1.1. Anaesthetics - Pain Flashcards
What is Pain?
An unpleasent Sensory and Emotional Experience associated with Actual / Potential Tissue Damage, or Described in terms of such Damage
With Regards to Treating Pain, what are the
- Physical benefits?
- Psychological benfits?
- a) Improved Sleep
- b) Better Appetite
- c) Fewer Medical Complications - M.I. / Pmeumonia
- a) Reduced Siffering
- b) Less Depression / Anxiety
With Regards to Treating Pain, what are the benefits for:
- The Family?
- Society?
- a) Improved functioning as a Family Member
- b) Able to keep working
- a) Lower Health Costs - Shorter Hospital Stays
- b) Able to contribute to the community
What are the Classifications of Pain under:
- Duration?
- Cause?
- Mechanism?
- Acute / Chronic / Acute on Chronic
- Cancer / Non-Cancer
- Nociceptive / Neuroathic
What is the difference between:
- Acute Pain?
- Chronic Pain?
- Pain of Recent Onset and probable Limited Duration
- Pain > 3 months / Lasting after normal Healing
Note - There is often no identifiable cause of Chronic Pain
What is the difference between:
- Cancer Pain?
- Non-Cancer Pain?
- Progressive - May be a mixture of Acute and Chronic
2. Many different causes - Acute or Chronic
What are the Features of Nociceptive Pain?
- Obvious Tissue Injury / Illness
- Protective Function
- Described as Well Localised and Sharp / Dull
Note - Also called Physiological / Inflammatory Pain
What are the Features of Neuropathic Pain?
- Nervous System Damage / Abnormality
- Tissue Injury may not be Obvious
- Does not have a Protective Function
- Described as:
- a) Burning, Shooting +/- Numbness / Pins and Needles
- b) Not Well Localised
What us the Physiology of Pain?
- Periphery = Tissue Injury - Chemical Release - Stimulation of Nociceptors - Signals in A-Delta / C Fibres
- Spinal Cord = Dorsal Horn - Nerve Synapse with Second Nerve - Ascend up opposite side of Spinal Cord
- Brain = Thalamus - Connection to Cortex / Limbic System / Brainstem - Pain Perception is in the Cortex
- Modulation - Descending Pathway (Brain - Dorsal Horn) - Decreases Pain signal
What is the Gate Theory of Pain?
Distraction Stimulus (Rubbing) Reduces pain by Inhibiton of Neurons
What is Neuropathic Pain?
Abnormal Processing of Pain Signal due to Nervous System Damage / Dysfunction, e.g.:
- Nerve Trauma
- Diabetic Pain
- Fibromyalgia
- Chronic Tension Headache
What are the Pathological Mechanisms for Neuropathic Pain?
- Increased Receptor Numbers
- Abnormal Sensitisation of Nerves - Peripheral / Central
- Chemical Changes in the Dorsal Horn
- Loss of Inhibitor Modulation
What are the Drug Classifications?
- Simple Analgesics - Paracetamol / NSAID’s
- Mild Opioids - Codeine / Morphine / Oxycodone / Fentanyl / Tramadol
- Antidepressants - Amitriptyline / Duloxetine
- Anticonvulsants - Gabapentin
- Ketamine - NMDA Receptor Antagonist
- Local Anaesthetics
- Topical Agents
What are the Treatments for Pain from the Periphery?
- Non-Drug Treatments - R.I.C.E.
- NSAID’s
- Local Anaestetics
What are the Treatments for Pain from the Spinal Cord?
- Non-Drug Treatments - Acupuncture / Massage / TENS
- Local Anaesthetic
- Opiods
- Ketamine
What are the Treatments for Pain from the Brain?
- Non-Drug Treatments - Psychological
2. Drug Treatments - Paracetamol / Opiods / Amitriptyline / Clonidine
What are the Advantages / Disadvantages of Paracetamol?
Advantages:
- Cheap / Safe
- Orally / Rectally / I.V.
- Good for Mild - Moderate / Severe Pain
Disadvantages:
1. Liver Damage in Overdose
What are the Advantages / Disadvantages of NSAID’s?
Advantages:
- Cheap / Generally Safe
- Good for Nociceptive Pain
- Works Synergisticly with Paracetamol
Disadvantages:
1. G.I. / Renal Side effects and Sensitive Asthmatics
What are the Advantages / Disadvantages of Codeine?
Advantages:
- Cheap / Safe
- Good for Mild-Moderate Acute Nociceptive Pain
Disadvantages:
- Constipation
- Not good for Chronic Pain
What are the Advantages / Disadvantages of Tramadol?
Advantages:
- Less Respiratory Depression
- Can be used with Opioids / Simple Anagesics
- Not a controlled Drug
Disadvantages:
1. Nausea and Vomiting
What are the Advantages of Morphine?
- Cheap / Generally Safe
- Can be given Orally / I.V. / I.M. / S.C.
- Effective if given regularly
- Good for:
- a) Moderate - Severe Acute Nociceptive Pain
- b) Chronic Cancer Pain
What are the Disadvantages of Morphine?
- Constipation
- Respiratory Depression in High Dose
- Misunderstandings about Addiction
- Controlled Drug
What are the Advantages / Disadvantages of Amitriptyline?
Advantages:
- Cheap / Safe in low dose
- Good for Neuropathic Pain
- Also treats Depression / Poor Sleep
Disadvantages:
1. Anti-Cholinergic Side Effects - Glaucoma / Urinary Retention
What are the potential Delivery Routes for Medication?
- Oral
- Rectal
- Sublingual
- Subcutaneous
- Transdermal
- Intramuscular
- Intravenous
What are the Delivery Routes for Local Anaesthetics?
- Epidural (+/- Opiates)
- Intrathecal (+/- Opiates)
- Wound Catheters
- Nerve Plexus Catheters
- Local Infiltration of Wounds
What are the different methods of Pain Assessment?
- Verbal Rating Score
- Numeral Rating Score
- Visula Analogue Score
- Smiling Faces
- Abbey Pain Scale - for Confused Patients
What are the Non-Drug Treatment Options?
- Physical - R.I.C.E. / Surgery / Acupuncture / Massage / Physiotherapy
- Psychological - Explanation / reassurance / Counselling
How are Drug Treatments decided?
- Neuropathic Pain - use alternative Analgesics +/- Psychological and Non-Drug treatments
- Acute Pain - WHO Pain Ladder:
Step 1 - Non-Opioids (Aspirin / SNAID’s / Paracetamol)
Step 2 - Mild Opioids (Codeine) +/- Non-Opioids
Step 3 - Strong Opioids (e.g. Morphine) +/- Non-Opioids
What is involved in the RAT Approach to Pain?
- Recognize
- Assess - Severity / Type / Other Factors
- Treat - Non-Drug / Drug Treatments
How is Pain Recognized?
- Ask
- Look - Frowning / Moving Easily / Sweating
- Other Know - Health Workers / Patient’s Family
How is Pain Assessed?
- Pain Score - At Rest / With Movement
- How it is Affecting the Patient - Move / Cough / Work
- Type of Pain - Acute vs Chronic / Cancer vs Non-Cancer / Nociceptive vs Neuropathic
- Physical Factors - other illnesses
- Psycholigical / Social Factors
How is Pain Treated with Non-Drug Methods?
- R.I.C.E.
- Nursing Care
- Surgery / Acupuncture / Massage / TENS
- Psychological
How is Pain Treated with Drug Methods?
- Mild - Paracetamol (+/- NSAID’s)
- Moderate - Paracetamol (+/- NSAID’s) + Codeine
- Severe - Paracetamol (+/- NSAID’s) + Morphine
