Question

Describe the pathophysiology of acute, chronic and referred pain including similarities and differences between them.

Explain factors that might impact the pathophysiology, diagnosis and prescription of treatment for acute, chronic and referred pain.

Answer 1

Pain is an unpleasant stimulus feeling or the sensation felt by oneself.

It is a form of discomfort where the others can feel it

*Acute pain "that occurs as suddenly in onset. and maybe resolve within weeks to the months. Acute pain persist not more than 3 -6 months

Tissue injury $\rightarrow$ receptor activation of peripheral pain receptors and their specific A-delta and c sensory nerve fibers (Nociceptors) $\rightarrow$ Unpleasant sensation or feeling discomfort

*Chronic Pain "is an ongoing damage or dysfunction of the peripheral or central nervous system that leads to neuropathic pain. It is ongoing and usually longer than 6 months.to may be years.

Ongoing/persistent tissue damage $\rightarrow$ persistent activation of the pain fibers $\rightarrow$ pain signals remains active in the nervous system $\rightarrow$ chronic pain

*Referred pain

Referred pain is also called as visceral pain felt at some distance from diseased or affected organ. Referred pain; In the referred pain the patient will experience a discomfort/pain.

Hyperactivity of the dorsal horn neurons   $\rightarrow$ brain misinterprets pain as originating from the cutaneous nerve that innervates an area.

But the fact, in this case, is at a site, other than the affected organ

eg: Pain in appendicitis

All the reasons behind the acute and chronic pain are almost same but the period of showing or exhibiting symptoms may vary.

*Causes of acute pain:

Surgery, broken bones dental works, burns or cuts, labor and childbirth birth

*Causes of chronic pain:

The chronic pain is most usually associated with

Headache, arthritis, cancer, nerve pain, back pain, fibromyalgia pain

*Causes of referred pain

The pain is associated with diseases or illness of the nearby area or viscera

$\rightarrow$ Diagnosis and treatment:

*Acute pain:

Diagnosis of acute pain is made by the symptoms exhibited by the patient.

Treatment options may include:

# Resting the affected part of the body

#Application of heat or ice

#Administration of NSAIDs

# Physical therapy

#Exercise

*Chronic Pain:

Diagnosis can be made by:

# Symptoms and history of illness, injury or surgery

# Blood tests

#Imaging studies such a CT, MRI, Nuclear scans and ultrasound

#Dye injection studies

#Electromyography and nerve conduction studies

Treatment options may include:

# Treatment options followed for acute pain

#Bioelectric therapy

#Stress reduction

#Opioid

#Muscle relaxant

#Secondary treatment options include: Antidepressants and anticonvulsant medications

#Nerve blocks

#Steroid injection for inflammation

# Acupuncture

*Referred Pain:

Diagnosis can be made by:

#History of illness injury or surgery

#Physical examination and system review

#Symptoms exhibited

#Blood tests

#Imaging studies to rule out the cause

Treatment options followed for referred pain:

#Analgesics or NSAIDs for pain

#Rule out the cause and need surgical management if needed

#Comfort measures

#opioid medications if needed