Term
| What are the two main routes of administration for the general anesthetics? |
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Definition
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Term
| What are the 5 characteristics of general anesthetics? |
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Definition
-LOC
-Analgesia
-Amnesia
-Skeletal muscle relaxation
-Inhibition of autonomic and sensory reflexes |
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Term
| What is the Ostwald coefficient? |
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Definition
The ratio of the conc. of anesthetic in blood to the conc. of anesthetic in the gas phase when the partial pressure of the anesthetic is equal in both phases.
-The larger the coeficient, the longer it takes to reach equilibrium, therefore, induction time is slower. |
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Term
| What is the affect of lipid solubility on inhalation anesthetics? |
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Definition
| the higher the lipid solubility the slower the recovery. |
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Term
| What is the relationship of minimal alveolar conc. (MAC) and potency? |
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Definition
| The lower the MAC the more potent. |
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Term
| Phase one of GA induction is what? and it depends on what 3 things? |
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Definition
Establishment of equilibrium between the inspired mixture and the lungs.
1. Initial conc. of gas in the inspired mixture.
2. Amount inhaled.
3. Second-gas effect. |
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Term
| In GA induction what is phase 2? and what does it depend on? |
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Definition
It is the passage of anesthetic from alveoli to the blood in pulmonary capillaries.
1. Ostwald coefficient - the lower the # the quicker it reaches equilibrium.
2. The partial pressure diff. of the agent in the alveoli vs. blood. |
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Term
| What is phase 3 of GA induction? What does it depend on? |
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Definition
It is the passage of gas from the blood into tissues, especially brain.
1. Solubility of gas in tissues
2. Partial pressure in blood relative to tissues.
3. Tissue blood flow. |
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Term
| How does obesity affect the rate of induction of GAs? |
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Definition
| It is slower than in lean people. |
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Term
| What two things speed the recovery from GAs? |
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Definition
-Higher ventilation rate
-Low solubility of the drug in blood or in lipids. |
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Term
| Anesthetics with a low Ostwald coeffiecient will have a ______ induction of anesthesia and a __________ recovery? |
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Definition
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Term
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Definition
| the minimum alveolar conc. at steady state which results in immobility in 50% of individuals when exposed to a noxious stimulus, such as surgical incision. |
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Term
| The lower the MAC value the _______ potent the anesthetic is? |
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Definition
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Term
| What causes the MAC value to decrease? |
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Definition
-the presence of adjuvant drugs, e.g., other anesthetics, opioids, sedative-hypnotics
-Hypothermia, hypotension and age |
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Term
| What is the most potent of the anesthetics? |
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Definition
| Methoxyflurane (MAC=0.16) |
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Term
| What is the least potent of the anesthetics? |
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Definition
| Nitrous Oxide (MAC=105.0) |
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Term
| The more lipid soluble an inhalation anesthetic, the ___________ the potency i.e. the lower the MAC value? |
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Definition
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Term
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Definition
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Term
| What is the MOA of GAs (except Ketamine)? |
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Definition
| Increase the GABA induced Cl current by over 50% by increasing the affinity of GABA for GABA-A receptors. |
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Term
| What is the MOA of katamine? |
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Definition
| selectively inhibits the NMDA receptor, thus blocking excitatory neurotransmission. |
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Term
| Of the four stages on anethesia, what is the target stage? |
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Definition
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Term
| What happens if you get to stage 4 of anesthesia? |
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Definition
-extremely dilated pupils
-RR very slow
-PR weak
-BP very low
They can go into respiratory failure. |
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Term
| What is the induction stage? |
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Definition
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Term
| What is the excitement phase? |
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Definition
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Term
| The loss of corneal blink reflex and a pattern of respiration that is regular in rate and depth are most reliable signs of what stage of anesthesia? |
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Definition
| III - surgery can proceed. |
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Term
| The MOA of inhalation anesthetics is not a factor in their ____________, but contributes to their _____________? |
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Definition
| duration of action, toxicity |
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Term
| An increase in the metabolic rate of inhalation anesthetics can cause what? |
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Definition
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Term
| T or F - High levels of fluoride from the metabolism of Methoxyflurane can cause Kidney damage? |
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Definition
| False. It causes liver damage |
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Term
| Adverse side effects in inhalation anesthetics? |
|
Definition
1. Malignant hyperthermia
2. Increased ICP in patients with brain tumor or head injury. |
|
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Term
| What causes malignant hyperthermia? |
|
Definition
| Succinylcholine in genetically susceptible individuals. |
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Term
| What is the treatment for malignant hyperthermia? |
|
Definition
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Term
| What are the objectives of preanesthetic medications? |
|
Definition
1. decrease patient anxiety
2. facilitate smooth and rapid induction
3. decrease muscle tone
4. alleviate undesirable side effects (nausea, vomiting, increased secretions).
5. relieve pre- and post-operative pain. |
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Term
| What are the long term SE of using Nitrous oxide? |
|
Definition
| B12 deficiency, neuropathy, leukopenia. |
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Term
| What are the SEs of Halothane? |
|
Definition
sensitized hear to catecholamines, can cause cardiac arrythmias.
-20% metabolism, releasing fluoride(possible liver damage) |
|
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Term
| Methoxyflurane side effects? |
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Definition
| Highly metabolixed (70%) to fluoride ion, and for this reason it is no longer in use. |
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Term
| What is the risk of liver damage with Enfluane? |
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Definition
| Minimal b/c only a very small amount is metabolized to release fluoride. |
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Term
| What is the risk of liver damage with Isoflurane? |
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Definition
| no metabolism, thus no fluoride release, and thus no risk of liver damage |
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Term
| What inhalation anesthetic is used when you want a rapid onset and rapid recovery? |
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Definition
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Term
| MAC values in children are generally _______ than in adults? |
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Definition
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Term
| What is the affect of low blood solubility on the rate of induction and recovery? |
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Definition
| Low blood solubility = rapid induction and recovery. |
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Term
Maintaining anesthesia at 1 MAC of halothane in one patient and at 1 MAC of enflurane in another patient means that?
a. the partial pressure in the alveolar space will be identical in each patient
b. the partial pressure of both agents in the brain will be identical
c. anesthesia will be deeper with the more potent agent.
d. the probability that either patient will move on skin incision is the same. |
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Definition
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Term
| T or F - IV anesthetics allow lower dose of inhalation anesthetics to be used, i.e. decrease MAC value. |
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Definition
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Term
| Why are IV anesthetics generally not used alone? |
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Definition
| They have a slower rate of elimination and therefore have a less easily controlled emergence. |
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Term
| What are the 7 classes of IV anesthetics? |
|
Definition
1. Barbiturates
2. Benzodiazepines
3. Etomidate
4. Opioid analgesics
5. Propofol
6. Dexmedetomidine
7. Ketamine |
|
|
Term
Barbiturates produce?
a. Sedation
b. analgesia
c. muscle relaxation
d. all of the above |
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Definition
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Term
| T or F - Barbiturates have a narrow therapeutic window? |
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Definition
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Term
| What is one advantage of Benzodiazepines in reguards to preanesthesia? |
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Definition
| They do not cause respiratory or cardiovascular depression. |
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Term
| What are some SEs of Etomidate? |
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Definition
| adrenocortical suppression at high doses, involuntary movements during induction and recovery. |
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Term
| What is the main SE of opioid toxicity and how is it treated? |
|
Definition
| Respiratory depression, naloxone. |
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Term
| What class of IV anesthetics can be combined with a neuroleptic drug to produce neuroleptic analgesia or neuroleptic anesthesia? |
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Definition
| Opioid analgesics (fentanyl + droperidol) |
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Term
| What is the main problem with propofol? |
|
Definition
| respiratory and cardiovascular depression. |
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Term
| What class of IV anesthetics when combined with inhalation anesthetics can decrease the MAC value by as much as 90%? |
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Definition
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Term
| What IV anesthetic produces "dissociative" anesthesia, where the patient remains conscious though amnesic and insensitive to pain? |
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Definition
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Term
| What are some of the adverse effects of Ketamine and how can they be avoided? |
|
Definition
High incidence, but less in childre, of dysphoria, hallucinations, unpleasant dreams, delirium during recovery.
adverse effects can be reduced by prior administration of a benzodiazepine. |
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