A working knowledge of pain evaluation is critical, because it serves to:

• Monitor the clinical condition over time.

• Analyse changes in response to treatment.

• Advance the principles and practice of pain management.

Moreover, The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) set a standard in 2000 for all healthcare organizations. It stated that all patients have a right to appropriate assessment (and management) of pain. As with all medical interactions, such evaluation will involve history, examination and appropriate special investigations.

Issues in pain measurement

The International Association for the Study of Pain (IASP) definition of pain states that ‘Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage’. Full assessment therefore requires:

• Multidimensional approaches to pain evaluation.

• An awareness that it is not necessary to be able to visualize an obvious nociceptive stimulus (directly, or by means of special investigations) for spontaneous pain or a central sensitization evoked response to occur.

Both the over-worked clinician and wider society frequently overlook these central features. Medical and para-medical staff are commonly observed utilizing unidimensional (e.g. visual analogue scale (VAS) and verbal rating scale (VRS)) pain assessment tools, thus failing to address other components of pain, for example affective and cognitive responses.