Induction Agent Dosages Flashcards
Propofol (alternate name)
Diprivan
Propofol structure:
Sedative/hypnotic
2, 6 diisopropylphenol
Lipid soluble, weak acid
Propofol MOA:
- GABA-A agonist (Beta subunit)
- Decreases rate of dissociation of GABA from receptor increasing the duration of chloride channel opening
- Hyperpolarizes cell
- Also inhibits NMDA, stimulates glycine
Propofol Onset:
30-60 sec
Propofol duration of action:
5-15 min
Propofol PB:
98%
Propofol metabolism:
CYP3A4, 2B6
60% liver,
30% kidneys,
10% lungs/small intestine
Propofol IV induction dose:
IV: 1-2.5 mg/kg (induction)
Propofol IV drip dose:
IV: 50-300 mcg/kg/min (maintenance drip)
Propofol IV Sedation drip dose:
IV: 25-75 mcg/kg/min (sedation)
Propofol IV antiemetic dosing:
IV: 10 mcg/kg/min or
10-20 mg q5-10 min (antiemetic)
Propofol side effects:
- Decreased BP (25-40%)
- Decreased SV
- Decreased CO
- Decreased CBF
- Decreased CMRO2
Propofol Contraindications / cautions:
- Crosses Placenta
- Decrease in elderly
- Discard after 6 hr of drawing up
- Do not mix with other agents (PE risk)
- Painful injection (Ph? Propylene glycol?)
- Myoclonus
- Bradycardic death
- Green urine – benign
- increased Lipid levels
Etomidate (alternate name):
Amidate
Etomidate structure:
Non-barbiturate hypnotic
imidazole derivative
ester, base, water soluble
Etomidate MOA:
- GABA-A agonist (Beta subunit)
- Decreases rate of dissociation of GABA from receptor increasing the duration of chloride channel opening
- Hyperpolarizes cell
Etomidate onset:
30-60 sec
Etomidate duration of action:
5-15 min
Etomidate PB:
75%
Etomidate metabolism:
Hepatic ester hydrolysis to ethyl alchohol
Etomidate IV dose:
IV: 0.2-0.6 mg/kg (do not exceed 20 mg, induction)
Etomidate side effects:
- Most CV stable (maintains coronary perfusion)
- Myoclonus
- PONV (30-40%)
- Adrenocortical suppression
- Decrease ICP
Etomidate Contraindications / cautions:
- Painful injection (Propylene glycol)
- Hiccups
- Avoid in pt with chronic steroid use
- Avoid in long surgeries (increased stress response)
- Avoid if previous anaphylaxis
Ketamine (alternate name):
Ketalar
Ketamine structure:
Disociative hypnotic
Phencyclidine derivative
Cyclohexanone hydrochloride
base, lipid soluble
Ketamine MOA:
- NMDA noncompetitive antagonist (glutamate normally stimulates opening and permeability to calcium, potassium, and sodium)
- mu, delta, kappa Opioid agonist
- Cholinergic receptor agonist (salivation)
- Also acts on MAO – inhibits 5Ht, dopamine & NE reuptake
Ketamine onset:
IV: 30-60 sec IM: 2-4 min
Ketamine duration of action:
10-20 min
Ketamine PB:
12%
Ketamine metabolism:
CYP3A4, 2B6
hepatic demethylation to norketamine
Ketamine IV induction dose:
IV: 0.5-2 mg/kg
Ketamine IM induction dose:
IM: 4-8 mg/kg
Ketamine IV maintenance dose:
IV: 5-10 mg boluses up to 0.5 mg/kg throughout procedure
Ketamine IV sedation/analgesia dose:
IV: 0.2-0.5 mg/kg q 2-3 min (sedation/analgesia)
Ketamine IM sedation/analgesia dose:
IM: 2-4 mg/kg (sedation/analgesia)
Ketamine side effects:
- Bronchodilation
- Tachycardia
- Dissociative state
- Increased salivation
- Nystagmus
Ketamine Contraindications / cautions:
- Avoid in open eye injury
- Avoid in increased ICP
- Avoid in pulmonary hypertension
- Does not block pharyngeal/laryngeal reflex
- Avoid as sole anesthetic for CAD (myocardial depressant)
- Emergence delirium
- Minimal effect on respiratory drive (minimal apnea risk)
- Inhibits NE reuptake (increased BP, increased HR, increased CO)
- Always give Versed as well
- Don’t give to schizophrenia patients
- May cause hypotension in catecholamine depleted pts
