372 Is the Mixing of Local Anaesthetic Agents for Perineal Block in TP Prostate Biopsy Patients Advantageous? a Comparative Study of Local Anaesthetic Efficacy

Aim

Traditional mixing of short and long-acting local anaesthetics for perineal blocks for TP Biopsies might risk altering their pH and allow the use of suboptimal dose of the mixed agents.

Method

This is a prospective study in which we look at 102 patients who have had transperineal prostate biopsies. The patients were divided into 2 groups according to the type of peri-prostatic local anaesthetic i.e. mixed (10mls of 1% lignocaine and 10 mls of 0.5% levobupivacaine) and non-mixed (20mls 0.5% levobupivacaine). Patients were asked to fill a pain score and satisfaction questionnaire after the procedure.

Results

The two groups were matched in their demographics including age, PSA and prostate volume.

The pain threshold was similar in both groups during administration of the perineal block. The difference in pain threshold between the ‘mixed’ vs ‘non-mix’ group was statistically significant during the biopsy sampling i.e., 4(std 2) for the ‘mixed’ and 2(std1) for the ‘non-mix’ group.

84.8% of the ‘mixed’ group vs 97.7% of the ‘non-mix’ group said they would recommend the procedure. The response was the same when asked whether they would repeat the procedure if required (84.4% in ‘mixed’ vs 97.7% in ‘non-mix’). The cancer detection rate had no statistical difference between the 2 groups although core-length’s taken from target lesions were shorter in ‘mixed’ vs ‘non-mixed’ group (mean 7mm vs 9.5mm).

Conclusions

Our study confirms that using a pure agent gave better pain scores with the same cancer detection rates as compared to mixed agents.