To drink but not to drive?

Management of cancer pain To the Editor: The article by Dr Gordon Coates' is timely. Two points occur to me on reading it. 1. The article should help to improve prescribing by doctors who are faced only occasionally with patients having pain from advanced cancer. The management Coates describes coincides with that in the Hospice Palliative Care Service in Western Australia, which is based on that developed by Saunders, Twycross and others in the United Kingdom. Although the scientific principles of pain control are beginning to be understood, detailed daily management of symptoms in end-stage cancer often taxes the skills of the general practitioner. This is one good reason why some doctors should gain experience and acquire skills in this field which touches so many aspects of patient care. Dr Robert Twycross told me that in the UK they are considering up to two years' training of a physician to be necessary before competence in the palliative and terminal care field is assured. It is essential to raise our general therapeutic standards in the way Dr Coates indicates, but it is also necessary to have Australian physicians with a special interest and skill in the multi-faceted management of terminal disease. I feel sure that this objective will be addressed by the Affiliation of Australian Palliative Care/Hospice Programmes and various State anti-cancer bodies. 2. Then, it is a common observation that within 48 hours of admission many sick patients experience relief of chronic pain without any increase in opioid medication. Pain is responsive to placebo administration in about one-third of a population. This placebo effect is characteristic of any sensitively run, well-staffed hospice, oncology ward or home care palliative care service. Recent research in neuroscience has advanced our understanding of this effect: "Treatments that ought to have no effect produce dramatic subjective changes". A neural network that selectively inhibits pain and has endogenous opioid (endorphin) links has been demonstrated, and could provide the structural basis for the placebo effect.2 The network begins in the midbrain, and projects descending pain inhibitory fibres onto the spinal cord. Stimulation of, or opiate microinjection into, specific midbrain centres results in inhibition of nociceptorinduced behaviour and neural response. The midbrain loci send descending axons to endon medullary neurons, which in turn have descending axons collected in the dorsolateral funiculus of the spinal cord. These terminate in the dorsal horn of grey matter throughout the length of the spinal cord. They synapse in specific layers of the dorsal horn that contain neurons which respond maximally to noxious stimuli impinging on them (via segmental spinal nerve C fibres). Endorphin release inhibits pain response, and artificial opioids act at this point. Chronic pain is often exacerbated by fatigue and sleeplessness caused by anxieties and tensions. The placebo effect of hospice admission as well as the oral morphine regimen has a likely, sound basis in neurobiological knowledge. This is an example of how laboratory research in basic science provides a helpful theoretical basis for sound clinical practice. David Allbrook, MRCS LRCP Departmentof Anatomyand Human Biology Hospice Palliative Care Service of Western Australia