0.5% solution was T11 (L4-T5) and was T10-11 (L4 -T4) with the 0.75% solution. The duration of analgesia at T12 (P < 0. 01) and the total duration of analgesia (P < 0.002) were longer in the 0.75% group. In addition, the area under the number of blocked segmen ts versus time curve was larger with the 0.75% ropivacaine solution (P < 0.001). The incidence of complete motor block of the lower limbs wa s higher (P < 0.02) and the total duration of motor block longer (P < 0.002) in the 0.75% group. No unexpected adverse events were registere d. We conclude that subarachnoid injection of glucose-free ropivacaine solutions results in a variable spread of analgesia, mostly accompani ed by a good quality of motor block, in particular with the 0.75% solu tion.