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