Urinary bladder scanning after day-case arthroscopy under spinal anaesthesia: comparison between lidocaine, ropivacaine, and levobupivacaine

Background. Micturition problems after spinal anaesthesia may delay hospital discharge. The use of lidocaine has raised concerns because of the occurrence of transient neurological symptoms (TNS). This randomized double-blind study was designed to compare the newer local anaesthetics with lidocaine regarding block characteristics, micturition problems, and discharge times in day-case spinals for arthroscopy. Methods. Ninety patients received either isobaric lidocaine 60 mg, ropivacaine 15 mg, or levobupivacaine 10 mg intrathecally. Urinary bladder volumes were measured by ultrasound imaging at regular time intervals until a post-voiding residual volume (PVRV) less than 100 ml was obtained. Micturition problems were classified in five groups ranging from no problems to those requiring catheterization. Results. Times to regain a Bromage-1 and -0 motor block were similar in the three groups but sensory block regression to L2 occurred at 145 (30) min in the lidocaine group, 25-30 min (P<0.05) faster than the other groups. Lidocaine allowed voiding after 245 (65) min and hospital discharge 265 (70) min after spinal injection, 40 min faster than in the two other groups. The incidence or degree of micturition problems were not different between after discharge, three patients (10%) receiving lidocaine complained of symptoms compatible with TNS. Conclusions. Our study suggested that the three local anaesthetics behave similar regarding quality of anaesthesia and motor block but voiding and discharge occurred significantly earlier with lidocaine although the 40 min difference was not impressive considering a spinal discharge time interval of 4-5 h.