General Anesthesia #3

Therapeutics-index range -- general anesthetics:
1. 0.5-1
2. 2-4
3. 5-10
4. > 10
Concerning measurement of anesthetic potency:
1. anesthetic potency is determined by measuring brain anesthetic concentration
2. anesthetic potency is determined based on alveolar gas concentration
3. both
4. neither
MAC:
1. Alveolar gas concentration that will produce retrograde amnesia in at least 20% of patients:
2. Alveolar gas concentration that will produce immobility in 50% of patients exposed to Led Zeppelin
3. Alveolar gas concentration that will produce immobility in 50% of patients exposed to painful stimuli
Anesthetic potency --
1. At equilibrium the partial pressure of the anesthetic gas in the lung is usually significantly higher than the partial pressure of the gas in the brain.
2. Concerning anesthetic gases -- there is a rapid equilibrium between blood and brain partial pressures
3. MAC values are highly dependent on the nature of the painful stimulus
4. MAC values are relatively sensitive to patient gender, height, weight, and anesthesia duration
Guedel's four stages of general anesthesia:
1. medullary depression
2. surgical anesthesia
3. delirium
4. analgesia/amnesia
5. all of the above
Apnea, non-reacted dilated pupils, circulatory failure, and hypertension are most likely associated with this stage of general anesthesia:
1. amnesia/analgesia
2. delirium
3. surgical anesthesia
4. medullary depression
Central gaze, constricted pupils, regular aspirations, and the anesthetic depth is sufficient that noxious stimuli does not cause reflexes or excessive autonomic effects
1. analgesia/amnesia
2. delirium
3. surgical anesthesia
4. medullary depression
Halothane (Fluothane) --
1. usually adequate analgesia
2. Likely to provide adequate muscle relaxation
3. commonly used in adults; less likely to be used in children
4. reversible reduction of GFR
Enflurane (Ethrane)--
1. Widely used in pediatric cases
2. may cause concern if patient has a seizure-disorder history
3. skeletal muscle relaxation:inadequate for surgery
4. Difficult adjustment of anesthesia depth due to significant effects on pulse and respiration
Considering enflurane (Ethrane), halothane (Fluothane), and isoflurane (Forane) -- cardiac output is well maintained --
1. enflurane (Ethrane)
2. halothane (Fluothane)
3. isoflurane (Forane)
Isoflurane (Forane):
1. minimal muscle relaxation
2. promotes uterine muscle contraction; desirable if uterine contraction is required to limit blood loss
3. stimulates airway reflexes -- increasing secretions, coughing, and laryngospasm
4. convulsive activity is associated with isoflurane (Forane), similar to enflurane (Ethrane)
Isoflurane (Forane) anesthesia --
1. rapid, smooth adjustment of depth of anesthesia with limited effects on pulse or respiration
2. easily controlled depth of anesthesia
3. significant renal toxicity
4. A & B
5. A,B & C
Associated with malignant hyperthermia
1. halothane (Fluothane)
2. isoflurane (Forane)
3. both
4. neither
Probably isoflurane (Forane) is the most widely used inhalation agent (USA):
1. true
2. false
Desflurane (Suprane) anesthesia:
1. associated with laryngospasm and coughing
2. relatively high solubility
3. typically provides adequate muscle relaxation
4. malignant hyperthermia may be a problem, as with enflurane (Ethrane)
Sevoflurane (Sevorane, Ultane):
1. low blood solubility
2. resembles desflurane (Suprane) in pharmacological properties
3. very commonly used
4. A & C
5. A, B & C
Nitrous oxide anesthesia:
1. relativity solubility of nitrous oxide prevents rapid absorption of significant quantities of gas
2. may be associated with diffusional hypoxia
3. nitrous oxide is typically used in combination with the inducing agent (e.g. thiopental (Pentothal), the skeletal muscle relaxant, and hyperventilation
4. B & C
5. A & B
Nitrous oxide:
1. effective muscle relaxation
2. should not be used in the patient has occluded middle ear
3. significant depression of myocardial contractility
4. significant respiratory depression
5. A, B & C
Nitrous oxide disadvantages
1. no skeletal muscle relaxation
2. weak anesthetic
3. air pockets in closed spaces expand
4. post-anesthesia hypoxia (diffusional hypoxia)
5. all of the above
Nitrous oxide advantages:
1. excellent analgesia
2. nonflammable
3. very rapid onset and recovery
4. A & C
5. A, B & C