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Abaraogu U.O.1, Dall P.1, Seenan C.1
1Glasgow Caledonian University, Department of Psychology, Social Work & Allied Health Sciences/ School of Health & Life Sciences, Glasgow, United Kingdom
Background: Peripheral Arterial Disease is a common clinical manifestation of systemic atherosclerosis. Intermittent Claudication (IC), defined as pain and discomfort in the lower extremities during walking and relieved by rest, is the most common symptom and constitutes a major barrier to exercise in these patients. Patients with IC have impaired quality of life due to reduced physical activity (PA) capacity and 3-4 times increased risk of mortality compared to age and sex matched controls. Current management is mainly pharmaceutical and focussed on secondary prevention. There is growing interest in pain management as a route to encouraging PA in this population, but evidence of effectiveness is limited.
Purpose: To review evidence for effectiveness of pain management interventions in patients with IC and to investigate patients' experiences to these interventions.
Methods: Seven databases and trial registers were searched for studies of pain management interventions for improving PA in patients with IC and/or the patients experiences with this intervention. Primary and secondary outcomes were pain intensity and PA, respectively.
Results: The search identified 3826 papers and five eligible studies reporting data on 122 participants were included in this review. Identified interventions included electrical stimulation (ES) usually in the form of Transcutaneous Electrical Nerve Stimulation (TENS), epidural L-Bupivacaine and oral slow release oxycodone. While a low quality observational retrospective study indicated that both oral slow-release Oxycodone and epidural l-Bupivacaine could be beneficial in pain relief in IC, one high quality trial suggested no such benefit with TENS intervention compared to placebo. Two trials reported improvement in maximal walking distance with ES compared to placebo [(High frequency TENS: 212m±297 vs 211m±244; p=0.025); low frequency TENS: 228m±218 vs 179m±153; p=0.043)], or baseline (chronic calf muscle stimulation: increase of 39m, 95%CI 7, 70; p 0.05). Three trials (one high quality) reported that ES delayed the onset of IC pain compared to sham [(low frequency TENS: 2944m±1323 vs 2299m±1101; p 0.0003); high frequency TENS: 82±112m vs 61±68m; p=0.004)], no treatment control (both TENS: 2944m±1323 and 2628±1290m vs 1390±335m;
p 0.001), or baseline (chronic calf muscle stimulation: increase of 35m, 95%CI 17, 52, P 0.001). No study reported data on daily PA, and there is lack of information about the experience of patients with the identified interventions. The overall quality of evidence supporting pain management for PA improvement is low.
Conclusion(s): Pain management, particularly using TENS appears to be beneficial for delaying the onset of claudication and improving maximal walking distance in patients with IC, but there are only low-quality published studies reporting heterogeneous outcomes on these modalities. High quality and suitably powered, randomised, placebo control trials are warranted, with priority given to assessing outcomes on daily PA, and patients perception of interventions, before a comprehensive evaluation for their use as a way to encourage PA can be undertaken.
Implications: Findings indicates that electrical stimulation, in the form of TENS shows promise as a novel therapy for PA improvement in patient with IC. Components identified by the review may be useful in designing pain management intervention to improve PA in this population.
Funding acknowledgements: Ukachukwu Abaraogu received funding from the TETFUND for a PhD being conducted at Glasgow Caledonian University.
Topic: Pain & pain management
Ethics approval: No ethical approval required. Review was registered with PROSPERO [Registration number: CRD42015027314].
All authors, affiliations and abstracts have been published as submitted.
