Background and objective: The α2-adrenoceptor agonist clonidine has potent central antinociceptive properties. The study was designed to investigate the effects of the combined subarachnoid administration of clonidine and prilocaine on spinal block and postoperative analgesia for the transurethral resection of tumours in the urinary bladder.

Methods: The controlled, prospective, double-blind study enrolled 40 patients scheduled for elective transurethral resection of bladder tumours under spinal anaesthesia with prilocaine. Patients were randomly assigned to receive an intrathecal injection of prilocaine 75 mg alone (control group) or in combination with clonidine 75 µg. We assessed haemodynamic changes (non-invasive arterial pressure, heart rate), pulse oximetry, the upper level of block, the onset and duration of sensory and motor block, postoperative analgesia and any adverse effects.

Results: There were no statistically significant differences in demographic data, heart rate, onset time or the levels of sensory or motor block. Analgesia lasted significantly longer in the clonidine group (498.4 ± 226.9 versus 187.2 ± 103.1 min; P < 0.05). The duration of motor block was longer in the clonidine group (165.5 ± 30.6 min) than in the control group (139.7 ± 40.4 min; P < 0.05) and the duration of sensory block was also longer in the clonidine group (157.3 ± 24.5 min) than in the control group (137.2 ± 31.2 min; P < 0.05). Fewer patients in the recovery room needed metamizol (dipyrone) in the clonidine group (5%) than in the control group (50%). Arterial pressure decreased significantly in the clonidine group 75-135 min after the block.

Conclusions: The addition of clonidine 75 µg to prilocaine 75 mg for subarachnoid anaesthesia increased the duration of sensory and motor block and reduced the need for additional postoperative analgesics by providing excellent analgesia for about 8 h during recovery from transurethral resection of bladder tumours.

Background and objective It is claimed that local anaesthetics have antimicrobial properties. Our aim was to investigate the antimicrobial effects of different concentrations of ropivacaine, bupivacaine, lidocaine and prilocaine on Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans.

Methods All local anaesthetic dilutions were exposed to microorganisms for 0, 30, 60, 120, 240 min at room temperature. The inoculums taken from diluted suspensions were reinoculated on blood agar and incubated for 18–24 h at 35°C and then the colonies were counted.

Results Ropivacaine did not inhibit any of the microorganisms tested. Bupivacaine reduced the viable cells of P. aeruginosa at 0.5% and 0.25% solutions. Lidocaine 5% and 2% and prilocaine 2.0% dilutions reduced the viable cells of all microorganisms tested. Prilocaine 1.0% reduced the viable cells of E. coli, S. aureus and P. aeruginosa. Lidocaine 1% reduced only the viable cells of P. aeruginosa and prilocaine 0.5% reduced only E. coli.

Conclusion Ropivacaine had no antimicrobial effect on microorganisms tested. Bupivacaine showed poor antimicrobial effectiveness. Lidocaine and prilocaine had more powerful antimicrobial effects than the other two local anaesthetics.

A 74-year-old woman was scheduled for surgical treatment of a carpal tunnel syndrome. An intravenous (i.v.) regional anaesthetic was performed using 1% prilocaine standard technique. Three minutes after injection of the local anaesthetic mild to moderate central nervous system symptoms developed, along with tachycardia, sweating and peri-oral paraesthesia. The evolution was favourable, no convulsions or other more serious events occurred. Despite showing adequate pressure inflation the tourniquet failed to accomplish its purpose. The patient recovered well without any sequelae.

The cause of hearing loss after spinal anaesthesia is unknown. Up until now, the only factor studied has been the effect of the diameter of the spinal needle on post-operative sensorineural hearing loss. The aim of this study was to describe this hearing loss and to investigate other factors influencing the degree of hearing loss. Two groups of 22 similar patients were studied: one group received 6 mL prilocaine 2%; and the other received 3 mL bupivacaine 0.5%. Patients given prilocaine were more likely to develop hearing loss (10 out of 22) than those given bupivacaine (4 out of 22) (P<0.05). The average hearing loss for speech frequencies was about 10 dB after prilocaine and 15 dB after bupivacaine. None of the patients complained of subjective hearing loss. Long-term follow-up of the patients was not possible.

The effect of the addition of clonidine 2 μg kg−1 to prilocaine 0.57% for intravenous regional anaesthesia (IVRA) in the arm was investigated in 56 healthy patients using a randomized, double-blind study. The characteristics of the sensory and motor block, quality of analgesia, development of post-operative pain sensations and haemodynamic variables were studied in three groups (IVRA with prilocaine, IVRA with prilocaine and clonidine, IVRA with prilocaine and systemic application of clonidine at tourniquet release). There were no significant differences between the groups concerning the onset and recovery characteristics of sensory and motor blockade, post-operative pain or side effects. In those patients receiving clonidine, mean arterial pressure decreased significantly (24–28%, respectively) after tourniquet release, while heart rate remained unchanged. Clonidine as an adjunct to prilocaine seems to be of limited benefit during and after intravenous regional anaesthesia.

The effectiveness of a Eutectic Mixture of Local Anaesthetics (EMLA cream) for pain control during renal extracorporeal shock wave lithotripsy (ESWL) was evaluated in a group of 20 patients who had not been able to tolerate a previous session without intravenous (i.v.) analgesia. EMLA cream (10 g) was applied on the skin over the area (64–100 cm2) where the shock waves were to be focussed. A second generation lithotriptor Siemens Lithostar was used. The following measurements were made: the shock wave (kV) maximum voltage, the number of successful stone fragmentations (SSF), the visual analogue scale score (0–10) for pain (VAS), and the tolerance scale score (1–4) for the tolerance for the procedure. Significantly higher voltage (17.9±0.6 kV vs. 16.2±0.8 kV), lower VAS scores (5.9±1.1 vs. 8.7±1.3), lower TS score (2.3±0.6 vs. 3.6±0.6) and a higher number of SSF (18 vs. 5) were found in those patients for whom EMLA cream was used. Intravenous analgesia was not needed in nine patients. Nine patients received fentanyl 0.05 mg, one 0.10 mg and another 0.15 mg. These favourable results were attributed both to the sequence of gradual voltage increments used and to the cutaneous analgesia produced by EMLA cream.