0806 - Principles of Pain Management

Question 1

How can pain be potentiated?

Answer 1

Pain fibres can be activated or sensitized by inflammatory mediators. Additionally, non-pain fibres responsive to large stresses (heat, pressure) can fire as well.

Question 2

How do NSAIDs, local anaesthetic and Antagonists/Opioids work?

Answer 2

NSAIDs and paracetamol hit inflammatory mediators (COX mainly).
Local anaesthetic hits membrane depolarisation (Na+ blockers).
NMDA Antagonists, calcium antagonists, and opioids all hit the synapses.
They can all also hit central perception and descending pathways.

Question 3

What are the two main pain fibre types?

Answer 3

A-delta - lightly myelinated high-threshold mechanoreceptors

C - Not myelinated, specific nociceptors.