Test 4 Notes: Janet Flashcards
What 2 things do we pay attention to when a patient is under anesthesia?
- Maintaining adequate depth
2. Vitals stay within acceptable limits
What 3 things are used to monitor HR & Rhythm?
- Esophageal stethoscope- rate
- ECG- rhythm
- Pulse ox- pulse
If the systolic BP is ____ the ____ disappears.
<60bpm
Pulse
ECG measures ____ only.
Electrical activity only
Explain the electrical flow of the heart.
Pulse originates in the SA node, travels to the AV node (depolarization) then to the bundle of HIS & to right and left bundle branches and finally to the purkinje fibers creating a contraction.
P wave
atrial depolarization
The SA node ____ during the P wave
Contracts
QRS complex
ventricle depolarization
The SA node ____ & the AV valve ____ during the QRS complex.
Relaxes
Contracts
The SA node is also known as the ____.
Pace maker
What happens during the T wave?
Ventricle re-polarizes and relaxes
What could cause an interference with the ECG?
Cautery (60 cycle)
Circulating H2O blanket (60 cycle)
Leads drying out (flat line: use gel for long surgeries)
What is a Lead II?
The standard PQRST waves
What are the 4 leads?
Black- left axillary
Red- left inguinal
White- right axillary
Green- right inguinal
What would a complete ECG lead set up include?
Lead I Lead II Lead III AVR AVL AVF
All of these leads have different polarities
Normal sinus rhythm general facts
Normal PQRST waves
Evenly spaced
Not missing anything
Respiratory sinus arrhythmia general facts
Regularly irregular
Must match respirations
Can be a normal finding
What happens with Respiratory sinus arrhythmias?
Heart rate increases with inhalation
and decreases with exhalation
Who can have a normal Respiratory sinus arrhythmia?
Dogs
NOT normal in cats!
What drug can make Respiratory sinus arrhythmias disappear?
Anticholinergics
more likely with atropine
Sinus Tachycardia would have a ____ cardiac output
poor
no time to fill
Sinus Tachycardia causes & interventions.
Too light- increase vaporizer
Drugs- nothing
Hypoxic- Increase flow meter and ventilate
Hypotension- Decrease vaporizer and give fluids or drugs
Hyperthyroid- Press on eyeball to stimulate vagus nerve
Anemia- Give fluids or blood transfusion
Cardiac dz- Drugs
Sinus Bradycardia drug of choice?
Atropine
Sinus Bradycardia values
Large dog= <100bpm
What can Sinus Bradycardia lead to if not treated?
Cardiac arrest
Sinus Bradycardia causes & interventions
Too deep- Turn down vaporizer
Alpha-2 Agonists- Give antagonist (Naloxone)
Vagal stimulation- Give Anticholinergics
Hypothermia- Keep warm
Hyperkalemia- Give IV fluids, Insulin/Dextrose
What could sinus tachycardia lead to if untreated?
Increased workload on the heart can lead to cardiac arrest
First degree A-V heart block basic facts
Prolonged P-R interval
Every P has QRS, but has a slow electrical flow
Difficult to see
If a first degree A-V block is not treated, what could it lead to?
2nd degree AV block
Second degree A-V block basic facts
Some P waves not followed by QRS
ventricle doesn’t contract for every atrium contraction
What is a second degree AV block also called?
Incomplete heart block
If there is a consistent 2nd degree AV block, the patient will have ____ cardiac output and low ____.
Bad cardiac output
Low pulse/heart rate
What is a third degree AV block also called?
Complete heart block
Third degree AV block basic facts
Prolonged QRS
Atrial and ventricular contractions are not in sync
Third degree AV blocks have ____ cardiac output and the QRS complex looks ____ & ____
Horrible
Wide & bizarre
What is the treatment for a 3rd degree AV block?
Pacemaker
resets electrical activity of the heart
If you have an abnormal ECG what are the first 2 things you should do?
Turn down the vaporizer
increase ventilations
Drug of choice for 2nd and 3rd degree AV blocks
Atropine
may or may not work for 3rd degree
Causes & interventions of 2nd & 3rd degree AV blocks
Too deep- turn down vaporizer Drugs (Alpha-2)- give antagonist Electrolyte imbalance (^K)- give fluids Acid/base imbalance- give fluids Myocardia Hypoxia- ventilate Cardiac Dz.- medical intervention
If your patient has respiratory acidosis to do hypercapnia what should you do?
Ventilate
PVC basic facts
Premature Ventricular Contractions
Originates somewhere in the ventricle
Ventricle contracting too rapidly
Wide and bizarre QRS complexes
What is a common cause of a pulse deficit
PVCs
PVCs have bad ____ due to ____
Cardiac output
the ventricles contracting too quickly- doesn’t get a chance to fill
What would an excessive PVC look like?
3 or more PVCs in a row- may need treatment
Ventricular tachycardia basic facts
Multiple VPCs in a row
Looks like ghosts holding hands
V-Tach causes a high ____
Heart rate
What is the drug of choice for V-Tach and PVCs?
Lidocaine-
CRI in fluids or IV injection
Causes and interventions of V-Tach & PVCs?
Too deep- decrease vaporizer Drugs (barbiturates)- no intervention Electrolyte imbalance- fluids Acid/base imbalance- fluids Myocardial hypoxia- ventilation Cardiac dz.- medical intervention Stress/pain- opioids or tranquilizers
V-Tach is common in ___ & ___ patients
GDV & HBC
Ventricular fibrillation basic facts
Irregular line
no PQRSTs
Heart is quivering
V-Fib patients have ____ cardiac output & could lead to ____ if untreated
little to no
cardiac arrest
V.fib treatments
Turn off vaporizer
Defibrillation
ABCDs of resuscitation
Hyperkalemia can cause ____ T waves and ____
Tall, spiked T waves
& bradycardia
What could tall and wide T waves indicate?
Myocardial hypoxia or hypothermia
Asystole basic facts/treatment
Flat line
Turn off vaporizer
ABCDs of resuscitation
What 2 things are pale MM & increased CRT caused by?
Peripheral vasoconstriction
Decreased tissue perfusion
What 3 things can cause Peripheral Vasoconstriction?
Hypothermia
Alpha-2 agonists
Pain
What 3 things can cause Decreased Tissue Perfusion?
Patient is too deep- decrease vaporizer
Bradycardia- give atropine
Hypotension- decrease vaporizer, give fluids, or drugs
What is cyanosis and what are the first 2 things you should do if your patient has this?
Hypoxia
Increase in the amount of unsaturated hemoglobin
- Ventilate
- Decrease vaporizer
When observing respirations what 3 things should you pay attention to?
Respiration Rate
Tidal Volume
Effort
What is the formula for choosing a res. bag?
60mls/kg
always round up to next liter
What could happen if your res. bag is too small?
Pneumothorax
Could be too inflated to accurately observe resps.
May show an increase on the pressure manometer
If your res. bag is too big it would ____.
Be too difficult to monitor respirations
Normal anesthesia RR = ____.
8-30rpm
Hypoventilation is ____rpm and has what 3 effects?
<8rpm
Decreased RR
Decreased TV
Increase in CO2 (hypercapnia/resp.acidosis)
What are 4 causes and interventions of hypoventilation?
Patient too deep– decrease vaporizer, ventilate
Obese patient– ventilate
Patient position– ventilate
Open thorax sx.– machine/manual ventilations
Hyperventilation may cause a decrease in ____ leading to respiratory ____.
CO2
Alkalosis
Hypoventilation may cause a ____ in CO2, leading to respiratory ____.
Increase
Acidosis
What are 3 causes and interventions of hyperventilation?
Patient too light– ventilate and maybe increase vaporizer
Metabolic acidosis– take over ventilations
Respiratory dz.– ventilate
When a patient is _____, less GA is needed due to it causing the MAC to be more potent.
Hypothermic
What are 4 complications of hypothermia?
Prolonged recovery
Prolonged clotting time
Delayed wound healing
Shivering increases O2 demands by 600%
What are 4 causes of hypothermia?
Decreased metabolic rate Drugs that cause vasodilation Neonates/Geriatrics/Emaciated pts. Open body cavity Shaving and scrubbing (alcohol)
How would you obtain the temperature during surgery?
Thermometer in nostril +1degree F
Feel ears/paws
What are some ways to prevent hypothermia?
Blankets Circulating H2O blanket Warmies- disk Fluid bag- be careful! Rice bag Warm IV fluids Bair Hugger Wrap feet
What are the 3 things that make up blood pressure?
Cardiac Output– “pump”
Vascular Resistance– “tubes”
Blood Vol.– “fluid”
What is the cardiac output equation?
Stroke Vol. X Heart Rate= CO (in mls/min)
What 3 values make up the arterial blood pressure?
Systolic– top #
Diastolic– bottom #
MAP– mean arterial pressure
What is the best indicator of tissue perfusion?
MAP= the average pressure in the arteries through a cycle
Hypotension systolic value=
<80mmhg
Hypotension MAP value=
<60mmhg
Systolic is an indication of when the ventricles are ____.
contracting
Diastolic is an indication of when the ventricles are ____.
relaxing
What are the 3 most important organs that need good perfusion?
- Kidneys
- Heart
- Brain
What are 3 causes of Hypotension?
- Excessive depth
- vasodilation
- bradycardia
- decreased CO
- Drugs
- Inhalant anesthetics
- Acepromazine
- Alpha-2s
- Blood loss
- hemorrhage
- hypovolemia
What are the first 3 interventions of Hypotension?
Decrease vaporizer
Bolus/Change fluid
Drugs
You should always anticipate fluid loss and ____ before surgery
Bolus fluids
What type of fluids are normally administered during surgery? At what rate?
Crystalloids
10mls/kg/hr
What are the 2 options when a bolus is needed?
3-5mls/kg (can be done twice)
double surgery fluids and run for 15min. (20mls/kg/hr)
What would be another option of fluids if your patient is having difficulty maintaining fluids?
Colloids
What are a few examples of Colloids?
Hetastarch
Dextran
RBCs
What do Inotrope drugs do?
Increase the force of cardiac contraction (pump)
What do Chronotropes do?
Increase the heart rate (pump)
What do Vasopressors do?
Cause vasoconstriction– increases BP (tube)
What are 3 common drugs to treat hypotension?
Dopamine
Dobutamine
Ephedrine
Dopamine is a ____ & ____ so it increases ____ and ____ output.
+ inotrope & + chronotrope
Increases renal perfusion and urine output
How is Dopamine administered?
It is diluted in fluids and given in micrograms/kg/min.
IV drip CRI
Dobutamine is a + ____ & lower + ____
+inotrope & lower +chronotrope
increases force of cardiac contractions and heart rate
Ephedrine is a +____, lower +____ & ____.
+Vasopressor, lower chronotrope & inotrope
How is dobutamine given?
Diluted in fluids -IV drip CRI
How is Ephedrine given?
IV injection
What are 4 benefits of Ephedrine?
Cheap
Easy to give
Can give 2 injections
Has a 20min. duration
With Ephedrine, you may see an increase in ____, but its main action is ____.
Heart rate
Vasoconstriction
What hypotension drug would you use for a shorter surgery?
Ephedrine
What hypotension drug would you use for a longer surgery?
Dobutamine or Dopamine drip
What are the 2 ways to measure BP?
Indirect- Doppler or Oscillometer
Direct- Direct Arterial Pressure
Doppler BP monitor measures?
Systolic BP and pulse
With a doppler the crystal (probe) should be placed ____ to the cuff
distal
How should the cuff of the doppler be measured?
The width of the cuff should cover 40% of the circumference of the limb or tail
How does the probe of a doppler work?
You place ultrasound gel on the probe and place it on the artery, it will emit high frequency sound waves and when the waves encounter the pulsating artery, it will create a whooshing sound (the pulse)
What are some problems with the doppler?
Not very accurate in cats
Probes are fragile
Cuff size must fit accurately
Works best on long, straight legged, hairless dogs
How does the Oscillometer blood pressure monitor work?
Machine automatically inflates cuff and reads Systolic, Diastolic and Mean arterial pressure, some also display a pulse
Also has a cat setting
Direct arterial pressure info.
Common in equine anesthesia
More accurate, but invasive
Indwelling catheter is placed in an artery and connected to a monitor
What does a Capnograph measure?
ETCO2 Insp.C02, and Respiratory Rate
What is the most common type of capnograph?
Side stream- monitors samples of gas from small tube attached between the ET tube and the breathing system
Inspiration CO2 should fall into what range?
0-5mmHg
End Tidal CO2 should fall into what range?
35-45mmHg
Normal Capnographs show ____ on the monitor and represent the ____.
Square wavelengths, RR
What are some causes of decreased ETCO2?
Increased RR
ET tube in esophagus
Respiratory arrest/cardiopulm. arrest
What can a decreased ETCO2 lead to?
Respiratory alkalosis
2 reasons for increased ETCO2
Decreased rate and tidal volume
What can increased ETCO2 lead to?
Respiratory acidosis
How do you correct increased ETCO2?
Increase ventilations!
you may also need to decrease the gas %
If you have increased Insp.CO2 that could mean ____ or the ____.
The soda lime granules are exhausted and need to be changed.
O2 flowrate is not high enough
What does a Pulse Ox measure?
% of Hgb saturated with Oxygen & Pulse
How does the Pulse Ox work?
By using 2 different lengths of light
Pulse Ox:
Red light measures ______.
Infrared light measured ______.
Reduced Hgb (unsaturated) Oxygenanted Hgb.
Pulse Ox:
What is a Plethysmograph & what does it indicate?
a pulse waveform
It indicates the pulse strength
Tall wave= strong
Short wave= weak
How do you place the Pulse Ox probe on the tongue?
With the sensor side ON TOP and the light side BELOW the tongue (light from above may interfere with readings)
Where can a pulse ox probe be placed?
Thin, hairless, non-pigmented area
Best & most common placement= tongue
The Pulse Ox probe cannot be placed on ___ some other places it will work are ____.
A black tongue (the pigment will absorb the light)
Lip, Pinna, Toe web, Achilles tendon, Vulvular fold
Rectal probes are also available (reflective probe) usually used for dentals
Pulse Ox readings should be ____ under anesthesia
> 95%
Pulse Ox:
Borderline Hypoxia=
Hypoxia=
Cyanosis=
(O2 Saturation)
Borderline= 90-95% Hypoxic= <85% patient is BLUE!
Pulse Oximeters can detect ____ before it is visually evident
Hypoxia
before it is Cyanotic
2 Probe reasons for decreased Pulse Ox readings
Probe placement- may be on pigmented skin, dry tongue, patient movement, overhead light
Probe pinching- can cause decreased perfusion to tongue
Perfusion issues for decreased Pulse Ox readings
Poor perfusion caused by hypotension, cradycardia, peripheral vasoconstriction,
Alpha-2 agonists!
Cold tongue = crappy readings!
Oxygen reasons for decreased Pulse Ox readings
ET tube may be disconnected, kinked, or in esophagus
O2 flow rate too low
Lung reasons for decreased Pulse Ox readings
Respiratory failure, inadequate ventilation
V/Q mismatch= alveolar ventilation/pulmonary perfusion ratio determines adequacy of gas exchange in lungs (see chart on worksheet)
Lung Dz.
What are 2 examples of V/Q mismatch & what is the result of both?
Pulmonary thromboembolism: V is okay, Q has bad pulmonary perfusion
Collapsed lungs: V has poor alveolar perfusion, Q is fine
End result= NO OXYGEN
What does the V & Q stand for in a V/Q mismatch?
V= alveolar ventilation Q= pulmonary perfusion
Heart reasons for poor Pulse Ox readings?
Poor perfusion due to bradycardia, arrhythmias, V/Q mismatch
How do you improve O2 Saturation?
Ventilate!!!! and maybe increase O2 flow rate
What are the most important things to continue monitoring post-op?
Respirations
MM color & CRT
Palpate pulse
What are 6 common post op complications?
Respiratory distress (esp. brachys) Hypothermia Vomiting Chewing/licking Hemorrhage Analgesics wearing off
What should you do if your patient is in respiratory distress Post-Op
Reposition- sternal Extend head & neck Pull tongue out Give O2 (mask or flow-by) Re-intubate if nothing works
If your patient is vomiting, how can you prevent them from aspirating
Lift butt up and put their face down
What are some signs of post op hemorrhage?
Prolonged hypothermia Pale MM, increased CRT Slow recovery Increase HR & RR Decreased BP
What should you do if you think your patient is hemorrhaging before getting the Dr?
Get PCV & TP
Do a centesis or ultrasound
What are 4 issues with brachycephalics
elongated soft pallet
narrow trachea
narrow nares
increased sympathetic tone
How to decrease risk of brachys
Decrease stress- tranq/sedatives Anticholinergics- glyco/atropine Pre Oxygenate- increase O2Sat.Hgb IV induction- faster Leave ET in longer