Multimodal Anesthesia (2) Flashcards
The emphasis on multimodal anesthesia for GA includes these 2 aspects:
Short acting Anesthetics Agents and Opioid Sparing
What happens if acute pain is left untreated?
Can progress to chronic pain
What are the classes of opioids?
Phenanthrene
Benzylisoquinolones
What structure is in most opioid agonists?
Piperdine ring
What class of opioid are morphine, codeine, and thebaine?
Phenanthrenes
What class of opioid is papaverine, noscapine?
Benzylisoquinolones (lack opioid acticity)
Which phenanthrene isomer has opioid activity?
L-isomer
What are the 3 opioid receptors? Describe characteristics of each:
Mu
Kappa
Delta
What is the preop dose for acetaminophen? What is daily tylenol max?
1000mg PO or Ofirmev 1g intraop
Max: 4g/day
What is the preop dose of gabapentin?
300mg PO
What tylenol dose is continued postop x1 week?
1000mg TID
What mag dose is continued post op x1 week?
Super mag 400mg BID (or mag aspartate 615mg TID or Magoxide 500mg BID)
What is the intraop dose for lidocaine?
1mg/kg infusion over 1 hour
What gabapentin dose is continued post op x1 week?
300mg TID
What is the intraop dose of ibuprofen and the max dose?
200-800 IV over 30 min (Q6H PRN)
Max: 3200 mg/day
With MAGA, what medications can be giver both in preop and post op?
Gabapentin
Tylenol
What is the MOA of Gabapentin?
- Structural analogue of GABA with no activity in GABA transmission
- Binds to voltage gates Ca++ channels
→enhances descending inhibition
→inhibits excitatory neurotrans release
What are the pharmacokinetics of Gabapentin?
- Lipid soluble
- Non protein bound (<3%)
- No drug interactions
- short 1/2 time (need redosing)
What are the uses of Gabapentin?
- Partial seizures in adults and kids
- Chronic pain syndromes
- DM neuropathy
- Post-herpetic neuralgia
- Reflex sympathetic dystrophy
- Phantom limb pain
- Fibromyalgia
What patients is Gabapentin contraindicated in?
MG and myoclonus
Reduce dose in elderly
What is the preemptive dose of Gabapentin for analgesia?
300-1200mg PO 1-2 hours prior to OR
What are side effects of gabapentin?
- Fatigue
- somnolence
- ataxia
- vertigo
- constipation
- abrupt withdrawal in seizure patients
- weight gain
What are the effects of NSAIDS?
What enzyme catalyzes synthesis of PG?
Cyclooxygenase