Induction Drugs Flashcards
Propofol (Diprivan)
Drug Class
&
MOA
GABAA Agonist
Gamma AminoButyric Acid (GABA) agonist; selectively modulates GABAA receptors
↑ Cl- conductance
Hyperpolarization of the postsynaptic cell membrane & functional inhibition of the postsynaptic neuron
Propofol (Diprivan)
Induction Dose
IV: 1.5-2.5 mg/kg
Induction DOC - GI cases & TIVA
Propofol (Diprivan)
Conscious Sedation Dose
Maintenance Dose
Conscious Sedation
IV: 25-100 mcg/kg/min
Maintenance
IV: 100-300 mcg/kg/min
Propofol (Diprivan)
Anti-emetic Dose
Anti-pruritic Dose
Anti-emetic
IV: 10-15 mg
Anti-pruritic
IV: 10 mg
Propofol (Diprivan)
Anti-convulsant Dose
IV: 1 mg/kg
Propofol (Diprivan)
Onset
Peak
Duration
Half-life
Onset
30 sec
Peak
2.2 min
Duration
1-8 min
Half-life
30-90 min
Propofol (Diprivan)
Metabolism & Elimination
Metabolism
Liver: CYP450
Lungs: 1st pass clearance
Elimination
Kidneys
Propofol (Diprivan)
Side Effects
CNS
↓ CMRO2, CBF, ICP
Autoregulation r/t CBF & PaCO2 are maintained
Can produce myoclonus
Respiratory
Dose-dependent depression of MV
INTACT hypoxic pulmonary vasoconstriction response
Can have bronchodilator activity
Cardiovascular
Inhibition of SNS: ↓ SBP/HR
Profound ↓ HR & asystole d/t baroreceptor reflex depression is possible
Propofol (Diprivan)
Considerations
Propofol Infusion Syndrome - Lactic Acidosis
Infusions of >75 µg/kg/ min for > 24 hrs
Allergy concern: Lecithin is found in egg yolk
Crosses the placenta but is rapidly cleared in neonatal circulation
Cloudy urine d/t uric acid crystallization;
Green urine d/t phenols
Inhibits PLT aggregation that is induced by TXA2 & platelet-activating factor
More effectice than ondansetron as anti-emetic
Etomidate (Amidate)
Drug Class
&
MOA
GABAA Agonist
Gamma AminoButyric Acid (GABA) agonist; selectively modulates GABAA receptors
↑ Cl- conductance
Hyperpolarization of the postsynaptic cell membrane & functional inhibition of the postsynaptic neuron
Etomidate (Amidate)
Induction Dose
IV: 0.2-0.4 mg/kg
DOC for unstable CV pts
No analgesic effects
Etomidate (Amidate)
Onset
Peak
Duration
Half-life
Onset
30-60 sec
Peak
1 min
Duration
3-5 min
Half-life
2-5 hrs
Etomidate (Amidate)
Metabolism & Elimination
Metabolism
Hepatic: Hydolysis by hepatic & plasma esterases
Elimination
Kidneys: 85% active metabolite in urine
Etomidate (Amidate)
Side Effects
CNS
Potent, direct cerebral vasoconstrictor
↓ CMRO2 & CBF by 35-45% & ↓ ICP
Respiratory
NO Δ in MV
↓Vt is offset by compensatory ↑ in RR
Cardiovascular
CV stable - None to little ↓MAP; Can worsen w/ hypovolemia; No Δ in HR
Etomidate (Amidate)
Considerations
High incidence of myoclonus (occurs in 50-80% of pts); Can be prevented by giving opioids/BZDs
Adrenocortical Suppression
Dose-dependent inhibition of the conversion of cholesterol to cortisol; stress response ↓ & ↓BP; longer mechanical ventilation; Occurs 4-8 hrs after initial dose
Caution: sepsis & hemorrhage
Ketamine (Ketalar)
Drug Class
&
MOA
Non-competitive inhibition of
N-Methyl-D-Aspartate (NMDA) receptors by glutamate & ↓ presynaptic release of glutamate postsynaptic neuron
Other receptor sites:
Opioid µ, K, δ, & weak σ
Weak GABAA
Ketamine (Ketalar)
Induction Dose
IV: 0.5-1.5 mg/kg
IM: 4-8 mg/kg
Ketamine (Ketalar)
Maintenance Dosing
IV: 0.2-0.5 mg/kg
IM: 4-8 mg/kg
Ketamine (Ketalar)
Analgesic Dosing
IV: 0.2-0.5 mg/kg
Ketamine (Ketalar)
Onset
Peak
Duration
Half-life
Onset
IV: 30-60 sec - IM: 2-5 min
Peak
IV: 1 min - IM: 5 min
Duration
10-20 min
Half-life
2-3 hrs
Ketamine (Ketalar)
Metabolism
&
Elimination
Metabolism
Liver: CYP450 & plasmaesterases
Metabolite
norketamine (1/3 potency)
Elimination
Kidneys
Ketamine (Ketalar)
Side Effects
CNS
Potent cerebral vasodilator
↑ CBF by 60%
Respiratory
No significant depression of ventilation
Ventilatory response to CO2 is maintained
↑ salivary secretions
↑↑ Bronchodilator activity; no histamine release
Cardiovascular
Mimics SNS stimulation:
↑BP, PAP, HR, CO, CMRO2, plasma Epi & NE levels
Blunted by pre-med w/ BZDs or inhaled anesthetics & N20
Ketamine (Ketalar)
Considerations
Emergence Delirium
Avoid in pulmonary HTN & ↑ICP
Inhibits plasma cholinesterases:
Prolongs apnea from succinylcholine
Give glycopyrrolate IV 0.2 mg to counter m-Ach effects of
↑oral secretions (Sialagogue)
