IASP Task Force for the Classification of Chronic Pain in ICD-11 Prepares New Criteria on Postsurgical and Posttraumatic Pain

Feb 9, 2016

Even though chronic pain affects an estimated 20 percent of people worldwide and accounts for nearly one-fifth of physician visits, it is represented in the International Classification of Diseases (ICD) in a highly unsystematic manner. One way to ensure that chronic pain receives greater attention as a global health priority is to improve the diagnostic classification.

In response to this need, IASP has created an international task force of pain experts headed by President Rolf-Detlef Treede that in close cooperation with the World Health Organization has developed a proposal for a systematic and pragmatic classification of chronic pain. The goal is to create a classification system for the upcoming 11th revision of the ICD that is equally useful in primary care and in settings for specialized pain management.

Two specialists in chronic postsurgical pain, Patricia Lavand’homme (University Catholic of Louvain, Brussels, Belgium) and Stephan Schug (University of Western Australia and Royal Perth Hospital, Perth, Australia) are part of IASP’s ICD-11 team. Their report here focuses on ICD revisions in postsurgical and posttraumatic pain.

Chronic pain, they write, has long been recognized as pain that lasts beyond the normal healing time, thus lacking the acute warning function of physiological nociception. For the purpose of the ICD, this was pragmatically defined as pain that persists or recurs for more than three months. Such pain is frequent after surgery and some types of traumatic injuries. For these instances, new diagnostic codes of postsurgical and posttraumatic pain have been created. They are defined as pain that began after a surgical procedure or a tissue injury (including burns) at the site of the trauma and lasts at least three months after this initial event.

In view of the different causality—planned surgical intervention as opposed to accidental injury—and from a medical-legal perspective, a separation between postsurgical pain and pain after all other trauma was regarded as useful, although similar processes may underlie the ensuing pain syndrome.

Surgical procedures that most frequently cause chronic postsurgical pain are breast surgery, herniotomy, thoracic surgery, and amputations. In around one-third of cases, chronic postsurgical pain is of neuropathic origin. It is known that pain that includes such a neuropathic component is usually more severe than nociceptive pain and often affects the quality of life more adversely.

In order to meet the criteria of the proposed diagnoses of chronic postsurgical pain, other causes of such pain (such as an infection or pain from a preexisting pain problem or the recurrence of a malignancy) need to be excluded. The new diagnosis will allow coding of postsurgical pain syndromes in a comprehensive and straightforward manner, thereby improving the recognition of chronic postsurgical pain and patient care.

In the proposed classification, chronic posttraumatic pain is conceived in parallel to postsurgical pain as pain that develops after a traumatic tissue injury (including burn injuries) and persists beyond three months after the initial trauma. Typical examples for chronic posttraumatic pain include posttraumatic osteoarthritis after joint injuries and chronic pain after acute back injury and whiplash injury as well as chronic pain syndromes following burn injuries.

Optional specifiers for each diagnosis allow recording the severity of the pain. Pain severity can be graded based on pain intensity, pain-related distress, and functional impairment. In addition, evidence for the presence of psychosocial factors may be recorded.

These pain diagnoses are now integrated in the beta version of ICD-11.

Inclusion of these categories in the classification will strengthen the representation of chronic pain conditions in clinical practice and research and contribute to IASP’s mission of studying pain and alleviating the suffering caused by it.