General Anesthetics Flashcards
loss of consciousness, amnesia, immobility
anesthesia
loss of pain sensation
analgesia
analgesia, amnesia, euphoria
Stage 1: anesthesia
Excitement, delirium, combative behavior
Stage 2: excitement
unconscious, regular respiration, decreasing eye movement
Stage 3: surgical anesthesia
respiratory arrest, cardiac depression/arrest, no eye movement
Stage 4: medullary depression
theory that the function of the excitable membrane protein is modified by dissolved anesthetics.
lipid theory
Mayerton-overton rule, hyperbaric pressure He can reverse anesthesia.
support lipid theory
Enantiomers have differential anesthetic potencies. Some chemical analogues of known anesthetics do not cause anesthesia.
counter lipid theory
cuases both significant enhancement of inhibition and inhibition of excitation
inhaled anesthetics
Inhibit excitatory NDMA and nicotinic receptors.
cyclopropane and ketamine, volatile NO and Xenon
enhancement of GABA transmission. Adrenocortical depression. Pain at injection site. Less CV and resp. depression than thiopental.
etomidate
rate of equilibration of inhaled anesthetics depends on what three things?
ventilation rate, plasma solubility, lipophilic character
preoperative anxiety and separation anxiety in children
midazolam
IV anesthetic. Enhances GABA. Rapid onset, recovery and no cumulative effects.
Propofol
most frequently used drug for induction of anesthesia, also used for maintenance in OR and ICU
Propofol
produces apnea after and induction dose
Propofol
Enhance GABA. Fast onset, slow recovery – hangover. Liver metabolized.
Barbiturates – Thiopental, Methohexital
routine induction agent. Tx – ICP and neuronal protection from focal cerebral ischemia. AE – vasoconstriction – gangrene, contraindicated in intermittent porphyria.
Barbiturates – Thiopental, Methohexital
perioperative anxiolytics. Anterograde amnesia, sedative hypnotic, antiseizure, anesthesia. Increase of GABA
BZ – diazepam, lorazepam, midazolam
OD of BZ give…
Flumazenil
IV NMDA inhibitor. Profound analgesia, stimulation of sympathetic NS, bronchodilation and minimal respiratory depression. AE – lacrimation, salivation, raised ICP.
ketamine
minimize hallucinations, vivid dreams, euphoria by combining ketamine with…
BZ – diazepam, lorazepam, midazolam
alternative to propofol and barbs for rapid IV induction of anesthesia.
Etomidate
Alpha-2 agonist. Adjunct to gen anesthesia. Short term sedation of intubated ventilated pts ICU. AE – heart block, bradycardia, asystole.
Dexmedetomidine
Inhaled agents currently in use.
halothane, NO, isoflurane, enflurane, desflurane, and sevoflurane.
volatile hepatotoxic, and malignant hyperthermia
halothane
produce signs of B12 deficiency – megaloblastic anemia. Outpt dental. Adjunct. AE – pneumothorax, post-op nausea.
NO
induction of anesthesia in children, maintenance in adults. Volatile. - sensitizes myocardium to catecholamines – arrythmias
Halothane
faster onset and recovery than halothane. Mostly maintenance. Isoniazid enhances metabolism. Requires MAC – less if administered with NO or opioids. AE – muscle relaxant, hypotension, seizure
Enflurane
similar to enflurane but no proconvulsive properties. Precipitates myocardial ischemia in pts with CAD. Airway irritant
Isoflurane
Maintenance. Airway irritant. Faster onset and recovery than isoflurane.
Desflurane
No airway irritation – except when reactant with baralyme. Widely used inhaled induction – especially in children.
Sevoflurane
allows pt to skip stages 1 and 2 of anesthesia
thiopental with inhaled anesthetic
maximize NO benefits while minimizing adverse effects.
NO with Isoflurane
