Term
| What are the general characteristics of neuromuscular blocking drugs? |
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Definition
-paralytic agents: msut ventilate the patient!
-provid skeletal muscle relaxation
-often used as adjuncts during anesthesia
-hypothermia
-do not cross BBB or placenta |
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Term
| True or False: Neuromuscular Blocking Drugs produce analgesia and unconsciousness htus can be used on an awake patient. |
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Definition
| -FALSE, do NOT produce analgesia or unconsiousness and CANNOT be used on consious patient |
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Term
| What are the two mechanisms for skeletal muscle relaxation? |
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Definition
-interference with ACh transmission in somatic nervous sysstem
-enhanced activity of endogenous inhibitory mechanisms |
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Term
| What are the two components of interference with ACh transmision in somatic nervous system? |
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Definition
-presynaptically
-postsynatpically |
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Term
| What are the two presynaptic mechanisms of interference with ACh transmission for skeletal muscle relaation? Give an example of each. |
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Definition
-Inh of ACh synthesis: Hemicolinium
-Inh of ACh release: Botulinum toxin |
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Term
| What are the two postsynaptic mechanisms of itnerference with ACh transmission for skeeltal muscle relaxation? Give an example of each. |
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Definition
-Persistent depolarization: succinuylcholine
-Competitive (non-depolarizing) blockade of ACh receptors: curare |
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Term
| What are the two drug types that give enhanced activity of endogenous inhibitory mechanisms and how do they work specifically? |
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Definition
-Benzodiazepines: GABA-ergic
-Guaifenesin: depression transmission through polysynaptic (interneuron) pathways |
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Term
| What are the indications for use of NMBs? |
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Definition
-facilitate intubation: more for humans
-control ventilation
-facilitate fracture reduction: traction would be more useful
-prevent eye rotation during eye surgery
-as a part of balanced anesthesia: especially in humans |
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Term
| What are the 4 types of neuromuscular blockade and give an example of I and II? |
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Definition
-Phase I: depolarizing block (Ex: succinylcholine)
-PHase II: competetive (non-depolarizing) block (curare-like)
-mixed: any combo of Phase I and II
-Dual block: occurs with excessive amounts or times of exposure to depolarizing agents |
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Term
| What is the sequene of muscle relaxation after neuromuscular blockade? |
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Definition
| -oculomotor m => palpebral m => facial m => tongue and pharynx => jaw and tai => limbs => pelvis m => caudal abdominal m => cranial abdominal m => intercostal n => larynx => diaphragm |
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Term
| What are the 4 main factors that inlfuence nneuromuscular blockade? |
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Definition
-temperature
-acid-base balance-fluid and electrolyte imbalance
-antibiotics |
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Term
| How does temeprature affect neuromuscular blockade? |
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Definition
-hyperthermia antagonizes competitive (non-depolarizing) blockade but enhaces/prolongs depolarizing blockade
-hypothermia prolongs competitive (non-depolarizing) NMB |
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Term
| How does acid/base balance influence neuromuscular blockade? |
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Definition
-respiratory acidosis augments competitive (non-depolarizing) NMB
-inadequate reversal of competitive block = resp acidosis enhances blockade = viscious cycle |
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Term
| How does fluid and electrolyte imbalance influence neuromuscular blockade? |
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Definition
-hypokalemia and hypomcalcemia potentiate competitive NM
-dehydration inc plasma conc of normal dose of competitive NMB, augmenting effect
-high Mg blood levels enhance both depolarizing and competitive NMBs
-NMB that occurs with electrolyte imbalance is referred to as a non-acetylcholine block |
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Term
| How do antibiotics influence neuromuscular blockade? Examples? |
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Definition
-may potentiate competitive NMB
-ex: Neomycin, streptomycin, gentamycin, kanamycin, paromycin, viomycin, polymyxin A and B, colistin, tetracycline, lincomycin, clindamycin |
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Term
| What are the characteristics of a depolarizing neuromuscular blockade? |
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Definition
| -paralysis is die to prolonged depolarization of motor endplate |
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Term
| How is paralysis of a depolarizing neuromuscular blcoade terminated? |
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Definition
| -termination of paralysis is due to metabolism of pseudocholinesterase => plasmachilinesterase |
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Term
| IS a depolarizing neuromuscular blockade reversible? Give an example of a depolarizing NMB. |
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Definition
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Term
Compare Succinylcholine and Acetylcholine regarding the following:
a) duration of motor endplate depol
b) hydrolyzed by enzyme _______
c) split products
d) location of enzyme |
|
Definition
a) S: 1-10 min & A: milliseconds b) S: plasmachilesterase & A: acetylcholinesterase
c) S: succinylmonocholine chloride and succinic acid & A: choline and acetate
d) S: plasma (pdc in liver) & A: nerve, muscle, RBCs |
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Term
| What are the adverse effects of succinylcholine? |
|
Definition
-hyperkalemia: use with caution in burn victims, patients receiving digitalis, massive m trauma victims
-muscle soreness
-histamine release
-potential bradycardia or tachycardia an d hypertension
-malignant hyperthermia (with halothane)
-deficiency/abnormal plasmacholinesterases (prolonged blockade) |
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Term
| What are the contraindications for using a depolarizing NMB? |
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Definition
-liver disease, chronic anemia, or malnutirtion decrease plasmacholinesterases
-hyperkalemia
-organophosphates
--glaucoma, penetrating eye wound |
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Term
| What are the characteristic so f a ceompetitive neuromuscular blockade? |
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Definition
| -competitive with ACh for postysynaptic Rc (no muscle fasciculation) |
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Term
| What are some exampless of a competitive NMB? |
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Definition
| -Pancuronium, atracurium, cis-atracurium |
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Term
| What type of drugs can be used to reverse a competitive blockade? |
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Definition
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Term
| Why should an anticholinegic be administered prior to reversal of a competitive blockade? |
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Definition
| -to block muscarinic effects (bradycardia, salivation, bronchial secretions) |
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Term
| The reversal drugs for competitive blockade cna also be used to diagnose and treat what disease? |
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Definition
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Term
| What does a respirometer measure? |
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Definition
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