Abstract and Keywords
This chapter examines pain management problems in terminally ill patients. Terminal pain is frequently treated ineptly and the public myth that death from cancer involves unremitting distress is perpetuated. There are many reasons why terminal pain has been so poorly controlled. These include misconceptions concerning the use of analgesics, medical reluctance, and inadequate finance. The chapter discusses the nature of terminal pain, the prevalence of different types of pain, and the clinical assessment of pain.
The greatest fear of the dying and their families is the fear of pain. Sadly, this fear has often been justified. Terminal pain is frequently treated ineptly and the public myth that death from cancer involves unremitting distress is perpetuated. The statement ‘I'm waiting for the pain to start’ continues to be heard.
There are many reasons why terminal pain has been so poorly controlled. Until recently, the care of the dying has rarely been included in the training of doctors and nurses. With a few notable exceptions, medical and surgical textbooks have ignored the problems of pain control. In addition, there are misconceptions concerning the use of strong analgesics with a widespread fear of ‘addiction’. In many parts of the world, the essential drugs are not available, due to government prohibition, medical reluctance, or inadequate finance.
However, the vast majority of patients dying with cancer and other diseases can be given good pain relief with the use of appropriate analgesics, adjuvant medication, and measures such as radiotherapy and nerve blocks. This relief can be sustained over long periods without impairment of the patient's alertness or personality and thus the quality of life can be maintained until the end.
Nature of terminal pain
A series of pictures painted by St. Christopher's patients illustrated how they saw the pain with which they presented. The (p.12) feeling of being impaled by a red-hot nail, of being totally isolated from the world by the encircling ‘muscles of tension’ with nothing but the hypodermic to pierce through them, the sudden jabs on movement, and the implacable heaviness of pain were all illustrated vividly. So too was the conviction that one is no better than some kind of scrap heap or exists at the mercy of the demolition squad, suffering blow after blow, as in the drawing by Mrs E. S. These paintings express feelings that are common to many patients dying of cancer. They show, in a visual way, the fact that pain comprises both the unpleasant sensation and the emotional reaction to it. Pain is a somatopsychic experience.
The chronic pain of cancer is quite unlike the acute pain of trauma or the resolving pain of the postoperative period. These pains are easily understood, and even borne, when recovery is expected in a short time.
(p.13) Cancer pain can appear to be unending, except by death. It is usually constant, worsening in severity, and associated with other unpleasant physical symptoms such as anorexia, vomiting, or dyspnoea.
Psychological factors greatly influence the perception of pain in terminal illness. Depression, anxiety, loneliness, and boredom will all lower the pain threshold. Such suffering is often termed ‘Total Pain’ and described as having physical, emotional, social, and spiritual components (Chapter 6). Unless these are all addressed the likelihood of successful pain control is small.
The World Health Organization (WHO) estimates that between 30 per cent and 50 per cent of cancer patients experience pain or are being treated for it. This percentage rises as the disease advances and about 70 per cent of those with advanced cancer suffer significant pain.
It is impossible to generalize about the degree of pain relief obtained but the situation has improved greatly over the last few years. This change is due to the increased impact of hospices, pain clinics, and palliative medicine services and to the initiative of the WHO Cancer Pain Relief Programme. This has provided guidelines for pain management and encouraged governments to make oral morphine available to all who need it (World Health Organization 1990).
Types of pain
Direct tumour involvement is the most common cause of pain in cancer patients. In most cases the pain is nociceptive, in that it is caused by mechanical or chemical stimuli in bone, viscera, etc. and conducted along intact somatosensory pathways. (p.14) However, a significant proportion of cancer pain is neuropathic, caused by damage in the central or peripheral nervous system.
Some common cancer pains are as follows:
Bone pain. Certain bone metastases produce prostaglandins which sensitize nociceptors and lead to pain. The pain is usually associated with local tenderness and is exacerbated by movement.
Neuropathic pain. This often occurs with tumour infiltration of the brachial plexus or lumbar plexus, or injury to nerve roots due to vertebral metastases. However, neuropathic pain can occur with many other types of damage to the central or peripheral nervous system and therefore many further pain syndromes occur. Nerve pain is felt in the appropriate dermatome; it is often described as ‘burning’ or ‘shooting’ and is associated with motor, sensory, or autonomic changes.
Visceral pain. This is due to tumour involving abdominal or pelvic organs.
Lymphoedema. This occasionally follows surgery and radiotherapy; more often it is due to recurrent tumour.
Intestinal colic from constipation or malignant obstruction.
Headaches from raised intracranial pressure.
A significant proportion of the pain experienced by patients with advanced cancer is due to a non-malignant cause. Examples are as follows:
Pain associated with cancer treatment. A thoracotomy scar may continue to be painful for months or years after surgery. Radiation therapy can cause immediate problems such as oesophagitis or long-term problems such as radiation fibrosis.
(p.15) Pain caused by debility. Patients with terminal disease are often bed or chairbound and develop the aches and pains of the immobile. Constipation is common, bedsores can develop rapidly as can thrush infections of the mouth.
Other painful diseases. Elderly patients often have other painful conditions, such as arthritis or piles.
Clinical assessment of pain
Terminal pain, or indeed any other symptom, should be approached as an illness in itself, one that will respond to rationally based treatment.
A careful history of the pain is necessary. This should include site(s), severity, duration, exacerbating and relieving factors, interference with daily living, response to previous treatment, and a verbatim description such as ‘like a red-hot poker’ or ‘painful pins and needles’. If possible, a body chart should be filled in by the doctor (or nurse) and patient together. The physical examination which follows should note any motor or sensory changes or local tenderness. The psychological state of the patient should be assessed, especially noting any evidence of depression. It is helpful to meet members of the family as well, they will often give additional information about the pain and its impact on the patient.
If the results of such a history and clinical examination are combined with the knowledge of pain mechanisms, it is usually possible to diagnose the cause of pain or pains. Sometimes further investigations are helpful but these may be impracticable in the very ill patient.
Management of pain
Treatment for pain should be started immediately, based on the presumptive diagnosis of its cause. Sometimes the response (p.16) to treatment will make the diagnosis clearer or allow further investigations to be done. Occasionally the patient is too confused or ill for a full assessment to be made and, in this situation, adequate analgesia must be given without delay. For most patients, a combination of the following will be required:
Adjuvant analgesic drugs
Psychological and emotional support
The last two methods should always be considered (see Chapter 4), but in the majority of terminally ill patients the correct treatment is with the skilled use of drugs and the support of patient and family (see Chapters 3, 4 and 6).
Continual reassessment of the patient's pain is required as new pains develop and old pains alter in their severity and response to treatment.