Pain

Question 1

Which of the following is not a first-line treatment for neuropathic limb pain?

1. Carbamazepine
2. Pregabalin
3. Duloxetine
4. Amitriptyline
5. Gabapentin

Answer 1

1. Carbamazepine is first line for trigeminal neuralgia but not neuropathic limb pain

All of the others are first line agents for neuropathic limb pain, and all of them including carbamazepine can be used as second-line agents.

Question 2

What are the risk factors for developing trigeminal neuralgia?

Answer 2

Female (2x more likely)
Multiple sclerosis
Hypertension

Question 3

What are the British Pain Society risk factors for opioid addiction?

Answer 3

Previous substance abuse
Current substance abuse
Poor social support
Concurrent psychiatric disease
Family history of substance abuse

Question 4

What are the types of chronic regional pain syndrome?

Answer 4

Type 1

After tissue injury, which is usually limb trauma

Type 2

After major peripheral nerve injury

Question 5

What are the signs and symptoms of complex regional pain syndrome?

Answer 5

Spontaneous pain
Hyperalgesia
Allodynia

These are not specific to one dermatome

Sweating
Oedema
Flushing
Trophic changes

Question 6

What are the indications for insertion of a spinal cord stimulator

Answer 6

Complex regional pain syndrome
Failed back pain surgery syndrome
Neuropathic pain due to peripheral nerve damage
Ischaemic pain due to peripheral vascular disease

Question 7

What are the contraindications to a spinal cord stimulator?

Answer 7

Systemic sepsis
Psychological barrier
Coagulopathy
Implanted cardiac device
Immunosuppression

Question 8

What are the components of a spinal cord stimulator?

Answer 8

Stimulator leads with electrodes
Impulse generator

Question 9

What are the perioperative implications of a spinal cord stimulator?

Answer 9

Avoid diathermy and use bipolar if needed
Relative contraindication to neuraxial blockade
Care with patient positioning

Question 10

How can local anaesthesia be used to control postoperative pain?

Answer 10

Local infilatration
Regional blockade
Neuraxial blockade
IV lidocaine infusion

Question 11

What are the signs and symptoms of opioid withdrawal?

Answer 11

Sweating
Tachycardia
Muscle aches
Insomnia
Yawning
Lacrimation
Agitation
Anxiety

Question 12

What are the conversion ratios of oxycodone to morphine, IV and oral?

Answer 12

Oral oxycodone is twice as potent as oral morphine

IV morphine is three times as potent as oral morphine

Question 13

Which are the two most effective options for treating bone pain associated with metastatic cancer?

Answer 13

Opioids are first line

Bisphosphonates reduce pain by inhibiting osteoclast activity. By this mechanism they also reduce the hypercalcaemia seen in metastatic cancer involving bone

Question 14

What are the features of pain in elderly people, according to the British Pain Society?

Answer 14

Verbal
- sighing
- grunting
- screaming
- offensive speech

Movement
- rocking
- hand wringing
- increased tone
- pacing

Facial expressions
- grimacing
- wincing
- lip puckering
- rapid blinking

Autonomic
- pallor
- sweating
- tachycardia and tachypnoea
- hypertension

Question 15

What is the definition of Chronic Post Surgical Pain?

Answer 15

According to the 2019 ICD-11 criteria:

• Pain develops or increases in intensity after surgery or a tissue injury
• Pain persists beyond the healing period, more than 3 months after event
• Pain is localised to area of injury or related to dermatome
• Other causes of pain must be excluded

Question 16

What are the risk factors for developing Chronic Post Surgical Pain?

Answer 16

Patient Factors
- Smoking
- Lower eductation level
- Comorbidities
- Pre-existing disability
- Addiction
- Young adult

Psychological factors - fear, depression, anxiety
- Obesity
- Unemployed
- Anaesthetic Factors
- Opioid use
- Regional vs general anaesthesia

Procedural Factors
- Long surgery
- Repeat surgery
- Complications
- Specific procedures - e.g. Breast surgery, Hip and knee arthroplasty

Question 17

What are the typical symptoms for Chronic Post Surgical Pain?

Answer 17

• Hyperalgesia (increased pain felt to painful stimulus)
• Allodynia (pain felt to non-painful stimulus)
• Dysaesthesia (unpleasant tingling)

Question 18

Which parameters are the strongest predictors of who is likely to develop Chronic Post Surgical Pain?

Answer 18

• Preoperative treatment with opioids
• Bone surgery
• Numerical rating scale pain score on postoperative day 14
• Presence of painful cold within the painful area 2 weeks after surgery

Painful cold within 14 days of surgery suggests central sensitisation with altered pain processing has occurred, and is a strong predictor of CPSP development.

Question 19

What pharmacological options exist for prevention of Chronic Post Surgical Pain?

Answer 19

• Regional anaesthesia
  We know that epidural analgesia reduces CPSP in thoracotomy patients, most likely because it reduces central sensitisation by preventing transmission of pain signals to the brain in the first place.
• Ketamine, particularly in patients already on lots of opioids
• Gabapentinoids such as pregabalin
• Intravenous lidocaine, although there’s no concensus on dose or duration, which is rather important to know
• Dexmedetomidine might help but doesn’t have any strong evidence

Question 20

Which procedures are most associated with Chronic Post Surgical Pain?

Answer 20

Laparotomy
Amputation
Mastectomy
Craniotomy
Thoracotomy
Knee and hip arthroplasty

Question 21

Why is chronic opioid use a risk factor for development of Chronic Post Surgical Pain?

Answer 21

• Opioid tolerance
• Increased central sensitisation
• Reduced descending inhibition
• Alteration of CNS reward system

There is also increased N-methyl-D-Aspartate (NMDA) receptor activity and microglial activation which may play a role.