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Vet Nursing I - Lecture > Anesthesia > Flashcards

Flashcards in Anesthesia Deck (16):



Define anesthesia

What types of anesthesia are there?

Loss of sensation

Depression or stimulation of CNS





Muscle Relaxation


Pain control


General Anesthesia


Define G.A.

What are the stages

Reversible state of unconsiousness

Administration of 1 or more anesthetic drugs

Patient cannot be aroused


Stages of G.A.

Light Surgical Anesthesia

Moderate Surgical Anesthesia

Deep surgical Anesthesia

Anesthetic overdose


Surgical Anesthesia


Describe S. A.

Stage of General Anesthesia

Sufficient amount of Anagesics and muscle relaxation

Patient doesn't move

Patient is unaware


Sedation vs. Tranquilization vs. Dissociatives


  • CNS Depression
  • Drowsiness
  • Slightly aware or unaware of surroundings
  • Can be aroused by stimulation
  • Used for minor procedures



  • Calmness
  • Aware of surroundings
  • Reluctance to move




Local Anesthesia



Describe L.A.

Targets small, specific area

Loss of sensation to the specific area



Topical Anesthesia


Describe T.A.

Superficial loss of sensation

Applied to the body surface


Regional Anesthesia


Describe R.A.


Nerve blocks

Loss of sensation to a limited area

i.e. Epidural Anesthesia


Balanced Anesthesia



Describe B.A.

Using multiple drug in smaller quantities

Maximizes benefirs

Minimizes adverse effects


Vital Signs


What are the vital signs

Heart Rate

Heart Rhythm

Respiratory Rate

Respiratory Deth

Mucous Membrane Color

Capillary Refill Time (CRT)

Pulse Strength

Blood Pressure

Body Temperature



Anesthetic Depth - Reflexes


Name and describe all the reflexes

Predicts responses to anesthesia at various depth

  • Palpebral
  • Pedal
  • Swallowing
  • Laryngeal (Epiglottis/vocal chords closes immediately when touched)
  • Papillary Light Reflexes (PLR) aka Dazzle reflex (constriction of pupils in response to light.  Present in light and medium anesthesia)
  • Corneal (for large animals: add drop of saline to eye. If eye retacts, reflex is present)


Anesthetic Depths - Pupil


Describe anesthestic depth based on eye postition

Eyeball position:

  • Looking straight ahead = light plane
  • eyeball looking ventro medially = medium anesthetic depth
  • Looked down then up with dilation = deep anesthetic depth. (check heart rate)

*Dead animals - looks straight ahead with dilated eyes


Mydriatic vs Miotic


Define Nystagmus

Mydriatic:  Dilated pupil (during stage 2 anesthesia)


Miotic:  Constricted pupil (light anesthesia)


Widely dilated pupil = deep anesthesia


Nystagums:  Oscillation of eyeball

  • Fast nystagums = light anesthetic depth




Stages & Planes of Anesthesia - Stage 1




  • Period of voluntary movement
  • Starts to lose consciousness
  • Increased heart rate & respiratory rate
  • Stage ends with loss of ability to stand and recumbency
  • There may be fear, excitement, disorientation, struggling, urination, defecation


Stages & Planes of Anesthesia - Stage 2



  • Period of involuntary movement (Excitement stage)
  • Irregular breathing, vocalization, struggling, paddling (unconscious behavior)
  • Increased heart rate & respiratory rate
  • Pupils dilated
  • Reflexes present
  • Stage ends with muscle relaxation, decreased respiratory rate and reflex activity


Stages & Planes of Anesthesia - Stage 3



Period of surgical anesthesia

Plane 1 - Light

  • Not adequate for surgery
  • Regular respiratory pattern
  • Reflexes are still present but decreased
  • Eyeball starts to rotate ventrally, pupils partially constricted
  • Endotracheal tube can be passed

Plane 2 - Medium

  • Suitable for surgery
  • Shallow respiration with decreased rate
  • Decreased blood pressure
  • Mildly decreased heart rate
  • Relaxed muscle tone
  • Pedal & swallow reflex are absent
  • Ventromedial eye rotation, moderate pupil size

Plane 3 - Deep

  • Deep anesthesia depth - excessive for most procedures except orthopedics
  • Low heart rate & respiratory rate
  • Decreased tidal volume
  • Reduced pulse strength
  • Delayed capillary refill time
  • Absent PLR
  • Central eyeball position, moderately dilated pupils
  • Absent reflexes
  • Relaxed muscle tone

Plane 4

  • Early anesthesia overdose
  • Fully dilated pupils
  • Dry eyes
  • Absent reflexes
  • Depressed cardiovascular system
  • Pale mucous membrance
  • Delayed CRT
  • Flaccid muscle tone
  • Abdominal breathing



Stages & Planes of Anesthesia - Stage 4



  • Period of anesthetic overdose
  • Cessation of respiration
  • Circulatory collapses
  • Death


*Resuscitate immediately to save patient