Pain Flashcards
1
Q
What are the Different Types of Pain?
A
- Nociceptive (damage to the tissues)
- Non-cancer acute
- Chronic
- Neuropathic pain (damage to the nerves)
- Cancer related pain
2
Q
What is Pain?
A
Unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage
3
Q
What is nociception?
A
Nociception is the neural process by which body detects noxious stimuli
4
Q
What is the process of Pain?
A
- Detection – nociceptors detect noxious stimulus
- Transmission – after detection done by calcium channels, there’s an influx of calcium ions through calcium channels which release vesicles containing new stimulatory receptors
- Central perception – emotionally will respond differently
5
Q
What is the Assessment of Pain?
A
- Vocalisation: whimpering, crying
- Facial expression: looking tense, frowning, look frightened
- Behavioural change: increased confusion, refusing to eat, rocking, look withdrawn
- Physiological change: Temperature, pulse or BP, flushing or pallor
6
Q
What is Acute Pain?
A
- Positive biological function – protective role
- Short duration (<12 weeks)
7
Q
What are the Goals of Treatment of Acute Pain?
A
- Relieve pain with minimal side effects
- Optimise function
- Prevent progression to chronic pain
8
Q
Is there specific treatment for acute pain?
A
- Specific treatment for the underlying condition and symptomatic management of pain which usually resolves with healing of the underlying illness or injury
9
Q
What is the Approach to Acute Pain Management?
If analgesics are required?
A
- Non-pharmacological approaches may be adequate in patients with mild pain
- If analgesics are required
- Use a stepwise approach starting at a step that corresponds to the severity of the patient’s pain
- Pick the analgesic based on the pain that is being reported
10
Q
What are the 5 Guiding Principles Pain Management of Analgesics?
A
- ‘By Mouth’: Oral forms preferred where possible
- ‘By the Clock’: Given at regular intervals rather than on demand
- ‘By the Ladder’: Adhere to principles of ladder
- ‘For the Individual’: Individualise therapy based on the level of the patient’s reported pain
- ‘Attention to Detail’: Monitor patient’s pain closely
11
Q
What is Chronic Pain?
A
- Pain which has been present daily for 3 months
- Persists after healing is complete or due to chronic disease
12
Q
Chronic pain may be precipitated by:
A
- Acute pain following surgery or injury
- Acute pain associated with illnesses such as HIV, herpes zoster
- Stroke resulting in central post-stroke pain syndromes
- Spinal cord injury resulting in radicular ‘at level’ pain, distal neuropathic pain and various musculoskeletal pain syndromes
- Therapy with antineoplastic drugs
13
Q
What are the Risk Factors for Transition from Acute to Chronic Pain?
A
- Disease that doesn’t abate
- Significance of the pain
- Inadequate pain relief
- Neuropathic nature of pain
- Patient factors (poor understanding of cause of pain and uncertainty about its significant)
- Inappropriate non-drug treatment (e.g. prolonged immobility)
14
Q
What are the General Principles for Managing Chronic Pain?
A
- Perform a comprehensive clinical assessment
- Focus on appropriate combinations of physical, psychological and pharmacological therapies
- Consider non-pharmacological therapies first if no need for immediate drug therapy
- Consider drug therapy if non-pharmacological therapies are unsuccessful or inappropriate
- If drug therapy is used, give each drug in an appropriate dose for required effects before adding other drugs
- Regularly review patients to check their pain control, function and quality of life and their need for ongoing or change of therapy
- Provide long-term support
15
Q
What are Pharmacological Management Strategies for Chronic Pain?
A
- If drug therapy is used, give each drug in an appropriate dose for required effects before adding other drugs
- Use regular medications and minimise PRNs (unlike cancer pain where we ‘maximise prns’)
- Avoid parenteral routes
- Avoid pethidine, benzodiazepines and long-term NSAIDs
- Optimise adjuvant/non-opioid analgesics
16
Q
What are Non-Pharmacological Modalities?
A
- Physical techniques
- Mind-body techniques
- Mind-based techniques
- Use of aids/orthotics and OT
- Social/environmental interventions
- Combination of any or all of the above
17
Q
In chronic pain, what should be taken into consideration before starting opioids?
A
- Explore all other treatment options, both physical and psychological
- Discuss the adverse effects and possible harms and benefits of long-term opioid therapy
- Obtain acceptance from patient about the expected outcome of therapy
- Explain that the opioid is being used as a trial and treatment will cease if there hasn’t been significant progress towards achieving treatment goals over 4 weeks
- Assess the potential for opioid abuse or misuse
- Obtain agreement about monitoring, treatment adherence and the consequences of non-adherence
18
Q
When changing from one opioid to another opioid, what should be taken into consideration?
A
- Always consider the dose potency (in relation to oral morphine) before swapping opioids
- When changing from one opioid to another, commence with 50%-75% of the calculated ‘equianalgesic’ dose and then titrate to response
19
Q
What is Neuropathic Pain?
A
- Dysfunction or damage to the nerves, spinal cord or brain
- Constant burning, episodic shooting or electric pain in a region where there’s a disturbance of sensory and/or motor function, particularly to pinprick and thermal (warm and cold) sensibility
20
Q
What are the 3 types of Neuropathic Pain?
A
- Hyperalgesia: increased responsiveness to normally painful stimuli
- Allodynia: painful response to normally non-painful stimuli
- Hyperpathia: abnormally painful reaction to a repetitive stimulus
21
Q
What is considered an appropriate positive clinically relevant end point in neuropathic pain?
A
- 50% reduction in the level of pain is considered an appropriate positive clinically relevant end point, although 30% is sometimes accepted
22
Q
If patient isn’t making progress in neuropathic pain, what referral should be made?
A
- If patient isn’t making progress, referral to a multidisciplinary pain management clinic may become necessary
23
Q
Neuropathic Pain is usually refractory to what?
A
- Usually refractory to simple analgesics including paracetamol, NSAIDs and opioids
24
Q
What is Trigeminal Neuralgia?
What is it treated with?
A
- Painful condition affecting nerves on the face
- Pain one side of the face, can be like an electric shock
- Treated with carbamazepine
25
What is Acute Herpes Zoster Pain?
How is it treated?
* Reactivation of varicella zoster virus
* Virus lies dormant in the DRG but causes an inflammatory response when reactivated
* Treatment
* If the rash has been present \< 72 hrs, antiviral treatment reduces acute pain, duration of the rash, viral shedding and ophthalmic complications
* Valaciclovir, Famciclovir, Aciclovir
* Pain may occur before, with or following rash
* Pain persisting \> 4 weeks after crusting of vesicles is considered Post Herpetic Neuralgia (PHN)
* Mild Pain – Paracetamol
* Severe Pain – Add Prednisolone to antiviral
* Alternatives for severe pain: TCA or opioid
* Topical: lignocaine ointment or lignocaine + prilocaine cream
* Advise patients not to apply on broken skin
26
What is the Treatment of Post Herpetic Neuralgia?
* Start with simple analgesics: paracetamol (or ice massage)
* If simple analgesia inadequate: consider adjuvant analgesics: TCA, gabapentin or pregabalin
27
What are the General management principles of cancer pain?
* Follow WHO step-ladder approach
AND/OR
* Pick the analgesic based on the pain that’s being reported e.g. nociceptive or neuropathic or other
28
What is the Therapeutic Strategy in Cancer Pain?
* Analgesia should include:
* Background/preventative component
* Take regularly, irrespective of pain status
* Breakthrough/as needed component
* To be taken when pain ‘breaks through’ background analgesia
29
How is Neuropathic Pain in cancer treated?
* Gabapentin has the best evidence
* Other AEDs, tramadol and TCAs also used
* Opioids usually use in combination with the medications used above
30
How is Breakthrough Pain Treated?
* Initially 1/6 to 1/10 of the background analgesia
* Ideally analgesics will have fast onset and short duration
* Give as needed with no strict minimum between doses
31
Breakthrough Pain Treatment: What are the Options?
* Morphine elixir/IR tablets, oxycodone IR tablets/elixir
* Onset in 30 mins and duration 4-6 hrs
* Transmucosal fentanyl, intranasal opioids and sub-cutaneous injections
32
Discuss Constipation due to Opioid use
* Dose related, tolerance doesn’t develop
* Prophylactic use in all patients
* 1st line treatment: docusate and senna
* Additional options include:
* Additional docusate
* Lactulose/Sorbitol
* Movicol
* Benefibre
* Suppositories/enemas
33
When should IR preparations be used?
* IR preparations: Breakthrough pain, works within 30 mins, take when pain starts
* Take prn medications as soon as they are required – pain better controlled
34
When should SR preparations be used?
Background pain, take on regular basis
35
What should you make patients aware of when starting opioids?
* May notice sedation, ‘fuzzy’/difficulty thinking or nausea
* Tends to be transient (7-10days)
* Caution with machinery driving
36
Discuss Changing between opioids/routes in Cancer Pain and Chronic Pain
* Cancer pain: change to 50-100% of equianalgesic dose
* Chronic pain: change to 50-75% of equianalgesic dose
