Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
gen anesthetics
UVa med pharmacology block 2
| Question | Answer |
|---|---|
| Isoflurane | Halogenated Ether - anesthesia maintenance - activates GABAa receptors ->incr inhibition Partition coef: 1.4, MAC 1.15, modest solubility sidefx: initial incr RR decr TV->resp depression, incr doses->decr BP, incr HR |
| Sevoflurane | Halogenated Ether - anesthesia maintenance - activates GABAa receptors ->incr inhibition part coeff: .6 MAC 2.0 solubility btw iso & des sidefx: same as isoflurane, mild odor |
| Desflurane | Halogenated Ether - anesthesia maintenance - activates GABAa receptors ->incr inhibition part coeff .42 MAC 6.0 lowest solubility sidefx: same as Isoflurane, irritates airway, can cause incr BP, tachycardia |
| Nitrous Oxide | anesthesia maintenance - inhibs NMDA glutamate receptors-> decr activation Part coeff .47 MAC 101 very low solubility fx: use w/other drugs |
| Thiopental | Barbituate for clinical anesthesia - activates GABAa receptor->inhibition fx: can cause significant cardiac depression - action terminated by redistribution |
| Midazolam | Benzo for anxiolysis/sedation - activate GABAa receptor->inhibition |
| Propofol | General anesthetic - induction for general anesthesia/sedation - activates GABAa receptor->inhibition |
| Etomidate | General anesthesia - activate GABAa receptors->inhibition fx: pain on injection, myoclonic mvmnts, decr cortisol/aldosterone synth |
| Ketamine | General anesthesia - inhibs NMDA glutamate receptors - causes analgesia, loss of aweareness sidefx: may cause hallucinations, incr salivation |
| Characteristics of Desflurane | Very similar to isoflurane Less soluble irritant to airway, can cause hypertension and tachycardia |
| True or False: "less solublility means faster onset" Why or why not? | TRUE More solubility would mean that a larger portion of the drugs needs to dissolved before an appreciable tension builds up. |
| Which stage of anesthesia is really an overdose? Define this stage. | Stage 4 Depression of vital medullary centers, cardiorespiratory depression |
| Which of these is solubility, concentration and which one is tensions? 1) Gas that is truly in solution 2) Gas suspended in microscopic gas phase | 1) Solubility 2) Tension 1 + 2) Concentration |
| Charactersitcs of Sevoflurane | Solubility between isoflurane and desflurane Mild odor, good for mask induction |
| What is the clinical goal of anesthesia? In terms of stages. Define this stage. | Make duration of stage 2 as brief as possible Stage 2: blockade of inhibitory pathways, facilitation of excitatory transmission --> disinhibtion, excitement, amnesia, irregular respirations, vomiting, incontinence |
| What observation suggests that hydrophobic pockets within receptor channels may be the target of anesthesia? | The Meyer-Overton relationship still holds when studying proteins in a lipid-free environment |
| What else causes membrane expansion that does not induce anesthesia? | Minor temperature increases |
| What is the driving force for partitioning of inhaled anesthetics? What does this mean about their pharmacokinetics? | Driving force is partial pressure NOT concentration, so pharmacokinetics are different from injected drugs |
| What do Nitrous Oxide (NO2) and Xe primarly inactivate? | NMDA glutamate receptors |
| What is Porpofol's main use? What else can it be used for? | Most commonly used to induce anesthesia Also effective for sedation |
| What do halogenated ethers primarily activate? | GABA receptors |
| What is the respiratory effect of all inhaled anesthetics? | First, increase respiration and decrease tidal volume Later, respiratory depressions |
| How do isoflurane, desflurane, and sevoflurane decrease BP? What does this mean for HR? | The decrease peripheral vascular resistance, thus they INCREASE HR |
| Which Barbituate is most commonly used in clinical anesthetia? Dangerous side effect? | Thiopenthal Can cause significant cardiac depression |
| Where is immobilization mediated by anesthesia? Where is unconsicousness mediated by anesthesia? What is the evidence? | Immobilization at the spinal cord, unconsciousness at the cerebral level It takes much higher doses to achieve immobilization in response to pain at the cerebral level alone |
| How does Ketamine's mechanism of action differ from other IV anesthetics? What side effects can it cause? What can block this side effect? | Acts via NMDA receptor blockade. May cause hallucinations but these are blocks by BDZ's |
| What is the current thinking about the interactions of most inhaled anesthetics? | Most interact with membrane lipids and/or proteins |
| Characterisitcs of Isoflurane | inhaled anesthetic less used these days, but standard for comparison moderately soluble |
| What are the blood pressure of effect of all inhaled anesthetics? When do they occur? | They all decrease BP at HIGHER concentrations |
| How does Etomidate compare to thiopenthal? What are some drawbacks of using this drug? | Does not decrease cardiac function as much Pain upon injection, myoclonic movements, and inhibts cortisol and aldosterone synthesis in adrenal cortex |
| What is Midazolam primarily used for? | Anxiolysis and sedation |
| What are some issues that complicate anesthesia investigation? | - multiple sites of action - different techniques can yield very similar results - no good depth-of-anesthesia measurements - no structure-function relationships |
| What are gas concentration, tension, and gas solubitlity analogous to when considering injected drugs (bound to plasma proteins)? | Concentration : total plasma concentration Tension : unbound, free plasma concentration which is the driving force for transport Solubility : degree of protein binding |
| Characteristics of Nitrous Oxide. What is a dangerous side effect | High MAC (101%) Requires other drugs (analgesic at lower concentrations) Very low solubility, few hemodynamic effects INACTIVATES METHIONINE SYNTHASE --> can depress bone marrow and fetal tissue at prolonged exposures |
| What is the interpretation of the Meyer-Overton relationship? What does this suggest? What evidence supports this suggestion? | For virtually all inhaled anesthetics, when applied at equipotent pressure, a concentration of 70mM is reached in a CNS site with chemical properties resembling olive oil. Suggests direct interaction with neuronal membranes |
| How does Halothane decrease BP? What does this mean for its effect on HR? | Depresses myocardial function, so it does not increase HR |
| What are the four anesthetic body-compartments and what are their anesthetic characteristics? | 1) vessel-rich (brain, heart,kidney, viscera) 2) Muscle groups (muscle, skin) 3) Vessel poor group (bone, ligament, cartilage) 4) Fat |
| How do most INTRAVENOUS anesthetics work? | activate GABA receptors, thus hyperpolarizing neurons and inhibiting their function |
| What are the three kinds of anesthesia? What are their characteristics? How are they typically induced? | Gen - unconsciousness, amnesia, immob, analgesia, reflex inhib, skel muscle relax inhalation, intravenous, combo Region-loss of sensation and muscle relax subarach/epidural; periph blockade Local-loss of sensation due to infiltration or topica |
Created by:
sam.mrosenfeld
Popular Pharmacology sets