General Anesthetics Flashcards
what are 3 effects of preanesthetic medication
decrease respiratory secretions
antiemetic effect
decrease gastric juice acidity and volume in case of aspiration
what are 2 mechanisms of action of general anesthetics
enhance inhibitory activity (GABA)
diminish excitatory activity
to achieve effective concentration in CNS, inhaled anesthetics require transfer from __ –>__–>__
alveoli–>blood–>brain
are general anesthetics with low blood:gas partition coefficient more or less soluble in blood
less
do general anesthetics with low blood:gas partition coefficient have slow or rapid induction and recovery
low= less soluble in blood= rapid induction and recovery
high blood:gas partition coefficient
=___ soluble (more or less)
=__ induction and recovery (faster or slowe)
high coefficient= more soluble= slower
the higher the lipid solubility, the more or less potent the general anesthetic
higher solubility= more potent
at low pulmonary flow rates, is general anesthesia onset faster or slower
faster
what is the form of elimination of most general anesthetics
through lungs
what general anesthesia undergoes partial metabolism in the liver, leading to hepatotoxicity
Halothane
what is the MAC value
median alveolar concentration that results in immobility in 50% of patients when exposed to pain
do highly lipid soluble anesthetics have higher or lower MAC
lower
does a lower MAC mean more or less potent
more
nitric oxide is a good __ but weak __
anesthetic or analgesic
good analgesic
weak anesthetic
what 2 effects are seen during recovery with NO
second gas effect
diffusional hypoxia
NO use is cautioned in those with __
pneumothorax
Halothane is a good __ but weak__
anesthetic or analgesic
good anesthetic
weak analgesic and muscle relaxant
what inhaled analgesic is commonly used in children
Halothane
what are 3 adverse effects of Halothane
hepatic necrosis
malignant hypertension
can induce arrhythmias
what commonly used anesthetic maintains coronary circulation and does not provoke seizures
Isoflurane
what is an adverse effect of Sevoflurane
nephrotoxicity
what mode of general anesthetics have rapid induction and are used for maintenance of anesthesia when inhalational general anesthetics are contraindicated
IV
recovery from intravenous general anesthetics is mainly by __
redistribution
what characteristic of the IV anesthetic Thiopental provides a limitation
consciousness is regained in 10-20 minutes
what is the main use of Thiopental
induction of anesthesia in neurosurgery
what property of Thiopental allows it to be used in head injury
decreased cerebral blood flow so there is no increase in ICP
Thiopental is contradicted in patients with __
porphyria
what is the most commonly used IV anesthetic
Propofol
why is Propofol the most commonly used IV anesthetic
produces a euphoric effect
less postanesthetic nausea and vomiting
short half life
what is the mechanism of action of the IV general anesthetic Propofol
increases binding and affinity of GABA for GABA-A receptor
what are 2 adverse effects of the IV general anesthetic Propofol
decreases BP
respiratory depression
what is Propofol infusion syndrome (PRIS)
acute refractory bradycardia leading to asystole
what is the mechanism of action of the IV general anesthetic Etomidate
GABA like effects with potentiation of GABA-A mediated chloride channels
what is the effect of repeated administration of IV Etomidate
suppresses steroid production
what IV general anesthetic induces dissociative anesthesia in which the patient is conscious without feeling pain
Ketamine
what is the mechanism of action of Ketamine
blocks NMDA receptors
what is the effect of Ketamine on cerebral blood flow
increases cerebral blood flow and ICP
what general anesthetic produces hallucinations during the postoperative/recovery stage
Ketamine
one of the main uses of ketamine as an anesthetic agent is for what
burn dressing and trauma surgery
what anesthetic can be used to manage acute severe asthma in children
Ketamine
