A breakthrough study by doctors at the Hospital Universitario Costa del Sol could change how patients with severe chronic pain are selected for an advanced treatment designed to provide long-term relief.
The research found that some patients currently ruled out for radiofrequency treatment could actually benefit significantly from the procedure.
The study, carried out by the hospital’s Physical Medicine and Rehabilitation Service, has been named the best piece of research presented by resident doctors at the 64th congress of the Spanish Society of Physical Medicine and Rehabilitation (SERMEF).
At the heart of the research is a question over a test currently used to determine whether chronic pain patients should receive radiofrequency treatment.
Radiofrequency is an interventional technique that targets nerves involved in transmitting pain signals and can provide prolonged relief for people suffering from severe chronic conditions.
Before undergoing the procedure, patients are typically given a diagnostic nerve block.
This involves injecting a small amount of local anaesthetic into the affected area under ultrasound guidance and monitoring how much their pain improves.
Traditionally, doctors have required the test to reduce a patient’s pain by at least 50% before considering them suitable for radiofrequency treatment.
But the Costa del Sol study suggests that threshold could be excluding patients who would benefit.
Researchers found that 30% of patients who failed to achieve the required 50% reduction during the preliminary test nevertheless experienced lasting pain relief and a significant improvement in their quality of life when subsequently given radiofrequency treatment as part of the study.
The discrepancy was even clearer when researchers compared the overall results.
Radiofrequency treatment ultimately achieved a success rate of 82.7%, while the preliminary nerve-block test produced an equivalent reduction in pain in only 51.8% of patients.
Researchers believe this is because the two treatments work differently within the body.
They explained that the local anaesthetic used during the initial test produces an immediate but extremely short-lived interruption to nerve signals.
Radiofrequency, by contrast, can trigger more complex changes in how pain signals are processed, potentially reducing pain over a much longer period.
Pulsed radiofrequency, which was used in 70.5% of patients involved in the research, is particularly associated with this neuromodulatory effect.
The study analysed 139 patients suffering from treatment-resistant chronic pain at the Marbella hospital.
Their average age was 64, with many suffering from debilitating joint conditions.
Around 28.1% had advanced osteoarthritis of the knee, while 54% suffered from conditions including rotator cuff tears and osteoarthritis of the shoulder.
Researchers argue that relaxing the current diagnostic threshold could therefore allow more patients suffering from serious chronic pain to access a treatment that may substantially improve their lives.
The team is proposing a change to national clinical guidelines so that patients who experience a more modest – but still clinically meaningful – improvement during the preliminary nerve-block test can also be considered for radiofrequency treatment.
The award-winning research, entitled Predictive value and clinical utility of diagnostic nerve block in the selection of patients for radiofrequency in refractory chronic pain, was carried out by fourth-year rehabilitation resident Enrique Vargas Escobar and second-year resident Mario Ginel, alongside Francisco Rivas Ruiz of the hospital’s Research and Innovation Unit.
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