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Introduction to Anesthesia

Anesthesia is utilized daily in most veterinary practices to provide sedation, tranquilization,

immobility, muscle relaxation, unconsciousness,

and pain control

Chapter 1

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Human Anesthesia

Dr. William T.G. Morton Dr. Oliver Wendell Holmes, Sr. 1846—diethyl ether

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Veterinary Anesthesia

1850s—ether and chloroform Early twentieth century—inhalation

anesthesia 1930s—injectable barbiturates

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Anesthesia

Loss of sensation Central nervous system (CNS) depression or

stimulation

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Use of Anesthesiain Veterinary Medicine

Effect Sedation Tranquilization Immobility Muscle relaxation Unconsciousness Pain control

Procedure Surgery Dentistry Grooming Diagnostic imaging Wound care Capture and

transport of wild animals

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General Anesthesia

Reversible Produced by administration of one or more

anesthetic drugs Characteristics

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Surgical Anesthesia

A stage of general anesthesia Analgesia and muscle relaxation Eliminate pain and patient movement during

the procedure

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A Continuum of CNS Depression

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Sedation vs. Tranquilization

Sedation CNS depression Drowsiness Drug-induced Various levels Slightly aware or

unaware of surroundings

Aroused by noxious stimulation

Uses: minor procedures

Tranquilization Calmness Patient is reluctant to

move Aware of

surroundings but doesn’t care

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Hypnosis vs. Narcosis

Hypnosis Drug-induced Sleeplike state Impairs patient’s

ability to respond to stimuli

Patient can be aroused with sufficient stimulation

Narcosis Drug-induced sleep Patient is not easily

aroused Associated with

narcotic drugs

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Local Anesthesia

Targets a small, specific area of the body Loss of sensation to a specific area Drug is infiltrated into the desired area

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Topical Anesthesia

Applied to body surfaces or a wound Produces a superficial loss of sensation

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Regional Anesthesia

Loss of sensation to a limited area of the body

Nerve blocks Epidural anesthesia

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Balanced Anesthesia

Using multiple drugs in smaller quantities Maximizes benefits Minimizes adverse effects Gives anesthetist greater control

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The Veterinary Technician’s Roleas an Anesthetist

Anesthetic machine Preparation Operation Maintenance

Administer anesthetic agents Endotracheal intubation Patient monitoring

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Anesthesia Challenges and Risks

Dose calculation and rate adjustment Vital signs and anesthetic depth Assess multiple pieces of information Patient management Anesthetic accidents

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Dose Calculation and Rate Adjustment

Narrow therapeutic index

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Vital Signs and Anesthetic Depth

Drugs may cause changes in cardiovascular and pulmonary systems

Changes may be lethal Patient must be closely monitored

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Assess Multiple Pieces of Information

Visual, tactile, and auditory From patient, anesthetic machines, and

monitors Must be able to make rapid decisions

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Patient Management

Understand physical parameters Understand anesthetic equipment Understand monitoring devices

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Anesthetic Accidents

The outcome can be devastating or lethal Owners may pursue legal action Prevent accidents by using high standards Keep meticulous records