29: Pain Management - Mahoney Flashcards
define pain
an unpleasant sensory AND emotional experience associated with actual or potential tissue damage, or described in terms of such damage
__________ of brain involved with sensory components of pain (location, intensity, quality), and the _________ system involved with emotional and cognitive aspects of pain
- lateral area
- limbic forebrain
rules for PCA pump-patient controlled analgesia
- alert patients
- IV site
- quick relief
- morphine or hydromorphone are first line agents
why use PCA pump over the IV infustion?
IV infusion-avoids peaks and valleys, but may see more sedation; use PCA pump instead
the rectal dose is generally the same as …
- equals oral dose
- morphine and oxycodone available as suppositories
- morphine works faster than oxycodone (30 min v. 90 min)
a phenol nerve block does what?
- kills the nerve
- numb instead of pain
step one drugs
- mild to moderate pain
- non-opiod (acetaminophen, NSAID, adjuvants)
do not exceed ______ mgs/day of acetaminophen or tylenol
3000-4000
what are the adjuvants?
all the “aunties”
- antidepressant, antihistamine, anticonvulsants, anti-anxiety agents, anti-inflammatories
drug of choice for bone pain
NSAIDs
- Useful first line for all forms of cancer, arthritis, neuropathies
- Use with caution with enteric ulcers, GI bleeds, thrombocytopenia, coagulopathies
- Have a ceiling effect** (can’t exceed a certain amount)
- Consider using cytoprotective agent (misoprostol or PPI)
antidepressants - which should you consider using with neuralgias
desipramine (Norpramine®), doxepin (Sinequan®), Nortriptyline (Pamelor®), duloxetine (Cymbalta®)
what anti-anxiety agents are useful in anxious patients?
lorazepam (Ativan®), clonazepam (Klonopin®), alprazolam (Xanax®)
which anticonvulsants should you consider using in neuropathic pain?
carbamazepine (Tegretol®), gabapentin (Neurontin®), pregabalin (Lyrica®)
which antihistamines are useful for agitation, may minimize pruritus associated with narcotics?
hydroxyzine (Vistaril®), promethazine (Phenergan®), diphenhydramine (Benadryl®)
_____ and _____ receptors when stimulated by glutamate cause pain.
_____ and ____ receptors (opioids) when stimulated cause analgesia.
- NMDA and AMPA receptors when stimulated by glutamate cause pain
- GABA and mu receptors (opioids) when stimulated cause analgesia
- Most common use is to combine them in topical compounds
NMDA, Ca channel blockers
- ketamine-requires close monitoring-not used often
- Amantadine
- pregabalin
AMPA, Na channel blockers
- Gabapentin
- Tegretol
- lidocaine, melixitine
glutamate blockers
- Gabapentin
- clonidine
GABA agonist
- Baclofen
- Benzodiazipines
- topiramate
alpha-2 agonist
- Clonidine
- prazosin
NE reuptake inhibitors
- Tricyclic antidepressants
- tramadol (Ultram)
- duloxetine
substance P inhibitors
topical capsaicin
alpha-1 antagonists
- Prazosin
- phentolamine
Non-NMDA calcium blockers
nifedipine
All of these are commonly used adjuvants for pain with narcotics, EXCEPT: Ibuprofen Phenergan® Ativan® Pregabalin ketamine
ketamine - bad side effects
step two
- pts who fail step one or with moderate pain
- step two opiod ( codeine, oxycodone, hydrocodone) + nosteroidal or adjuvant
Consider increasing the dose of the scheduled therapy if patient receives more than___ extra doses per day
two
opiods cause constipation. how do you combat this?
senokot S bid
- senna (stimulates colon) + docusate (stool softner)
why do opiods cause constipation?
Binding of opioids to peripheral opioid receptors in the GI tract results in:
- absorption of electrolytes, such as chloride, with a subsequent reduction in small intestinal fluid.
- abnormal GI motility.
____ of the population are unable to convert codeine to morphine
- 10%
- slow metabolizers
what are the step two opioids?
- Codeine or Tylenol (300 mgs) with codeine (#1, 2, 3, 4: 7.5, 15, 30, and 60mgs, respectively)
- Hydrocodone or acetaminophen with hydrocodone (Vicodin®, Norco®, Lortab®, Lortab® elixir)
- Hydrocodone-ibuprofen (Vicoprofen®)-200/7.5 mgs-administer after food with fluid
- Oxycodone [Percocet®, Percodan®, generic, oxycodone controlled-release (Oxycontin®)]
- Percocet® (oxycodone/acetaminophen) 325/2.5, 325/5, 325/7.5, 325/10 *** know dosages
do narcotics have a ceiling effect?
No
give until it works or the side effects are too bad
step three
- pt who fail step tow or with severe pain
- step three opiod (morphine) + non-steroidal + adjuvants
step three opiods
- Morphine-available as MS Contin®; liquid available as Roxanol® (20mg/ml)
- Hydromorphone (Dilaudid®)
- Methadone (Dolophine®) - accumulation occurs over time; provide additional analgesic initially for breakthrough-respiratory depression common-requires 36 hours of observation after administration due to the discrepancy between analgesic effect and half-life (clearance from body may take up to 59 hours, while analgesic effects last only 4 to 8 hours)
how do you use the fentanyl patch?
Fentanyl Patch®-change every three days; need to start on another opioid initially due to slow accumulation through skin for first 12 hours; start with 12ug/hr and increase up to 100 ug/hr if needed
best for breakthrough pain
Transmucosal fentanyl®
- works in 10 min
- less constipation
- ** only lipophilic narcotic
________ are contraindicated for cancer pain and post-op pain due to fact that they are agonist/antagonist drugs
Talwin®, Nubain®, Stadol®, Buprenex®
_____ does have addiction potential; use in caution in patients on SSRI’s (Prozac®)
ultram
______ are an adjuvant when used to control headache, n/v associated with brain tumors; pain associated with spinal tumors, bony and neuropathic pain
corticosteroids
Dexamethasone-2-10mgs q6h po/IV
what are the disadvantages of long duration opioids?
- inconsistent release and absorption
- potential systemic effects
- continued occurrence of breakthrough pain in 50% to 90% of patients
*** side effects of opioids
- Sedation or euphoria [d/c narcotic]
- Constipation [laxatives]
what is respiratory depression?
less than 10 bpm and pt somnolent
how do you administer narcan and why? **
- for respiratory depression
- Narcan®, 0.4 to 2 mgs IV, IM or subQ every 2 minutes up to 10 mgs
- O2 at 6 l/min via nasal cannula
preferred choice to counteract N/V
Ondansetron (Zofran®)-4 mgs IV once-also available p.o
drugs to combat N/V
- -Promethazine (Phenergan®) or hydroxyzine (Vistaril®)- 25 mgs po, rectally, or IM q6h
- Droperidol (Inapsine®)-0.625 mgs IV; 1.25 mgs IM
- –Metocloparamide (Reglan®)-10 mg IV once; good for pre-op prevention in oral dose
- Ondansetron (Zofran®)-4 mgs IV once-also available p.o. (preferred choice**)
A patient calls you at home after surgery relating nausea and vomiting. Your best option is:
Phone pharmacy for Phenergan® suppository
what can you use for sepsis-associated shivers?
Meperidine (Demerol®):5-25 mgs IV/IM every 10-15 minutes not to exceed 50 mgs
Relative Potencies ***** Morphine Codeine and hydrocodone Methadone Oxycodone and hydrocodone Hydromorphone Sublimaze (Fentanyl®)
Morphine-1.0 Codeine and hydrocodone (?)-0.15 Methadone-1.5 Oxycodone and hydrocodone (?)-2.0 Hydromorphone-10.0 Sublimaze (Fentanyl®)-100.0
- First, determine the total daily dosage of the current narcotic
- Second, multiply by the potency factor if it less potent than the current drug or divide by the potency if it is more potent than the current drug
- Patient on total daily dose of 20 mgs of morphine and you want to switch to oral oxycodone (20 mgs / 2 = 10 mgs of oxycodone daily )
- Patient on total daily dose of 20 mgs of morphine and you want to switch to oral Tylenol #3 (20mgs x 7 = 140 mgs of Tylenol #3 daily)
rule of “ 2s and 8s “ with PCA pump
- 2 refers to the amount of analgesic in mgs or micrograms
- 8 refers to time in minutes for the drug to reach maximum concentration in the blood
- Loading dose-first dosage
- Interval dose-subsequent dosages
- Lockout-minimum time in minutes between consecutive doses
PCA pump settings for morphine, dilaudid, fentanyl
morphine: 2 loading, 2 interaval, 8 lockout, 20 max dose
dilaudid: .2 loading, .2 interval, 8 lockout, 2 max dose
fentanyl: 20 ugs loading, 20 interval, 8 lockout, 200 max
If the patient is not getting adequate control on the pain pump,________ minutes to find what works best for the patient.
double the dose every 8 min to find what works best for the pt
Continuous infusion rates
Morphine:
Dilaudid:
Fentanyl:
Morphine: 2 mgs/hr
Dilaudid: 0.2 mgs/hr
Fentanyl: 25-50 ugs/hr
The strongest narcotic on a mg per mg basis is: Morphine Hydrocodone Hydromorphone Sublimaze methadone
sublimaze
