McKenna's Pharmacology for Nursing, 2e

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General and local anaesthetic agents

Learning objectives Upon completion of this chapter, you should be able to:

1. Describe the concept of balanced anaesthesia. 2. Describe the actions and uses of local anaesthesia. 3. Describe the therapeutic actions, indications, pharmacokinetics, contraindications, most common adverse reactions and important drug–drug interactions associated with general and local anaesthetics. 4. Outline the preoperative and postoperative needs of a person receiving general or local anaesthesia. 5. Compare and contrast the prototype drugs thiopentone, midazolam, nitrous oxide and lignocaine with other drugs in their respective classes. 6. Outline the care considerations, including important teaching points, for people receiving general and local anaesthetics.

Test your current knowledge of general and local anaesthetic agents with a PrepU Practice Quiz!

Glossary of key terms amnesia: loss of memory of an event or procedure anaesthetic: drug used to cause complete or partial loss of sensation analgesia: loss of pain sensation balanced anaesthesia: use of several different types of drugs to achieve the quickest, most effective anaesthesia with the fewest adverse effects general anaesthesia: use of drugs to induce a loss of consciousness, amnesia, analgesia and loss of reflexes to allow performance of painful surgical procedures induction: time from the beginning of anaesthesia until achievement of surgical anaesthesia local anaesthesia: use of powerful nerve blockers that prevents depolarisation of nerve membranes, blocking the transmission of pain stimuli and, in some cases, motor activity plasma esterase: enzyme found in plasma that immediately breaks down ester-type local anaesthetics pre-medication: medication administered prior to surgery to facilitate sedation and general anaesthesia unconsciousness: loss of awareness of one’s surroundings volatile liquid: liquid that is unstable at room temperature and releases vapours; used as an inhaled general anaesthetic, usually in the form of a halogenated hydrocarbon

GENERAL ANAESTHETIC AGENTS Barbiturate anaesthetics thiopentone Non-barbiturate general

Amides bupivacaine cinchocaine levobupivacaine lignocaine mepivacaine prilocaine ropivacaine

midazolam propofol Anaesthetic gases ethylene nitrous oxide Volatile liquids desflurane

isoflurane methoxyflurane sevoflurane

LOCAL ANAESTHETIC AGENTS Esters amethocaine benzocaine

anaesthetics droperidol ketamine