The Green Whistle: A Novel Method of Analgesia for Transrectal Prostate Biopsy

1. No. 008 The Green Whistle: A Novel Method of Analgesia for Transrectal Prostate Biopsy Jeremy Grummet1,2,3, Sean Huang2,3, Alex Konstantatos2,3, Mark Frydenberg1,2,4 1Bairnsdale Regional Health Service, Bairnsdale, Australia; 2Monash University, Melbourne, Australia; 3Alfred Health, Melbourne, Australia; 4Southern Health, Melbourne, Australia Introduction The TRUS biopsy of the prostate is a well-known source of pain. Optimal analgesia must be effective, low cost, easy to use and have minimal side effects. Currently, periprostatic infiltration of local anaesthetic is recognised as gold standard1. However, its actual uptake by clinicians is poor. A USANZ prostate biopsy audit in 2005 indicated only 33% of Urologists used this approach. Figures internationally have ranged from 11% to 36%2,3. The commonly used approach is intravenous sedation, but this is labour intensive, costly and comes with anaesthetic risks. A recent literature review by Autorino et al.1 suggested that the “optimal technique remains to be established. Further studies addressing this issue are warranted.” Penthrox™ is inhaled methoxyflurane, a halogenated ether previously used as an anaesthetic agent with significant analgesic properties at low doses. It is approved by the Therapeutic Goods Administration for use in painful minor procedures and has had over 3 million uses in Australia4. Results 42 consecutive men from April 2010 to April 2011 involved Mean age was 65.3 years (range 51 – 81) Median pain score was 3 (IQR 2-5) Only adverse side effects: brief light-headedness and sickly sweet taste All patients happy to undergo repeat biopsy with same method of analgesia No correlation seen between pain scores vs. age or pain scores vs. number of biopsy cores Penthrox™ inhaler with packaging and methoxyflurane. Fluid poured through distal end (right side) into absorptive pad and patient breathes in and out of ‘whistle’ (left side). Aim This pilot study was conducted to determine the feasibility of using a novel inhaled analgesic agent (Penthrox™) in reducing the pain associated with TRUS biopsy of the prostate. • Methods • Each Penthrox unit prepared as per manufacturer’s instructions • Patients instructed in use and started inhaling Penthrox prior to insertion of rectal probe • Placed in left lateral position • 2% lignocaine jelly applied onto and inside anal canal to act as lubricant • 10 – 16 cores taken in each session by Urologists (JG and MF) • Patients coached during procedure and encouraged to breathe deeply • Verbal Rating Scale employed immediately after • Patients also asked if they would be happy to undergo same procedure in future if indicated • Data recorded prospectively • Patients observed for 30 minutes in recovery area Conclusions This pilot study suggests that Penthrox may have a role as analgesia for TRUS biopsy. It may provide safe, adequate analgesia that is easy for urologists to use and avoids excessive resources. Our results indicated a median pain score of 3 with an interquartile range of 2 to 5. Further research into this novel inhaled analgesic agent is warranted. References AutorinoR, et al. How to decrease pain during transrectal ultrasound guided prostate biopsy: a look at the literature. J Urol 174: 2091-7, 2005. Davis M, Sofer M, Kim SS, Soloway MS. The procedure of transrectal ultrasound guided biopsy of the prostate: a survey of patient preparation and biopsy technique. J Urol 167: 566, 2002 Fink KG, Schmid HP, Paras L, Schmeller NT. Prostate biopsy in central Europe: results of a survey of indication, patient preparation and biopsy technique. Urol Int. 79(1): 60-6, 2007 Babl F, Barnett P, Palmer G, et al. A pilot study of inhaled methoxyflurane for procedural analgesia in children. PaediatrAnaesth 2007;17:148–53 Acknowledgements The authors would like to thank Trish Werndly, Tim Walden and Glennys Wallace for their generous support of this study. There are no affiliations between the authors of this study and Medical Developments International Ltd., manufacturers of Penthrox™. Poster presentation sponsor