Anesthesia Flashcards
Anesthesia
Define anesthesia
What types of anesthesia are there?
Loss of sensation
Depression or stimulation of CNS
Sedation
Tranquilization
Immobility
Muscle Relaxation
Unconsciousness
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
Sedation
- CNS Depression
- Drowsiness
- Slightly aware or unaware of surroundings
- Can be aroused by stimulation
- Used for minor procedures
Tranquilization
- Calmness
- Aware of surroundings
- Reluctance to move
Dissociatives
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
Describe
- 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
Describe
- 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
Describe
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
