Week 3 - PCA & Epidurals Flashcards
define opioid naive
Pt who has not used opioids for more than seven continuous days during the previous 30 days
define dermatome
Area of the skin supplied by nerves from a single spinal root
define pruritus
Severe itching of the skin
define paresthesia
Abnormal touch sensation that occurs without an outside stimulus
Ex. burning or prickling
define tinnitus
Experience ringing or other noises in one or both of your ears
define dysgeusia
Bad taste in the mouth
define glabella/ glabellar
Smooth part of the forehead above and between the eyebrows
define neuraxial
Administration of medication into the subarachnoid or epidural space
what is a PCA pump?
Computerized systems programmed for individual patient use for pain medication administration
what is a dose interval for a PCA pump?
- Set at 6 or 8 minutes for post-op pt
- Pt can give themselves 1 dose of medication every 6-8 minutes
what is a lock out time for a PCA pump?
- Set at 1-4hrs
- Controls how much medication a pt can receive in the 1 or 4 hour period
What are the benefits of having a 1 hour lockout vs. a 4 hour lockout for a PCA pump?
Lets nurse monitor PCA use more closely and adjust dosing as needed to control pain
What should a nurse do if a patient attempts to activate his PCA more than twice the number of doses actually delivered?
Increase the dose according to standing orders or request an order for a dose increase or a shorter dose interval
what are clinician boluses for PCA pumps?
Extra doses of medication that you can administer to manage increased pain
According to the article: Why are basal infusions not recommended for opioid-naïve patients? (this is up to the ordering physician, but thought may be changing around narcotic dosing).
Add little to pain control while increasing the risk of over sedation
Why is PCA considered to be superior to the intermittent administration of IV analgesics?
- Pt experiences better pain relief
- Pt maintains control over pain relief
- Pt has pain under control can breathe deeply/ ambulate early > aids in recovery and reduces risk of complications
- May shorten length of hospital stay
What is the most common type of PCA-related adverse event?
Programming errors causing overmedication or undermedication
How can you reduce the likelihood of having a med error with a PCA?
get independent double check
What types of patients are NOT appropriate for PCA? Why?
- Confused pt
- Pt not able to push the button independently
- Infants/ young children
- Obese
- Have asthma
- Sleep apnea
- Pts taking other drugs that potentiate opioids (muscle relaxants, antiemetics, sleeping medications)
- Must be able to understand the concept and willing to follow instructions and be physically able
can CPA be used safely with children?
yes
What is PCA by proxy and why is it dangerous?
- PCA pump is activated by someone other than the pt commonly relatives or friends
- Cause significant over sedation
How can the design of a PCA pump lead to adverse events?
- If button looks like call bell > pt may push by accident
- Doesn’t have an alert to let pt know that dose was delivered > pt may keep pushing button b/c they may think they didn’t get the dose
What are the most common types of PCA pump programming errors?
- Confusing mL and mg
- Confusing PCA bolus doses and basal rate
- Loading dose programmed where basal rate should be entered
- Wrong lockout settings selected
- Wrong concentration selected
How can you prevent med errors with PCA?
- Learn to use PCA pumps in facility
- Accept only PCA orders written on preprinted order sets
- Develop list of pts who are good PCA candidates
- Get an independent double check
What is the more effective method of monitoring for respiratory depression: oxygen saturation or capnography?
capnography
Why is it important to monitor for over sedation with a PCA?
To assess for respiratory depression, overdose
Which drug is the reversal agent for opioids such as morphine, hydromorphone, or fentanyl?
naloxone
If you are able to rouse a sleeping patient who had a PCA, and he is able to answer some questions, does this mean that he is not experiencing over sedation or respiratory depression?
no
What patient factors place a patient at higher risk for adverse reactions to PCA?
- obesity
- low body weight
- sleep apnea
- asthma
what are the 3 types of pain?
- nociceptive
- visceral
- neuropathic
describe nociceptive pain
- somatic
- injury to body tissue
describe visceral pain
- pain that comes from the visceral organs
ex. GI, heart
describe neuropathic pain
central and/ or peripheral nerve pain
what are the 2 classifications of pain?
- acute
- chronic
describe the pain pathway
- transduction
- transmission
- perception
- modulation
describe the transduction portion of the pain pathway
- noxious stimuli
- causes cell damage with release of sensitizing chemicals
- substances activate nociceptors/ lead to action potential
what are the sensitizing chemicals that can be released during the transduction portion of the pain pathway?
- prostaglandins
- bradykinin
- serotonin
- substance P
- histamine
describe the transmission portion of the pain pathway
action potential continues from:
- site of injury to spinal cord
- spinal cord to brain stem/ thalamus
- thalamus to cortex for processing
describe the perception portion of the pain pathway
conscious experience of pain
describe the modulation portion of the pain pathway
- neurons originating in brain stem descend to spinal cord/ release substance that inhibit nociceptive impulses
what are some pain therapies that are used in the transduction portion of pain
- NSAIDs
- local anaesthetics
- antiseizure drugs
- corticosteroids
what is the mechanism of action for pain therapy in the transduction portion of pain?
- all block action potential initiation
- NSAIDs block prostaglandin production
what are some pain therapies that are used in the transmission portion of pain
- opioids
- cannabinoids
what is the mechanism of action for opioid pain therapy in the transmission portion of pain?
block release of substance P
what is the mechanism of action for cannabinoids pain therapy in the transmission portion of pain?
inhibit mast cell degranulation and response of nociceptive neurons
what are some pain therapies that are used in the perception portion of pain
- opioids
- NSAIDs
- adjuvants
what is the mechanism of action for opioid pain therapy in the perception portion of pain?
decrease conscious experience of pain
what is the mechanism of action for NSAIDs pain therapy in the perception portion of pain?
inhibit cyclo-oxgenase action
what is the mechanism of action for adjuvants pain therapy in the perception portion of pain?
dependent on specific adjuvant
what are some pain therapies that are used in the modulation portion of pain
tricyclic antidepressants
what is the mechanism of action for tricyclic antidepressants pain therapy in the modulation portion of pain?
interfere with reuptake of serotonin and norepinephrine
what is a significant issue for postoperative patients?
pain
pain can lead to physiological changes such as what?
- heart rate
- respirations
- blood pressure
- immune function
- healing
What routes can a PCA be administered?
- IV
- subcutaneous
- patient controlled epidural anesthesia (PCEA)
what are prerequisites for PCA use?
- pt must be cognitively capable of understanding concept
- able to physically press button
- willing to control own pain this method
- not sedated from other meds
what are some safety risks for PCA use?
- med error
- use of narcotic drugs
- close nurse monitoring of side effects
- system locked/ accessed by staff only
- pt understanding
what are 3 common types of opioids used?
- morphine
- HYDROmorphone
- fentanyl
what is the onset of action for morphine?
- 17 minutes
- delay across blood-brain barrier
what is the duration of morphine? what is the half life?
duration - 4 to 5 hours
half-life - 2 hours
what is considered the gold standard for pain relief?
morphine
what is the onset of action for HYDROmorphone?
15mins
what is the duration and half life for HYDROmorphone?
duration - 4 to 5 hours
half-life 2-3 hours
how much more potent is HYDROmorphone compared to morphine ?
5-7 times more potent
what is the onset of action for fentanyl?
effective in 4-5 minutes
what is the duration for fentanyl?
can last longer than elimination of half-life if linger infusion times/ obese pt
what is the half-life of fentanyl?
- initial redistribution in 13 mins
- elimination half-life 3-4 hours
how much more potent is fentanyl compared to morphine?
80-100 times more potnent
what are side effects of a PCA?
- increase risk of respiratory depression
- sedation
- N&V
- urinary retention
- reduced gastric motility/ constipation
in regards to PCA side effects, who is at a greater risk of experiencing N&V?
- females
- non-smokers
- intra-operative opioids used
- history of post-op N&V
- long surgery (increases by 60% for q30mins)
in regards to PCA side effects, what causes reduced gastric motility/ complications?
- CNS and intestinal binding of opioids
when do you use narcan?
- RR <8/ min
- sedation scale of 4
where do you find the dose of narcan to administer?
- PPO
- MAR
how may times can you repeat administering narcan?
q2min x 4 until pt is awake
if Benadryl is ineffective for pruritus, what can you give?
small doses of narcan either IM or subcut q1h
what is the preferred route for narcan administration?
IV
is complete pain relief a realistic goal for a pt post surgery?
no pain goal is around 3-4/10
what is an epidural?
intermittent/ continuous infusion of analgesic agents into epidural space for purpose of providing pain contorl
what are the 3 components of the spinal cord?
- dura mater
- arachnoid mater
- pia mater
describe the dura mater
outermost/ toughest layer
describe the arachnoid mater
thin membrane covering the brain and spinal cord
describe the Pia mater
most inner layer that clings tightly to the brain and spinal cord
how many different categories are there of dermatomes? what are they? how many are in each?
4 different ones
Cervical (C) - 8
thoracic (T) - 12
lumbar (L) - 5
Sacral (S) - 5
local anaesthetics block what?
initiation and transmission of electrical impulses along nerve fibres
intraspinal administered analgesics are what?
highly potent b/c delivered close to opioid receptors in dorsal horn of spinal cord
epidural opioid therapy involves what?
- inserting catheter into epidural space
- injecting analgesic either by intermittent bolus or continuous infusion
what does epidural anesthesia produce?
produces:
- autonomic nervous system blockade
- anaesthesia
- skeletal muscle paralysis in area of affected nerve
in regards to epidural anesthesia what order is the sensory system affected?
- transmission of autonomic
- somatic sensory
- somatic motor impulses
what medications are involved in epidurals?
- opioids
- local anesthetics
what types of opioids are involved in epidurals?
- morphine
- HYDROmorphone
- fentanyl
what types of local anesthetics are involved in epidurals?
- bupivacaine
- ropivacaine
- lidocaine
for epidural analgesia autonomic blockade usually extends to what?
about 2 dermatomes above sensation
what does the recovery from epidural blockade look like?
- motor function comes back first
- sensation is next
- autonomic nerves come last (vasodilation, temperature)
what are the pros to using epidural medications?
- pt report high levels of satisfaction/ high levels of pain control
- reduce incidence of pulmonary complications post surgery
- reduce cardiac complications
- lower doses of analgesics needed
what are the risks/ cons to using epidural medications?
- requires higher level of care from HCP
- potential life threatening complications
- higher cost than oral/ IV analgesia
what does a higher level of care from a health care provider include in regards to risks/ cons to using epidural medications?
- anesthesiologist inserts epidural
- anesthesia department monitor pt with 24hr availability
- frequent monitoring/ care by RN
epidural analgesia/ anesthetics are particularly effective at managing pain following surgery to what?
- chest
- abdomen
- pelvis
- lower limbs
what do you need to assess with an epidural?
- epidural catheter length
- insertion site/ dressing
- use ice > assess sensation/ dermatome levels
-motor function of lower extremities - pain level
- sedation score
- S&S of complications
- vital signs
- urinary output
complications of PCEA and epidurals can arise from what?
- the route/ technique
- medications
- secondary complications
in regards to complications of PCEA and epidurals what are some examples of problems that can arise from the route/ technique?
- epidural hematoma
- postural puncture headache
- local anesthetic toxicity
in regards to complications of PCEA and epidurals what are some examples of problems that can arise from medications?
- opioid or sedative-induced respiratory depression
- nausea/ vomiting
in regards to complications of PCEA and epidurals what are some examples of problems that can arise from secondary complications?
- opioid or anesthetics may cause urinary retention
- catheterization increases risk of UTI
describe how SPINAL medication is different than epidural
- sub-arachnoid space into CSF
- affects motor function below level of injeciton
- assessed using touch to pt skin
- anaesthetic option for lower body surgery
describe how EPIDURAL medication is different than epidural
- epidural space
- sensory block/ sometimes motor block
- assessed by using ice to pts skin
