Acute pain management Flashcards
At what dose does the risk of harm increase significantly (morphine )
120mg a day
Is morphine appropriate for long term chronic pain therapy
There is a lack of robust evidence to support opioid’s in long term treatment of pain
What are the 3 main receptors that opioids work on
Mu - most clinically relevant
Delta
Kappa
Which demographics are at most risk with Opioid therapy
Respiratory disease such as sleep apnoea
Hepatic/ renal dysfunction
Older adults
People who are at risk of developing problematic Opioid use and patient who have Co morbid mental health conditions
Morphine has low lipid solubility can it penetrate the blood brain barrier?
Yes, but slowly. So onset is slower than fentanyl, which has high lipid solubility and rapid onset
In G.P. practise how many patient prescribed Morphine for chronic pain feel they benefit from it
1 in 10
When was the last guidance on chronic pain published by NICE
April 2021
What are the two classes of Non Cancer Chronic pain
Primary: No underlying condition appear out of proportion to observable injury
Secondary: is secondary to underlying condition (E.G. Arthritis)
Chronic pain is divided in to two categories’
Cancer and Non cancer
Pain signals move through afferant and efferent pathways what is the difference?
Afferant is incoming towards the dorsal horn and the Efferent is away
What are the 3 types of modulation of pain
Segmental inhibition
Endogenous (Opioid system)
Descending inhibitory system
how many steps on th WHO analgesic ladder
- Non opioid i/c adjuvants
Mild opioid i/c Adjuvants
Strong opioid i/c adjuvants
A potential 4 step is considered nerve blocks such as epidurals
What are the 4 A’s of effective analgesia
Analgesic
Activities of daily living
Adverse effects
Aberrant drug taking behaviours
In the new Nice guidelines 2021
what are the two sub categories’ in The Active section of Non Pharmacological management of pain
Active Behaviours: Corrective posture or exercise
Active Cognitive:
Relaxation or meditation
In the new Nice guidelines 2021
what are the two sub categories’ in The Passive section of Non Pharmacological management of pain
Passive Behaviours: Hot baths and diets
Conventional: medication acupuncture
What are the 3 classes of analgesia
Non opioids such as NSAIDs & paracetamol
Adjuvants such as Anticonvulsants’ & antidepressants
And opioids both weak codeine and Dihydrocodeine or Strong such as morphine and fentanyl
What are the two types of NSAIDS
Selective: Blocking COX 2 only
Non selective Blocking Blocking both COX 1 and COX 2 pathways
How do NSAIDs work
After injury Aracadonic acid is produced which interacts with exisiting COX 1 Producing COX2 producing histamines, inflammation and pain. Non selective NSAIDs interfere with the reaction with COX 1 and selective interfere with the reaction with COX 2
What is a rule of thumb for prescribing opioids for break through pain
A patient with no renal or hepatic co morbidities should be prescribed 20- 30mg oral morphine a day it should be titrated until a balance of side effects and pain control is achieved and break through pain relief should be no more than one tenth to one sixth of the total daily dose
What are the 4 perils of opioids
Tolerance
Physical dependence
Addiction
Opioid withdrawal
What is the difference between physical dependence and addiction
Physical Dependance is Neuro pharmacological as a result of Neuro adaptation and neuro plasticity Addiction is Neuro pharmacological and behavioural influenced by genetic psychosocial and environmental factors
How do you move from one opioid to another if the patient has built up a tolerance
Use the equitable tables in the BNF the standard unit is a 10mg dose of morphine
How do anti depressants work as analgesia
They are prescribed generally at a tenth of the antidepressant dose but they inhibit neuro transmission of pain (To be used with caution in the Elderly)
How do anticonvulsants work
They can enhance the effect of analgesia co administered. Specifically gabapentiods stabilise the neuro membrane which inhibits neuro transmission of pain, which can give rise to Euphoric effects (reclassified in 2018)
In the 2012 NICE Guide lines for neuropathic pain What 4 medications are offered
Try amitriptyline Duloxetine Gabapentin or pregabalin if one doesnt work offer one of the other 3 Tramadol should only be used for rescue and Capsaicin for localised pain or if the patient cant take oral medication
