Related Experiment Video
Updated: Jun 22, 2026
04:30
Stimulated Single Fiber Electromyography (SFEMG) for Assessing Neuromuscular Junction Transmission in Rodent Models
Published on: March 8, 2024
[Prolonged neuromuscular block after mivacurium: case report.]
1Instituto Nacional do Câncer.
Revista Brasileira De Anestesiologia
|May 27, 2009
Summary
Prolonged neuromuscular block can occur after mivacurium administration, even with normal preoperative screening. Anesthesiologists must manage this by sedating patients and providing mechanical ventilation until full recovery.
Area of Science:
- Anesthesiology
- Pharmacology
- Biochemistry
Context:
- Outpatient procedures are increasing due to short-acting drugs.
- Mivacurium is a common neuromuscular blocker for these procedures due to its short duration and enzymatic metabolism.
Purpose:
- To report a case of prolonged neuromuscular block after mivacurium administration.
- To discuss management strategies for this complication.
Summary:
- A patient experienced prolonged neuromuscular block post-mivacurium, diagnosed by low plasma cholinesterase activity.
- Management involved sedation and mechanical ventilation until muscle strength returned.
Impact:
- Preoperative screening for plasma cholinesterase activity may not predict prolonged block.
- Anesthesiologists should be prepared to manage this complication and counsel patients on atypical cholinesterase variants.
Related Concept Videos
01:17Nondepolarizing (Competitive) Neuromuscular Blockers: Mechanism of Action
Nondepolarizing neuromuscular blockers induce paralysis by competitively blocking nicotinic acetylcholine receptors at the muscle end plate. Examples include pancuronium, mivacurium, vecuronium, and rocuronium. These quaternary ammonium derivatives are administered intravenously, are poorly absorbed, and are excreted via the kidneys.
Competitive antagonists prevent acetylcholine from binding to its receptor, inhibiting membrane depolarization. Without conformational changes or intrinsic...
Competitive antagonists prevent acetylcholine from binding to its receptor, inhibiting membrane depolarization. Without conformational changes or intrinsic...
01:27Nondepolarizing (Competitive) Neuromuscular Blockers: Pharmacological Actions
Nondepolarizing neuromuscular blockers prevent the membrane depolarization of muscle cells and inhibit muscle contraction. These are usually administered with anesthetics to achieve complete muscle relaxation. Upon administration, these drugs first block the small, rapidly contracting muscles of the face and hands, followed by the larger muscles of the trunk and the intercostal muscles. The diaphragm is the last muscle to be affected.
Although all competitive neuromuscular blockers are designed...
Although all competitive neuromuscular blockers are designed...
01:11Nondepolarizing (Competitive) Neuromuscular Blockers: Pharmacokinetics
All neuromuscular blocking agents are injected intravenously because they are poorly absorbed from the GI tract. Rapid onset is achieved with intravenous administration, although absorption is also adequate from an intramuscular injection. Since these agents are highly ionized, they do not readily penetrate cell membranes or cross the blood-brain barrier.
Instead, they are transported by the blood to different tissues. Muscles with a greater blood supply (arteries) and blood flow receive more...
Instead, they are transported by the blood to different tissues. Muscles with a greater blood supply (arteries) and blood flow receive more...
01:28Depolarizing Blockers: Mechanism of Action
Depolarizing blockers act on skeletal muscle fibers' membranes and induce their depolarization. Most depolarizing blockers have two quaternary N+ atoms that bind the nicotinic acetylcholine receptors and cause neuromuscular blockade within minutes.
Succinylcholine is the most commonly used depolarizing blocker. Chemically, it constitutes two molecules of acetylcholine joined together by an acetate methyl group. They act on the receptors in the same way as acetylcholine. Because succinylcholine...
Succinylcholine is the most commonly used depolarizing blocker. Chemically, it constitutes two molecules of acetylcholine joined together by an acetate methyl group. They act on the receptors in the same way as acetylcholine. Because succinylcholine...
01:31Skeletal Muscle Relaxants: Therapeutic Uses
Skeletal muscle relaxants are used to relax muscle tone and alleviate painful muscle contractions. However, the choice of skeletal muscle relaxants depends on the duration of the surgical procedure in order to minimize potential side effects. Skeletal muscle relaxants like neuromuscular blocking agents [NMBAs] are commonly employed as adjuvants alongside general anesthetics in clinical settings. NMBAs are also used to maintain controlled ventilation during surgery of the larynx or pharynx as...
01:19Depolarizing Blockers: Pharmocokinetics
Depolarizing blockers are administered through intravenous injection. Succinylcholine is the most common choice of depolarizing blockers in emergency clinical practices. Although they have a rapid onset, they readily diffuse away from the motor end plate into the extracellular fluid. They are metabolized by enzymes such as liver butyrylcholinesterase and plasma pseudocholinesterases. This produces a short duration of action, typically 5-10 minutes long, unlike nondepolarizing blockers, which...