Download Local & General Anesthetics

Local & General Anesthetics
Ch 11
General Anesthesia
Alters responses of the Central Nervous
system
 Causes one or more of the following

Pain relief
 Muscle relaxation
 Relaxation of reflexes
 Deep sleep


Commonly used during surgery
Main Categories

Inhaled – may be liquid or gas
Nitrous oxide – gas
 Halothane – liquid

 Several

others that end with –ane
Inhaled drugs are used together with IV
drugs to provide the best level of sedation
for the patient & procedure = Balanced
Anesthesia
Intravenous

Fentanyl


Versed


Anticholinergic – decreases secretions
Demerol, morphine


Benzodiazepine - amnesia
Atropine


Opioid analgesic – pain relief
Opioid analgesics – lighter pain relief
Vistaril, phenergan, seconal

Sedative/hypnotic – lighter amnesia/sedation
Local Anesthetics

AKA Regional anesthetics
Block nerve conduction in specific area of body
 Prevents pain sensation


2 Forms
Topical
 Parenteral (injected)

Topical

May be patch, cream or lotion, liquid, spray
Dermoplast
 Lidocaine
 Pontocaine
 EMLA cream

Parenteral

Spinal


Into the space surrounding the spinal cord
Epidural
Through catheter into the epidural space just
outside the spinal cord
 May remain in place for continuous infusion

Infiltration – to numb area to be sutured
 Nerve block – stop impulses from specific
nerve (example: chronic back pain)

Neuromuscular Blockers
Used during surgery
 Paralyze respiratory and skeletal muscles
 Requires artificial ventilation
 Also used in ICU with ventilator patients

CNS Depressants &
Muscle Relaxants
Ch 12
Sedatives
Reduce nervousness
 Reduce excitability
 Reduce irritability
 Do Not cause sleepiness

Hypnotics
Reduce nervousness
 Reduce excitability
 Reduce irritability
 Do cause sleep

Sedative-Hypnotics
Drugs that can have either sedative or
hypnotic effect
 3 classifications

Barbiturates
 Benzodiazepines
 Miscellaneous agents

Barbiturates
Are Habit-forming (addictive)
 Rapidly lead to toxicity
 Depress respirations
 Used for

Anesthesia
 Control convulsive conditions
 Prevent epileptic seizures

Barbiturates, cont’d

Phenobarbital


Most commonly prescribed
Forms
Tablets
 Capsules
 Elixirs
 Injections
 Suppositories

Benzodiapines
Relatively safe
 Most commonly prescribed
 Used for

Sedation
 Sleep induction
 Skeletal muscle relaxation
 Reduce anxiety

Benzodiazapines, cont’d

Examples
Temazepam = restoril
 Zolpidem = ambien


Antidote is flumazenil = romazicon
Muscle Relaxants
Act on the CNS
 Benefit is more from sedation than from
relaxation of muscles
 Primarily used for relief of muscle spasms



Best when used with physical therapy
No specific antidote
Miscellaneous agents

Chloral hydrate = Noctec
Oldest in this category
 Relatively short duration of action
 Does not suppress REM sleep


Tizanidine = zanaflex

Treats muscle spasms
Antiepileptic Agents
Ch 13
Epilepsy
Common name for seizure disorder
 Not a disease
 CNS dysfunction



Momentary lapses to total body convulsions
Action not completely known

Alter electrolytes
Treatment
Diazepam = valium
to stop seizure once it has started
Phenytoin = dilantin
to prevent future seizure activity