Pain is classified in six ways.1.Acute pain is the presence of severe discomfort or an uncomfortable sen-
sation that has a sudden onset and subsides with treatment. For example, a
fractured bone causes acute pain since the uncomfortable sensation occurs
suddenly when the bone is broken and subsides when the bone is immobi-
lized in a cast. Pain associated with myocardial infarction (heart attack),
appendicitis, and kidney stones are also examples of acute pain. Acute pain
can be treated with NSAIDs or opioid analgesics.
2.Chronic pain is a persistent or recurring pain that continues for six months
or more. This is the pain from cancer and rheumatoid arthritis and other
chronic conditions. Chronic pain is treated with combinations of NSAIDs
and opioid analgesics as well as medications to reduce swelling and anxiety.
3.Visceral pain is the dull and aching pain caused by stimulating nerve end-
ings in smooth muscle or sympathetically innervated organs. Visceral pain
is referred pain. This makes it difficult to localize the source of the pain.
Pain of a myocardial infarction (MI) is an example of visceral pain. MI can
be described as crushing chest pain and also described as pain in the left
arm or hand and even the shoulder, left back, or the left ear. Visceral pain
is best treated with opioid analgesics.
4.Somatic pain is pain occurring from skeletal muscles, fascia, ligaments, ves-
sels and joint. Somatic pain is an aching, throbbing pain over the affected
area. Somatic pain is best treated with nonsteroidal anti-inflammatory agents.
5.Neuropathic pain is a burning, shooting, and sometimes tingling pain
that is caused by peripheral nerve injury. This is caused by the invasion of
a cancerous tumor or nerve damage. Neuropathic pain is treated with a
combination of medications such as anticonvulsants, tricyclic antidepres-
sants, and opioid analgesics.
6.Psychogenic pain is pain caused by psychiatric illness or psychosocial
stimuli such as anxiety, depression, and fear. Drug therapy alone may
bring brief relief. Psychotherapy may bring long-lasting relief from psycho-
genic pain.Pain Assessment
The most common method used to assess pain is the pain scale. One of the pain
scales ranges from zero to 10. Zero is freedom from pain; 10 is the most severe(^308) CHAPTER 16 Narcotic Agonists