Monitoring Anesthesia Flashcards
Values that reflect Oxygenation
Mucous Membrane Color
Hemoglobin Saturation
Measurement of Arterial Blood O2
Values that reflect Circulation
HR Heart Rythym Pulse Strength CRT Mucous Membrane Color Blood Pressure
Values that reflect Ventilation
RR Respiratory Depth Breath Sounds Expired CO2 Levels Measurement of Arterial CO2
The most important tools for monitoring are?
Your hands, eyes, and ears
Only rely on machines for this
Values that you cannot get on your own (Blood Pressure, ECG, SPO2)
Appropriate ❤rate for dogs under anesthesia
Large: 60-140 bpm
Small: 70-160 bpm
Appropriate ❤rates for cats under anesthesia
120-180 bpm
What is an Esophageal Stethescope used for?
Listen for a heartbeat
What does a CRT measure?
Tissue perfusion
If a CRT is longer than this, it means that tissue perfusion is not adequate
2 seconds
What can pale mucous membranes indicate?
Blood loss
Anemia
Poor perfusion
Cyanosis
Purple or blue discoloration MM
Emergency!
Icterus
Yellow MM discoloration
May indicate severe liver disease or hemolysis
Where can you take a pulse?
Lingual, femoral, metacarpal/metatarsal, and dorsal pedal arteries
Pulse strength should be ?
Strong and match the heart beat
Weak pulses may indicate this
Hypotension
Causes of weak pulses
Excessive anesthetic depth, cardiac insufficiency, excessive blood loss
One soaked 3x3 gauze equals this much blood
5-6ml of blood
One soaked 4x4 gauze equals this much blood
10ml of blood
A healthy animal can tolerate this much of blood loss during sx
13ml/kg blood loss
Anesthetic agents are expected to reduce this volume
Tidal volume
What is tidal volume?
The amount of air inhaled with each breath
Tidal volume rate
10-15 ml/kg
How can respiration rate be evaluated?
By watching the patient’s chest or the reservoir bag on the anesthetic machine
What is “Bagging the Patient”
The process of manual ventilation (gently squeezing the reservoir bag forcing O2/gas into the patient’s lungs)
Bagging the Patient can be used for this
⬆ Anesthetic depth
⬆ Respiratory rate
To reverse atelectasis
Atelectasis
The collapse of alveoli
One lung collapse due to trach tube too far down
Hyperventilation
Increase in respiratory depth
Tachypnea
Increase in respiratory rate
Causes of hyperventilation and/or tachypnea
⬆ CO2 in the blood
Underlying pulmonary disease
Surgical stimulation
⬇ In anesthetic depth (animals too light)
You should not hear this when evaluating breath sounds
Crackles or wheezes
One of the most common complications of anesthesia
Hypothermia
The greatest decrease in body temperature is within this time of anesthesia
The first 20 min
Methods to avoid hypothermia
Circulating warm water heating pads IV fluid line warmer Hot water bags/rice socks Saran Wrap/bubble wrap Bair hugger Warm towels Heated surgery table Baby booties on the paws
What does ECG measure?
The electrical activity of the heart
Electromechanical dissociation
EKG continues even if your patient’s heart is not contracting
Sinus Tachycardia is diagnosed when a patient’s HR under anesthesia is this
> 200 bpm in CAT
180 bpm in SM DOG
160 bpm in LG DOG
Causes of Sinus Tachycardia
Drug related (atropine, ketamine) Response to surgical stimulation Early hypoxia, hypotension Pre-existing conditions of the heart, thyroid Emergency treatment
Applying pressure here can stimulate this
Vagal activity
Sinus Bradycardia is diagnosed when a patient’s ❤rate under anesthesia is this
<100 bpm in a CAT
Causes of Sinus Bradycardia
Can be drug related (Xylazine, Dexamedetomadine, Opioids)
⬆ Anesthetic depth
Hypothermia
Treatment for Sinus Bradycardia
Can give reversal agents or Atropine
What are AV ❤blocks?
Electrical impulse through the heart is not being transmitted efficiently
1st degree AV ❤block
There is a P wave for every QRS complex , but the P-QRS interval is prolonged
2nd degree AV ❤block
Some P waves are not followed by QRS complexes
3rd degree AV ❤block
The atria and ventricles are contracting independently. No normal relationship between P waves and QRS complexes
2nd and 3rd degree blocks can be seen after administration of this
Alpha-2-agonist
VPC
Ventricular Premature Contractions
Impulse arising from the ventricular muscle causing an uncoordinated heart contraction
How do QRS complexes appear with VPCs?
Wide and bizarre
VPCs can be caused by?
Hypoxia
❤ Disease or Trauma
Release of this can stimulate the formation of VPCs?
Epinephrine release
What can forcibly restraining an animal during the induction of anesthesia cause?
VPCs
Is Ventricular Tachycardia and emergency?
YES!
What can Ventricular Tachycardia be treated with?
Lidocaine given IV
Fibrillation
Contraction of small muscle bundles within the atria or ventricles
The 2 types of Fibrillation
Atrial Fibrillation and Ventricular Fibrillation
Atrial Fibrillation
No P-waves
High HR
Normal QRS complexes
Ventricular Fibrillation
Absence of QRS complexes
Cardiac arrest is imminent with this fibrillation
Ventricular fibrillation
Systolic Pressure
The contraction of the ventricles as it propels blood through the aorta m, pulmonary artery, and other major arteries
Diastolic pressure
The pressure that remains when the heart is resting between contractions
MAP
Mean Arterial Pressure
Best indicator of organ perfusion under anesthesia
What is Ventricular Tachycardia
More than 3 VPCs in a row, more than 15 in one min, or VPCs + falling blood pressure
