Local Anesthetics: Question Set #4

Factors which may enhance bupivacaine (Marcaine) toxicity:
1. pregnancy
2. calcium channel blockers
3. propranolol (Inderal)
4. B & C
5. A, B & C
Electrophysiological effect(s) of local anesthetics:
1. increased phase 0 slope
2. increased action potential conduction velocity
3. decrease P-R interval
4. none of the above
Toxicity: stereoisomerism effects
1. R-enantiomer of bupivacaine (Marcaine): less toxic than S-enantiomer
2. ropivacaine (Naropin) less toxic than bupivacaine (Marcaine)
3. both
4. neither
Lidocaine (Xylocaine) effects on ventilatory response to hypoxia
1. enhancement of ventilatory response to arteriolar hypoxemia
2. depression of ventilatory response to arteriolar hypoxemia
Bupivacaine (Marcaine) effects on ventilatory response carbon dioxide:
1. stimulation
2. inhibition
3. no effect
Most frequent use of local anesthetics:
1. prevention and treatment of cardiac arrhythmias
2. management of increased intracranial pressure
3. regional anesthetia
4. analgesia
5. management of grand mal seizure
Placement sites for regional anesthetia:
1. Bier block
2. subarachnoid
3. peripheral nerve block
4. topical use
5. all of the above
Anatomical location(s) for topical/surface local anesthesia
1. esophagus
2. genitourinary tract
3. tracheobronchial tree
4. B & C
5. A, B & C
Most commonly used local anesthetics for rhinolaryngologic cases:
1. tetracaine (pontocaine)
2. lidocaine (Xylocaine)
3. cocaine
4. all the above equally frequently used
Advantages of cocaine for use in rhinolaryngologic cases:
1. less bleeding
2. improve surgical visualization
3. both
4. neither
Cocaine substitution for use in rhinolaryngologic cases
1. lidocaine (Xylocaine) + oxymetazoline (Afrin) combination.
2. tetracaine (pontocaine) + oxymetazoline (Afrin) combination
3. both
4. neither
Effective agents for topical local anesthesia:
1. tetracaine (pontocaine)
2. procaine (Novocain)
3. chloroprocaine (Nesacaine)
4. B & C
5. A & C
Clinical uses for nebulized lidocaine (Xylocaine) -- surface anesthesia
1. treatment for intractable cough
2. anesthesia of upper & lower respiratory tract before bronchoscopy or fiber-optic laryngoscopy
3. both
4. neither
Definition: eutectic mixture local anesthetics (EMLA)
1. the combined mixture is significantly more potent then either drug alone
2. the combined mixture is metabolized more rapidly
3. the combined mixture is preferentially excreted by the kidney
4. the combined mixture has a melting point lower than either drug alone
5. none of the above
Clinical uses of EMLA:
1. myringotomy in adults and children
2. venipuncture
3. arterial cannulation
4. lumbar puncture
5. all the above
EMLA cream not recommended if:
1. patient is taking phenytoin (Dilantin)
2. the application is to a skin wound
3. the patient is taking mexiletine (Mexitil)
4. B & C
5. A, B & C
Appropriate local anesthetic for patients allergic to bupivacaine (Marcaine) and procaine (Novocain):
1. lidocaine (Xylocaine)
2. prilocaine (Citanest)
3. dyclonine (Dyclone)
4. cocaine
5. bupivacaine (Marcaine)
Most common local anesthetic choice for local infiltration
1. ropivacaine (Naropin)
2. bupivacaine (Marcaine)
3. lidocaine (Xylocaine)
In peripheral nerve block:more distal anatomyis typically anesthetized last
1. true
2. false
In mixed peripheral nerves (motor/sensory)-- sequence of anesthesia
1. motor first
2. sensory first
3. depended on anatomical locations within the nerve fiber
And peripheral nerve blockade, why lidocaine (Xylocaine) has a shorter time to onset compared to bupivacaine (Marcaine):
1. lidocaine (Xylocaine) is more lipophilic
2. bupivacaine (Marcaine) is subject to extensive ester hydrolysis
3. lidocaine (Xylocaine) is present to a greater extent in an un-ionized form
Local anesthetic not recommended for their block or for local infiltration:
1. ropivacaine (Naropin)
2. bupivacaine (Marcaine)
3. tetracaine (pontocaine)
4. lidocaine (Xylocaine)
Local anesthetic not recommended for Bier block
1. lidocaine (Xylocaine)
2. prilocaine (Citanest)
3. bupivacaine (Marcaine)
Local anesthetic agents not recommended for Bier block
1. chloroprocaine (Nesacaine)
2. bupivacaine (Marcaine)
3. ropivacaine (Naropin)
4. B & C
5. A, B & C
For Bier block (intravenous regional anesthetia):reduced systemic toxicity risk
1. prilocaine (Citanest)
2. lidocaine (Xylocaine)
Local anesthetic agent suitable for epidural anesthesia
1. ropivacaine (Naropin)
2. mepivacaine (Carbocaine)
3. lidocaine (Xylocaine)
4. B & C
5. A, B & C
Relatively reduced motor effects: local anesthetic beneficial for obstetrical patients and labor
1. bupivacaine (Marcaine)
2. ropivacaine (Naropin)
Often no zone of sympathetic nervous system blockade:
1. epidural
2. spinal
Zone of differential motor blockade: average two segments below the sensory level
1. epidural
2. spinal
Larger local anesthetic dose required
1. epidural
2. spinal
Factors affecting local anesthetic doses in spinal anesthesia
1. segmental level of anesthesia required
2. patient height
3. duration of anesthesia required
4. A & C
5. A, B & C
Not suitable for spinal anesthesia:
1. tetracaine (pontocaine)
2. chloroprocaine (Nesacaine)
3. lidocaine (Xylocaine)
4. bupivacaine (Marcaine)
Factor(s) affecting spread of drug following lumbar injection:
1. glucose addition
2. distilled water addition
3. both
4. neither
Physiological effects of spinal anesthesia: consequences of sympathetic blockade
1. arteriolar dilation
2. hypotension
3. both
4. neither
Effect on heart rate of T1-T4 blockade:
1. tachycardia
2. bradycardia