Efficacy of Inhaled Methoxyflurane (Penthrox) as Adjunct for Urologic Procedures Under Local Anesthetic: A Pilot Study

Not Applicable

Completed

• Conditions: Scrotum Disease; Hydrocele Male; Spermatocele; Scrotal Hematocele; Anesthesia, Local
• Interventions: Drug: Methoxyflurane; Other: Control

• Registration Number: NCT07192198
• Lead Sponsor: University of Manitoba

Brief Summary

We wish to perform a prospective randomized controlled pilot study at the Men's Health Clinic and Health Science's Centre to assess whether or not the use of Penthrox as an adjunct to LA is associated with improved pain tolerance and anxiety levels than local anesthetic alone

Detailed Description

This non-blinded, randomized controlled trial is to be conducted at both the Men's Health Clinic and Health Sciences Centre in Winnipeg, Manitoba. All eligible patients between the ages of 18-65, undergoing andrology and male infertility under local anesthetic or select endourology procedures under loco-sedation, will be invited to participate in the study. Patients will be excluded if; history of substance use disorder, history renal impairment, history of liver dysfunction, previous hypersensitivity to Penthrox or related agents, personal or family history of malignant hypothermia. They will be randomly assigned in a 1:1 ratio using a computer-generated random list. For penoscrotal cases, patient will be randomized to Penthrox + local infiltration of 50/50 lidocaine and bupivacaine mixture vs local infiltration alone. For select endourology procedures, patients will be randomized to Penthrox + topical local anesthetic vs IV sedation + topical anesthetic. Participants may begin using the Penthrox 10 minutes prior to procedure start given its median time of onset of 5 minutes. In the post-operative recovery area, patient will be asked to complete a questionnaire related to pain and anxiety of procedure.

Baseline characteristics such as age, use of analgesics, prior history of procedure under loco-sedation, history of chronic pain, baseline pain level (Brief Pain Inventory), pre-procedural anxiety (State Trait Anxiety Inventory) will be collected.

Study Timeline

• Study First Submitted: 2024-02-16
• Study Start: 2024-04-17
• Primary Completion: 2024-11-27
• Study Completion: 2024-12-19
• Status Verified: 2025-09
• Study First Submitted QC: 2025-09-23
• Last Update Submitted: 2025-09-23
• Study First Posted: 2025-09-25
• Last Update Posted: 2025-09-25

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 40

Inclusion Criteria

• Adult patients undergoing hydrocelectomy, spermatocelectomy, epididymectomy, testicular biopsy, scrotal lesion or cyst excision under local anesthesia alone will be included.

Exclusion Criteria

• Patients will be excluded if their procedure was to be performed with sedatives (e.g., inhaled nitrous oxide gas, oral, or IV sedation) or did not provide consent to be randomized

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Intervention arm-Penthrox	Methoxyflurane	Participants can begin using penthrox 10 minutes prior to procedure start, given its median onset time of 5 minutes
Control arm	Control	Patients in the control arm will only receive local infiltration.

Primary Outcome Measures

Name	Time	Method
Pain with local anesthetic infiltration	Immediately post-infiltration, intraoperatively	Using a visual analogue pain scale \[range 0-10; 0 = no pain, 10 = maximal pain\], pain will be assessed as reported by the patient when the local anesthetic injection is administered
Procedural pain	Immediately post-operation	Using a visual analogue pain scale \[range 0-10; 0 = no pain, 10 = maximal pain\], pain will be assessed as reported by the patient post-operatively to determine their pain

Trial Locations

Locations (1)

Men's Health Clinic; 🇨🇦 Winnipeg, Manitoba, Canada