Apex-IV anesthetics Flashcards
2,-6 Diisopropylphenol
Propofol
Diso-PROPYL-phenol
What is the preservative in generic propofol that can precipitate bronchospasm in asthmatics?
Sodium metabisulfate
What is disodium edetate
The preservative found in diprivan
Why should generic propofol be avoided in infants?
Bc it’s preservative benzyl alcohol cant be given to infants
Induction dose of Propofol
1.5-2.5mg/kg IV
Antiemetic effects of propofol are seen at what dose?
10mcg/kg/min
(or 10-20mg IVP)
Onset of propofol
30-60 seconds
Duration of propofol
3-8 minutes
Metabolism of propofol
Liver (P450 enzymes)
+extrahepatic metabolism (lungs)
The active metabolite of propofol
none
Why is propofol likely safe to administer in those with egg allergies?
Bc most people with egg allergies are allergic to the albumin in the egg whites.
Egg lechin is derived from the YOLK (think yellow cap)
Is propofol safe to give in someone with a soy allergy? why or why not?
bc any soy proteins capable of producing an immune response are removed during the refining process
soy safe and peanut safe
3 ways to decrease burning of propofol
- Inject into a larger/more proximal vein
- Lidocaine prior or mixed
- Opioid prior
What is wakening from propofol due to?
Redistribution out of the brain
When must propofol in a syringe be discarded?
What about in a vial/tubing?
syringe- 6 hours
vial/tubing = 12 hours
Risk factors for Propofol infusion syndrome (6)
Prop > 4mg/kg/hr (67mcg/kg/min) [dose]
Inufsion > 48 hours [length]
Sepsis (inadequate o2 delivery)
continuous catecholamine infusions
High dose steroids
Significant cerebral injury
Explain propofol infusion syndrome
Prop contains long chain triglycerides (LCT)
increased LCT load impairs oxidative phosphorylation and fatty acid metabolism
- this starves cells of o2 > esp in cardiac and skeletal muscle
S/S PIS
*Refractory bradycardia > asystole + at least one of the following:
- metabolic acidosis (base deficit > 10mmol/L)
- Rhabdo
- Enlarged or fatty liver
- Renal failure
- HLD
- Lipemia (cloudy plasma or blood) - may be an early sign
Tx of PIS (7)
D/C propofol
*Maximize gas exchange
-cardiac pacing
PDE inhibitors
Glucagon
ECMO
CRRT
Which drug?
Propofol
Respiratory effects of propofol
Decreased respiratory drive
CV effects of propofol (4)
Decreased BP, SVR, preload, contractility
CNS effects of propofol (5)
decreased CMRO2 (cerebral o2 consumption
decreased CBF, ICP, and IOP
*anticonvulsant properties (very rare reports of it inducing seizures)
T/F - Propofol has minor analgesic effects
False- none
PKA of propofol
11
Does propofol affect the CO2 response curve?
Yes, it shifts it to the right (less sensitive to CO2) > resp depression &/or apnea
T/F: Propofol inhibits hypoxic ventilatory drive
True
Propofol vials must be cleansed with ____% isopropyl alcohol first.
70%
What turns urine green or cloudy with propofol infusion?
*Does it indicate renal impairment or dysfunction?
Green = phenol exretion
Cloudy = increased uric acid secretion
*does not suggest renal impairment or dysfunction
Does propofol at the gaba-A receptor reduce or increase RMP?
reduces RMP (moves it further away from TP)
What organs are primarily responsible for propofol metabolism?
Liver (P450) & lungs
Does propofol increase or decrease the apneic threshold?
Increases it (more likely to become apneic)- closer to threshold = more likely to happen
What drug is Lusedra?
Fospropofol
Phosophono-O-methyl-2,5-Dissopropylphenol
Fospropofol
MOA of fospropofol +(onset and duration)
Prodrug - it’s metabolized into propofol by the enzyme Alkaline Phosphatase (in the blood)
*slower onset (5-10 mins), longer duration (15-45 mins)
T/F: Fospropofol is prepared as an aqueous solution
True - doesn’t burn or support microbial growth like propofol
Side effect of Fospropofol
Genital and anal burning
Initial and repeat bolus’s of fospropofol and frequency
initial: 6.5mg/kg
repeat bolus: 1.6mg/kg
(not more than q4min)
Active metabolite of fospropofol
Propofol
Fospropofol –> Propofol + _______ + ________
how is it metabolized?
Propofol + Formaldehyde + Phosphate
Formaldehyde is metabolized to formate and excreted in the urine
What drug?
Fospropofol
Primary MOA of Ketamine
NMDA antagonist (antagonizes glutamate, causes of dissociative state)
What are the secondary MOAs by which ketamine works (6)
Opioid (treats pain)
MAO (treats depression)
Serotonin (treats depression)
NE (SNS stimulant)
Sodium channels (SNS stimulant)
Muscarinic (increased secretions)
*think: pain, depression (2), SNS (2) & secretions
What happens when glutamate binds to the NMDA receptor?
Where does ketamine bind to the receptor and what happens when it does?
The mag core pops out and calcium and sodium enter the cell (depolarization)
Ketamine binds to the PCP receptor and when that happens, glutamate can no longer bind. Therefore, Calcium and sodium can’t enter the cell so no depolarization takes place
Ketamine causes dissociative anesthesia at the __________ (place in brain)
Thalmus
T/F: ketamine leaves airway reflexes intact
True
Ketamine onset:
IV:
IM:
PO:
IV: 30-60 seconds (same as propofol, etomidate)
IM: 3-5 minutes
PO: variable
Clearing organ of ketamine
Liver
Ketamine induction doses:
IV, IM, PO
IV: 1-2mg/kg
IM: 4-8mg/kg
PO: 10mg/kg
Bolus dose of ketamine
onset/duration
- 2-0.5mg/kg
onset: 1-2 minutes
duration- 10-20 minutes
How long may it take after dosing ketamine to return to full orientation?
60-90minutes
T/F: Ketamine has an active metabolite
True : Norketamine
Opioid-sparing doses of ketamine
0.1-0.5mg/kg
1-3mcg/kg/min
Clearance of Ketamine
Liver- P450 enzymes
Excretion of ketamine
Renal *caution- active metabolite can build in renal impairment
T/F: Ketamine does not alter respiratory drive
true
Which IV anesthetic increases oral secretions
Ketamine (muscarinic effect)
CV effects of ketamine (4)
increased SNS tone, SVR, HR, CO
CNS effects of ketamine (4)
increased ICP, IOP, nystagmus, analgesia
Which IV anesthetic causes emergence delirium and lowers the seizure threshold
Ketamine
T/F: Ketamine should be avoided in patients with a seizure hx
True - lowers seizure threshold (TP drops closer to RMP)
True/Fale: Ketamine is a safe drug to give in someone with acute intermittent porphyria
False
2-(o-cholophenyl)- 2 (methylamino) cyclohexanone hydrochloride
Ketamine
*It’s called ketamine because it has a ketone group and an amine group
2-(o-cholophenyl)- 2 (methylamino) cyclohexanone hydrochloride
(you can also maybe use cyclohexanone thinking your brain feels like a cyclone on ketamine)
Which Iv induction agent is a Arylcyclohexylamine
(amine group + cyclone)
Ketamine
Which drug is a phencyclidine derivative?
Ketamine (PCP derivitive)
PKA of ketamine
7.5 (basic bitches love ketamine)
T/F: ketamine is a racemic mixture
True
Which drug
Ketamine
5 patient populations to avoid ketamine in
- CAD (indirect sympathomimetic - increases cardiac workload and O2 consumption)
- Pt’s with hx seizures (lowers threshold for seizures)
- Increased ICP
- Hypertensive patients
- Pt’s with RV failure (increases pulm vas resistance)
(sub hypnotic doses <0.5mg/kg usually don’t activate the SNS)
2 ways ketamine effects the lungs
- bronchodilation (good for asthma/COPD)
- increased pulm. vasc resistance (caution in severe RV failure/pulm HTN)
T/F: ketamine is direct myocardial depressent
True! It will be seen in patients with depleted catecholamine stores (sepsis, hf, sympathectomy) - need an intact SNS to have the sympathomimetic effects
How does ketamine affect the CO2 response curve
It doesn’t
T/F ketamine is a good choice for ocular surgery
False- causes nystagmus
Best way to prevent emergence delirium and hallucinations associated with ketamine
Benzos (midaz > diaz)
Risk factors for emergence delirium from ketamine (4)
age > 15
female
ketamine dose > 2mg/kg
hx personality disorder
Does ketamine relieve somatic or visceral pain more?
Somatic
What agent prevents opioid-induced hyperalgesia as seen after remi infusions?
Ketamine
Which induction agent blocks central sensitization and wind-up in the dorsal horn of the spinal cord?
Ketamine
Plasma protein binding of:
Dexmedetomidine, Midazolam, Diazepam, Lorazepam, Propofol, Etomidate, Ketamine
Propofol & Diazepam = 98%
Midazolam & Dexmedetomidine = 94%
Lorazepam = 90%
Etomidate = 75%
*Ketamine = 12%
MOA of etomidate
GABA-A agonist