Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Aneasthesia > Maintenance of Anaesthesia > Flashcards

Maintenance of Anaesthesia Flashcards

0
Q

What are potential problems with ET tubes? how can they be prevented?

A
  • occlusion of end of ET tube (prevented by Murphy’s eye)
  • endobronchial intubation - mucus in the tube may cause occlusion and infection, ^ resistance and only ventilating one lung (don’t push too far!)
  • compression of inside of tube or stretching of tracheal wall (listen for gas escaping until none escapes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

When can you intubate?

A

> suficient depth of anaesthesia

  • eyes rotated ventrally
  • minimal, sluggish palpebral reflex
  • loose jaw tone
  • no swallowing reflex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What side effects do anaesthetic agents have?

A

DOse dependant

  • CV depression(v CO, vasodialtion, v BP)
  • resp depression (v RR, v TV, v MV)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Do most GA provide anaesthesia?

A

No

except: KETAMINE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why is analgesia required even if animal is unconcsious?

A
  • prevent unconcious upregulation of pain processing pathways
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What ROA are available for anaesthetic maintainence?

A 
> IV
- TIVA
- Intermittent boluses 
- CRI 
> Inhalational
> Both ("balanced technique)
- partial intravenous anaesthesia (PIVA) 
> occasionally (rarely) single IM injection sufficient (eg darting wild animals)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why must you be careful when intubating cts?

A

Laryngeospasm

  • spray lidocaine “intubeaze”
  • CAVE: easy to overdose -> local anaesthetic toxicity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 6 aspects of balanced anaesthesia?

A
  • minimise stress
  • analgesia
  • mm relaxation
  • v amount of drugs (so use more types)
  • v autonomic reflex activity
  • unconciousness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which GA drugs can be used for injectable maintainence of anaesthesia?

A 
> best for CRI 
- propofol
- alfaxolone
> best for intermittent boluses
- ketamine
- thiopental
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which GA drugs can be used for inhalational anaesthesia?

A
  • isoflurane and sevoflurane [licensed smallies]
  • halothane [old fashioned]
  • desflurane [new but expensive]
  • N2O
  • xenon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What 2 ways can TIVA be carried out?

A

> intermittent boluses
+ simpler, require less equipment
- swinging plane of anaesthesia so ^ risk toxicity
CRI
- need pump/cri infuser
+ TCI : calculate amount of drug to deliver by measuring plasma concentration, ie. minimum infusion rate (=MAC??)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How are most inhalational agents administered and removed?

A

Lungs

excpetion: halothane metabolised in liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How may redistribution of inhalational agents affect anaesthesia?

A
  • fat soluability -> slow recovery from long anaesthetic

- vessel-rich (brain, kidneys) v vessel-poor tissues (skin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which factors affect inhalational agent uptake?

A

Pressure gradient from vaporizer to brain
- vaporiser setting
- anaesthetic circuit volume
- alveoli (eg. pulmonary oedema)
- blood
- brain
> Brain concentration approximates alveolar concentration (equililbrium) so expirational concentration (End tidal concentration)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which factors affect speed of induction?

A
  • ^ partial pressure in lungs = high partial pressure in brain
  • if agents v. soluable in blood will remain there -> v partial pressure in brain
  • slower induction and recovery for more soluble agents
  • CF. injectable agents which SHOULD be dissolvable in blood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the blood/gas partition coefficient?

A
  • no. parts gas in blood: alveolus
  • high number means gas v. soluble and slower induction and recovery
  • more soluble agents also slower change of depth of anaesthesia during maintainence
16
Q

What is the potency of the inhalational agents? How is this related to blood/gas coefficient?

A
  • how much inhalational agent is needed

- inversely proportional to solubility in blood!!

17
Q

Define MAC. What does it depend on and how is it used clinically ?

A
  • minimum alveolar concentration required to prevent movement in 50% of animals in response to painful stimulus
  • clinical anaesthesia aim for ~1.25-1.5x MAC
  • depends on other desative/anaesthetic agents (MAC sparing)
  • differs between species
18
Q

Which factors can change MAC?

A
  • hypothermia v/hyperthermia ^
  • age: very young/old v, young fit^
  • severe hypoxaemia or hypercapnia v
  • severe hypotension v
  • CNS depressant drugs v
  • exctiation ^
  • pregnancy v (eg. ceasar)
19
Q

Which factors do NOT affect MAC?

A
  • length of anaesthesia
  • gender
  • blood pH (7.35-7.45 normal, unless severe)
20
Q

MAC values of isoflurane and sevoflurane in dog, cat horse and human?

A

Look at table

21
Q

Is sevoflurane licensed in all animals?

A

Not cat and horses

22
Q

Which volatile anaesthetic agent reduces CO most severely?

A

Halothane

23
Q

Which inhalational agent has greatest metabolism in the liver?

A

halothane

24
Q

Potential side effects of sevoflurane?

A
  • theoretically toxic to kidney
  • reacts with hot and dry carbon dioxide absorber (nephrotoxic too) less of an issue with high flow systmes but with low flow systmes bad
25
Q

Pros and cons of isoflurane?

A

+ cheap

  • irritant and stronger smelling
  • vasodilation and CV depression
26
Q

Pros and cons of sevoflurane

A 
\+ v CV effects
\+ maintains better cerebral perfusion better (Always use for MRI) 
\+ better tolerated, less irritant
- compound A reaction with soda lime 
- expensive
27
Q

Pros and cons of N2O?

A
  • MAC 200%!! (must be used with other agents)
  • less important now that insoluble agents are routinely used
  • diffusion hypoxia at end of anaesthesia (diffuses rapidly into lungs v partial pressure of o2. Advise switch off N2O 15 mins before end of surger yand give pure O2)
    + mild analgesic (=ketmine mechanism of action)
    + very insoluble (quick)
    + can speed onset of other agents (2nd gas effect)
28
Q

Health risk assocaited with N2O?

A
  • teratogen
  • vitamin B12 deficiency (> sensory neuropathy, myelopathy, encepalopathy)
  • atmospheric pollution (proper scavenging v important)
29
Q

When is recovery considered to be over?

A
  • 48hrs smallies

- 5-7d equine

30
Q

When can extubation be carried out?

A
  • when swallowing reflex returns
  • cats slightly earlier to prevent laryngospasm
  • later if concerned about airway (brachycephalic dogs, vomiting risk, ruminants active regurgitation - leave tube in until they chew it)
31
Q

What is involved in recovery?

A
  • monitor HR< RR, temp
    +- oxygen and fluid therapy
  • temperature - active/passive warming esp. SA
  • post-op analgesia
  • nursing care (bladder empty [place catheter in horses as standard, bandages comfortable)

Aneasthesia (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions