Pain


 What is Pain?

Pain is an unpleasant sensory and emotional experience.  It usually occurs from tissue damage.  Most acute pain goes away after the tissue has healed.  Pain is considered to be chronic when it continues after the tissue has healed and persists for more than 3 months.  Inadequate treatment of pain can cause unnecessary suffering, disruption of life style, loss of income, and loss of self-esteem.

Pain can be divided into two categories based on the tissue of origin:

  1. Neuropathic pain.

2. Nociceptive pain.

Neuropathic pain is caused by irritation, injury or damage to peripheral or central nervous tissue. Examples include sciatica, neuropathy, carpal tunnel syndrome, and spinal cord injury. It is often described as tingling, burning, shooting, electric-shock, and stabbing. 

Nociceptive pain arises from an injury or disorder of tissue outside the nervous system that activates specialized pain receptors called nociceptors.  Pain that arises from nociceptive receptors in the skin, muscles, bone, and joints, is further characterized as somatic pain.  The pain is described as aching, throbbing, less often, sharp.  This type of pain can occur from arthritis, osteoporosis, and ischemic limb pain. Pain that arises from nociceptive receptors in internal organs is characterized as visceral pain. It tends to be poorly localized, and is commonly described as deep, dull, pressure, or cramping. Examples include peptic ulcer, gastroesophageal reflux disease (GERD), menstrual pain, urinary bladder infection, and kidney stones.

Mixed pain is a combination of neuropathic and nociceptive pain.  This may be seen in migraine, sickle cell disease, or cancer. The acute pain of sickle cell disease (SCD) is thought to be mostly nociceptive and related to vaso-occlusion resulting in tissue injury. However, patients with SCD also have chronic pain and there is evidence that a component of such pain is neuropathic. Effective pain management requires attention to both pain mechanisms. Regrettably, studies suggest that approximately 70% of individuals with advanced cancer experience pain, and about 25% of them pass away without receiving adequate relief.

 

What is the standard treatment for Pain?

The World Health Organization’s (WHO) 3-step “analgesic ladder” is an excellent guide for appropriate treatment of pain based on its intensity.

STEP 1

  • Mild Pain: Nonopioid analgesics
  • Recommended drugs: Aspirin (ASA), Acetaminophen (Acet), and NSAIDs.
  • +- Adjuvants

STEP 2

  • Moderate Pain: Mild opioids used in combination with ASA, Acet, or NSAIDs
  • Recommended: Codeine, Hydrocodone, Oxycodone
  • +- Adjuvants

STEP 3

  • Severe Pain: Strong opioids
  • Recommended: Morphine, Hydromorphone, Oxydocone, Methadone, Fentanyl
  • +- Nonopioid analgesics
  • +- Adjuvants

 

 

Most nociceptive pain is opioid-responsive, but effective doses may produce intolerable side effects.   Neuropathic pain is usually opioid-resistant.  Many patients require the addition of adjuvant analgesics like antidepressants and anticonvulsants.

Patients who do not respond to the 3-step analgesic ladder should be considered for treatment in a comprehensive multi-disciplinary pain clinic.  Transcutaneous electrical nerve stimulation (TENS), nerve blocks, epidural steroid injections, are commonly used, depending on the cause of the pain.

We offer a variety of treatments to patients who have failed standard medical pain management.

 

Nerve Block

Joint injection

Implantable Spinal infusion pump (Morphine pump)

Spinal Cord Stimulation