Exam 1 Flashcards
The ____ Soluble an Inhalant Anesthetic is, the More Potent it is
More
*Ex. If the MAC of Sevoflurane is 2%, and a MAC of Isoflurane is 1%. Which is more Potent?
If you need 2mg/kg of Sevoflurane to get the patient to Sleep, and 1mg/kg of Isoflurane to get the Patient to Sleep, you need much more Sevoflurane than Isoflurane to get the Patient to Sleep. If you need Less of the Drug to get the animal to Sleep, it is More Potent. Therefore, Isoflurane is More Potent!!
Isoflurane has a Lower MAC and therefore is more Potent
The Higher the Flow Meter Setting, the ____ the Patient will Reach Equilibrium
Faster
*Flowmeter Rate is much Higher for Induction. The Patient will Reach Equilibrium as fast as Possible. After Equilibrium is Reached, the Flowmeter Rate is turned down for Maintenance.
The Patient was Premedicated with Fentanyl IV and Midazolam IV. The Patient was Induced with Propofol and Ketamine. Isoflurane, Oxygen, CRI-Fentanyl and LRS Fluids were used for Maintenance. Its been 20 Minutes since the Discontinuation of Inhalant Anesthetic and the Patient is Still Unresponsive with No Palpebral Reflex and Eyes are Ventral Medial. What is Causing the Prolonged Emergence from Anesthesia?
Fentanyl can Accumulate when used as CRI- Drugs can still be Lingering Around the Body
Non Invasive tool that Measures ETCO2 mmHg and InCO2 mmHg that is used clinically to:
- Monitor breath by breath Ventilation/Apnea/Respiratory Rate
- Indicate abnormal Ventilatory Patterns
- Measure Rebreathing of CO2
Capnography
*ETCO2 = End Tidal Carbon Dioxide (Normally 35-45 mmHg)
*InCO2 = Inspired Carbon Dioxide
Which Inhalant Anesthetic has the Highest Blood Gas Solubility?
Halothane
*Longest Onset and Longest Recovery
Most commonly used Alpha 2 Agonist Premedication in Small Animals that has a Quick Onset of 1-3 Minutes and has Lasting Effects for 90-120 Minutes
Dexmedetomidine
Rebreathing Systems are Used on Patients that Weigh Greater than ____kg
3kg
* 1kg = 2.2 lbs
*If Patient Less than 3kg is put on a Rebreathing System their Inspiratory CO2 will Rise
Stage of Anesthesia from Initial Administration of Induction agents to Loss of Consiousness where Breath Holding or Rapid Respiration may occur as well as Salivation, Urination, Defecation and Pupil Dilation
Stage I
What ASA PS would you Give this Patient?
A. ASA 1
B. ASA 2
C. ASA 3
D. ASA 4
E. ASA 5
ASA 3
*Placement of a feeding tube is not an Emergency
The more _____ an Anesthetic Agent is in Blood, the Slower the Induction
Soluble
*The Less Soluble an Anesthetic Agent is in Blood, the Faster the Induction- The less uptake by Blood, the more gas available to be passed on to the Brain
*The Less Soluble an Agent is, the Lesser its uptake into tissues and the Faster it reaches Equilibrium
Know this Graph!!!
*Be able to Pick out Baseline and ETCO2 (End Tidal) on Exam!!
*Very Important- KNOW THIS
*CO2 mmHg should always go back to Baseline (0 mmHg) during Inspiration, UNLESS we are Rebreathing. If we are Rebreathing CO2 then it will be Elevated off the Baseline- KNOW THIS
*If it is every Elevated off the baseline during Inspiration then Check equipment and see what is happening
What is Occuring in this Patient based on this Capnograph Waveform?
Hyperventilation
*Breathing out Too Much CO2
Most Commonly used Phenothiazine that works as a Dopamine (D1 and D2) Receptor Antagonist in the CNS leading to Tranquilizing and Antiemetic Effects
Acepromazine
*Dopamine Receptor Antagonist in the CNS
Most Common Artery for Cannulation of Invasive Blood Pressure in Dogs
Dorsal Pedal
Summary of What we Want to Achieve in Stage III (Surgical) Anesthesia
*Should see no Palpebral effect in Dogs and Cats
Barbiturate Induction agents, Thiopental, are very _____ with a pH Greater than 10, which if given IM can cause Thrombophebitis and Tissue Necrosis
Alkaline
*Tissue Sloughing
D. Bradycardia
Induction agent that acts by Enhancing Inhibitory effects of GABA at GABAa Receptors that works as an Anticonvulsant, Antiemetic and provides Excellent Muscle Relaxation
Propofol
*No Analgesia
Mixed Opioid Agonist-Antagonist Premedication that can be used to Reverse Sedative or Respiratory Effects of Pure mu Agonists
Butorphanol
Which One of the Factors can Prolong Emergence from Anesthesia:
A. Reduced Cardiac Output
B. Decreased Protein Binding
C. Impaired Hepatic Metabolism
D. Hypoxia
E. All of the Above
All of the Above
*Decrease Protein Binding- You need to have Adequate Amounts of Protein to take the drug to the Liver. Decreased Protein Binding means more of the Drug will be in the ACTIVE form causing a prolonged effect
Equation for Speed of Induction if Patient is in an Induction Chamber
Time Constant (min) = Volume (L) / Flow (L/min)
*Volume = Volume of Chamber
“Wash In” Period = 3. Have to Take Time Constant and Multiply by 3 to Determine Speed of Induction
*Ex. If your Induction Chamber is 2 Liters and the Flowmeter is set to 2 Liters/Minute
Time Constant = 2 Liters/ 2 Liters/Min
Time Constant = 1 Minute x 3 = 3 Minutes for Induction
Induction and Maintenance of General Anesthesia with Intravenous Drugs
Total Intravenous Anesthesia (TIVA)
Flow meters where Nitrous Oxide and Oxygen are used together (N2O:O2) should not exceed a ratio of ____, because it can cause Hypoxemia
2:1
Alpha 2 Agonist Premedication that is used Only on Large Animal and is believed to Produce less Ataxia than Xylazine and therefore is Popular for use in Dentals and other Standing Procedures
Romifidine
True/False: Etomidate is the Ideal Induction Agent for Patients with Heart Problems and Neurosurgeries
True
*Etomidate- Ideal in Heart Failure Patients and Brain Surgery
What Induction Agent should be avoided in Esophageal Obstruction Patients?
Etomidate
*Etomidate should be Avoided in Obstructed Patients because Etomiate is the Only Induction Agent that causes Nausea, Vomiting and Retching
Etomidate Induction Agent Supresses _____ Function for 2-3 Hours after Single IV Administration, and should be avoided in Addisonian Patients
Adrenocortical
*Contraindication for Etomidate- Addisonian
If an Inhalant Anesthetic has a ____ Solubility, a Lot of the Drug will be Solube in Fat, Muscle, and Blood. If the Anesthetic is Dissolved in these tissues, it is less likely to be transported in its Active form to the Brain
High
*The HIGHER the Solubility, the SLOWER the Onset and SLOWER the Drug will reach Equilibrium
*We want the Anesthetic to have Low solubility in the Blood so it will stay in its Active Form and Reach the Brain Faster
What Three Types are Drugs are Commonly Combined as Ketamine-Based Protocols for TIVA in Equines
Alpha 2 Agonist
Ketamine
Guaifenesin
*Xyalzine, Ketamine and Guaifenesin (GG) = Triple Drip
*TIVA Mainly used in Equine. Not used in Small Animals often
Capillary Refill Time is a Gross assessement of Blood Volume and Peripheral Perfusion. Normal CRT is 1-2 Seconds. What does a CRT Greater than 2 Seconds or Less than 1 Second Suggestive Of?
CRT > 2 seconds = Poor Perfusion/ Vasoconstriction
CRT
Rank the Inhalant Anesthetics from Most Potent to Least Potent
Halothane- Most Potent
Isoflurane
Sevoflurane
Desflurane- Least Potent
Spring Loaded Valve that Limits Pressure Buildup Within the Circuit and is ALWAYS kept Open unless delivering Manual, controlled or assisted Ventilation
Adjustable Pressure Limiting (APL) ( AKA “Pop-Off “) Valve
*Only Close the Valve when Giving a Manual Breath to the Patient or when Leak Testing the Machine
*If the Valve remains closed Pressure will Build up in the Breathing Circuit and cause Barotrauma in the Patient
Premedication that Enhances the Inhibitory Neurotransmitter GABA leading to Minimal Sedation, Muscle Relaxation, and Antiseizure effects with Minimal Cardiovascular and Respiratory Effects
Benzodiazepine
*Ex. Diazepam and Midazolam
What Induction Drugs lead to:
- Decreased Cerebral Blood Flow
- Decreased Metabolic Oxygen Consumption (CMRO2)
- MARKED Respiratory Depression (APNEA)
- Decreased Reponse to Increase PaCO2 Levels
Barbiturates
*Decreased Response to PaCO2 Levels- Need a Higher Partial Pressure of Carbon Dioxide for the brain to detect a problem and increase Respiration
Most Common Opioid Antagonist that is used to Reverse pure mu and mixed Agonist/Antagonists because it has a high affinity for mu and Kappa receptors but no intrinsic activity
Naloxone
*Reverses Analgesic and Sedative effects of Opioids
Opioid Premedication that is a Partial mu Agonist and an Antagonist at Kappa Receptors that is not adequate for Severe Pain but has a Higher Receptor affinity and can Displace a Pure mu Agonist making it difficult to Antagonize
Buprenorphine
* High affinity for mu Receptor- very hard to antagonize (Reverse)
Precision Vaporizers that are Agent Specific and Located Outside of the Patients Breathing Circuit
Vaporizer Out of Circuit
*Agent Specific- have to use the Anesthetic Gas that the Vaporizer was Built for
In Small Animals a Normal Central Venous Pressure (CVP) is between 0-10 mmHg. If the CVP measure is High, the patient is _____ and Fluids should be Stopped
Hypervolemic
Two common Drugs that cause Postoperative Delirium
Benzodiazepines
Opioids
*Reverse Benzodiazepine with Flumazenil and animal should Calm Down
Which Three Drugs on this Chart are Good for use as CRI?
Midazolam, Ketamine, and Propofol
*Midazolam, Ketamine and Propofol are commonly used for Constant Rate Infusions
*Etomidate and Diazepam are NEVER used as CRI because they are formulated with Propylene Glycol
*Thiopental- Accumulates in Tissues if Redosed and increases Recovery time
True/False: Barbiturate Induction Agents have Cumulative Effects and Repeated Dosing should be Avoided
True
*Ex. If you Induce with Thiopental and the Patient became light, you would not want to Redose with Thiopental
Which Benzodiazepine given Orally has been associated with Hepatic Failure in Cats?
Diazepam
Which Premedication is Characterized by these Negative Effects:
Respiratory Depression
Hypoxemia
Bradycardia
Vomiting/Defecation/Salivation
Miosis (Dogs)
Mydriasis (Cats)
Opioids
*Opioids can cause Disruption of Patient Thermoregulation leading to Panting
*Mydriasis- Dilation of Pupils
Miosis- Constriction of Pupils
Cylinder Attachment that is Used for the Larger H and G Cylinders where Cylinders are attached to the Pipline via a DISS fitting
Diameter Index Safety System (DISS)
*For H and G tanks Only
In Large Animals we use _____ in Electrocardiography, which Accentuates the P Wave and leads to a Large Negative Wave
Lead 1
*AKA Base Apex
What Induction agent Lacks preservatives and should be Discarded within 6 Hours of Opening
Propofol
Anesthesia that is Induced by Drugs that Dissociate the Thalamocortic and Limbic Systems characterized by a Catatonic State where the eyes remain open and swallowing reflexes remain functional. Skeletal Muscle rigidity is Common unless a Muscle Relaxing Drug is Given in Conjunction
Dissociative Anesthesia
*Most Common Dissociative Drugs- Ketamine and Tiletamine
Capacity (Liters) of Oxygen and Nitrous Oxide Gas contained in an
E Cylinder
Oxygen- 660 Liters
Nitrous Oxide- 1600 Liters
*E Cylinder is the Smallest Tanks (Easiest to Carry)
How do you determine when to Change the Nitrous Oxide Cylinder?
Moisture/ Frost Line
*As Gas within the Tank Evaporates, a Frost Line appears on the outside of the Tank. You can Follow the Frost Line along the Tank and Replace the Tank when the Frost Line gets close to the Bottom
*Can also change the tank as soon as the pressure gauge begins to move
330 Liters
Cylinder Attachment that is for E Cylinders Only and uses a Hanger Yoke Site for E Cylinder Attachment
Pin Index Safety System
*Used for E Cylinders Only
Anesthetic that Requires a Special Precision Vaporizer because it has a Very High SVP at 660 mmHg and Boils at 23 Degrees Celsius
Desflurane
*Made a Special Vaporizer that is Always Heated to make sure that the Gas stays in one type of Form
Charcoal Absorption absorbs Halogenated Anesthetic gases, such as Isoflurane and Sevoflurane. What two Substances does Charcoal not Absorb?
Nitrous Oxide (N2O) and Carbon Dioxide (CO2)
*KNOW THIS
*Change Charcoal Absorber when 50 grams gained from Original Weight
Endotracheal Tubes with the Largest Diameter have ____ Airway Resistance
Decreased
*The Larger the Diameter the Less Airway Resistance
*Photo- Examples of Endotracheal Tube Size in mm
True/False: There should be No escape of gas from around the endotracheal tube when the APL Valve is Closed and the RB is Squeezed to 20 cmH20
True
A Capillary Refill Time (CRT) Less than 1 Second is Indicative of a _____ State, which can be assocaited with Systemic Inflammation, Heat Strock, Distributive Shock and Hyperthermia
Hyperdynamic
What ASA Physical Status would you give this patient?
A. ASA 1
B. ASA 1E
C. ASA 2
D. ASA 2E
E. ASA 3
ASA 1E
*Considered an Emergency because we want to treat the Laceration ASAP
Neonates/Pediatric and Geriatric Patients recieved ____ Doses of Anesthetics compared to Adult Animals
Decreased
*Neonates and Geriatrics have Lower Basal Metabolic Rates (BMR)
State of Complete Unconsciousness characterized by Insensitivity to Pain, Muscle Relaxation, Absence of Reflex Response, that is a Reversible Process
General Anesthesia
*It is a Reversible Process!!
Plane of Surgical Anesthesia (Stage III) known as “Medium Anesthesia” used for most surgical Procedures characterized by stable Respiration and Pulse Rate
Plane II
Record Vital Signs (HR, RR, BP ect.) every ____ Minutes During Anesthesia
5-10 minutes
*Record Keeping is very Important during Anesthesia- If you didn’t Write it down, it didn’t happen
*Make sure you write the Total mg of Drug that was Given
What are the Electrocardiology Placements in Small Animals (Lead II) of the White, Black and Red Leads?
White Lead - Right Elbow
Black Lead- Left Elbow
Red Lead- Left Stifle or Abdomen
*ALWAYS ON LAB FINAL
“Gold Standard” and More Accurate way of Measuring Blood Pressure
Direct (Invasive)
Gold Standard of Blood Pressure Monitoring that Provides the Beat by Beat blood Pressure Values. The Catheter is inserted into an Artery with a connection of pressure tubing between the arterial catherter and some form of manometer or blood pressure transducer
Direct Blood Pressure
*Catheter inserted in Artery- Asepsis is Very Important
Two Most Common Arteries for Cannulation of Invasive Blood Pressure in Cats
Femoral
Coccygeal
When using a Doppler to Monitor Blood Pressure, the Width of the Cuff should be about ___% circumference of the Limb
30-40%
*Same for all Indirect Methods!!
*If the Cuff is too big or too Tight the Pulse will be Underestimated
When Using a Doppler to Moniter Blood Pressure in Ruminants, what Artery is the Doppler Probe placed over?
Median Artery
B. Every 5-10 minutes
In Which Breed of Dog, has Phenothiazines (Acepromazine) been reported to cause Severe Hypotension, Bradycardia and Death
Boxers
*Acepromazine should be avoided in Boxers
Which Alpha 2 Adrenoreceptor Agonist is Very Selective for Alpha 2 Leading to less Cardiovascular Effects
Dexmedetomidine
*Don’t use Xylazine in Small Animals anymore because Dexmedetomidine is Much more selective for Alpha 2 and will lead to Less Cardiovascular Effects
Benzodiazepine Premedication that can be Given IM or IV that is Shorter acting with less risk of Accumulation and a better Choice in Sick, Debilitated and Older Patients
Midazolam
Premedications that Couple to G-Protein Receptors that ultimately Decrease conductance through Calcium Channels and Open Inward Potassium Channels leading to Hyperpolarization and Decreased Propogation of Action Potentials
Opioids
Premedications that are coupled to G-Protein receptors and lead to CNS effects including Sedation, Euphoria, and Dysphoria that are used as Analgesics
Opioids
*Euphoria- Feeling of Intense Excitment and Happiness
Dysphoria- Feeling of Disatisfaction and Unhappiness
*Opioids are used for Analgesia During Surgery
Opioid premedication that is a Synthetic pure mu agonist that causes less sedation and is the Least Likely of the mu Agonist Opioids to cause Vomiting
Methadone
*Used on Patients that we really don’t want to Vomit
Goals of ____ Include a Smooth Transition from Awake to Stage III Surgical Anesthesia, that is often met via use of Injectable Anesthetic
Induction
*Goal of Induction- Awake to Stage III Surgical Anesthesia
True/False: Barbiturate Induction Agents are safe for use in Patients with Underlying Cardiac Disturbance
False
*Barbiturates Cause Cardiac Arrhythmias and should be avoided in patients with Underlying Cardiac Disturbance
Which Induction Agent Causes:
- Respiratory Depression/ Initial Apnea
- Minimal Cardiovascular Depression
- Dose Dependent Fetal Depression
Alphaxalone
The Induction agent ____, is made with Propylene Glycol, which is Hyperosmolar and can lead to ACUTE Hemolysis
Etomidate
*Can get Acute Hemolysis when we Inject Etomidate at Rapid Large Boluses in Small animals- AVOID Prolonged Infusions
Two Dissociative Induction Agents used, that have a Rapid Onset of 60-90 Seconds where the Patient’s Eyes are Open/Moving, the Swallowing Reflexes are Intact and there is Increased Skeletal Muscle Tone
Ketamine
Tiletamine
*These are Often paired with Sedative or Benzodiazepine to Minimize Muscle Tone
Which Induction Agents lead to:
- Eyes Open/Moving
- Swallowing Reflexes Intact
- Increased Skeletal Muscle Tone
Dissociative Anesthetics
*Always Add Muscle Relaxant (Benzodiazepine) with Dissociative Induction Agents
B. Enhances GABA on GABAa Receptor
Benzodiazepine Induction Adjunct that is Water Soluble that can be administered IM, IV or IN (Intranasally)
Midazolam
Which Induction Adjucts are Commonly Combined with Ketamine because they Provide Great Muscle Relaxation
Benzodiazepines (Diazepam/Medazolam)
*These Two Adjuncts can be combined with Propofol and Etomidate as well
Inducation Adjunct that is a Centrally acting Muscle Relaxant used in Horses, Cattle, Small Ruminants and Swine
Guaifenesin
*Not used in Small Animal
TIVA Drug that has a Non Irritating Formulation, Wide Safety Margin, Rapid Recovery and is Noncumulative
Alphaxalone
*Gaining Popularity for TIVA
Rank the Inhalant Anesthetics from Lowest Blood Solubility to Highest Blood Solubility
Desflurane- Lowest (Fastest Onset and Recovery)
Sevoflurane
Isoflurane
Halothane- Highest (Longest Onset and Recovery)
Induction Agent that is Rapid Acting, Ultra Short Duration of Action that is Noncumulative and made of Propylene Glycol
Etomidate
Characteristic “Shark Fin” appearance on Capnograph indicates Bronchospasm or ______
Obstructed Airway
Constant Rate Infusions (CRI) are a Multimodal Approach with Respect for the Pain Pathway where an Inhalant is used in Combination with One or a Combination of What Three Drug Choices?
Opioids (Ex. Morphine, Hydromorphone)
Lidocaine
Ketamine
*KNOW
*MLK (Morphine, Lidocaine, Ketamine) is common in Canine Patients
Blind-ended Tube passed into the Thoracic Esophagus to the Level of the Heart, allowing us to assess Heart Sounds, Rate, and Rhythm as well as Respiratory Sounds and Rate
Esophageal Stethoscope
Which Inhalant Anesthetic has the Greatest Vapor Pressure?
Desflurane
*Vapor Pressure- Desflurane > Halothane> Isoflurane> Sevoflurane
*Know the Rankings of Vapor Pressures
The ____ the Cardiac Output, the Lower the Concentration of Inhalant at Alveoli, and the Slower the Induction
Higher
*Higher Cardiac Output- More Inhalant being pumped away from the Lungs and the Slower the Onset
Induction Agents that Increase Heart Rate and Blood Pressure leading to Tachycardia and Hypertension
Dissociative Agents (Ketamine)
*Only Induction Agent that causes Tachycardia and Hypertension
True/False: In Large Animals you must Push all Induction Agent
True
*Give all Inducation Agent AT ONCE in Large Animals
Two Hoses Used for Re-Breathing Systems
Circle Hose
Universal F
Gold Standard for Measuring Oxygenation and Ventilation in Arterial Blood Sample
Blood Gas Analysis
Three Most Common Arteries for Cannulation of Invasive Blood Pressure in Horses
Facial
Transverse Facial
Lateral Metatarsal
_____ is not Observed in Deeper stages and is an Indication in Horses that they are in a Light Stage of Anesthesia and may Wake up
Lacrimation
The Lower the Arterial Oxygen Tension, the ____ the Arterial Oxygen Saturation
Lower
*Know these Values-
90% Saturation adds up to 60 mmHg = Severe Hypoxemia
Ideally want to keep it above 95% Saturation
Stage of Anesthesia characterized by:
Loss of Consciousness
Involuntary Movement/Delirium
Patient Reacts to External Stimuli
Laryngeal Spasm, Vomiting, and Regurgitation
Eyelash and Palpebral Reflexes are Prominent
Nystagmus in Horses
Stage II
*Ex. Nystagmus in Horse
When Administering Inhalant Anesthetics, the _____ the Blood Solubility, the Faster the Active Drug will Reach the Brain and the Faster Equilibrium will be Reached
Lower
*Solubility Determines Induction Speed and Recovery Speed
Inhalant Anesthetics _____ Heart Rate due to Vagolytic Activity
Increase
*Inhalants DO NOT cause Bradycardia
*As you keep a patient asleep for a longer period of time with Inhalants, Heart Rate will Gradually Continue to Increase
In a Series of Flow Meters, the ____ Flow Meter is always the Last Meter in the Series and therefore closest to the Patient
Oxygen
*Most Universities have a Flow meter for Oxygen, Nitrous Oxide and Medical Grade Air. The Oxygen Flow Meter is always the last in the series
*In case of a Leak in a Flow Meter, you want Oxygen closest to the Patient to Reduce the Risk of Oxygen escaping from the Leak. If Oxygen is the Last Flow Meter and there is a Leak in another Flow meter, that will not effect the amount of Oxygen delivered to the animal
Benzodiazepine Induction Adjunct that is NOT Water Soluble and is Formulated with Propylene Glycol that is administered IV Slow Only
Diazepam
*Do Not use CRI- Propylene Glycol = Acute Hemolysis
Oxygen is a Gas, therefore as Gas is depleted from the Tank the Pressure Gauge wil move. _____ is a combination of Liquid and Gas and as Gas is depleted the Pressure Gauge will not Move until the Tank is almost Empty
Nitrous Oxide
Initially, Alpha 2 Adrenoreceptor Agonists (Dexmedatomidine) cause Vasoconstriction and Rise in Arterial Blood Pressure, followed by a _____, where the Cardiac output can Fall 30-50% due to decreased Heart Rate and Increased Peripheral Vascular Resistance
Reflex Bradycardia
*Xylazine can Increase Cardiac Sensitivity to Catecholamine Induced Arrhythmias- Mainly used in Equines and not Small Animal
110 Minutes
*Questions on Exam will be similar to this!
D. All of the Above
Gauge on Anesthesia Machine that Measures Pressure within the Breathing Circuit and should Always read Zero unless performing leak checks or providing IPPV
Breathing System Pressure Gauge
*IPPV = positive pressure ventilation- giving the Patient a Breath
Non-Rebreathing System
Injectable Agents Administered during Inhalant Anesthesia to Minimize inhalant Requirements and ensure adequate pain relief
Constant Rate Infusion (CRI)
Commonly used TIVA Drug that has a Fast onset, Short Duration, and Rapid Distribution and Metabolism
Propofol
*Do NOT use Propofol 28 for TIVA because it contains Benzyl Alcohol
Alpha 2 Agonist Premedication that is typically only Used in Large Animals and has a Longer Duration of Action of 90-120 Minutes
Detomidine
*Used in Large Animals Only and has an Onset of Action that is Longer than Xylazine
Ultra-short Acting Barbiturate Induction agent that lasts 5-15 Minutes
Thiopental
*Awake to Stage III in 15 Minutes- Time to Intubate and Turn on Vaporizer
*Most commonly used Barbiturate Induction Agent, however Not Available in the United States
In Small Animals a Normal Central Venous Pressure (CVP) is between 0-10 mmHg. If the CVP measure is Low, the patient is _____ and Bolus Fluids should be given
Hypovolemic
Which Inhalant Anesthetic has the Lowest Blood Gas Solubility?
Desflurane
*Fastest Onset and Fastest Recovery
What are the Electrocardiology Placements in Large Animals (Lead I) of the White, Black and Red leads?
White Lead- Right Jugular Furrow
Black Lead- Left Axilla Region
Red Lead- Any Site Remote from the Heart
Cylinder Attachment that is Always Rapid to Connect and Disconnect that has Gas Specific Fittings
Quick Coupler
*Most common Type of Attachment
Induction Adjunct used in Large Animals that Disrupts Nerve Impulse transmission that provides Skeletal Muscle Relaxation and Laryngeal and Pharyngeal Muscle Relaxation
Guaifenesin
*No Analgesia or Sedation
A. Tingflurane
Thiopental
Propofol
On a Rebreathing System, What should the Oxygen Flow Rates be at:
- Start of Inhalation Anesthesia
- Maintenance
- End of Inhalation Anesthesia
Start of inhalation Anesthesia = 50-100 mls/kg/min (High)
Maintenance = 20-50 ml/kg/min (Semi Closed Flow)
End of Inhalation Anesthesia = 50-100 mls/kg/min (High)
*Start off with High Oxygen Flow Rate to get more Anesthetic to the Patient. Maintenance should be Half the Oxygen Flow of the Start of Inhalation. High Oxygen Flow at the end of Anesthesia when the Patient is recieving 100% Oxygen to Dilute out the Anesthetic Faster
Horses May show signs of Nystagmus in Which Stage of Anesthesia?
Stage II
*Nystagmus- Light Patient that could Wake up
*Stage III and IV- No Palpebral Reflex
Your Inducing a Cat in a 10 Liter Induction Chamber. The Flowmeter is set to 2 Liters/Minute. What is the Speed of Induction?
15 Minutes
Time Constant = 10 Liters/( 2 Liters/minute)
TIme Constant = 5
*Have to Wait 3 Time Contants to Reach 95% Wash In
5x3 = 15
Opioid Premedication that is a Partial mu agonist and Antagonist at Kappa Receptors that can be given IV, IM or via Oral Transmucosa in Cats that has a duration of action of 4-8 hours
Buprenorphine
What is the Reversal Agent for Benzodiazepines (Diazepam and Midazolam)?
Flumazenil
Which of the following is a Neuroleptanalgesic Drug Combination:
A: Acepromazine + Opioid
B. Benzodiazepine + Opioid
C. Alpha 2-Agonist + Opioid
D. All of the Above
All of the Above
*KNOW- be able to pick out on exam
Induction Agents that act as N-Methyl-D-Asparate (NMDA) Antagonists that are Important for Windup and Chronic Pain Relief that can be Administered IM, IV, Rectal, Nasally ect.
Dissociative Anesthetics (Ketamine)
Part of Anesthesia Machine where a Ball or Bobbin rises within a glass tube to a Heigh Proportional to the Flow of Gas through the Tube, used to measure the Flow Rate
Flowmeter
*When using the Ball you Measure Half Way up the Ball. When Using a Bobbin you measure at the Top of the Bobbin
Capacity (Liters) of Oxygen and Nitrous Oxide Gas contained in an
H Cylinder
Oxygen- 6600 Liters
Nitrous Oxide- 16,000 Liters
*H Cylinder is the Heaviest Tank
What are the Three “Killers” on the Anesthesia Machine?
- Flowmeter (Too Little Oxygen)
- Vaporizer (Too Much Anesthetic)
- Pop-off Valve (Too Tight- Pressure Buildup)
Inhalant Anesthetics Cause Which of the Following?
A. Decrease Heart Contractility
B. Vasolidation
C. Decrease Blood Pressure
D. Decrease Cardiac Output
E. Increase Heart Rate
F. All the Above
All the Above!!!
True/False: When Preforming a C-Section, Propofol, Alphaxalone, and Etomidate are approved Induction Agents
True
*Thiopental is contraindicated in C-Sections
Which Induction Agents cause:
- Apneustic Breathing (Shallow,Irregular)
- Increases Heart Rate and Blood Pressure (Tachycardia and Hypertension)
- Sensitize Heart to Catecholamine Induced Arrhythmias
Dissociative Agents (Ketamine)
*No Apnea with Dissociative Drugs- Ketamine
*Avoid Ketamine in Patients with Cardiac Disorders- Ketamine can cause Arrhythmias
Two Types of Non-Rebreathing Systems
Mapleson D
Mapleson F
*Mapleson D is Prefered because it has its own Pressure Gauge and APL Valve
Induction agent that acts by Binding GABA Receptors to Produce Hypnosis with a Duration of Action less than 10 Minutes that is Ideal for Patients with Significant Underlying Cardiovascular Dysfunction
Etomidate
*With Etomidate given Alone, there are no changes in Cardiovascular Perimeters. Etomidate is a good option in Heart Failure Patients
Blood Pressure Measurement Technique where a Catheter is Fed into the Right Atrium of the Heart and measures Hydrostatic Pressure within the Vena Cava. This is a Method of determining if there is “room” for more Fluids in the Vasculature
Central Venous Pressure (CVP)
Benzodiazepine Premedication that is a Propylene Glycol Formulation with a Duration of Action of 1-4 Hours that may cause Paradoxical Excitement and Aggression
Diazepam
*Do not Give IM
Calculation to Determine how many Minutes of Oxygen is Remaining in an E Cylinder
*Liters cancel out and leave you with Minutes Remaining
Indirect Blood Pressure Measurement that Involves Occlusion of an Artery by Inflatable Cuff and Detection of Returning Blood Flow distal to the occlusion site as pressure in cuff is reduced
Doppler Monitoring
Phenothiazine which is Administered IM that has long lasting effects of 4-8 hours and causes some Muscle Relaxation but has No Analgesic Effect. This Premedication also has Anti-histamine, Anti-Nausea, and Anti-Arrhythmic Properties
Acepromazine
*No Reversal Agent for Acepromazine
*“Ace Eye”
Alpha 2 Antagonist that is Used to Reverse the Effects of Xylazine
Yohimbine
B. Stagflurane
*The Lower the MAC, the More Potent the Drug
You only need 3.6 mg/kg of Stagflurane to Get the Patient to Sleep, and with Tingflurane you need 5.4 mg/kg to get the Patient to Sleep
MAC is ____ Proportional to Potency
Inversely
*Higher the MAC, the LOWER the Potency
Opioid Premedication that is unique because it is Metabolized by Nonspecific esterases throughout the body, Mainly in Skeletal Muscle, that is a clinical advantage for extremely Rapid Clearance that is not Dependent on Liver or Kidney Function
Remifentanil
*Given CRI due to Rapid Clearance
*Useful in situations where Intense Analgesia is needed for a short time Period
True/False: Precision Vaporizers have Back Pressure Compensation and Temperature Compensation
True
*Non-Precision Vaporizers do not have Back Pressure or Temperature Compensation
Opioid Premedication that is a Semi-Synthetic pure mu agonist that is 5-10x’s more Potent than Morphine that provides dose-dependent Analgesia
Hydromorphone
Build of Pressure leading to Barotrauma
*When you leave the APL Valve closed it stops Gas from going out the Scavenging therefore pressure can build up in your system and can lead to Barotrauma
What Induction Agent leads to:
- Significant Cardiovascular Depression
- Decreased Stroke Volume
- Decreased Blood Pressure
- Cardiac ARRHYTHMIAS!!
Barbiturates
*Cardiac Output = Heart Rate x Stroke Volume
Monitor for Both Cardiovascular and Pulmonary Systems that gives us the % of Hemoglobin Saturated with Oxygen and Reads Pulsatile Blood Flow (Arteries)
Pulse Oximeter
True/False: Etomidate should NEVER be Given as a Constant Rate Infusion (CRI) because the Propylene Glycol will cause Acute Hemolysis
True
Disadvantages of _____ Include:
- Time Limit of App. 1 Hour
- Less Controllable than Inhalant Anesthesia
- Hypoxemia
Total Intravenous Anesthesia (TIVA)
*Inhalants recommended for > 60-90 min. Procedures
Equation to Calculate Clearance of a Drug
Dose / AUC
*AUC = Area under the Curve
AUC = [Drug] versus Time Curve
*KNOW THIS
What Induction Agent Causes:
- Dose Dependant Transient Apnea
- Minimal Change in Heart Rate and Cardiac Output
- Myoclonus
- Nausea/Vomiting/Retching
Etomidate
*Little/no change in Cardiovascular perimeters
*Myoclonus- Muscle Twitching
Which Induction Agent, with Repeated Administration in Cats, can lead to Heinz Body Anemia (RBC Oxidative Injury)
Propofol
*Heinz Body Anemia- Not a concern if only using Propofol Once in Cats, but Propofol should not be provided Multiple Days in a Row to Cats
True/False: Thiopental Barbiturate Induction Agent is Contraindicated for C-Sections and in Pregnant Patients
True
*Thiopental causes Fetal Respiratory Depression
Which Premedication should be Avoided in:
- Boxers
- Patients with Liver Disease or Portocaval Shunts
- Von Willebrands Disease
- Shock or Cardiovascular Disease
Acepromazine
*Acepromazine is Metabolized in the Liver- in animals with Liver disease it will take a long time for the patient to recover if given Acepromazine
Alpha 2 Antagonist with a Higher Alpha 2 Selectivity that is used to Reverse Dexmedetomidine
Atipamezole
Which Inhalant Anesthetic should be avoided in Patients with Liver Dysfunction, because 20-40% of the Inhalant must be Metabolized by the Liver
Halothane
*All other Inhalants are Minimally Metabolized by the Liver
What is Occuring in this Patient based on this Capnograph Waveform?
Hypoventilation
*Not Breathing out enough CO2 with every Breath- CO2 is Rising
Acceptable Values during Anesthesia for Dog, Cat and Horse
*Know the Normal Heart Rate Ranges
Part of the Anesthesia machine that Bypasses the Vaporizer and Delivers 35-75 Liters Per Minute (LPM) of Oxygen Directly to the Patient Breathing Circuit
Quick Flush
*Delivers Oxygen that is Anesthetic Free to the Patient
Vacuum Collection is an ____ Scavenging System
Active
_____ Determines the Rate in Which Inhalant Anesthetic Reaches Equilibrium
Solubility
*The LOWER the Blood Solubility, the FASTER the Onset and the FASTER it will Reach Equilibrium
When you Leak Test the Machine, A Leak Less than ____ml/min is considered Acceptable
300ml (0.3L)
*Why you bring Pressure Gauge to 30 and Make sure it Holds when Leak Testing
The Pressure Reduction Valve Reduces Cylinder Pressure to a Fixed ___ psi to Provide a constant Pressure of ___ psi to the Flowmeter
50 psi
Do Not Use the _____ Valve on a Small Patient attached to a low Volume Breathing Machine, such as a Non-Rebreathing System
Quick Flush
*In small patients on a Non-Rebreathing system, if you were to hit the quick flush valve you would over inflate the Lungs and Cause Trauma, Pneumothorax, and Lung Collapse
Most Common Artery for Cannulation of Invasive Blood Pressure in Cattle, Sheep and Goats
Auricular
Indirect Blood pressure Measurment where Blood flows through an artery causing Vibrations in the Arterial wall, which is translated to air in pressure cuff, which can be detected and transduced to electrical Signals
Oscillometric
We want to ____ Patients prior to Anesthesia to prevent Aspiration Pneumonia, Bloat, Impaired Ventilation and potential Gastric Rupture
Fast
*Small Animals- should be Fasted 6-12 hours Prior to Surgery
*Neonates/Pediatrics should not be Fasted prior to Surgery- Risk of Hypoglycemia if Fasted
Memorize this Chart: ASA Physical Status (PS) Categories
Propofol 28 contains benzyl alcohol and is NOT labeled for use in ____
Cats
* No Propofol 28 (Green Label) in Cats
Commonly Used Opioid Premedication that has a High Affinity for mu receptors and is Hydrophilic leading to a longer duration of Action (4-6 hours) with CNS effects of Sedation, Euphoria and Dysphoria
Morphine
How to Calculate What Size Rebreathing Bag to Use
Body Weight (kg) x Tidal Volume x 5
*Tidal Volume is Normally 10-20 mls/kg
Opioid Premedication that is a Synthetic pure mu agonist that is 100x’s more potent than morphine and is dosed in Mcg/kg and has a short duration of 30 Minutes
Fentanyl
*Transdermal Fentanyl patches
When Filled with Oxygen, H and E cylinder Tanks will have _____ psi (pounds per square inch) of Pressure
2,200 psi
*In an E tank, the 2,200 psi is equivalent to 660 Liters
*In an H Tank, the 2,200 psi is Equivalent to 6,600 Liters
Stage of Anesthesia known as “Surgical Anesthesia” characterized by Unconsciousness with progressive depression of Reflexes, Good Muscle Relaxation and Regular Slow Breathing with a Loss of Vomiting and Swallowing Reflexes
Stage III
Breathing System that Includes a CO2 Absorber and is Characterized by a One-Way Circular Pattern where the Patient Re-Inhales what he Exhaled. This Type of System is Not used on Smaller Patients
Rebreathing System
*Patient Re-Inhales what it Exhales. CO2 Absorber makes sure the Patient isn’t breathing in its Exhaled CO2
System that uses Much Higher Flow Rates than a Rebreathing System and is Always Used on Patients that Weigh Less than 3kg where there is no Device for absorbing CO2, and therefore More Gas Waste and Atmosphere Pollution occurs due to High Flow Rates
Non-Rebreathing System
*Uses a Higher flow Rate to make sure CO2 is pushed out the Scavenging. The Patient Never rebreaths any of the Exhaled Gases
*Very High Flow Rates- 200-300 ml/kg/min
Inhalant Gases that are used to Maintain General Anesthesia, should have a ____ Blood Solubility, be Non-Flammable, Non-Toxic and Stable in the Environment
Low
*KNOW THIS!!!
*Anesthetics with Low Blood Gas Solubility = Fast Onset and Short Duration
Calculation to Determine Remaining Oxygen in an E Cylinder
*Cross Multiply and Solve for X
*X will tell you how many Liters of Oxygen are left in the Cylinder
Which Inhalant Anesthetic has the Lowest MAC
Halothane
*Halothane is the MOST Potent. It has the HIGHEST Blood Gas Solubility and therefore you need the Least Amount of it
What is Occuring in the Patient based on this Capnograph Waveform?
Rebreathing
*Not going back to Baseline
