None listed
Conditions
Brief summary
There will be a research nurse who will randomise and initiate patient treatments (placebo or clonidine) as described below, but who will not participate in any other aspect of the patient’s care or assessment. A trained collaborator will pack sixty serially numbered envelopes with either active or placebo patch and cover, together with instructions for its use. The envelopes will be prepared in such a way that the contents cannot be determined by feel. They will be held in a box in series order in the anaesthetic department. A master copy of the randomisation code will be held on computer by this collaborator. Each envelope will contain a slip stating that the patient is to be given clonidine or placebo. In the case of a clonidine allocation the envelope will contain one clonidine TTS-1 patch whose expiry is known to extend beyond the duration of the trial. In the case of a placebo allocation the envelope will contain one square shaped inert patch which will enable the research nurse to simulate application of a patch to the affected area in the placebo patients. Finally, the envelope will contain an opaque occlusive dressing that will be placed over the clonidine patch or bandaid dressing so that neither the patient nor any other staff will be able to determine the treatment allocation. Once consent is completed, a trained collaborator will draw the next consecutive envelope from the file in the department. They must record the trial number from the envelope in the space provided on the patient’s trial data form (Appendix 2). They will then visit the patient to apply the patch or “placebo patch” as directed by the pain team staff. The patch must be applied directly over the maximally tender point adjacent to the wound. Collaborators must ensure the patient does not watch what they are doing, and should refer to the patch as the “trial patch” rather than a clonidine patch, placebo or any other term that might influence the patient’s perception of their treatment allocation. The patch will remain in place for 24 hours. The dressing and patch will be removed by a collaborator(research nurse), and the identity of the underlying patch will continue to be concealed from the patient and trial investigators.
Interventions
Clonidine patch applied to the site of neuropathic pain . Patch to be applied for 24 hours. (clonidine dose in patch = 2.5mg)
Sponsors
Tim Short
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used)
Eligibility
Sex/Gender
All
Age
0 to No maximum
Healthy volunteers
No
Inclusion criteria
patients who fit the following criteria: The diagnostic criteria of Hayes et al (2002) have been modified for this study. They propose that 5 of 8 features suggestive of neuropathic pain need to be present for the diagnosis to be made. One of these features (history consistent with nerve injury) is considered satisfied in all caesarian section patients in view of their surgical history. Another, (associated autonomic features) is neither sought nor seen frequently in caesarian section patients. We are therefore left with 4 of 6 features as follows:1.Pain in the absence of evidence of ongoing tissue damage2.Character of pain from any of: burning, stabbing, pulsing.3.Paroxysmal or spontaneous pain4.Presence of any of: allodynia, hyperalgesia, hyperpathia5.Pain within an area of sensory deficit6.Associated dysaesthesias
Exclusion criteria
1.Known previous hypersensitivity to clonidine or clonidine patches2.Current treatment for other neuropathic pain states3.Current treatment with clonidine, tricyclic antidepressants, anti convulsants, or oral sodium channel blockers eg mexiletine.4.Patients who would normally require an interpreter for informed consent or to properly interpret pain scoring.5.Patients with a vertical surgical incision.6.Patients with severe bradyarrythmia due to sick sinus syndrome or 2nd or 3rd degree AV block.7.Discharge or transfer anticipated within following 24 hours8.Refusal of informed consent.9.Patients currently on other antihypertensive agents.10.Patients in whom an ilioinguinal nerve block has been performed.
Outcome results
None listed