At all steps of the analgesic ladder, an adjuvant therapy should be introduced as soon as the nature of the pain is clear.
An adjuvant is not usually analgesic, but is capable of relieving pain in certain specific pain situations. Selection of an appropriate adjuvant is a key element of a rational and evidence based approach to management of pain in children. It depends on diagnosis of the type of pain (see below).
Adjuvants are more specific, but not necessarily more potent, than analgesics.
There are many different ways to classify pain. For the purposes of selecting adjuvant mediations, the most useful is:
Characterised by disordered sensation (numbness, allodynia, dysaesthesia, hyperaesthesia) a plausible nerve distribution such as a dermatome or, in the case of sympathetic mediated pain, with a vascular distribution. Central or thalamic pain, resulting from direct damage to the thalamus, is a special example of neuropathic pain that may be difficult to identify and treat.
Characteristically: focal, deep seated, intense, occurring in the context of conditions causing metastasis or osteopenia. Where these are complicated by pathological fracture or joint dislocation, may present as incident pain.
Typically intense but short lived, often occurs in children without the cognitive or verbal ability to identify its location. Between painful episodes, the child may be pain free.
Typically: Follows acute brain inury such as perinatal asphyxia or intra-cerebral bleed. Caused by amplification of pain and anxiety. Occurs in the neonatal period, but may also result from trauma, infection or malignancy in older children.
Incident pain is breakthrough pain from an intermittent cause (e.g. fracture) rather than from inadequate background analgesia. It can be difficult to treat and specialist paediatric (or, if that is not available, adult) palliative medicine advice should be sought.