Why should Chronic Pain Management be multidisciplinary?
Pain is one of the commonest symptoms in patients attending OPDs. While pain is defined as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage”, chronic pain is any pain that has persisted beyond the expected illness or injury, arbitrarily defined as lasting beyond the expected time course, or “3 months”. Low back pain (LBP) & osteoarthritis (OA) are ranked 2nd only to cancer as leading cause of disease burden in the world. While LBP with point prevalence ranging from 12% to 33% is highest contributor to disability, knee OA with prevalence of 6% & 13.7% in urban and rural community is fourth common cause of disability in the world. Neuropathic pain is a common contributor in many pains and exact incidence is not known. Pain is also one of the dominant symptoms in cancer patients especially advanced cancer.
Chronic pain is better explained by a biopsychosocial model rather than a biological model (more useful in acute pain), which suggests that chronic pain is end result of biological (underlying pathology), psychological and social problems. The answer to the question as to why any pain becomes chronic lies in various micro mechanisms happening simultaneously in peripheral and central nervous system after any injury. Central sensitization or wind up is an important phenomenon responsible for signal amplification occurring at the level of dorsal horn and higher centers involved in the pain pathway in the CNS. Various receptors like NMDA, NK1, AMPA are involved and lead to increased spontaneous activity of dorsal horn neurons, expansion of receptive field size and reduction in the threshold for neural activation.
‘‘Pain management continues to be the most difficult problem facing medicine today.’’ These words by Jason R. Bauer and Charles E. Ray, Jr puts chronic pain management in right perspective as of date because despite the technological advances in medical science for the diagnosis and treatment of various diseases, managing chronic pain, its suffering and disability still remains inadequate. The reason for this is explained by the biopsychosocial model for the origin of chronic pain, according to which for managing chronic pain we need to have a strategy in place which looks into and addresses all the factors responsible for giving rise to chronic pain, whether these are biological due to the underlying pathology, psychological or social. Therefore a multidisciplinary approach is a prerequisite for the efficient management of chronic pain.
A multidisciplinary chronic pain management team comprises of medical doctor (a Pain Physician/ Surgeon), a Psychiatrist and Psychologist for managing the psychological comorbidity and a Physical medicine professional for physical therapy. While dealing with a patient in chronic pain apart from the physical basis or underlying pathology giving rise to chronic pain, factors which suggest psychological comorbidity or physical disability should be specifically sought and should be addressed while making the overall treatment plan.
The role of Pain Physician lies in the proper assessment of the chronic pain condition in order to pinpoint its cause and its management by interventional pain procedures if not responding to conservative management. The interventional pain procedures are minimally invasive procedures (injections), mostly done on day care basis which are meant to either deposit a drug (local anaesthetic/ steroid) near the pain generator, ablation of nerves or implantation of intrathecal pumps or spinal cord stimulators. Interventional pain procedures are used for therapeutic pain relief as well as to confirm the diagnosis.
There is ample evidence that the psychological factors play a significant role in the experience, maintenance and exacerbation, if not the cause of pain. Since there are no cures for chronic pain and some level of pain will persist in most pain sufferers regardless of treatment, psychological approaches are useful complements to more traditional medical and surgical approaches.
A comprehensive pain management program should include the services of a Physiatrist, who can offer various physical modalities such as therapeutic heat and cold, hydrotherapy, ultrasound, electricity, TENS, manual techniques in addition to active exercises. Physical techniques benefit the patients by causing functional restoration, maximizing and maintaining pain relief for long and a feeling of control of one’s own pain.
A multidisciplinary approach is certainly of benefit in chronic pain patients to help them relieve their pain and bring them back to functionally active life.
- Multidisciplinary rehabilitation for chronic low back pain: systematic review. Jamie Guzman, Rosmin Esmail, Kaija Karjalainen, Antti Malmivaara, Emma Irwin, Claire Bombardier BMJ. Jun 23, 2001; 322(7301): 1511–1516.