Pre-operative & Intra-operative Patient Care Flashcards
What is the purpose of MONITORING?
To warn anesthetist of changes in depth or patient status to facilitate an early response
At what point do irreversible CNS and cellular changes occur?
3-5 minutes after cessation of blood flow
When should monitoring begin? When should it end?
Begins pre-operative –> Recovery
An individualized anestesia plan provides a basis for what 3 things?
- Drug selection
- Monitoring
- Anticipated complications and plan of action to address them
What are signs of too light of anesthetic depth?
Arousal
Awareness
Movement
Pain
What are signs/consequences of too heavy of anesthetic depth?
Decreased cardiovascular function
Decreased respiratory function
Slow recovery
What 3 things together maintain tissue/organ perfusion with oxygenated blood?
- Oxygenation
- Ventilation
- Circulation
What 5 things are involved in monitoring a patient?
- Anesthetic depth
- Oxygenation
- Ventilation
- Circulation
- Body temperature
What do you call the inhalant anesthetic concentration in the lungs required to prevent purposeful movement in 50% of animals in response to a noxious stimulus?
Minimum alveolar concentration
MAC
(Concentration being exhaled and what is in the brain)
What is the MAC for isoflurane for a dog?
1.28%
What is the MAC for isoflurane for a cat?
1.63%
What is the MAC for isoflurane for a horse?
1.4%
What does DO2 stand for?
Delivery of oxygen to tissues
What is DO2 equal to?
CO x CaO2
CO = cardiac output CO = HR x SV
CaO2 = oxygen content of blood CaO2 = HbO2 + PaO2
When is the best time to check capillary refill time?
Pre-operatively
What are the 2 methods of checking blood pressure?
Indirect
Direct
What are the indirect methods of blood pressure?
Doppler:
Pulse & systolic blood pressure
Place probe over peripheral artery (limb or tail)
Oscillometric:
Systolic, diastolic, & mean arterial blood pressures at a set time interval
Blood pressure cuff on peripheral limb or tail
What do the direct methods of checking blood pressure measure?
- Systolic blood pressure
- Diastolic blood pressure
- Mean blood pressure
What is the equation for minute ventilation?
Frequency (f) x tidal volume (Vt)
What is the most useful measurement for detection of apnea or hypoventilation?
End tidal carbon dioxide
What does PaCO2 stand for?
Partial pressure of carbon dioxide in the blood
What is a normal PaCO2?
35-45 mmHg
An increase in PaCO2 = hypoventilation
Does this cause acidosis or alkalosis?
Acidosis
A decrease in PaCo2 = alkalosis
Does this cause hyperventilation or hypoventilation?
Hyperventilation
What factors might cause the gums to appear DARK pink?
- Vasodilation
- Drugs
- Increase in CO2
- Endotoxemia
What does SpO2 measure?
What is normal SpO2?
SpO2 is an indirect measure of PaO2
95-99%
What are the probe sites for SpO2?
Tongue Prepuce Ear Lip Interdigital space
True or false:
SpO2 is accurate at all times.
False
SpO2 is limited in its abilities as it is not helpful in estimating PaO2 in patients breathing 100% oxygen
What are the 5 consequences of hypothermia in patients?
- Decreased MAC
- Increased risk of surgical infection
- Impaired wound healing
- Impaired platelet function
- Decreased coagulation
Why do we give IV fluids during anesthesia?
- Maintain intra-vascular volume
- Compensate for vasodilation effects of drugs
- Maintain acid/base balance
- Maintain electrolyte balance
Shock dose of IV fluids is 1 blood volume - what is that in the dog, cat, and horse?
Dog = 9% Cat = 7% Horse = 10%
What percentage of a shock dose should be used for hypovolemia?
1/4 - 1/2 the dose
Which crystalloid should be given to a hyperkalemic patient?
0.9% Sodium chloride
Which crystalloid should be used for “liver patients”?
Plasmalyte A
Which type of fluids stay in the vascular space for a short time?
Which stay for a long time?
Short time = crystalloids
Long time = colloids
Which type of fluid might you use for a patient with low albumin levels?
Colloids
Which type of fluid contains large molecular weight molecules?
Colloids
What 2 effects does hypertonic saline have on biological systems?
How does it produce these 2 individual effects?
- Increased blood volume
Draws water from interstitial space - Increased blood pressure
Venoconstrictor
What components make up whole blood?
- RBC
- Protein
- Platelets
- Clotting factors
What components make up packed RBC?
- RBC
2. PCV 80-90%
What components make up fresh frozen plasma?
- Albumin
- Plasma proteins
- Clotting factors
Which type of blood product might you give to a hypoalbuminemic patient?
Fresh frozen plasma
Which blood product allows for the most oxygen carrying capacity?
Packed RBC
Which blood product allows for correction of oncotic pressure?
Fresh frozen plasma
Which blood product should be used for patients with prolonged clotting times?
Fresh frozen plasma
What is the term used for an aversive sensation and feeling associated with actual or potential tissue damage>
Pain
What are the 5 parts of pain?
- Transduction
- Transmission
- Modulation
- Projection
- Perception
Where does transduction occur?
At tissue level
Explain transduction…
Specialized nerve endings (nociceptors) transform mechanical, thermal, chemical stimuli into action potentials
Explain transmission…
Action potential is trasmitted via sensory nerves to dorsal root ganglion -> via dorsal root nerves to grey matter or spinal cord
Which part of pain do local anesthetics and nerve blocks act against?
Transmission
Which part of the pain tract amplifies OR suppresses impulses?
Modulation
Which type of medications work against modulation?
Opioids
Alpha-2 agonists
NMDA antagonists
NSAIDS
Which part of the pain tract is associated with “wind up”?
Modulation
Where does modulation work?
Synapse with neurons in the dorsal horn of spinal cord grey matter
Which part of the pain tract is associated with nociceptive information being conveyed to the brain by nerve tracts?
Projection
Which part of the pain tract do general anesthetics work against?
Perception
What other drug work at the level of perception?
Opioids
Alpha-2 agonists
Sedatives
Which part of the pain path is associated with integration, processing, and recognition of sensory info occurring in multiple areas of the brain?
Perception
When it comes to age, which patients are at an increased anesthetic risk?
Geriatric patients - decreased organ reserve
Pediatric patients - increased risk of hypoglycemia, hypothermia, decreased drug metabolism
What should your pre-anesthesia physical exam focus on?
Cardiovascular
Respiratory
CNS
What lab tests should be run on a normal, healthy animal less than 5 years of age?
Packed cell volume (PCV)
Total protein (TP)
Azostrip
Blood glucose (BG)
What lab tests should be run on an animal above 5-7 years of age?
CBC
Chem
UA
What tests should be ran for neoplasia?
Thoracic radiographs
CT
What tests should be run for heart disease/murmur?
Thoracic radiographs
ECG
What tests should be run for trauma?
Thoracic radiographs
Abdominal radiographs
What is the risk for a dog or cat in Classes I or II?
0.12%
What is the risk for a dog or cat in Classes III-V?
4.8%
What is the risk for a horse undergoing non-emergency surgery?
1%
What is the risk for a horse undergoing emergency surgery?
2-10%
In what 3 situations would you proceed immediately to anesthesia and surgery?
- Excellent prognosis
- Continual blood loss
- Acute abdomen (colon torsion, colic, GDV)
Which drug has a tendency to cause hypotension?
Acepromazine
Which drugs have a tendency to cause excitation?
Benzodiazepines
What is the anesthetic protocol for a cat?
Dexmedetomidine + an opioid
Opioids: Butophanol Buprenorphine Methadone Hydromorphone
+/- ketamine for aggressive patients
What is the anesthetic premed protocol for a horse?
Sedative + an opioid
What are the alpha-2 agonists for horses?
Xylazine
Detomidine
Romidfidine
What are the NSAIDs for horses?
Phenylbutazone
Flunixin
What are the premed options for cattle?
May or may not need premed
Xylazine
Butorphanol
What is the anesthetic premed plan for goats and sheep?
Butorphanol +/- benzodiazepine +/- xylazine
What problems can Xylazine cause in sheep?
Hypoxemia
What drugs might you use for anesthetic induction in a dog?
Propofol
Ketamine/benzodiazepine
Alfaxalone
What drugs might you use for anesthetic induction in goats and sheep?
Ketamine w/ benzodiazepine
What might you use for anesthetic induction in cattle?
Triple drip: GG + xylazine + ketamine
What are the anesthetic related complications?
Hypotension Cardiac arrhythmia Cardiac arrest Respiratory insufficiency Hypothermia/hyperthermia Myopathy/neuropahty (equine, cattle)