Use of the Methoxyflurane as Pain-killer in the Prehospital Management of Acute Myocardial Infarction
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Methoxyflurane, Morphine.
- Who it may be relevant to
- Registry conditions: STEMI - ST Elevation Myocardial Infarction. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- France
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
* Chest pain is the main symptom of acute myocardial infarction. A precocious analgesic treatment is justified by patient's comfort and unfavorable hemodynamic consequences of persistent pain. Morphine is the painkiller historically prescribed in this situation. Morphine has never been evaluated vs placebo and is strongly suspected to decrease oral anti-platelet efficacy. Then, morphine has been downgraded, in the 2017 European guidelines (European Society of Cardiology - ESC) from I to IIa. To find alternative treatment is required. * The methoxyflurane is an anesthetic gas used in emergency setting for about twenty years. It is now commonly used in France. Its analgesic properties have been demonstrated. Its main advantages are its maneuverability as it is delivered by inhalation, i.e. without (before) any venous access and self-administered by the patient. Tolerability is good. It could be an excellent alternative to morphine.
Interventions
- Drug Methoxyflurane
Patient's self-administration of methoxyflurane (Penthrox®) with dedicated inhaler Initial dose: 3 mL (1 vial). A second 3 mL dose can be used. Treatment: from inclusion to hospital arrival. - Drug Morphine
Morphine intra-venous infusion: 3 mg bolus repeated every 5 minutes until obtaining VAS ≤ 3. Treatment: from inclusion to hospital arrival
Primary outcome measures
- Demonstrate that methoxyflurane self-administered by the patient is at least as efficient in achieving pain relief that morphine [Time frame: at 30 minutes]
Secondary outcome measures (9)
- Compare the impact of the treatments on heart rate [Time frame: at 30 minutes]
- Compare the impact of the treatments on arterial blood pressure [Time frame: at 30 minutes]
- Compare the impact of the treatments on pulse oximetry [Time frame: at 30 minutes]
- Compare the impact of the treatments on ECG [Time frame: at 30 minutes]
- Compare tolerance of the treatments on respiratory depression [Time frame: at 30 minutes]
- Compare tolerance of the treatments on sedation [Time frame: at 30 minutes]
- Compare tolerance of the treatments on dizziness, pruritus, nausea, vomiting, headache [Time frame: at 30 minutes]
- Compare the impact of the treatments on pain relief [Time frame: From randomization until the first documented pain divided by two, assessed up to 30 minutes]
- Compare the impact of the treatments on pain relief [Time frame: From randomization until the first documented pain relief, assessed up to 30 minutes]
Eligibility criteria
Inclusion criteria
- Patient age ≥ 18 years
- Patient managed in pre-hospital setting for a ST elevation myocardial infarction (STEMI) : Chest pain < 12 hours with moderate to severe pain (VAS > 6/10) or STEMI on ECG according to 2017 ESC guidelines
Exclusion criteria
- Previous analgesic treatment for this episode of chest pain
- Hypersensitivity to morphine, methoxyflurane, any fluorinated anesthetic or any of the excipients listed in SmPC,
- Decompensated respiratory failure (in the absence of artificial ventilation),
- Severe hepatocellular insufficiency (with encephalopathy),
- Acute head trauma and intracranial hypertension in the absence of controlled ventilation,
- Uncontrolled epilepsy,
- Treatment with buprenorphine, nalbuphine and pentazocine, naltrexone, nalmefene or sodium oxybate,
- Breastfeeding, in case of initiation or continuation after birth of a long-term treatment.
- Known malignant hyperthermia or genetic predisposition of the patient.
- History of serious adverse effects of the patient or his family after administration of inhaled anesthetics.
- History of signs of liver damage after use of methoxyflurane or after anesthesia with a halogenated hydrocarbon.
- Clinically significant renal impairment.
- Known renal failure with creatinine clearance below 30 ml/min or undergoing extracorporeal renal replacement therapy.
- Altered level of consciousness due to any cause, including head trauma, drug or alcohol use.
- Clinical evidence of cardiovascular instability (PAS <90 mm Hg).
- Clinical evidence of respiratory depression.
- Incapacity to self-assess pain intensity
- Incapacity to methoxyflurane self-administration
- Known pregnancy, breastfeeding, minors or incapacity (curatorship or guardianship)
- Participation in another interventional study involving human participants or being in the exclusion period at the end of a previous study involving human participants
- Absence of a Social Security
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Open label
- Primary purpose
- Treatment
Study locations
France · 1 center
- Hôpital Avicenne — Bobigny
Identifiers
NCT: NCT07445737 · APHP180610 · 2025-523349-86-00