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24 Cards in this Set
- Front
- Back
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What do Neuromuscular blocking agents do?
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Bind to nicotinic M receptors and block receptor activation causing the muscle to relax
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How can muscle function be restored after using a neuromuscular blocking agent?
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Eliminate the drug from the body or increawse the amount of acetylcholine
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What are the pharmacologic effects of neuromuscular blocking agents?
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-MUSCLE RELAXATION
-Hypotension- release of histamine causes BP to lower due to vasodilation -No effect on CNS- DO NOT DIMINISH CONSCIOUSNESS OR PERCEPTION OF PAIN-- EVEN WHEN ADMINISTERED IN DOSES THAT PRODUCE COMPLETE PARALYSIS |
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Neuromuscular blocking agents
How long do peak effects take? How long does recovery take? |
-15-20 minutes
- 1 hour |
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What are the therapeutic uses of neuromuscular blockers?
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-Muscle relaxation during surgery, mechanical ventilation, and endotracheal intubation
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Adverse effects of neuromuscular blockers
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Respiratory arrest from paralysis of respiratory muscles
----MAKE SURE ARTIFICIAL VENTILATION IS IMMEDIATLEY AVAILABLE Hypotension |
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Precautions and Contraindications of using neuromuscular blockers
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-Myasthenia Gravis- use with caution this disease is already characterized by muscle weakness- normal dosage could produce paralysis instead of the expected minimal effects
-Electrolyte disturbances- Low K+ can enhance paralysis high K+ can reduce paralysis-- IMPORTANT TO MAINTAIN NORMAL ELECTROLYTE BALANCE |
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Neuromuscular blockers drug interactions
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-General anesthetics- ENHANCE the actions of neuromuscular blockers- dosage should be reduced to avoid excessive neuromuscular blockade
-Antibiotics- can intensify the response to neuromuscular blockers -Cholinesterase inhibitors- can decrease the effects by reducing the degradation of ACh in COMPETITIVE neuromuscular blockers (it is the opposite in a depolarizing neuromuscular blockade) |
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What are the two clinical applications of cholinesterase inhibitors decreasing the response to competitive neuromuscular blockers?
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- Management of overdose with a competitive neuromuscular blocker
-Reversal of neuromuscular blockade following surgery and other procedures |
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What nursing management is required when dealing with neuromuscular blockers toxicity?
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-Provide respiratory support
-Provide a cholinesterase inhibitor to reverse neuromuscular blockade -Antihistamines can be given to reverse hypotension |
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What are the (5) Competitive neuromuscular blockers?
What is the (1) Depolarizing neuromuscular blocker? |
-Atracurium (Tracrium), Cisatracurium (Nimbex), Pancuronium, Rocuronium (Zemuron), Vcuronium (Norcuron)
-Succinylcholine (Anectine, Quelicin) |
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Which neuromuscular blockers promote histamine release?
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Atracurium (Tacrium) & Succinylcholine (Anectine, Quelicin)
Cisatracurium (Nimbex- promotes MINIMAL histamine release |
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How does succinylcholine work?
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-Keeps the end plate from repolarizing making it in a state of constant depolarization
-Initially contracts and then is held in a state of relaxation (paralysis) |
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Difference between competitive and depolarizing neuromuscular blockers?
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(1) Paralysis from succinylcholine is preceded by transient contractions
(2) Paralysis from succinylcholine becomes less intense more rapidly |
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When does succinylcholine peak and then fade?
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Peaks in 1 minute
Fades completely 4 to 10 minutes later |
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When would succinylcholine be used?
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With quick things
-Endotracheal intubation -Electroconvulsive therapy -Endoscopy Poorly suited for mechanical ventilation and surgery |
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Adverse effects of succinylcholine
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Prolonged apnea because of low pseudocholinesterase activity due to genetic makeup (CONTRAINDICATED FOR THESE PATIENTS)
---can figure out if they have a low pseu... with a blood sample or by administering a tiny test dose of succinylcholine Malignant Hyperthermia- characterized by muscle rigidity associated witha profound elevation of body temp Post op muscle pain develops 12 to 24 hours after surgery Hyperkalemia- succinylcholine promotes the release of potassium from tissues --most likely in patients with burns, multiple trauma, denervation of skeletal muscle or upper motor neuron injury (CONTRAINDICATED for these patients) |
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Treatment of malignant hyperthermia?
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-Immediate discontinuation of succinylcholine and the accompanying anesthetic
-----switch to a nontrigger anesthetic -cooling the patient with external ice packs and IV infusion of cold saline -Administering IV dantrolene (stops heat generation by reducing skeletal muscle metabolic activity) |
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Succinylcholine drug interactions
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Cholinesterase inhibitors- intensify the efects of succinylcholine (opposite of competitive)
Antibiotics- can intensify effects of succinylcholine |
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Management for succinylcholine overdose
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Supportive only
DO NOT use cholinesterase inhibitors- they will make it worse |
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Ongoing evaluation and Interventions to minimize APNEA
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Get intubation and mechanical ventilation immediately available
Monitor respiration constantly during the period of peak drug action When drug is discontinued take vital signs at least every 17 minutes until recovery is complete A cholinesterase inhibitor can be used to reverse respiratory depression (Except in the case of succinylcholine) |
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Ongoing evaluation and interventions to minimize HYPOTENSION
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Antihistamines can be given to counteract the histamine release
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Ongoing evaluation and interventions to minimize MALIGNANT HYPERTHERMIA
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Assess for family history of the reaction (its genetic)
Stop succinylcholine and the offending anesthetic Substitute a safer anesthetic Cool with ice packs, cold IV saline Give dantrolene |
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What do you do if the patient has muscle pain with succinylcholine?
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-Reassure the patient this is normal
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