Inhaled methoxyflurane and intranasal fentanyl for prehospital management of visceral pain in an Australian ambulance service
- 1School of Nursing, Midwifery and Postgraduate Medicine, Edith Cowan University, Joondalup, Perth, Australia
- 2St John Ambulance, Western Australia Ambulance Service, Belmont, Australia
- 3Rural Clinical School, University of Western Australia, Perth, Australia
- 4School of Exercise, Biomedical and Health Science, Edith Cowan University, Joondalup, Perth, Australia
- Correspondence to Mr Steven Johnston, School of Nursing, Midwifery and Postgraduate Medicine, Edith Cowan University, 270 Joondalup Drive, Joondalup, Perth, Western Australia 6027, Australia;
- Accepted 5 January 2010
- Published Online First 13 May 2010
Objective This study analysed the analgesic effect and changes in vital signs associated with administration of inhaled Methoxyflurane (MTX) and/or intranasal Fentanyl (INF) for prehospital management of visceral pain.
Method A retrospective, observational study reviewing 1024 randomly selected records of patients with presumed visceral pain administered MTX (465), INF (397) or both (162) by the Western Australian Ambulance Service between January 2004 and February 2006. Clinical variables assessed included systolic blood pressure, pulse rate, respiration rate and Glasgow Coma Scale score. Pain was assessed utilising Visual/Verbal Analogue Scale pain scores.
Results Overall effects on vital signs appeared favourable 5 min after use and at hospital arrival with either agent alone or in combination. As sole agents, MTX produced the greatest initial pain scores reduction (2.0 (1.7 to 2.2) vs 1.6 (1.4 to 1.8)) (mean (95% CI), and INF provided greater pain reduction by hospital arrival (3.2 (2.9 to 3.5) vs 2.5 (2.1 to 2.9)). While both agents were effective, INF provided a greater pain score reduction for cardiac (3.0 (2.6 to 3.4) vs 2.3 (1.8 to 2.8)), female (3.4 (2.9 to 4.0) v 2.5 (2.0 to 3.0)) and age 75+ patients (3.2 (2.5 to 3.8) vs 1.8 (1.0 to 2.5)). Combined use of agents was not advantageous.
Conclusions MTX and INF are effective agents for providing visceral pain analgesia in the prehospital setting. While MTX provided a more rapid onset of pain relief, INF provided superior analgesia after subsequent doses and in female, cardiac and older patients.
Competing interests None.
Ethics approval Ethics approval was provided by the Human Research Ethics Committee of Edith Cowan University.
Provenance and peer review Not commissioned; externally peer reviewed.