Anesthesia Flashcards
Triad of anesthesia
amnesia, algesia, muscle relaxant
what are some main conditions to consider prior undergoing anesthesia
cardiovascular problems and respiratory disease
what effect will anesthesia have besides numbing to the site?
decreased respiration and blood pressure
General anesthesia MOA
increase GABA-A–>CNS depression
activate K+ channels for hyperpolarization
Inhibit Glutamate NMDA receptors–>decrease excitatory NT
which inhalable anesthetic can be used for mask induction?
Sevoflurane
Blood:Gas partition coefficient determines what? what is the relation to the drug and onset?
solubility in blood
the lower coefficient–>the less soluble–> faster onset and recovery
what can increase potency of an anesthetic?
Age(elderly), **exposure to other CNS depressant, increase PaCO2, severe anemia/hypoxemia
What is the limitation of nitrous oxide
LOW potency; incomplete anesthetic; has insufficient potency for surgical anesthesia
what is the 2nd gas effect from nitrous oxide?
↓induction time for primary agent
↓Required concentration of primary agent
↓toxicity of primary agent
what are some disadvantages of N2O
lack potency
cannot be used as sole agent
lack skeletal muscle relaxation
potential airpockets in closed space to expand
which halogenated agents has very rapid onset and recovery, and excellent minute-to minute control?
Desflurane, sevoflurane
what are the general adverse effects for halogen agents?
- Depression of cardiovascular function
- Depression of respiration and response to CO2
- Decreased blood flow to liver and kidneys
- Organ toxicity—varies by agent
- Malignant Hyperthermia
which halogen drug is safest to use for people with impaired liver and kidney functions due to lower toxicity
Isoflurane
Which anesthetic agent is frequently used as IV drip anesthetic?
propofol
Dissociative Anesthesia
intense analgesia, catalepsy and amnesia: patient is immobilized, appears awake but no awareness or recollection after recovery
What anesthetic has dissociative anesthesia?
Ketamine
“Emergence phenomenon”
Emergence process is unpleasant: dreams, hallucination, disorientation
what drug causes emergence phenomenon
ketamine
Which drug can be used to substitute for thiopental/propofol in high risk patients?
Midazolam
Analgesic adjuvant drugs
morphine/fentanyl/sufentanyl/opioids
Antiemetic adjuvant drugs
Scopolamine
Anticholinergic
Scopolamine, glycopyrrolate
Ideal anesthetic agent includes
amnesia algesia muscle relaxant unconsciousness Areflexia-eliminiate noxious reflexes -good min to min control smooth and rapid induction/recovery -Wide margin of safety and few adverse effects
what anxiolytic/hypnotic drugs are used as adjuvant drugs?
Midzolam and diazepam, thiopental
what are the 4 stages of anesthesia? which stages would you want to get out as soon as you can?
- analgesia
- excitement
- surgical anesthesia
- Medullary suppression
2 and 4. least time in
which agent is the “milk of amnesia”
propofol
Perineural infiltration
injection of agent at one or more site around specific area where anesthesia is desired
disadvantage: large amt of drug in one area could lead to systemic toxicity
what are the advantages/disadvantages of spinal block
advantage: affects large body area w/ small amt of drug. patient can be conscious with min disruption of respiratory and cardiovascular function
disadvantage: could reach brain via CSF
epidural block and its advantages
injection into EXTRADURAL space to block nerve roots. can stilll target larget part of body w/ small amt of drug and avoids CSF, so will not get to brain
when you have high Cm, what type of fiber, pH and potency will you have
larger fiber, decrease in pH, and decrease in potency
which fibers will be blocked first? last?
B fibers: preganglionic, small and myelinated
A-alpha(motor, proprioception)–last
what type of nerve fiber is most sensitive and would be blocked first
nociceptive (sensory) nerves, preganglionic, myelinated
what is the effect on increasing calcium concentration?
increase Cm, decrease potency
what do you NEVER do with an LA?
inject LA w/ vasoconstrictor into areas with end arterioles (digi,toes, nose, penis)
which LA is more prone for systemic toxicity
Amides
which LA is more prone for causing allergic rxn?
ester
which anesthetic drug can be given orally or injection
Lidocaine
which Local anesthetic drug has high incidence of Transient neurologic symptoms w/ spinal administration?
lidocaine
which drug is frequently used for epidural infusion/ labor analgesia/post op pain
bupivacaine
which LA increases risk of cardiotoxicity
bupivacaine
which drug should be used that has less cardiotoxicity effect and less potent
levobupivicaine
Which is the primary use for dental anesthetic
Articaine
what is PABA prone for
allergic rxn
what do you always have to do prior to giving a patient ester LA
check if patient have rxn towards PABA
which ester LA is ONLY topical use?
Benzocaine
which ester agent is used for labor anesthesia?
chloroprocaine
EULA, use? and what is it composed of
mixture of lidocaine and prilocaine in oil-water emulsion.
topical anesthetic on intact skin
what is a topical used for pediatrics in ER
tetracaine, Adrenalin, and cocaine
what are the neurolytic agents, and what is its use?
ethyl alcohol and phenol;
permanent block in terminal cancer or other chronic condition
primary goal of preanesthetic medication
- Reduction in requirement for inhalation agents
- increase rate of induction
- decrease anxiety
- reduction in acidity and volume of gastric contents
- relief of preo/postop pain
- reduction in side effects associated w/ inhalational agents
