Patients and Pre-Anesthetic Considerations

Question 1

Definition of General Anesthesia

Answer 1

-Reversible state of unconsciousness, immobility, muscle relaxation, and loss of sensation throughout the entire body produced by administration of one or more anesthetic agents

-A patient cannot be aroused even with painful stimulation

-Commonly used to prepare patients for surgery or other acutely painful procedures

Question 2

Definition of Surgical Anesthesia

Answer 2

A specific stage of general anesthesia in which there is a significant degree of analgesia and muscle relaxation to allow surgery to be performed without patient pain or movement

Question 3

Definition of Analgesia

Answer 3

A loss of sensitivity to pain

Question 4

Definition of Sedation

Answer 4

-Drug-induced CNS depression or drowsiness that vary in intensity from light to deep

-Patient generally minimally aware or unaware of its surroundings but can be aroused by noxious stimulation

-Often used to prepare patients for diagnostic imaging, grooming, wound treatment, or other mild procedures

Question 5

Definition of Tranquilization

Answer 5

-Drug-induced state of calm in which the patient is reluctant to move and is aware of but unconcerned about its surroundings

-Term often used interchangeably with sedation even though they are not exactly the same in meaning

Question 6

Definition of Hypnosis

Answer 6

-Drug induced sleeplike state that impairs the ability of the patient to respond appropriately to stimuli

-Term somewhat imprecise as it is used to describe various degrees of CNS depression*

*In textbook, used to mean a sleeplike state from which the patient can be aroused with sufficient stimulation

Question 7

Definition of Narcosis

Answer 7

Drug-induced sleep from which the patient is not easily aroused and that is most often associated with the administration of narcotics

Question 8

Definition of Local Anesthesia

Answer 8

-Loss of sensation in a small area of the body produced by administration of a local anesthetic agent in proximity to the area of interest

-Example: Infiltration of local anesthetic into the tissues surrounding a small tumor to facilitate removal

Question 9

Definition of Topical Anesthesia

Answer 9

-Loss of sensation of a localized area produced by administration of a local anesthetic directly to a body surface or to a surgical or traumatic wound

-Example: Use of ophthalmic local anesthetic drops in the eye before an ophthalmic examination and application of local anesthetic to an open declaw incision for the purpose of pain control

Question 10

Definition of Regional Anesthesia

Answer 10

-Larger areas can be targeted by use of regional anesthesia, which refers to a loss of sensation in a limited area of the body produced by administration of a local anesthetic or other agent in proximity to sensory nerves

-Can be produced with a variety of techniques including nerve blocks and epidural anesthesia

Question 11

Benefits of Balanced/Multimodal Anesthesia

Answer 11

-Maximizes the benefits of each drug

-Minimizes adverse side effects

-Gives the anesthetist the ability to produce anesthesia with the degree of CNS depression, muscle relaxation, analgesia, and immobilization appropriate for the patient and procedure

Question 12

Anesthetic drugs have a ___ therapeutic index.

Answer 12

Narrow

Question 13

Most anesthetic drugs cause temporary changes in ___ and ___ function.

Answer 13

-Pulmonary and Cardiovascular function

Question 14

List some of the effects of anesthetic drugs on pulmonary and cardiovascular function.

Answer 14

-Decrease in cardiac output, respiratory rate, tidal volume, and blood pressure

Question 15

List the criteria and a representative condition for a Class PS2 patient.

Answer 15

-Patient with mild systemic disease

-Neonatal, geriatric, or obese patients, mild dehydration

Question 16

List the criteria and a representative condition for a Class PS3 patient.

Answer 16

-Patient with severe systemic disease

-Anemia, moderate dehydration, compensated major organ disease

Question 17

List the criteria and a representative condition for a Class PS4 patient.

Answer 17

-Patient with severe systemic disease that is a constant threat to life

-Ruptured bladder, internal hemorrhage, pneumothorax, pyometra

Question 18

List the criteria and a representative condition for a Class PS5 patient.

Answer 18

-Moribund patient that is not expected to survive without the operation

-Severe head trauma, pulmonary embolism, GDV, End-stage major organ failure

Question 19

Explain how anesthetics should be dosed on obese patients and why.

Answer 19

-Anesthetics should be dosed accordingly to lean body weight (excluding body fat) instead of total body weight

-Fat increases total body weight, but not the volume or weight of the nervous tissue on which anesthetics exert their effect

-Administration of a dose calculated using total body weight results in an anesthetic overdose

Question 20

List the physical exam findings on a patient that is 5% dehydrated.

Answer 20

-Minimal loss of skin turgor
-Semidry mucous membranes
-Normal eyes

Question 21

List the physical exam findings on a patient that is 5% dehydrated.

Answer 21

-Moderate loss of skin turgor
-Dry mucous membranes
-Weak rapid pulses
-Enophthalmos (depressed globes within orbits)

Question 22

List the physical exam findings on a patient that is >10% dehydrated.

Answer 22

-Considerable loss of skin turgor
-Extremely dry mucous membranes
-Tachycardia and weak/thready pulses
-Hypotension
-Severe enophthalmos
-Altered level of consciousness

Question 23

Describe the signs associated with a lethargic patient.

Answer 23

-Mildly depressed
-Aware of surroundings
-Can be aroused with minimal difficulty (verbal or tactile stimulus)

Question 24

Describe the signs associated with an obtunded patient.

Answer 24

-Very depressed
-Uninterested in surroundings
-Responds to but cannot be fully aroused by a verbal or tactile stimulus

Question 25

Describe the signs associated with a stuporous patient.

Answer 25

-Sleeplike state
-Nonresponsive to verbal stimulus
-Can be aroused only by a painful stimulus

Question 26

Describe the signs associated with a comatose patient.

Answer 26

-Sleeplike state
-Cannot be aroused by any means; unresponsive

Question 27

A decreased heart sound intensity in a nonobese patient may indicate ___.

Answer 27

Pericardial or pleural effusion

Question 28

Horses may exhibit ____ when at rest.

Answer 28

1st or 2nd degree atrioventricular block

Question 29

Cats and most other exotic mammals such as rabbits, ferrets, and rodents should always have ___.

Answer 29

-Normal sinus rhythm
-Sinus arrhythmia is not normal in these species

Question 30

What is a sinus arrythmia?

Answer 30

-A rhythm in which the heart rate cyclically increases during inspiration and decreases during expiration

-Differentiated from abnormal rhythms by observing the respirations - abnormal rhythms not associated with breathing

Question 31

1st Degree AV Block

Answer 31

-Caused by a conduction delay through the AV node and is recognized by a prolonged PR interval on an electrocardiographic tracing

-Causes no noticeable change in the heart sounds and therefore can be detected only by electrocardiography

Question 32

2nd Degree AV Block

Answer 32

-Caused by a periodic block of electrical conduction through the AV node and is recognized by missing QRS complexes on the ECG tracing

-On auscultation, periodic pauses representing skipped beats are audible

-Not normal for more than one beat to be skipped in a row

Question 33

___ and ___ are more sensitive to opioids than dogs and ruminants.

Answer 33

Horses and cats

Question 34

Use of ___ should be avoided in ruminants.

Answer 34

-Anticholinergics

-Can cause their saliva to become thick and ropy, which can lead to airway occlusion or cause them to regurgitate during any point during anesthesia

Question 35

Vesicants

Answer 35

Agents that damage tissue when they’re delivered perivascularly