Induction Agents Flashcards
Propofol
Induction dose:
MAC Sedation Dose:
1-2.5 mg/kg IV
MAC — 25-75 mcg/kg/min
The general anesthesia sedation/maintenance dose of Propofol is:
25-200 mcg/kg/min
Indications for Propofol (5)
Induction and MAC
TIVA
Outpatient surgery and endoscopy
Antiemetic
Malignant Hyperthermia
MOA of Propofol:
GABA agonist
Cardiac and respiratory effects of Propofol:
Decreases CO, BP, SVR (slight decrease in HR until pt is asleep then increases to compensate for CV decreases)
dose-dependent respiratory depression
Decreased Vt
Increased RR (at maintenance doses)
Bronchodilator (direct effect on intracellular Ca++)
T or F: Propofol is a neuro protective drug
T
Propofol CNS effects:
- neuroprotective — decrease CBF, CMRO2, and ICP & decreased SVR may cause decreased CPP
- anticonvulsant
Contraindications of Propofol (3)
Allergies to soybean oil or soy products
Allergies to egg and egg products
Allergies to sulfite
Correct onset and duration of Propofol:
Onset: <1 min
**”30 seconds or so…”
Duration: dose and rate dependent
Metabolism of Propofol occurs in:
Hepatic
Kidney and lungs (account for ~ 30%)
Excretion of Propofol is via:
Renal System
unconventional use of propofol and MOA
10 mg IV for PONV and pruritis
MOA related to spinal cord suppression
T or F: propofol is good for WPW ablations because it has no AV or SN node depression
T
clinically when you should avoid propofol use
cardiac unstable or hemorrhaging
is propofol lipid soluble
yes
protein binding of propfol
97-99%
why can propofol injections be painful and what can you do to decrease it
glycerol; lidocaine 1 mg/kg
T or F: propfol has analgesic effects
F
T or F: Propofol is a chiral compound
F– not chiral
how is propofol partially reversed
physostigmine
induction dose of Ketamine:
IV
IM
1-2 mg/kg IV; 4-5 mg/kg IM
***in low dosing can be opioid sparing
infusion dose of Ketamine
1-2 mg/kg/hr
other name for Ketamine
Ketalar
other name for propfol
diprivan
indication for Ketamine (6)
- induction
- sedation
- sedation for mentally challenged or non-compliant such as kids
- CV collapse
- “bad” epidural/spinal
- Good for OB.
- tamponade ***she didnt say this !?
contraindication of Ketamine (4)
- Right heart dysfunction (decreases PVR)
- increased ICP
- Critically ill/shock pts ( catecholamine depletion r/t shock — will cause profound hypotension and unopposed direct myocardial depression)
- psych patients (will make them hallucinate)
MOA of Ketamine (3)
- noncompetitive NMDA antagonist that blocks glutamate
- stimulates the SNS: inhibits the reuptake of norepi
- dissociative anesthesia — dissociation btwn thalamocortical and limbic system
CV system effects of Ketamine
- increase BP, HR, CO, PAP, CVP, CI
- increases myocardial O2 requirements
in what CV patient should you be especially cautious of using Ketamine
pt with severe RIGHT heart dysfunction
Respiratory system effects of Ketamine (4)
- minimal depression
- maintain upper airway reflexes
- increased oral secretions (effects on muscarinic receptors)
- bronchodilator (used in bronchospasm dilator)
Neuro system effects of Ketamine (5)
- cerebral dilator (increased ICP)
- potential to produce myoclonic activity (usually considered an anticonvulsant though)
- prolongs and enhances effects of NMBDs
- emergence delirium
- Hallucinogenic: phencyclidine derivative
other system effects of Ketamine
- increased lacrimation and salivation –> premedicate with anticholinergic
what are a few clinical judgments necessary for Ketamine? (4)
- used in OB (NOT preeclamptic)
- ketamine dart 3-4 mg/kg for mentally challenged
- not good for brain lesions d/t increased ICP
- MAY be used as a last resort for status epilepticus
onset of Ketamine
IV
IM
IV- 30 seconds
IM 2-4 minutes
duration of Ketamine
IV
IM
IV 10-15 min
IM 15-25 min
metabolism of Ketamine
hepatic by demethylation via CYP 450
*active metabolite, Norketamine, is 1/3-1/5 as potent
excretion of Ketamine
Renal
T or F: Ketamine provides analgesia w/o airway compromise
T
more potent stereoisomer of Ketamine
S (+)
T or F: for Ketamine, there is a functional dissociation between thalamocortical and limbic systems
T
protein binding of Ketamine
only anesthetic that has low protein bind (12% or 20% depending on source)
describe the cataleptic state of Ketamine
pt eyes remain open with slow nystagmic gaze
other name for Thiopental
pentathol
induction dose of Thiopental
3-5 mg/kg IV
how should you adjust the induction dose of Thiopental for elderly
reduce by 30%
indications for Thiopental (4)
- induction/sedative
- hypnotic
- anticonvulsant
- treatment of ICP (Neuro cases)
contraindications of Thiopental (3)
- Acute intermittent Porphyria
- variegate Porphyria
- status asthmaticus (**d/t histamine release)
MOA of Thiopental (2)
- activates GABA — short acting barbituate
- decreases RAS (small histamine release)
CV effects of Thiopental
Hypotension
Depresses myocardium and relaxes vascular smooth muscle
respiratorey effects of Thiopental
resp depression
Neuro effects of Thiopental (3)
- potent cerebroconstrictor
- decreased CBF
- decreased ICP
GI effects of Thiopental
N/V
T or F: Thiopental has analgesic effects
F- may actually lower pain threshold; thus increasing sensitivity to pain
onset of thiopental
30-60 seconds
duration of Thiopental
5-30 min