Eligibility

Local study conflicts

• Co-enrolment with CLARITY PAD is permitted
• Additional co-enrolment may be allowed, however, this need to be checked with the study team first.
  Please contact the research nurse team on cuh.rdt@nhs.net or via secure chat Placement Research Study to facilitate.

Inclusion Criteria:

• Aged 18 years or older
• Undergoing elective or emergency MLLA (BKA, TKA, or AKA) for complications of PAD, diabetes and/or acute or chronic infection
• Able to assess pain using NRS
• Life expectancy of greater than two weeks
• (For people of childbearing potential)* Willing to undergo a preoperative pregnancy test and agree to either use a highly effective method of contraception or abstain from sexual intercourse for 7 days after MLLA.
• (For male participants with female sexual partners who are considered to be of childbearing potential)* Willing to agree to use a condom or abstain from sexual intercourse for seven days after MLLA


• *A person is considered to be of childbearing potential i.e. fertile, following menarche and until becoming post-menopausal unless permanently sterile. Permanent sterilisation includes hysterectomy, bilateral salpingectomy and bilateral oophorectomy. - A postmenopausal state is defined as no menses for 12 months without an alternative medical cause. A high follicle stimulating hormone (FSH) level in the postmenopausal range may be used to confirm a post-menopausal state in women not using hormonal contraception or hormonal replacement therapy. However in the absence of 12 months of amenorrhea, a single FSH measurement is insufficient

Exclusion Criteria:

• Undergoing MLLA for trauma or cancer
• Undergoing digital, metatarsal, tarsal amputation, disarticulation of the hip or hindquarter amputation
• Undergoing simultaneous bilateral amputations
• Undergoing MLLA revision (excluding previous guillotine amputation)
• Allergy or intolerance to the PNC or local anaesthetic agents, or chronically taking class 1B anti-arrhythmic agents or local anaesthetic agents, for example in the form of transdermal patches.
• Expected to be sedated for more than 24 hours postoperatively
• Unable to provide consent due to incapacity (as defined by the Mental Capacity Act 2005)
• Vulnerable or protected adults.
• People who are currently pregnant or breastfeeding
• Previously enrolled in PLACEMENT (excluding PLACEMENT feasibility trial) for a prior MLLA

Notes

Patients who met the inclusion criteria but who subsequently would not be suitable include:

• Patients where a planned MLLA was not performed (due to patient choice, anaesthetic, or
• Patients where a MLLA was performed but the appropriate nerve was not identified
• Patients who, due to instability in the intra-operative period, require admission to the ICU postoperatively and are most likely to be sedated for more than 24 hours
• Patients who, due to instability in the intra-operative period, are not expected to survive more than two weeks.

If the patient is eligible:

• Inform the patient that they may be eligible for a research study
• Gain verbal agreement in principle before proceeding. Explain:
• Taking part in research is likely to improve the quality of their care
• Risks are carefully controlled - research is safe
• Explain the uncertainty that exists with respect to treatment of their condition
• If they change their mind they can withdraw their participation at any point

Step-by-Step Guide to Recruitment:

Eligibility confirmation

• Eligibility can only be confirmed by medical team on delegation log.
  Mr Graeme Amble, consultant vascular surgeon, is the PI and will know which members of staff who are delegated this role.

Gaining formal consent

1. Clinical team to have initial conversation with the patient and ask if details can be passed onto the research nurse team . This could be at an out patient appointment or at time of admission which may be an emergency event.
2. Research nurse team to send out PIS and follow up to see if they are interested.
3. Delegated medical team member to receive consent on paper face to face. Research nurses will ensure the doctor receiving consent has the correct version of the form.
4. Doctor to complete smartphrases on EPIC .PLACEMENTCONSENTANDELIGIBILITY

Contacting the Research Team

• The research nurse team is available from 08am-16pm Monday to Friday;
• In research team working hours contact the team via:
  • Secure Chat: Research Delivery Team
  • Email: cuh.rdt@nhs.net

Randomisation procedure

• Only members of the study team on the delegation log can complete randomisation.
• During core hours Monday to Friday, a research nurse will attend theatre to randomise at an appropriate time.
• Outside of these times, one of the medical team will attend if possible.
• Alternatively, the randomisation allocation will be placed in a sealed envelope and given to the theatre team to open once the perineural nerve has been identified.

Carrying out the intervention:

• Only members of the surgical team that have received training from PI Mr Graeme Ambler can insert the catheter.
• This training must be documented on trial specific training forms. Please contact the nurse team to facilitate.
• There is no need to provide GCP or research CV or be on the main delegation log if the only role undertaken in the context of the trial is insertion of the catheter.

Disposition and follow-up:

• Patient follow up is as per standard of care.
• In addition, the research team will complete questionnaires daily until 5 days post procedure.
• All trial follow up following discharge will be completed remotely.

Links for further information:

Link to trial site