Figure 3-1. Muscle depolarization.
3-4. USE OF THE NEUROMUSCULAR BLOCKING AGENTS
The neuromuscular blocking agents are used with general anesthetics to provide
sustained muscle relaxation. This sustained muscle relaxation reduces the tone of the
skeletal muscles (that is makes them flaccid or flabby) during surgical procedures.
Because of this skeletal muscle relaxation, the surgeon can easily cut through the
3-5. CLASSIFICATION OF THE NEUROMUSCULAR BLOCKING AGENTS
The neuromuscular blocking agents are classified as either non-depolarizing
agents or depolarizing agents.
a. The non-depolarizing agents compete with the neurotransmitter,
acetylcholine, for the muscle receptor site. Therefore, they prevent depolarization. This
produces flaccid paralysis of the skeletal muscles for a period of about one hour-
depending upon the concentration of the agent administered. The non-depolarizing
blocking agents are often referred to as competitive neuromuscular blocking agents.
Examples of non-depolarizing blocking agents are curare, vecuronium (Norcuron),
pancuronium (Pavulon), and cisatricurium (Nimbex).