Anaesthesia: Intro and Sedation and Premedication Flashcards
What is general anaesthesia?
The physiological state between being conscious and dead- the maintenance of ‘sleep’
What is the job of a vet for anaesthesia?
To anticipate, mitigate and minimise the risk of morbidity or mortality by:
Adequate preparation
Stabilisation
Protocol planning
Delivery
Monitoring
What are some general considerations of anaesthesia?
ASA status, aim of the anaesthesia, nature of the procedure, surrounding, equipment, knowledge, helpers
What skills are needed for anaesthesia?
(Day 1 Competencies)
- Ensure patient airway
- Giving O2
- Know how to apply IPPV- intermittent positive pressure ventilation
- IV catheter- give drugs IV
- Basic CPCR
Outline the general process of anaesthesia?
Premedication
Induction
Maintenance
Recovery
What is the ASA and what is the ASA status?
ASA is the american society of anesthesiologists
ASA status is the general health of the animal and the patient risk
What are the different ASA classifications?
ASA 1- Normal healthy animals
ASA 2- Mild systemic disease
ASA 3- Moderate systemic disease
ASA 4- Severe systemic disease, constant life threat
ASA 5- Moribund, not expected to survive following 24 hours
What ate the three aims of anaesthesia?
Unconsciousness
Analgesia
Muscle relaxation
What is balenced anaesthesia and what are the benefits of it?
Anaesthesia produced by safe doses of two or more agents or methods of anaesthesia, each of which contributes to the total desired effect
Benefits: reduction of dose of each component, reduction of the side effects, optimised post-operative analgesia
How does nature of the procedure influence general anaesthesia?
Duration of procedure
Pain level of procdure
Localisation- head/neck eg
Recovery time
How is analgesia managed in anaesthestic protocol?
Pre-emptive analgesia= treat pain before
Part of balanced anaesthesia/analgesia = reduction of requirment
Analgesia during recovery
What equimpent is needed for general anesthesia?
Depends but generally:
Oxygen source
Anaesthetic machine
Breathing system
IPPV/ventilator
Venous access/ infusion pumps
Monitoring
What is the risk of mortality of humans, cats, rabbits and horses?
1 in 2000 humans
0.11% of cats
just under 1 in 100 rabbits
1 in 100 horses will die
Most important factor is pre-exisitng disease
What is the difference between sedation and premedication?
Sedation:
may be used as an alternative to general anaesthesia
Non-invasive procedures
Non-painful procedures
Premedication- administered prior to anaesthesia
Terms often used interchangeably
Why sedate instead of premed?
To relieve patient anxiety
Facilitate handling
Analgesia
Muscle relaxation
To enable procedures
Why premedicate instead of sedate?
Smooth induction of anaesthesia
Smooth maintenance of GA
Smooth recovery of GA
Reduce required dose of induction/maintenance
What would the ideal premed or sedative do?
Relieve fear/anxiety
Be safe
Reliable and predictable effect
Quick onset, appropriate duration of action
Easy to administer (route, volume, non-irritating)
Minimal CV, Resp and other side effects
Provide analgesia
How can the cascade be used for sedatives and premeds?
Use the cascade to your advantage
Drugs for food producing animals must have an MRL
Use drugs to provide adequate analgesia
Use drugs to provide adequate sedation
What are considerations of sedation and premed?
- Reason for sedation/premed
- What drugs you can use- food producing/cascade
- Will there be pain
- Are your drugs safe to use in this case
- Will your drugs effectively sedate this patient
- What if it doesn’t work?
Why would you sedate/premed pre-appointment and what are your options?
For use of patients who are known to be anxious
Equine- acepromazine oral gel, detomodine oromucosal gel
Dogs and Cats- gabapentin 2 hours before appointment, Trazadone- caution if history of seizures
What opioids could be used for sedation/premed what are the advantages and problems?
Butorphanol
Buprenorphine
Methadone
Fentanyl
(morphine)
Advantages- may be adequate alone, often good sedation if the animal presents very painful
Disadvantages- Respiratory depression
What phenothiazines could be used for premed/sedation?
Acepromazine
What alpha 2 receptor agonists could be used for sedation/premed?
Xylazine, Detomidine, Romifidine, Medetomidine, Dexmedetomidine
Sympathomimetics
