Analgesia Flashcards
Is pain pathological or physiological?
both
What type of pain do we want to get rid of?
Pathological pain
What is nociception?
perception of pain
how the sensory nervous system responds to harmful or potentially harmful stimuli
What are thye 4 components of loeser’s concept of pain?
Nociception
pain
suffering
pain behaviours
What is neuropathic pain?
Pain which is caused by damage or disease affecting the somatosensory nervous sytem
Why is pain integral to the process of inflammation?
promotes healing by limits use of affected areas
Do we have pain receptors in the body?
No, other receptors which detect other stimuli contribute to the nociception of pain.
When sensory stimuli reaches a certain threshold for a receptor, pain can be felt
List some examples of source of pain
Trauma
Inflammation
ischaemia
post-operative pain
neuropathic pain
Define acute pain.
Response to traumatic injury, natural or therapeutic process
lasts less than three months duration
What type of pain lasts less than three months?
acute pain
Define chronic pain
pain lasting more than 3 months duration.
underlying cause potracted or on-going, may not be identifiable.
What type pain is on-going and may be poorly localised?
chronic pain
List the benefits for treating pain in patients
Humanitarian - rewarding
cost-effectivenss - fewer complications
reduced complications for patient
reduced physiological stressors
Why are some surgeons reluctant to pescribe opioids post op?
Opioids can alter physiological process in the following ways
Repress respiration rate -you want to get patient out of bed as soon as possible
lower blood pressure - undesirable after vascular surgery.
Why might a surgeon be be reluctant to prescribe opioids after vascular surgery?
Blood pressure is lowered can lead to renal failiure
what are the main 2 management options for pain?
Block Transmission (e.g. local anesthetics)
attenuate source of pain (i.e. reduce inflammation, NSAIDs)
remove source of pain (i.e. surgery)
What knowledge is key to effective pain management?
pain transmission
modes of action of analgesic drugs
pain assessment
side - effects/ adverse reactions
evaluate medication
Give examples of pharmacological pain relief routes
oral/enteral
intra-venous
patient controlled analgesia (PCA)
subarachnoid/ epidural
localised infiltration
nerve block
rectal
subcutaneous
sublingual
Why is it not advised to give respiratory patient inhalation anesthetic? what is usually given instead?
Theses types of analgesia may lower respiration rate
can make patient very lethargic
anaesthesia usually given via spinal route
Is the half life for inhalation anesthesia usually long or short?
short
Why are bariatric patients usually given spinal anesthesia over inhalation anaesthesia?
Bariatric patients usually hold a high amount of adipose tisssue.
gaseous anaethtic goes to their skin.
Since half life of gaseous anaesthesia is short, a high dose needs to be administered to saturate fat before it infiltrates the bloodstream.
this could lead to respiratory arrest due to large amount of medication seeping out of adipose tissue even after administration
What is a common sublingual pain relief medication?
GTN
What are the two major forms of analgesia?
opioids and non-opioids
give examples of common non-opioid medication?
morphine
pethidine
codeine
Give examples of common non-opioid medication?
aspirin,paracetamol, diclofenac, ibuprofen
what term could describe an opioids agonists or antagonists?
agonist
Describe the action of opioids in modulating pain relief
opioid molecules binds toreceptors on preganglionic nerves thus open up K+ channels allowing potassium to flow out of the cell preventing depolarization wave to move through the nerve cell. therefore neurotransmitter cannot be release
Why can opiods be described as agonist?
They mimic the action of endogenous ligands (endorphins, ekephalins, dynorphines) to enhance action.
Which of the following endogenous ligands neurotransmitters or hormones:
enkephalins
endorphines
dynorphines
horme: endorphine
neurotransmitters: enkephaline, dynorphine
What is deccusation?
when fibers cross from one side of a structure to the other
What term describes when fibers cross from one side of a structure to the other?
deccusation
List some of the effects of opioids.
cough centre depression
diaphoresis
euphoria
pupil constriction
flushing
respiratory, rate and rhythm depression.
vasodilation
smooth muscle constriction - billiary spasm
decreased peristalsis
increased bladder tone
can an increase in opioids cause receptor upregulation or down regulation?
down regulation
When blood pressure drops to low, which organ is most affected?
kidney’s
What is the most important clinical side-effect which is induced by opioids?
decreased peristalsis
What is meant when a drug has a high first pass effect?
it has a high affinity to be metabolised by the liver thus greatly reducing concentration
What acute adverse side effects are associated with opioids?
respiratory depression
vascular smooth muscle vasodilation:
hypotension ->renal impairment->Reduced drug clearance
What are the contra-indications for using opioids>?
Head injuries
pregnancy/lactation
Why is head injury a contra-indication for taking opioids?
risk of brain pressure
impairs brain function assessment
Why is Pregnancy/;actation a contra-indication for taking opioids?
Passes through placental barrier and can cause respiratory depression and hypotension in the baby
Which opioid is an exception for pregnant/lactating women?
pethidine
What are the nursing care implications for patients prescribed with opioids?
Properly assess patient prior to administration of drug i.e.:
other conditions-disorders present
previous meds
sensitivity to opioids
What nursing care must be implemented on a patient who is on opioids?
monitor vital signs
overdose treatment?: Naloxone
Monitor for adverse effects
What medication treament is administered to patient who may have overdosed on opioids?
Naloxone
What consideration should be taken into account prior to administering an opioid to a patient?
depenedence
toloerance
age
pregnancy/lactation?
pain assessment
