Related Concept Videos

Local Anesthetics: Clinical Application as Intravenous Regional Anesthesia01:16

Local Anesthetics: Clinical Application as Intravenous Regional Anesthesia

Intravenous regional anesthesia or the Bier block technique is used to anesthetize a specific limb or extremity. It uses exsanguinated or blood-drained vessels to transport local anesthetics or LAs to the peripheral nerve trunks. Lidocaine without vasoconstrictors like epinephrine is most commonly used for this technique. Other drugs used are prilocaine, ropivacaine, and chloroprocaine. Bupivacaine is not recommended for this technique due to its high cardiac toxicity.
One of the advantages of...
Drugs Acting on Autonomic Ganglia: Blockers01:28

Drugs Acting on Autonomic Ganglia: Blockers

Ganglionic blockers inhibit autonomic activity by blocking nicotinic receptors in the autonomic ganglia, suppressing impulse transmission. These blockers lack selectivity between sympathetic and parasympathetic ganglia and are ineffective as neuromuscular junction antagonists. They can be categorized into two groups:
Depolarizing Blockers: Pharmocokinetics01:19

Depolarizing 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...
Nondepolarizing (Competitive) Neuromuscular Blockers: Pharmacokinetics01:11

Nondepolarizing (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...
Nondepolarizing (Competitive) Neuromuscular Blockers: Pharmacological Actions01:27

Nondepolarizing (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...