Penthrox alone versus Penthrox plus periprostatic infiltration of local analgesia for analgesia in transrectal ultrasound-guided prostate biopsy

Background: The objective of this study was to compare pain intensity in patients undergoing transrectal ultrasound (TRUS)-guided biopsy of the prostate with Penthrox alone compared with Penthrox plus periprostatic infiltration of local analgesia (PILA).

Method: Seventy-two subjects participated in this study after receiving appropriate education. Forty-two patients self-administered inhaled Penthrox (3 mL methoxyflurane) alone for analgesia (Group A), followed by 30 patients who self-administered Penthrox and received PILA with 5 mL of 2% lignocaine. All subjects had TRUS biopsy performed. Immediately after the procedure, patients were asked to rate their pain intensity using a numerical verbal rating scale from 0 to 10.

Results: Baseline characteristics of the two groups were similar. Patients in Group B reported significantly lower post TRUS biopsy median pain intensity of 2 (1-3) compared with Group A subjects who reported a median post TRUS biopsy pain intensity of 3 (2-5) (P = 0.014). A total of 72 men underwent TRUS-guided biopsy. All patients indicated they would be happy to have another TRUS-guided prostate biopsy in the future.

Conclusion: Our study shows that Penthrox plus PILA shows promise as an efficacious and easily tolerated analgesic technique for outpatient TRUS biopsy, keeping resource use to a minimum. Planning for a multi-centre, double-blind randomized control trial comparing Penthrox plus PILA with PILA alone is presently underway.