General Anesthetic Flashcards
What leads to higher potency in inhalatioal aneshtetics?
Lipid solublity determines potency
What do inhalational anesthetics work on for its effects?
GABAa receptors which are Cl- channesl to produce an IPSP
Is there an antidote for inhaled anesthetics?
No
What influences potency and the MAC level for inhaled anesthetic?
Age, Temperature, Medicine
What happens with increased cardiac output with inhaled anesthetics?
Slower induction of effects
What is Fa/Fi?
End Tidal Partial Pressure (aka brain partial pressure)/Inspired concentration
What do we measure to get the measurement of the inhaled drug in the pt?
Measure hte expiratory concentration of anesthetic
What determines the anestheic uptake into blood after delivery to alveoli?
Solubility
Partial Pressure Difference
Cardiac Output
Whichis imore soluble in blood halothane or NO?
Halothane is very soluble in blood
NO is not soluble
Why does halothane take a long time to reach equilibrium?
Halothane likes to be in blood- > blood can thus hold halothane as it diffuses throuhg -> longer time to reach eqiulibrium
Thus it takes longer to spill over into brain as well than NO
What a does a lamda value indicate?
Blood/Gas Partition coefficient
What is solubility?
How much a gas diffuses from alveoli into arterial blood
More soluble gas will take longer to equlibriate due to rapid solubilization into blood
Which organs do the inhaled anesthetics reach first?
BHLK: Brain Heart Lung Kidneys which are vessel rich organs
Then skin and muscle
Last: Fat
How does increased C.O decrease induction?
Increased blood flow near alveolus slows equilibrium due to increased uptake of anesthetics -> brain concentration takes longer time to reach equilibrium now if heart rate is higher
How do pts emerge from the anesthetics?
Turn off gas and give 100% oxygen or extubate to protect airway
What are hte side effects of general anesthetics?
Decreases Cardiact output and O2 consumption
Decreased vascular resistance (vasodilations)
Increased blood flow to brain but decreased CMRO2 (cerebral metabolic rate of O2 ) => uncoupling
Which anesthetic has hte most rapid onset and recovery?
Sevoflurane
Which anesthetics have a medium rate of onset and recovery?
Isoflurane
Enflurane
Halothane
Which anestheic is an incomplete anesthetic?
NO
What is propofol?
IV anesthetic agent
Can be used to maintain anesthetic to keep pts asleep
How does propofol work?
IPSP via gaba receptor
What are the effects of propofol?
Decreased CMRO2 and ICP in brain
Veno/Vasodilation
Respiratory Depression
What is thiopental?
Barbiturate using GABA
Not avilable in US
What are the effects of thiopental?
Decreased CMRO2 and Vasoconstriction
What is ketamine?
NMDA receptor antagonist for dissociative anesthesia (Pt looks awake despite being asleep)
What is ketamine used for?
Induction and short procedures Pain Control Keep breathing (Bronchodilator) and does not decrease respiratory drive
What are the effects of ketamine?
Increased CMRO2, Cerebral blood flow and ICP
Inc BP and HR
What are hte indications for ketamine?
Trauma
Asthma
What is Etomidate?
GABA receptor agonist anesthetic with the least CV side effects
What are the effects of Etomidate?
Vasoconstrictor and dec CMRO2
Decreased adrenal -> dec NE -> body response to stress ddecreased
