Treatment of pain in severe burns

Burn pain can cause psychologic and functional difficulties, and is difficult to predict from wound depth. The initial painful stimulation of nerve endings by the burn with continued painful stimuli result in peripheral and central mechanisms causing amplification of painful stimuli, and the development of chronic pain syndromes that can be difficult to treat. In order to assess the effect of analgesic interventions it is essential to measure the patient's pain in a simple and reproducible manner. A number of tools exist for this measurement, ranging from longer and more detailed techniques such as the McGill pain questionnaire most suited to relatively stable pain, to visual analogue scores and picture-based scores for children. Pain management begins with the acute injury, with initial measures such as cooling of the burn and use of inhalational agents such as oxygen/nitrous oxide mixtures. On arrival in hospital, for any but trivial burns, intravenous opioids are appropriate and should be administered as small intravenous boluses titrated against effect. Following the initial resuscitation, pain may be divided into background pain and that associated with procedures. These often require different analgesic interventions. Background pain may be treated with potent intravenous opioids by infusion or patient controlled analgesia and then on to oral, less potent opioids, followed by other oral analgesics. Often drug combinations work best. More severe procedural pain may be treated with a variety of interventions from a slight increase in therapy for the background pain to more potent drugs, local blocks, or general anaesthesia. In addition to drug-based methods of managing burn pain, a number of nonpharmacologic approaches have been successfully employed including hypnosis, auricular electrical stimulation, massage, and a number of cognitive and behavioural techniques.