Management of pain

Perhaps because of the complex mechanisms of pain sensation, a number of techniques from different disciplines and cultures may be effective in pain relief. The efficacy of any one method is not predictable in individual patients. Management methods include:

• distraction - 'Taking the patient's mind off the pain' by giving them other things to think about. Even conversation with family or friends may be effective, but the relief only lasts for the period of distraction
• relaxation techniques - These can be particularly effective where anxiety exacerbates pain
• hypnosis - May be very effective in some (suggestible) people, ineffective in others
• Transcutaneous Nerve Stimulation (TENS) - Local electrical stimulation of the skin, adjacent to the painful site, has been found effective in some types of chronic pain
• acupuncture - This certainly works for some people although the mechanism remains obscure
• nerve blocks - This usually implies regional anaesthesia to block the transmission of the pain impulses
• surgery - Operations may be of a number of different kinds: removal of a large lesion so relieving pressure, or bisection of nerves carrying pain impulses
• analgesics - Pain killing drugs are probably the most reliable means of pain relief in most patients

The analgesic ladder

Analgesic drugs need to be utilised in a logical sequence for best results. In 1986 the World Health Organisation (WHO) proposed an 'analgesic ladder' in which drug therapy is titrated to the severity of the pain. Only when pain is not controlled should the step up to the next level of therapy be taken. In some cases, efficacy is improved by the addition of adjuvant drugs, such as NSAIDs added to an opiate (which is often effective in cancer bone pain), or a corticosteroid added to a weak opiate to reduce inflammation.

Analgesic Ladder (WHO 1986)

Analgesic therapy

Pharmacological (drug) treatment of pain can be grouped into three classes.

Local anaesthetics

Drugs such as lignocaine interfere with transmission in the nerves carrying pain impulses. As their name suggests, they are only effective in the immediate locality of their application. They may be rubbed into the skin, sprayed or sucked in the mouth (eg. for sore throat or mouth ulcers) or locally injected (eg. for tooth extraction).

Prostaglandin synthetase inhibitors

Prostaglandins have the effect of sensitising nociceptors to painful stimuli. Aspirin and related drugs (NSAIDs) inhibit the enzyme cyclo-oxygenase resulting in a reduction of prostaglandin synthesis.

Pharmacological treatments of pain

Opiates

Opiates such as morphine are centrally-acting analgesics which bind to neuro-receptors in the pain pathways of the midbrain and therefore inhibit the sensation of pain. They may also have an action in the gate region of the spinal cord, blocking the upward transmission of pain impulses.