None listed
Conditions
Brief summary
Ingrown toenails are a common presentation to any podiatry setting (Borges et al., 2017; Khunger & Kandhari, 2012). Although the true prevalence of this condition is difficult to determine, it has been reported to occur in approximately 2.5-5% of the population (Vural et al., 2018). Treatment often involves surgical excision using a local anaesthetic digital ring block (most commonly using plain lidocaine) (Eekhof et al., 2012). These injections can be a source of pain and anxiety for patients. If patients have a severe needle phobia, they are often referred to have the procedure conducted in theatre under a general anaesthetic. Hundreds of South Australians are currently on the public elective surgery waiting list for this procedure, the majority of which are triaged as a Category 3 with a recommended waiting time of within 365 days (Australian Institute of Health and Welfare, 2023). These patients risk prolonged infection, pain, and deterioration of their condition, which can place unnecessary emotional and economic burden on the patient, and the health care system (Oudhoff et al., 2007). SA Health, as the provider of public health in South Australia, have recently approved the use of inhaled methoxyflurane by Podiatrists who meet prescribing requirements. The use of methoxyflurane for podiatric surgical procedures can provide a lower risk and more timely alternative for patients with a needle phobia to receive care without the need for general anaesthesia (Jephcott et al., 2018). In this situation, methoxyflurane can be used as an analgesic prior to and during the local anaesthetic injections enabling many more patients to have their procedure performed in outpatient (OPD) clinics. In addition to improving patient outcomes, this could reduce elective surgical waiting lists and the demand for surgical services, reducing the overall cost that these procedures would otherwise have on the health care system. Hypothesis: Is self-administered, inhaled methoxyflurane (Penthrox®) effective in reducing pain during local anaesthetic administration in a Podiatry Outpatient setting?
Interventions
Self-administered inhaled methoxyflurane (via a hand-held Penthrox inhaler) as pre-injection analgesia.
Once off dose: 3mL methoxyflurane 99.9% inhalation solution.
Participants will be instructed to inhale and exhale through the mouthpiece of the inhaler. If a higher concentration of analgesia is required, the participant will be instructed to occlude the diluter hole with their finger.
Duration: The participant will be instructed to take 6 slow breaths through the inhaler before the local an
Self-administered inhaled methoxyflurane (via a hand-held Penthrox inhaler) as pre-injection analgesia. Once off dose: 3mL methoxyflurane 99.9% inhalation solution. Participants will be instructed to inhale and exhale through the mouthpiece of the inhaler. If a higher concentration of analgesia is required, the participant will be instructed to occlude the diluter hole with their finger. Duration: The participant will be instructed to take 6 slow breaths through the inhaler before the local anaesthetic is administered. The participant may then take additional breaths as required while the local anaesthetic is being administered. (Approx 5 minutes). Once the local anaesthetic has been administered, the inhaler will be removed from the participant and disposed of accordingly. The participant will be closely monitored by a Registered Nurse who record observations including oxygen saturation, heart rate, respiratory rate, sedation score, adverse events and ensure the inhaler is used as instructed.
Sponsors
Claire Huxtable
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
o 18 years of age and over o A painful ingrown toenail which requires a minor surgical procedure o Ability to self-administer methoxyflurane via a hand-held Penthrox® inhaler.
Exclusion criteria
o A documented history of cognitive impairment or are otherwise unable to give informed consent o Allergy to methoxyflurane or any other medication or agent required for the procedure o A personal or familial history of malignant hyperthermia o Previous history of a significant head injury o Significant renal impairment (eGFR<60mL/min) o Significant cardiac or respiratory illnesses o Women who are pregnant, planning to become pregnant or breastfeeding o Patients taking concurrent drugs with known clinically significant nephrotoxic effects (patients taking tetracyclines, aminoglycosides, colistin, amphotericin B, barbiturates, alcohol, isoniazid and rifampicin will be excluded). o Patients who have received methoxyflurane on the day prior to the procedure or 15 mL (5 bottles) in the week prior to the procedure. o Neurological Assessment: Absent protective sensation upon monofilament testing. o Vascular Assessment: Clinically significant Peripheral Arterial Disease. o Patients who are not willing or able to fast for 6 hours prior to the planned procedure.
Outcome results
None listed