Week 3- PCA, epidural Flashcards
3 types of pain
2 classifications
- Nociceptive (somatic) – injury to body tissue
- Visceral – pain that comes from the visceral organs (ie. GI, heart, etc.)
- Neuropathic – central and/or peripheral nerve pain
Acute – subsides with healing; under 6 months
Chronic – persistent, can be debilitating, often associated with a long term illness
pain pathway
- transduction (release of sensitizing chemicals)
activate nociceptors and lead to generation of an action potential - transmission
- injury, sc, brain, thalamus, cortex for processing - perception (conscious experience of pain)
- modulation (neurons originating in the brain stem descend to the spinal cord and release substances
meds that impact transduction
CLAN
NSAIDs
Local anaesthetics
Antiseizure drugs
corticosteroids
Mechanism of action
NSAIDs
Local anaesthetic
antiseizure drugs
corticosteroids
block prostaglandin production
block AP initiation, inhibit cyclo-oxygenase action
block AP initiation
block AP initiation
pain drugs affecting transmission
opioids
cannabinoids
opioids
cannabinoids
MOA
- block release of substance P, decrease conscious experience of pain
- inhibit mast cell degranulation and response of nociceptive neuron
pain meds impacting perception
noa
NSAIDs
Opioids
adjuvants (relaxation, imagery, muscle relaxant)
adjuvants (relaxation, imagery, muscle relaxant)
MOA
dependent on specific adjuvant
modulation pain meds
tricyclic antidepressants (eg. amitriptyline)
tricyclic antidepressants MOA
interfere with reuptake of serotonin and norepinephrine
Pain can lead to physiological changes, such as
5
increase Heart rate Respirations Blood pressure
Immune function
Healing
what is a PCA
method of pain management via infusion that permits patients to self-administer small amounts of pain relieving medications via a specially designed pump.
routes of PCA
3
- IV
- subcutaneous or intraspinal delivery (Patient Controlled Epidural Anaesthesia- PCEA) of medication to reduce pain (usually opioids)
benefits of PCA
- report better analgesia and lower pain scores than those only receiving nurse administered opioids
- Fewer post operative complications may arise because earlier and easier ambulation occurs as a result of effective pain relief
Benefits of using a PCA compared to nurse administered opioids
Overall patient satisfaction is much higher (lower pain scores)
Patient has sense of control over their pain control and healing
Improved patient outcomes/fewer post op complications because earlier ambulation occurs as a result of effective pain management
Pharmacokinetic control much more stable
pt spends more time in ____ when having a PCA
therapeutic range
indications of PCA
4
- Patient must be cognitively capable of understanding the concept
- Able to physically press the button
- Willing to control their own pain this method
- Not sedated from other medications
safety/risks of PCA
- Medication errors
- Use of narcotic drugs including their risks
- Close nurse monitoring of side effects
- System locked and accessed by staff only
- Patient understanding
IV morphine
onset
duration
half-life
comments
17 mins
4-5 hours
2 hours
considered gold standard for pain relief. metabolites are excreted by the kidneys (90%) in first 24 hours
Hydromorphone IV
onset
duration
half life
comments
10 times more lipophilic than morphine. effective analgesia effects in 15 mins
4-5 hours
2-3 hours
5-7 times more potent than morphine
fentnyl
onset
duration
half life
comments
effective analgesic in 4-5 min
can last longer then elimination half life if longer infusion times/obese pt
initial redistribution in 13 min
elimination half life 3-4 hours
80-100 times more potent than morphine. need to watch for delayed res depression
metabolized by the liver, does not produce histamine release.
PCA side effects depends on
drug being administered
some PCA side effects
6
- increase risk of respiratory depression
- sedation
- N/V
- urinary retention
- pruritis
- reduced gastric motility
NV occurs in ___% of pts
who’s at higher risk
20-30%
female
non-smokers
use of intra-operative opioids
history of PONV
duration of surgery (increases by 60% for each 30 mins of surgery)
constipation is caused by
both the CNS and intestinal binding of opioids.
Increased tone in the small and large intestine combined with decreased peristalsis allows
for increased absorption of water from the feces
when to give narcan
RR <8/min
sedation scale of 4
naloxone dose
may repeat
0.1 mg STAT
may repeat q2min x4 until pt is awake
If Benadryl is ineffective for pruritis,
small doses of narcan can be given IM or SC if ordered
pt should have enough pain relief to
- breathe freely, sleep and perform activities
for most patients the pain goal should be around 4 or less on the pain scale.
calculating medication given in a period of time
- check every 4 hours
- totaled every 12 hours
total med calculated =
PCA doses (given by patient)
clinician boluses
continuous (basal) infusions
A patient has a PCA of hydromorphone 0.2 mg/mL. The orders indicate that the patient should receive:
- A continuous infusion of 2 mg/hr
- Each PCA dose is 0.8 mg
- Each clinician dose is 0.5 mg
After 4 hours, the nurse checks the PCA history and finds that the patient received:
- The continuous infusion
- 52 PCA attempts
- 34 PCA doses
How much hydromorphone did the patient receive in 4 hours?
35.2 mg
of pt unrousable
follow PPO
- Taking a complete set of vitals signs and assess the sedation score.
- Applying oxygen 6-8L/min via mask
- Rousing the patient and encourage deep breathing
- Naloxone 0.1 mg stat. Repeat up to q 2 min x 4 prn for resp. depression
- Notify APS physician
- Reassess resp. rate q 15 min for 2 h following last dose
Epidural opioid therapy involves inserting a catheter into
the epidural space and injecting an analgesic, either by intermittent bolus doses or continuous infusion
Intraspinal administered analgesics are highly
potent because they are delivered close to the opioid receptors in the dorsal horn of the spinal cord
Local anaesthetics block
the initiation and transmission of electrical impulses along nerve fibres.
Dura mater
arachnoid mater
pia mater
- Dura Mater – outermost / toughest layer
- Arachnoid Mater – thin membrane covering the brain and spinal cord
- Pia Mater – most inner layer that clings tightly to the brain and spinal cord.
Dermatome Memory Aids:
T10 – “to the belly button” (but-ten)
L3 – “to the knee”
L4 – “to the floor”
S1 – “around the bum”
What spinal nerves innervate the diaphragm?
C3, 4, 5 – “keeps the diaphragm alive”
epidural usually still have
motor function
local anesthetic with epidural
bupivacaine
morphine can
3 SE
float in CSF, travel to brain,
late onset of resp depression
While receiving epidural analgesia
ideally______
autonomic blockade
sensation
no motor block
- Autonomic blockade usually extends about 2 dermatomes above sensation
- Sensation is blocked (to manage pain)
onset of epidural blockade
- Sympathetic nerve fibers are smallest and are blocked first:
Vasodilation
Temperature - Sensation is next (touch)
- Then motor block (paralysis)
recovery from epidural blockade
- Motor nerves are the largest, so motor function comes back first
- Sensation is next (touch)
- Lastly come the autonomic nerves:
Vasodilation
Temperature
pros of epidural analgesia
4
- high levels of satisfaction AND higher levels of pain control
- Reduces incidence of pulmonary complications after surgery (e.g. atelectasis and pneumonia)
- Reduces incidence of cardiac complications after surgery (e.g. myocardial infarction)
- Much lower doses of analgesics are needed for intraspinal delivery in comparison with other routes, including intravenous
risks/cons epidural analgesia
- Requires higher level of care from healthcare providers:
Anesthesiologist to insert epidural
Anesthesia department to monitor patients with 24 hour availability - Frequent monitoring and care by Registered Nurses
- Potentially serious or life-threatening complications
- Higher cost than oral or IV analgesia
epidural analgesia Is particularly effective at managing pain following surgery to:
4
chest
abdomen
pelvis
lower limbs
everything related to epidural is
yellow
What to assess with an Epidural
6
Measurement of the Epidural Catheter
Exit site and dressing
Degree of motor and sensory block
Pain intensity rating
Sedation score
Assess for signs and symptoms of complications
when to call APS
- Resp depression
- excessive sedation
- Significant change that happens quickly (HR,BP)
Uncontrolled pain
Headache esp worse when sitting or standing lay them flat
New onset back pain
New numbness or tingling
Increase temp or increase WBC count
PCEA
Patient Controlled Epidural Analgesia
- Unlike IV PCA, providing a continuous background epidural infusion, plus the patient-controlled doses, provides better relief than bolus doses alone
- Patients achieve better pain control with larger doses less frequently, rather than smaller doses more frequently
- PCEA allows patients to use less medication that a continuous epidural infusion while receiving better pain control
- Usually involves BOTH opioid and local anesthetic
A nurse is caring for a client with an epidural infusion of Fentanyl and Bupivacaine
The postoperative orders state: “AAT” (activity as tolerated)
When will it be appropriate to get the client up?
Should the nurse use any particular precautions?
- Do they have motor block, can you lift your legs up, march in place, assess mobility first.
- Stand beside pt, get walker, chair,
Patients with PCA or epidurals are at risk for developing complications
the route:
3
Epidural hematoma (feel sire make sure not raised)
Postdural puncture headache
Local anesthetic toxicity
medication complications
Opioid or sedative-induced respiratory depression
Nausea and vomiting
secondary complications
Opioids or anesthetics may cause urinary retention, requiring catheterization
Catheterization increases the risk of urinary tract infection
s/s of Local anaesthetic toxicity
TICCS
circumoral paresthesia; tinnitus, irritability, tremor, seizures and cardiac dysrythmias
Bupivacaine 0.1% =
0.1 𝑔𝑟𝑎𝑚𝑠 𝑖𝑛 100 𝑚𝐿
A patient has an epidural of fentanyl 2 mcg/mL and bupivacaine 0.125%. The orders indicate that the patient should receive:
- A continuous infusion of 5 mL/hr
- Each patient-controlled dose is 2 mL
After 4 hours, the nurse checks the epidural history and finds that the patient received:
-the continuous infusion
-3 patient-controlled attempts
-2 patient-controlled doses
How much fentanyl and bupivacaine
did the patient receive in 4 hours?
bupivacaine= 30 mg
fentanyl= 48 mcg
spinal
- location
- affects
- assessed using
- _____option for what ype of surgery
Sub-arachnoid space into CSF
Affects motor function below level of injection
Assessed using touch to patient’s skin
Anaesthetic option for lower body surgeries
epidural
- location
- type of block
- assessed by using
- if it a single dose
Epidural space
Sensory block and sometimes motor block
Assessed by using ice to patient’s skin
If it’s a single dose (epiMorph), monitoring includes Q1h pulse, O2 and RR for 12 hours, then Q2h for 12 hours
spinal anesthesia is induced by
location
injecting local anesthesia at the lumbar level of the subarachnoid (intrathecal space (L4/L5)
spinal/intrathecal causes a
reversible nerve block of the anterior/posterior roots, posterior root ganglion, and portions of the spinal cord which results in loss of autonomic, sensory and motor activity (total blockade)
indications for spinal/intrathecal
2
- can be preferred for procedures of the lower abdomen and lower extremities
administers as a one time injection (can last 60 mins- 12 hours)
epidural anesthesia can be induced at
any level of the spinal column
epidural
- the level of the catheter insertion is determined by
the segment of dermatomes to be anesthetized
local anesthetics diffuse across the
dura mater into the CSF and block the spinal nerve roots to interrupt transmission of impulses
local anesthetics can cause both
sensory/motor blockade
epidural may be preferred anesthesia compliment to
2
GA intra/post op pain management or as the main anesthesia method for abdo/lower extremity surgery
epidural cath placement
lumbar
thoracic
caudal
level provides anesthesia for lower abdo, groin, hips, perineum and lower extremities
level provides a segmental block, useful for post op pain management in the upper abdominal and thoracic region
used more in pediatrics for surgeries in the lower abdomen/genitalia or lower extremities
steps for epidural removal
as student must be supervised by RN
Check Dr. orders
Stop pump
Note how many mLs remaining in bag
Prepare pt. and do teaching
Don PPE
Remove dressing and slowly pull out catheter, if any resistance is felt, reposition the patient and try again. If resistance is felt, stop and call anesthesia
Check end of catheter to ensure it is intact
Place sterile dressing over the site. Hold pressure if drainage
Perform focused epidural assessment post removal and do regular checks for 12 hours post removal
Waste remaining amount of medication with another RN
What are the benefits of having a 1-hour lockout vs. a 4 hour lockout?
patients can have smaller doses more often
Why are basal infusions not recommended for opioid-naïve
patients?
adds little to pain control and risk for oversedation
What types of patients are NOT appropriate for PCA?
- children under 5
- pt risk for oversedation
- confused OA
What is the more effective method of monitoring for respiratory depression:
capnography
- measures end tidal carbon dioxide
What patient factors place a patient at higher risk for adverse reactions to PCA?
4
- obesity
- underweight
- sleep apnea
- asthma
sedation scale
S= sleep
1= awake and alert
2=slightly drowsy, easily rousable
3= frequently drowsy, rousable, drifts off to sleep during conversation
4= somnolent minimal or no response to painful stim
common side effects
pruritis
nausea
vomiting
urinary retention
headache
hypotension
level of motor block
assessment
0= no block, full flexion of knee and feet
1= partial just able to move knee
2= almost complete, able to flex feet
3= complete block unable to move feet or knees
