Veterinary Anaesthesia Module 3010

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Questions and Answers

What is the primary purpose of premedication in anesthesia?

To reduce equipment usage during surgery

To eliminate the need for monitoring

To induce immediate sleep in patients

To provide adequate time for drugs to work (correct)

Which of the following sites is NOT recommended for intramuscular (IM) administration?

Quadriceps

Epaxial muscles

Abdominal muscles (correct)

Neck muscles

What is a key consideration during the administration of pre-oxygenation?

High fraction of inspired oxygen (FIO2) can be administered in various ways. (correct)

It is necessary only for emergency situations.

It should be avoided if the patient shows anxiety.

It should only be done for sedated animals.

Which of the following is NOT included in the essential equipment for induction of anesthesia?

Patient monitoring devices Signup and view all the answers

What is important to ensure during IV cannula placement?

Aseptic technique should be strictly followed. Signup and view all the answers

What is the recommended safe range for ET tube cuff pressure?

20–30 cmH2O Signup and view all the answers

Which of the following methods can be used to measure ET tube cuff pressure?

Minimum occlusive volume technique Signup and view all the answers

What does a lower ET CO2 value indicate in relation to ET tube cuff inflation?

Leaking of anesthetic agents Signup and view all the answers

Prior to ET tube insertion, the length of the tube should be measured from which anatomical location?

Thoracic inlet Signup and view all the answers

How can you confirm that the ET tube is correctly placed in the trachea?

Observe for condensation on the tube Signup and view all the answers

Which of the following could result from over inflation of the ET tube cuff?

Tracheal ischemic necrosis Signup and view all the answers

What is the first step in the ABCD mnemonic after induction?

Airway Signup and view all the answers

Which factor is NOT typically considered when choosing the size for an ET tube?

Patient length Signup and view all the answers

What is the primary purpose of fasting guidelines before anesthesia?

To reduce gastro-oesophageal reflux and aspiration pneumonia Signup and view all the answers

Which of the following medications may be considered for stressed or anxious patients prior to transport?

Trazodone Signup and view all the answers

What is the recommended fasting period for dogs and cats before anesthesia?

6 hours Signup and view all the answers

Which physical status classification indicates a higher anesthetic risk according to the ASA system?

ASA IV Signup and view all the answers

What equipment should be checked for proper functioning before anesthesia?

O2 supply and anesthetic machines Signup and view all the answers

What is a common modification needed for diabetic, neonatal, or geriatric patients regarding fasting times?

Reduce fasting times Signup and view all the answers

Which of the following statements about fluid therapy in anesthesia is correct?

It is primarily used to treat hypovolaemia and dehydration. Signup and view all the answers

What is the primary purpose of continuous monitoring during the recovery phase of anesthesia?

To ensure patient safety and detect complications Signup and view all the answers

Why is oxygen supplementation considered during anesthesia preparation?

To ensure adequate oxygen delivery to the patient Signup and view all the answers

Which of the following factors can lead to a delay in recovery from anesthesia?

Comorbidities like hepatic disease Signup and view all the answers

What is a characteristic sign of emergence delirium in a patient recovering from anesthesia?

Uncoordinated thrashing and restlessness Signup and view all the answers

During the extubation process, which monitoring characteristic is specific to cats?

Strong medial palpebral reflex Signup and view all the answers

What should be done to minimize the risk of complications immediately after anesthesia maintenance is discontinued?

Ensure the patient is in a calm and warm environment Signup and view all the answers

Which of the following agents is commonly used for providing sedation during recovery if required?

Acepromazine Signup and view all the answers

Which stage of anesthesia corresponds to a state of extreme CNS depression?

Stage of surgical anesthesia Signup and view all the answers

What is one of the critical signs to evaluate in dogs during recovery monitoring?

Swallowing ability Signup and view all the answers

What is the primary characteristic of general anaesthesia?

Controlled, reversible depression of the Central Nervous System Signup and view all the answers

Which of the following best describes analgesia?

Absence of pain in response to normally painful stimuli Signup and view all the answers

What is balanced anaesthesia?

Simultaneous use of multiple drugs and techniques to achieve general anaesthesia Signup and view all the answers

Which of the following components is NOT an ideal characteristic of an anaesthetic agent?

Causes significant cardiovascular depression Signup and view all the answers

What does regional anaesthesia provide?

Insensibility to pain in a limited but larger body area Signup and view all the answers

What stage of anaesthesia involves patient preparation and monitoring?

Pre-anaesthetic care Signup and view all the answers

Which of these drugs would be ideal for anaesthesia according to its characteristics?

A drug with a long shelf-life and no toxic effects Signup and view all the answers

What process occurs during nociception under general anaesthesia?

Encoding noxious stimuli through transduction, transmission, and modulation Signup and view all the answers

In what way does local anaesthesia differ from general anaesthesia?

It provides absence of pain in a circumscribed body area Signup and view all the answers

What is a potential complication of anaesthesia that must be monitored for?

Cardiovascular instability Signup and view all the answers

Study Notes

Introduction to Veterinary Anaesthesia

Hanna Machin, lecturer in Veterinary Anaesthesia, delivered the online learning module (3010, 2024) at the University of Surrey.
This module covers premedication, injectable and inhalational anesthetic agents, monitoring in veterinary anaesthesia, common complications and accidents, fluid therapy, and pain management.

Practical Sessions

Practical 2: Includes anaesthetic machine checks, breathing system safety, endotracheal intubation (dog and cat), and monitoring and patient instrumentation.
Practical 4: Covers intravenous cannulation.

Online Learning

The online learning component includes topics like: introduction to anaesthesia, anaesthetic equipment, ECG interpretation, capnography waveforms interpretation, fluid therapy, and CRI calculations.

Learning Objectives

Define general anesthesia, local anesthesia, and analgesia
Describe the components and stages of general anesthesia
Explain the process of anesthesia, including patient preparation and immediate post-anesthetic care.

Definitions

Anaesthesia: Lack of feeling/sensation (from Greek).
General Anaesthesia: State of unconsciousness produced by drug administration; characterized by controlled, reversible depression of the central nervous system (CNS) and perception.
Analgesia: Absence of pain in response to stimulation that would normally be painful.
Nociception: Process of encoding noxious stimuli (transduction, transmission, modulation of nociceptive stimuli) under general anaesthesia.
Local Anesthesia (Analgesia): Loss of pain sensation in a circumscribed body area
Regional Anaesthesia (Analgesia): Insensibility to pain in a larger (but limited) body area. Usually defined by the innervation pattern of affected nerves.

The Triad of General Anaesthesia

Unconsciousness
Hypnosis
Amnesia
Muscle Relaxation
Analgesia

The Ideal Anaesthetic Agent

Rapid onset
Rapid recovery
High lipid solubility
Does not accumulate with prolonged infusion
Analgesic at sub-anaesthetic concentrations
No (or minimal) cardiovascular depression
No (or minimal) respiratory depression
No emetic effects
No pain on injection
No excitation
No emergence phenomena
Does not interact with other agents
Safe following extravascular injection.
No toxic effects
No histamine release
Water-soluble formulation
Long shelf-life at room temperature

The Anesthesia Timeline

Pre-anesthetic evaluation and anesthetic plan
Patient preparation (stabilization, fasting, chronic medications)
Equipment preparation
Induction
Premedication
Maintenance of anesthesia & monitoring
Recovery
Discharge

Pre-anesthetic Evaluation

Obtain client history
Perform physical examination
Discuss risks and procedure
Evaluate the patient's resuscitation status
Collect samples (e.g., blood work)
Confirm signed consent
Assess for comorbidities (e.g., diabetes, hyperthyroidism)
Stabilize pre-existing conditions

Stabilize Pre-existing Conditions

Medical management (diabetes, hyperthyroidism).
Fluid therapy (hypovolemia, dehydration).
Analgesia.
Anxiolysis.
Oxygen supplementation.

Chronic Medications & Anti-Anxiety

Continue scheduled medications (e.g., thyroid medication, behavior/analgesia).
Consider anti-anxiety/sedative medication(s) (e.g., trazadone, gabapentin) 2 hours pre-transport.
May require discontinuation 2 weeks prior.

Fasting Guidelines

General Fasting guidelines for healthy patients (different for patients with pre-existing conditions, high risk considerations).

ASA Physical Status Classification System

Classifies patients based on health status to assess anesthetic risk. Higher ASA status = higher risk.

Equipment Preparation

Check O2 supply, scavenging system, anesthetic machine(s), breathing system, endotracheal tubes, intubation tools, monitoring equipment, rewarming devices, and emergency drugs.
Ensure equipment is functional, and necessary drugs are available.

Premedication

Administered intravenously (IV), intramuscularly (IM), or subcutaneously (SC).
Requires careful monitoring throughout
Needs adequate time for drugs to take effect
Ensure a calm and quiet environment.
Increase dosage/add drugs if sedation level insufficient.

IV Cannula Placement

Used for administration of fluids and medications.
Essential for blood sample collection.
Important for patient welfare in emergencies.
Requires aseptic technique.

Pre-oxygenation

Administering high fraction of inspired oxygen (FiO2) prior to induction.
Beneficial for patients with expected difficulty during ventilation or intubation. Delay onset of Hb desaturation during apnoea → Hypoxemia.
Can cause stress, so must be tolerated

Before Starting: Anaesthetic Safety Checklist

Confirm patient information, owner consent, and procedure.
Check IV cannula, airway equipment, and anesthetic machine.
Complete pre-procedure time-out, communicating any risks. Assess and confirm the plan for recovery.
Assign person to monitor the patient throughout.

Induction of Anaesthesia

Use endotracheal tubes of various sizes
Inflate ET tube cuff properly
Select the correct induction agent
Use laryngoscope, helper/mouth-gag, and swab to ensure correct placement
Apply local anesthetic and lube

How to Choose the Correct ETT Size

Select at least 3 tube sizes: one above, and one below expected size.
Reference formulas/tables for patients, but ensure careful consideration of overweight patients.

Endotracheal Intubation

Insert laryngoscope blade under epiglottis, press to visualize trachea.
Using the tube, carefully insert until the lungs expand properly. Maintain constant monitoring (e.g., capnography, etc).
Attach breathing system with oxygen and monitor proper parameters (e.g., ETCO2 ).

Securing the Airways

Proper inflation of ET tube cuff is critical.
Avoid over-inflation—risk of tracheal ischemia.
Ideal pressure range for cuff: 20–30 cmH2O
Use minimum occlusive volume technique and specific devices (syringe devices).

After Induction

Monitor airway, breathing, circulation, drugs/depth of anesthesia, equipment, and forms.

Monitoring

Ongoing monitoring is essential. Use various devices to track vital signs.

Stages of Anaesthesia

Classifies patients based on different stages of anesthesia, using different criteria (e.g., muscle movement/reflexes, pupil responses).

Maintenance of Anaesthesia

Administration of inhalational agents, injectable agents, and/or supplemental oxygen.

Recovery Checklist

Communicate safety concerns regarding airway, breathing, circulation, temperature, pain.
Check if assessment and interventions plan & analgesic plan is confirmed and appropriate.
Ensure a person is assigned to monitor the patient.

Extubation

Keep patient in sternal position (if possible).
Deflate and remove the ET tube.
Monitor the animal for signs of discomfort (swallowing or movement).

Recovery

Starts after maintenance agents are discontinued. Monitor consciousness and respond promptly to any complications.
Ensure use of safe environment, patient warming, fluid therapy, eye lubrication, and proper padding. Use pain scoring and analgesia (or sedation).

Recovery Delay

Causes of delayed recovery include excessive anesthetic depth, drugs with extended duration of action, prolonged surgery, comorbidities, hypothermia, hypoglycemia, poor circulation, and hypoxemia.

Emergence Delirium

Characterized by stress, unease, anxiety, vocalization, panting, restlessness, and uncoordinated thrashing.
May be caused by hypoxemia, pain, and recent opioid administration.
In some cases, sedation can aid in recovery

Post-Operative Care Plan

Comprehensive form tracking anesthesia and post-operative care. This may vary from facility to facility.

References

Various publications from 2020, BSAVA, and AAHA provided.

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Description

This quiz explores the key concepts of veterinary anaesthesia as taught in the online learning module at the University of Surrey. It covers essential topics such as anaesthetic agents, monitoring techniques, and practical skills necessary for administering anaesthesia in dogs and cats. Prepare to test your knowledge on this critical area of veterinary practice.