Abstract

Pain management in outpatient gynecology procedures is crucial for patient comfort and procedure success. Penthrox ( methoxyflurane) ,an inhaled analgesic has been widely in conscious patients with trauma in Accident and Emergency services, but its application in Gynecology remains underexplored.

Methoxyflurane is a fluorinated anesthetic however the dose in Penthrox inhaler is in significantly lower doses than required for a general anesthetic, thus minimizing nephrotoxic risk by reducing fluoride accumulation.

Penthrox can be offered to women having ambulatory gynecology procedures where moderate to severe pain (pain score >4/10) is expected and where Entonox and paracervical block are currently used like:

1.      Outpatient hysteroscopy, polypectomy, fibroid resection using MyoSure tissue retrieval system.

2.      Outpatient Endometrial ablation (Thermablate/ NovaSure)

3.      Insertion/retrieval of Intrauterine device

4.      Manual vacuum aspiration (MVA)

5.      Cystoscopy urogynaecological procedures like removal of impacted pessaries.

Penthrox is contra-indicated in patients with severe renal impairment, hypersensitivity to methoxyflurane , genetically predisposed malignant hyperthermia, liver dysfunction after halogenated anaesthetics and those requiring repetitive high dose exposure. Penthrox is also contraindicated in patients with altered consciousness from head injury, substance use or alcohol and in those with cardiovascular instability or respiratory depression.

Common side effects of Penthrox include dizziness, headache, nausea , dry mouth ,somnolence, cough, euphoria, fatigue and mild hypotension. Use Penthrox with caution in elderly patients and patients with risk factors for renal and hepatic impairment.

Penthrox provides a promising, fast-acting solution for pain relief in outpatient procedures, which can be self- administered by the patient offering a sense of self-control.

Dr.Lovely Thomas has completed her MBBS from Government Medical College, Trivandrum, Kerala, India followed by post- graduation ( MS OBGY) in the subject of obstetrics and gynaecology at Government Medical College , Trivandrum, Kerala ,India. She has gained experience working in various regions of Kerala following her post-graduation. She has successfully cleared Member of Royal College of Obstetrician and Gynaecologists (MRCOG) and is currently employed in the UK.