2. Introduction and Rationale
• Prior to 2008, 4 vital signs were routinely monitored
• Temperature
• Pulse Rate
• Respiratory Rate
• Blood Pressure
• To assess pain, communication is required, therefore we are not just
treating numbers
• Pain can lead to many adverse effects to patients
3. What is pain?
• Definition : Pain is an unpleasant sensory and emotional experience
associated with actual or potential tissue damage or described in
terms of such damage – International Association for the Study of
Pain
4.
5. Why is it important to Control Pain? Adverse
Affects of pain
• Physiological
• CVS – increased HR, BP risk of MI
• Resp – atelectasis, orthostatic pneumonia
• Neuro- endocrine – increase in stress hormones
• MSK – immobility, DVT
• GI – Ileus
• Higher risk of Developing Chronic pain
• Psychological
• Anxiety, Insomnia
• Economic
• Increased in hospital complications
• Prolonged length of stay
• Increased cost
• Reduced productivity
6. Classification of Pain
Basis of Classification Types of Pain
Duration Acute
Chronic
Acute on Chronic
Cause Cancer Pain
Non- Cancer Pain
Mechanism Nociceptive Pain
Neuropathic Pain
7. Acute Pain Chronic Pain
Onset and timing Sudden onset Insidious
Duration Less than 3 months More than 3 months
Signal A warning sign of actual or
potential tissue damage
Can be a false alarm
Severity Severity correlates with amount of
damage
Severity may be out of proportion.
Good days vs bad days
CNS involvement CNS intact CNS may be dysfunctional
Psychological effects Unrelieved pain can cause anxiety,
sleeplessness
Often associated with depression,
anger, fear, social withdrawal
Common Causes Surgery, trauma, inflammatory Neuropathic pain, cancer pain,
chronic illnesses (arthritis, chronic
pancreatitis, adhesion colic)
8. Nociceptive Pain Neurophatic pain
Causes Obvious tissue injury Nerve injury, or central/peripheral
nervous system abnormality
Function Protective function No discernible biological function
Description Sharp, dull, throbbing, well
localised
Burning, poorly localised
Aggravating/relieving factors Aggravated by movement, relieved
by rest
Spontaneous pain
Other symptoms Related to underlying pathology Numbness, pins and needles
9. How to assess pain?
Category 0 1 2
Face No particular
expression or smile
Occasional
grimace, frown
Clenched jaw,
constant quivering
Legs Normal/relaxed Uneasy, restless Kicking, legs drawn
up
Activity Lying quietly,
moves easily
Squirming, tense Arched, rigid,
jerking
Cry No cry (awake or
asleep
Moans and
whimpers
Crying, screams,
sobs
Consolability Content, relaxed Distractable Difficult to console
14. Placebo Antidepressants Anticonvulsants
Examples Normal Saline Amitryiptyline Gabapentin, Pregabalin,
Carbamazepine
Onset 1 week 1-2 weeks
Mechanism of Action Tricyclic antidepressant,
blocks reuptake of
serotonin and
norepinephrine.
Anticonvulsant, binds to
auxiliary subunit of
voltage-sensitive Ca2+
channels
Adverse Drug reactions Weight gain, constipation,
dizziness, headaches
Drowsiness, dizziness,
tremors
Dosage Amitryptiline -50mg TDS Gabapentin – 300mg OD
15. Case Study 1
• 46 year old female has just underwent a laparoscopic
cholecystectomy for acute cholecystitis. She was given a dose of
Paracetamol 1g, and Colecoxib 200mg.
• 4 hours later, she still complains of pain with a pain score of 7/10.
1. What would you do before prescribing additional antibiotics?
2. What additional antibiotics would you prescribe?
16. Case Study 2
A 66 year old gentleman in HDU who is post exploratory laparotomy
day 7 is now restless, trying to get out of bed, and appears to be
delirious. During your previous review of the patient he is already on
PCM, Tramadol, and S/C morphine and appeared comfortable at the
time.
1. How would you assess the patient and what course of action would
you take?
17. Case Study 3
• You are in ED, and a 26 year old lady presents with RIF pain for 1 day,
associated with nausea and vomiting. She complains of a pain score
of 4/10.
1. How would you manage this patient’s pain?
18. Case Study 4
• A 36 year old gentleman is post op day 2 wound debridement over
the scrotal region for Fournier’s Gangrene. You are tasked with
changing his dressing today. He claims that the pain is unbearable
during dressing. He is on PCM and Tramadol already.
1. What would be your course of action?
19. Case 5
• A 70 year old male patient presents with a generalised abdominal
pain for 1 day associated with NBO. On examination, his abdomen is
rigid, tender with positive rebound tenderness. He is on PCM,
Colecoxib and tramadol, with a pain score of 10/10.
• What would be your next course of action?
20. References
• Pain as the 5th Vital Sign Guideline: 3rd edition MOH 2018
• “Is the WHO Analgesic Ladder Still Valid?”
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2902929/
• Frank Shann Drug Doses seventeenth edition
• https://academic.oup.com/bjaed/article/14/4/153/293533
• https://pubmed.ncbi.nlm.nih.gov/9686247/
Editor's Notes
Pain with number 7
Step up vs step down
Anaesth team escalation for nerve blocks, PCA pump, regional blocks, spinal blocks
Paracetamol – how does it work? https://academic.oup.com/bjaed/article/14/4/153/293533
Gabapentin doesn’t actually bind to gaba receptors - https://pubmed.ncbi.nlm.nih.gov/9686247/
Assess pain score again, escalate to weak opiods
- Patient has AUR – check the CBD and flush/replace
Reassurance, placebo and serve medication/ step up analgesia if necessary.
Escalate to your MO, the patient has signs of peritonism, and analgesia will not solve the cause of the pain.
