A Pilot Study on the Use of Methoxyflurane (Penthrox®) for Pain Control in the Emergency Department

NCT04618497 | Completed Phase 3

• 1 other identifier: HKECREC-2020-064
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

Patients commonly visit the emergency department (ED) for pain after musculoskeletal injury and need early treatment with analgesic. Prompt and adequate pain relief can reduce suffering and promote early discharge and return to work. Nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids are the major injectable analgesic used for moderate to severe pain in EDs in Hong Kong. They are given via intravenous or intramuscular route for faster onset of action to achieve rapid pain relief in the emergency setting. However, injections are invasive and can be distressing for patients. Methoxyflurane (Penthrox®) is recently introduced to our emergency department as an inhalational analgesic. It has been granted registration approval in Hong Kong since 2018, but it is not widely used in the locality. Methoxyflurane is a volatile fluorinated hydrocarbon self-administrated by inhalation through a portable hand-held whistle-shaped inhaler device (Penthrox®) to relieve pain associated with trauma or minor surgical procedures in stable and conscious patients. In this study, the investigators will evaluate the efficacy and safety Penthrox® in the treatment of acute traumatic pain in hospital emergency department setting by comparing it to another conventional analgesic commonly used.

Conditions

Acute Traumatic Pain

Outcome Measures

Primary Outcomes (1)

• The change in pain intensity over 60 mins in terms of 100-mm VAS

  Patients are instructed to complete a questionnaire with visual analogue scale (VAS), a 100-mm horizontal straight line whereas"0" at the left end indicates "no pain at all" and "10" at the right end indicates "the worst possible pain I can imagine".

  Measure at baseline and at 5, 15, 30 and 60 minutes after drug administration

Secondary Outcomes (7)

• Blood pressure

  Measure at baseline and at 5, 15, 30 and 60 minutes after drug administration

• Pulse Rate

  Measure at baseline and at 5, 15, 30 and 60 minutes after drug administration

• Oxygen saturation

  Measure at baseline and at 5, 15, 30 and 60 minutes after drug administration

• Level of sedation

  Measure at baseline and at 5, 15, 30 and 60 minutes after drug administration

• Drug-related adverse events

  After drug administration until the end of the observation period (1 hour)

Study Arms (2)

Inhalational methoxyflurane (Penthrox)

EXPERIMENTAL

Drug: Methoxyflurane

Intramuscular ketorolac

ACTIVE COMPARATOR

Drug: Ketorolac

Interventions

Methoxyflurane DRUG

Each patient in the methoxyflurane group will use one Penthrox inhaler under supervision of trained personnel. After priming the inhaler with 3 mL of methoxyflurane, patient is instructed to inhale through the mouthpiece to obtain analgesia, and then exhale back into the mouthpiece so that any unmetabolized methoxyflurane can be adsorbed by activated charcoal chamber. First few breaths should be gentle and then breathe normally through Inhaler. Onset of pain relief is rapid and occurs after 6-10 inhalations. If stronger analgesia is required, patient can cover the diluter hole with a finger during inhalation. Patients are able to titrate the amount of methoxyflurane inhaled and should be instructed to inhale intermittently to achieve adequate pain control.

Also known as: Penthrox

Inhalational methoxyflurane (Penthrox)

Ketorolac DRUG

Each patient in the ketorolac group will receive one dose of 30mg intramuscular ketorolac injected at gluteal muscle by nursing staff as usual daily practice.

Also known as: Toradol

Intramuscular ketorolac

Eligibility Criteria

• Age: 18 Years - 64 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Patients of both sexes from 18 to 64 years of age
• Presented to the ED in Ruttonjee Hospital for musculoskeletal injury within 72 hours of onset (Types of injury include contusion, sprain, crushing, burn, laceration, fracture and dislocation)
• Moderate pain at screening (10-point Numeric Rating Scale ≥4 to ≤7)

You may not qualify if:

• Critical or life-threatening condition requiring resuscitation
• Limb-threatening condition or any injuries requiring immediate management
• Hemodynamically unstable (systolic blood pressure \<90 mmHg, diastolic blood pressure \<60mmHg)
• Respiratory distress with respiratory rate \>20 breath per minute or oxygen saturation \<95% on room air
• Pregnant or breastfeeding women
• Impaired consciousness from any cause such as head injury and acute intoxication, based on the judgement of investigator
• Any physical, visual or cognitive conditions that may affect patient's ability to use visual analog scale for self-assessments of pain intensity
• Concomitant use of other analgesic within 5 hours (8 hours for diclofenac sodium) prior to presentation to ED
• Other pre-existing chronic pain condition
• Unable or refuse to provide written informed consent
• Unable to understand and converse in the language spoken
• Contraindication to inhalational methoxyflurane
• Known personal or family history of hypersensitivity to methoxyflurane or any fluorinated anesthetics
• Known pre-existing clinically significant renal or hepatic impairment
• Known personal or family history of malignant hyperthermia

Sponsors & Collaborators

• Hospital Authority, Hong Kong: lead

Study Sites (1)

Hospital Authority

Hong Kong, Hong Kong

Location

MeSH Terms

Interventions

Methoxyflurane; Ketorolac; Ketorolac Tromethamine

Intervention Hierarchy (Ancestors)

Ethyl Ethers; Ethers; Organic Chemicals; Methyl Ethers; Indomethacin; Indoles; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds

Study Officials

• Ka Ying Wong, MB ChB

  Hospital Authority, Hong Kong

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Medical Officer

Model Details: Patients will be enrolled on a convenience basis. After being seen and screened by investigators, patients who meet all inclusion and non-exclusion criteria will be enrolled and randomized 1:1 by drawing from equal preset numbers of envelopes. Patients will receive either inhalational methoxyflurane or intramuscular ketorolac. Patients and investigators are not blinded to the treatment due to the nature of drug administration.

Study Record Dates

• First Submitted: October 23, 2020
• First Posted: November 6, 2020
• Study Start: October 28, 2020
• Primary Completion: November 21, 2020
• Study Completion: November 21, 2020
• Last Updated: December 8, 2020

Record last verified: 2020-12

Locations

HK (1)