IV Anesthetics Flashcards
What is the MOA of propofol?
It increases the duration of time Cl ion channels remain open in GABA-A receptors
What is the cardinal indictor of propofol infusion syndrome?
Refractory bradycardia that progresses to asystole
Most people with egg allergies are allergic to:
the albumin in the egg whites
When is propofol infusion syndrome most likely?
In children receiving doses > 4mg/kg/hr for greater than 48 hrs
What is the treatment for propofol infusion syndrome?
Pacing
PDE inhibitors
ECMO
Which preservative is present in diprivan?
EDTA, which does not have any side effects
Which preservatives are present in off brand propofol?
Metabisulfate, which can cause asthma attacks
OR
Benzyl alcohol, which should be avoided in infants
What dose of propofol can resolve itching?
As little as 10 mg
What is the onset time for fospropofol?
5-10 minutes
What is the duration of fospropofol?
15-45 minutes
What preservatives are present in fospropofol?
None! Its an aqueous solution and doesn’t require preservatives
What enzyme converts fospropofol to propofol?
Alkaline phosphatase
What is the IV induction dose of Ketamine?
1-2 mg/kg
What is the IM induction dose of Ketamine?
4-8 mg/kg
What is the PO induction dose of ketamine?
10mg/kg
What is the induction dose of etomidate?
0.2-0.4 mg/kg
What is the recommended opioid-sparing dose of ketamine?
0.2-0.5mg/kg
What should always be given with an etomidate induction?
It will not suppress the SNS response to laryngoscopy, so you should also use an opioid or esmolol
Which induction agent has the highest rate of PONV?
Etomidate
Does etomidate cause seizures?
In a person without epilepsy, no.
In a person with epilepsy, it can create epileptiform activity, which makes it useful for mapping seizure foci
WHY does etomidate cause adrenal depression?
It inhibits 11 beta hydroxylase, which is the enzyme that catalyzes cortisol production
How long does a single dose of etomidate produce adrenal suppression?
5-8 hours
What is Thiopental’s MOA?
GABA-A agonist
What are the respiratory effects of Thiopental?
It decreases respiratory drive and causes histamine release, which can lead to bronchoconstriction
What are the CV effects of Thiopental?
It causes hypotension and myocardial depression, but the baroreceptors remain intact so you get rebound tachycardia
Which anesthetic is the gold standard for ECT therapy?
Methohexital
What is Thiopental’s drug classification?
It’s a barbituate
What happens if Thiopental is injected intra-arterially?
Vasoconstriction and crystal formation
Need a vasodilator and/or an SGB
What are the two classes of barbituates?
Which produces more hypotension: thiopental or propofol?
Propofol
Thiopental provides neuroprotection in which circumstances?
Focal ischemia (CEAs)
NOT
Global (infarct, MI)
What is usually the first symptom of acute intermittent porphyria?
GI pain and N/V
What should be done preop in a patient with known porphyria?
Reduced NPO time and IV hydration prior to induction
Glucose supplementation
Heme Arginate
Which meds are safe in patients with porphyria?
Pretty much none of the IV induction agents, but:
Opioids
Inhalation agents
NMBs and NMB reversals
Midazolam
Vasopressors
Beta blockers
Which vasodilator should be used in the event of intra-arterial thiopental administration?
Phenoxybenzamine
OR
Phentolamine
What is the induction dose for methohexital?
1-1.5 mg/kg
Precedex does not reliably provide ________
Amnesia
What is the nasal dose of precedex in children for anxiolysis?
3-4 mcg/kg 1 hr before surgery
What is the PO versed sedation dose for anxiolysis in children?
0.5-1 mg/kg
Rank in potency:
Midazolam
Diazepam
Lorazepam
- Lorazepam
- Midazolam
- Diazepam
Why is midazolam suspended in water and not lipid?
It has an imidazole ring
At physiologic pH it is lipophilic
In acidic environments (in the vial) it is hydrophilic
How do benzodiazepines impact the GABA-A receptor?
Increase the NUMBER OF TIMES it opens and closes (vs. the duration of opening)
What is the initial dose of flumazenil?
0.2 mg
If the initial dose of flumazenil is insufficient, what is the follow up dose?
Additional 0.1mg increments until desired effect
What happens physiologically in response to flumazenil reversal?
Pretty much nothing
Unlike narcan, there’s no amplified SNS state
Does flumazenil reverse amnesia?
Usually no. Just the sedation.
What is the duration of action of flumazenil?
30-60 minutes
What is the induction dose of fospropofol?
6.5 mg/kg
