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56 Cards in this Set
- Front
- Back
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Man who first recognized the anesthetic effects of N2O in 1800?
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Humphry Davy
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Man who first administered ether in 1842?
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C.W. Long
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Anesthetic agent developed in 1956 that represented a significant advancement in development of anesthetic agents?
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Halothane (sweet odor, non-flammable, highly potent)
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Commonly used inhalation agents (except N2O) are what chemical structure?
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ethers (r-O-r) or aliphatic hydrocarbons w/ no more than 4 carbon atoms
**longer than 4 carbon atoms=decreased production of anesthesia |
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What does halogenation refer to? What does it influence?
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*Refers to the addition of flourine (F), chlorine (Cl), bromine (Br), or iodine (I) to hydrocarbons and ethers
*Influences potency, arrhythmogenic properties, flammability, and chemical stability |
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Increasing the number of halogen atoms within a volatile agents favors what? Reduces the occurence of what?
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*cardiac dysrhthmias
Halothane has 5 halogens *Flammability is reduced and chemical stability enhanced by substituting H atoms w/ halogens |
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Increasing the number of flourine atoms to an anesthetic molecule reduces what?
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Biodegredation
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Which agent used at DMH undergoes the most metabolism?`
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Sevo (5-8%)
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Lipid solubility of an inhaled anesthetic agents is directly proportional to what?
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potency
*higher the oil/gas PC, the more potent it is *iso is very potent *higher the oil gas PC, lower the MAC |
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Mechanisms by which the spinal cord mediates immobility to painful stimuli w/ anesthetics?
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*enhancing background K+ currents
*reducing spontaneous action potential firing of spinal neurons via glycine receptors (GABA) |
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Areas in the brain which IA affect?
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brainstem, cerebral cortex, and hippocampus
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Most likely site of action for volatile anesthetics?
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GABA receptor (subtype A)
*ligand gated Cl- channel |
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MAC-awake
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minimum alveolar concentration at which 50% of subjects will respond to command "open your eyes"
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What is MAC-BAR
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the MAC necessary to block the adrenergic response (changes in plasma norepi, HR, rate pressure product and MAP)`
*requires a greater depth of anesthesia than that to produce skeletal muscle relaxation *usually 1.2-1.3 X MAC |
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What effects does hypocarbia and hypercarbia have on the brain?
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*Low CO2 constricts vessels and elevated CO2 dilates vessels
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Better control of CBF via manipulation of PaCO2 with what 2 agents?
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1.0 MAC Iso and 67% N2O
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What type of anesthesia may be necessary for neurosurgical procedures?
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TIVA may be considered as pt needs to wake up quickly for post surgical neuro assessment
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Emergency phenomenon (delirium & agitation) in children results during emergency in what 2 IA agents?
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sevo and des
*may be reduced by analgesics or sedatives |
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Increasing MAC progressively decreases MAP? Compare iso, sevo, and des
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Des>iso>sevo in regards to decreasing MAP w/ increasing MAC
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Iso, des and sevo do what to MAP, CO, and CI?
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Decrease them
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How do des, sevo, and iso reduce MAP?
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by decreasing SVR
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How does Halothane lead to a reduce in MAP?
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direct myocardial depressionion versus a reduction in preload
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How does N2O affect MAP? Cardiac contractility?
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activates the sympathetic nervous system and increases SVR which can also increase SVP and arterial pressures
*direct neg inotropic effect |
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Compare reductions in CI w/ iso, halothane, and des?
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Halothane>iso>des
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At deeper levels of anesthesia, iso and Des do what to HR?
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increases it
*may pretreat w/ fentanyl, especially with steep increase in HR produced by des |
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As MAC hours of anesthesia increase w/ iso, sevo, and des, what happends to CI and HR? Pupil size?
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slight increase
*mydriasis also present |
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How do volatile anesthetic agents reduce myocardial contractility?
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by reducing Ca2+ concentration in cardiac and vascular smooth muscle
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What is coronary steal syndrome? What 2 agents are capable of this?
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a reduction in perfusion of ischemic myocardium w/ simultaneous improvement of blood flow to nonischemic tissue (usually occurs w/ HoTN)
*iso and des |
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What effect do iso, sevo, and des have on coronary circulation?
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produce coronary vasodilation w/ sevo having the LEAST effect
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What is APC?
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anesthetic preconditioning: help protect the myocardium from ischemic and reperfusion insult
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Which 2 IA agents will not produce bradycardia and AV nodal conduction disturbances?
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des and iso
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What does the term "sensitization" refer to?
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the ability of the volatile agents to reduce the quantity of catecholamines necessary to evoke dysrhythmias
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Significant arrhythmias can occur w/ the use of inhalational agents and what cardiac drug?
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amiodarone
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N2O does what to pulmonary vascular resistance? Volatile agents?
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*increases it
*decrease PAP *1.6 MAC Des increases it |
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IA agent effects on the respiratory system?
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*decreased response to CO2 (increased apneic threshold)
*depressed Vt *increased RR *depressed hypoxic drive (caution in ppl for whom this is their drive to breathe) *relax airway smooth muscle and produce bronchodilation |
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IA agent effects on the renal system?
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*decreased GFR
*decreased intraop UOP |
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What IA least alters renal integrity? What tests can be used to determine renal alternation?
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*Desflurane
*retinol binding protein & NAG |
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What variables increase the amount of Compound A formed w/ sevo? What are the effects of compound A?
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low fresh gas flows, high sevo concen., and dry soda lime
*produces corticomedullary tubular necrosis in rats? |
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What do volatile anesthetics do to total hepatic blood flow?
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*reduce it (halothane has most significant effect)
*But iso, sevo, and des increase or maintain hepatic artery flow |
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Patient type that is prone to halothane hepatitis?
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obese patients: increased enzymatic activity in CYP-450 2 E1
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What compound is yielded w/ des and iso metabolism?
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TFA-protein molecules
*triflouroacetylated (TFA) |
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Chronic exposure to N2O can lead to inactivation of which vitamin?
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B12: disrupts DNA synthesis
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Which volatile anesthetic agent produces the greatest degree of NM relaxation?
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sevo>iso>halothane
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What 2 IAs can potentiate the effects of succ?
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iso and N2O
*accelerate transition from phase I to phase II block |
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Which anesthetic gas is acceptable for MH patients?
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N2O when combined w/ other IV anesthetic agents
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Treatment for MH?
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Dantrolene 2.5 mg/kg IV every 5 min up to 10 mg/kg
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Advantages of N2O?
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analgesia, rapid uptake and elmination, little cardiac or resp depression, nonpungent, allows less potent anesthetic to be administered
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Disadvantages of N2O?
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expansion of closed air spaces, requires high concen., diffusion hypoxia, teratogenic
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Advantages to halothane?
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cheap, effective in low concen., and excellent bronchodilator
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Disadvantages to halothane?
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slow uptake/elimin., biotransformed, hepatic necrosis, catecholamine induced ventricular ectopy, impairs pulmonary macrophage activity and cilia activity, MH TRIGGER
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Advantages to isoflurane?
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moder muscle relaxation, decreased CMRO2, min biotransformation, maintain CO d/t vasodilation, cheap
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Disadvantages to isoflurane?
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pungent, airway irritant, negative inotrope, MH trigger
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Desflurane advantages?
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rapid uptake/elim., stable molecules, min biotransformation
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Desflurane disadvantages?
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airway irritant, low boiling point, sympathetic stimulation, expensive, special vaporizer, MH trigger, increased concen.=HTN, tachy
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Sevoflurane advantages?
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rapid uptake/elim, nonpungent (good for inhal. induction), CV effects similar to iso
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Sevoflurane disadvantages?
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susceptive to biotransformation, reacts w/ soda lime, increases serum flouride, expensive, MH trigger
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