Low Dose Methoxyflurane for Pain Relief During Minor Out-patient Urologic Procedures

Inclusion Criteria: 1. Conscious adult patients \>= 2. Patient is scheduled for cystoscopy And: * BOTOX injections for Overactive Bladder /Neuogenic Detrusor Overactivity, * Diagnostic hydrodistention for painful bladder syndrome * Biopsy or cauterization of bladder tumors * Biopsy, cauterization and/or injection of Hunner's lesions * Visual urethrotomy/bladder neck incision=/- injection of stricture * Evaluation of the complex urinary tract problems 3. Patient (patient/or patient's authorization legal representative) should understand the nature of the study and provide written informed consent 4. Patient is able to follow all study requirements and procedures and complete required questionnaires Exclusion Criteria: 1. An altered level of consciousness, due to any cause, including head injury, drugs,or alcohol 2. Clinically significant renal impairment 3. Women of child bearing potential who are pregnant or peri partum, including labour 4. A history of liver dysfunction after previous MEOF use or other halogenated anesthetics 5. Hypersensitivity to MEOF or other halogenated anesthetics, or to butylated hydroxytoluene 6. Known or genetically susceptible to malignant hyperthermia or a history of severe adverse reactions in either patient or relatives 7. Exacerbation of an underlying condition (i.e., chronic pain) 8. Clinically evident or potential hemodynamic instability as per the opinion of the investigator 9. Clinically evident respiratory impairment as per the opinion of the investigator 10. Prior treatment with PENTHROX within 3 months