Methoxyflurane delivered by ‘green whistle’ (penthrox) provides rapid pain relief for children aged six years and older with acute trauma injuries, a major international trial from Children’s Health Ireland (CHI) has found. 

The study team found that children who received methoxyflurane experienced a faster and greater reduction in pain.

Only one in 10 of those treated with methoxyflurane needed rescue pain medication, compared to one in three in the untreated group.

The MAGPIE Trial, led by Prof Michael Barrett, co-investigator Dr Carol Blackburn and research nurses Madeleine Niermeyer, Ellen Barry and Rachel Gallagher, was supported by the hospital’s ED team and evaluated the use of methoxyflurane in more than 240 children aged six to under 18 years presenting with moderate or severe pain in emergency settings. 

Children who received methoxyflurane were found to have experienced a faster and greater reduction in pain compared to those given a placebo treatment.

Children, in pain, described the pain relief while inhaling the green whistle. Importantly, just one in 10 of those treated with methoxyflurane needed rescue or extra pain medication, compared to one in three in the placebo group. 

While some mild side effects such as dizziness, euphoria and altered taste were more common in the methoxyflurane group, these were expected, short lived and well tolerated.

The study was conducted through the CHI Clinical Research Centre, which is supported by the Health Research Board and Children’s Health Foundation. 

The trial, which has now concluded, supports wider paediatric adoption of methoxyflurane as part of standard pain relief protocols in EDs and pre-hospital settings, according to Prof Barrett, consultant in paediatruc medicine, CHI at Crumlin.

“The success of the MAGPIE trial is a testament to the dedication and professionalism of our entire team in CHI. Delivering a randomised controlled trial for children in pain in a busy 24/7 paediatric ED is no small feat, balancing emergency care with rigorous research protocols, all while supporting children and families in distress. I’m incredibly proud of our staff,” he said.