Understanding How to Manage Cancer Pain
- Pain remains one of the major fears of cancer patients. Adequate pain control takes time but can be achieved in a majority of cases.
- In the minority of cases when pain cannot be eliminated, it can be controlled so as to allow the patient to perform activities important to him or her.
- Pain is a totally subjective experience. Pain is "whatever the experiencing person says it is, existing whenever he says it does." The cause of pain cannot always be determined.
- Pain management can be a frustrating and stress provoking experience for the patient and the individuals who attempt to provide relief measures.
- Fear of addiction is a barrier to adequate pain management. Addiction occurs when all thoughts are consumed in when the next dose is or how to get it, it is a psychological dependence. Far less than 1% of cancer patients receiving narcotics will become addicted. The overwhelming majority of people stop taking narcotics when the pain stops.
- Physical dependence is often confused with addiction. After repeated administration of a narcotic, withdrawal symptoms occur when it is not taken.
- Tolerance occurs frequently in cancer patients taking narcotics. After repeated administrations of a narcotic, a given dose begins to lose its effectiveness. For equal effectiveness, increase the dose or decrease the interval. When the patient is taking morphine for pain, it is important to note that there is no ceiling dose due to tolerance. Therefore, cancer patients may be on very high doses of this drug.
- Health care providers are often concerned about the respiratory depressive effects of high doses of narcotics, however, tolerance to narcotics usually assures tolerance to respiratory depressant effects of the drugs.
- Sources of pain in the cancer patient include pressure of the tumor on a nerve , invasion of a bone, obstruction of the GI or GU tracts.
- Anxiety and depression are often associated with physical pain. Pain is seldom purely psychogenic or purely physical.
- Pain assessment can be difficult since it is a subjective assessment, only the person with the pain can assess it.
- Acute pain is usually associated with accepted expressions of pain ( increased heart rate and blood pressure, moaning, sleeplessness, inability to work, absence of laughter)
- Chronic pain may have no observable characteristics, the patient may "appear" comfortable and it is important for the caregiver and health care provider to believe the patient's complaints of pain.
- The most commonly used pain assessment scale is a scale of 0 to 10, with 0 being no pain at all and 10 being the worst pain imaginable.
- Pain assessment should include location and duration of pain, characteristics (throbbing, sharp, steady, dull, aching, stabbing), relieving and aggravating factors.
- Assess current pain medication regimens including effectiveness and tolerance of side effects.
- Drug therapy is the cornerstone of cancer pain management. It must be individualized to each patient.
- The World Health Organization has developed a three step
hierarchy which is proven to be effective in relieving pain in about
90% of cancer patients:
- use the simplest dosage schedules and least invasive pain management modalities first
- for mild to moderate pain use aspirin (unless contraindicated), acetaminophen, or non- steroidal anti-inflammatory drugs (Step 1)
- when pain persists or increases, add an opioid (Step 2)
- if pain continues or becomes moderate to severe, increase the opioid potency or dose (Step 3)
- schedule doses on a regular schedule to maintain the level of drug that will help prevent recurrence of pain
- administer medications for long-term cancer pain on an around-the-clock basis (usually sustained release preparations) with additional doses for breakthrough pain as needed.
- All patients on narcotics should be on a bowel regimen to prevent constipation (see Constipation module for sample bowel regimen).
- When patients cannot tolerate oral routes of medication, consider rectal administration, IV infusion, subcutaneous infusion, patient controlled analgesia by pump or intraspinal narcotic administration.
- Non-pharmacologic interventions may include relaxation techniques, distraction, hypnosis, topical stimulation of skin (heat/cooling, massage, vibration, menthol, accupuncture).