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CPS > Anaesthesia > Flashcards

Anaesthesia Flashcards

1
Q

Define anaesthesia

A

Controlled depression of the CNS so as to produce a lack of awareness of painful inputs (nociception)

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2
Q

What area of the brain do anaesthetic agents ideally work on and why?

A

Minimal depression of hindbrain functions (preventing depression of cardiovascular centres) while having depressive effect on forebrain

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3
Q

Why is unconsciousness required?

A

To allow pain free surgery (no nociception)

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4
Q

Define nociception

A

The response to a stimulus that may be painful

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5
Q

Define pain

A

The conscious awareness of nociceptive input

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6
Q

What are the desired effects of anaesthesia?

A
  • Hypnosis
  • Anti-nociception (analgesia)
  • Muscle relaxation
  • Areflexia
  • Maintenance of oxygen delivery
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7
Q

What are the potential risks of anaesthesia?

A
  • Direct toxicity (reaction to drug)
  • Indirect toxicity (e.g. halothane causing liver damage killing patients a few days later)
  • Accidents
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8
Q

What are the features of successful anaesthesia?

A
  • No CV depression
  • No reduction in oxygen tissue delivery
  • No cardiac dysrhythmias
  • No cerebral hypoxia
  • Survival
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9
Q

How is anaesthetic risk classified?

A
  • American Society of Anesthesiologists (ASA) Physical Status Classification
  • Categories I to VI
  • VI not currently used (donor status)
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10
Q

Describe category I anaesthetic risk physical status

A

Normal healthy patient, no discernible disease e.g. elective spay, castration, dentistry

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11
Q

Describe category II anaesthetic risk physical status

A
  • Pre-existing disease
  • No discernible systemic signs
  • E.g. skin tumour, fracture without shock, uncomplicated hernia, localised infection, compensated cardiac disease
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12
Q

Describe category III anaesthetic risk physical status

A
  • Pre-existing disease
  • Mild systemic signs
  • e.g. fever, dehydration, mild anaemia, mild cachexia, moderate hypovolaemia
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13
Q

Describe category IV anaesthetic risk physical status

A
  • Pre-existing disease
  • Severe systemic signs
  • e.g. uraemia, toxaemia, severe dehydration and hypovolaemia, severe anaemia, cardiac decompensation, emaciation, high fever
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14
Q

Describe category V anaesthetic risk physical status

A
  • Moribund patient
  • Not expected to survive with or without intervention
  • Extreme shock and dehydration, terminal malignancy or infection, severe trauma
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15
Q

How can anaesthetic risk be minimised?

A
  • Evaluation and planning
  • Support with oxygen at all times
  • Fluids
  • Warmth
  • Monitoring during anaesthesia and recovery
  • Anaesthetic record sheets
  • Trained anaesthetist
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16
Q

Outline the normal process of anaesthesia

A
  • History and examination
  • Formulate anaesthetic plan (ideally multiple)
  • Place cannula
  • Induce anaesthesia with injectable agent via cannula
  • Intubate, check ABC
  • Connect to anaesthetic machine, supply volatile anaesthetic agent in oxygen
  • Alter inspired concentration in response to physical signs
  • Supply analgesia
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17
Q

List the 3 key components for a balanced anaesthetic

A
  • Hypnosis
  • Anti-nociception
  • Muscle relaxation
  • Aka Triad of Anaesthesia
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18
Q

What is hypnosis?

A
  • Artificially induced “sleep”

- More like lack of awareness (cannot be woken)

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19
Q

What is anti-nociception?

A
  • Blocking of reaction to painful stimulus

- Are not perceiving pain but nociception can still occur

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20
Q

Where can nociception be blocked?

A
  • Transduction using NSAIDs
  • Transmission suing local anaesthetics
  • Spinal cord with opioids and alpha-2 agonists
  • CNS with opioids
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21
Q

Why is muscle relaxation require in anaesthesia?

A
  • Intubation

- To gain access to surgical site

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22
Q

How can muscle relaxation be induced?

A
  • Using more of the same agent producing hypnosis (but will decrease all physiological functions)
  • Centrally acting muscle relaxant e.g. diazepam, midazolam
  • Using specific neuromuscular junction blocking agent e.g. curare
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23
Q

Describe the stress response in anaesthetised animals

A
  • Anaesthesia increases cortisol
  • Initial increase in BP and subsequent decrease as administer more or anaesthetic agent
  • Patient becomes cold as stop the physiological processes that keep it warm
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24
Q

Why is balanced anaesthesia important?

A
  • Improves success rate and recovery
  • E.g. one agent may have all 3 effects of triad but decreased brainstem function also caused, may lead patient to crash
  • By using combination of agents can have better control of all 3 parts of triad
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25
Q

Describe the traditional method of monitoring “depth of anaesthesia”

A
  • 4 stages
  • Look at pupil position
  • Resp pattern
  • Pulse rate
  • Blood pressure
  • No longer used
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26
Q

Describe the modern method of monitoring “depth of anaesthesia”

A
  • 3 states: conscious, anaesthetised, dead
  • Level of CNS depression can be altered and monitored
  • Signs relating to muscle relaxation and physiology
  • Eye position, 5 classifications (A to E)
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27
Q

Describe eye position A in anaesthetic monitoring

A
  • Conscious

- Pupils responsive to light

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28
Q

Describe eye position B in anaesthetic monitoring

A
  • Some CNS depression

- Eye rotates ventrally and medially

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29
Q

Describe eye position C in anaesthetic monitoring

A
  • Operative levels of anaesthesia
  • Eye rotated ventromedially
  • Mostly see white of eye and a little of iris
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30
Q

Describe eye position D in anaesthetic monitoring

A
  • Too much CNS depression

- Only whites of eye visible

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31
Q

Describe eye position E in anaesthetic monitoring

A
  • Pupil fixed centrally and gaping
  • Non-responsive to light
  • May appear same as A but is emergency stage
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32
Q

Describe the signs of too much CNS depression in anaesthesia

A
  • Resp rate down, heart rate down, blood pressure down

- Animal loses ability to maintain normal physiology

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33
Q

What is an important consideration when monitoring CNS depression in horses?

A
  • Need to assess both eyes, as may be doing different things

- Eyes tend to be doing the same thing in small animals, cows, sheep, alpacas

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34
Q

Define local anaesthetic

A

Blocking of peripheral nerves

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35
Q

Define tranquilisation

A

Relief of anxiety

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36
Q

Describe sedation

A

Central depression, drowsiness, less aware of surroundings but may still be anxious

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37
Q

Define narcosis

A

Drug induced sleep produced by narcotics (opiates e.g. morphine, methadone)

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38
Q

Describe dissociative anaesthesia

A

Induced by drugs such as ketamine, dissociate the thalamo-cortical and limbic systems
Normal reflexes are still present but are unconscious (may appear awake)

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39
Q

What are potential sites of application of local anaesthetics?

A
  • Topical
  • Infiltrative
  • Conductive
  • Epidural
  • Subarachnoid
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40
Q

Name the different types of cannula

A
  • Over the needle
  • Through the needle
  • Peel away cannula
  • Seldinger/over the wire cannula
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41
Q

Describe over the needle cannulas

A
  • 24-10 gauge needle, 1.9-12.3cm long
  • Relatively stiff material
  • Central stylet, cannula placed over the top, insert whole set into vein, slide cannula off stylet into the vein
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42
Q

Describe through the needle cannulas

A
  • Large bore insertion needle
  • Cannula passed through the needle
  • Used for central veins
  • Not commonly used, mainly ICU settings
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43
Q

Describe peel away cannulas

A
  • Place through an over the needle cannula
  • Insert needle with peel away sheath, remove needle leaving just the sheath
  • Insert cannula through the sheath
  • Peel away sheath leaving just the cannula
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44
Q

Describe Seldinger/over the wire cannulas

A
  • Start with clean site, place normal IV cannula into jugular vein
  • Pass wire down cannula, into vein
  • Remova cannula leaving the wire in the venous space
  • Add dilator to open up tissues
  • Once dilated, feed cannula over the wire and into the vein
  • Secure in place, remove wire, left with cannula deep into vascular system
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45
Q

Describe the ideal biological properties of IV cannula materials

A
  • NOn-irritant
  • Non-carcinogenic
  • Non-thrombogenic
  • Non-toxic
  • Resists microbial adhesion
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46
Q

Describe the ideal physical properties of IV cannula materials

A
  • High tensile strength
  • Resists compression
  • Optimum flexibility
  • Low friction coefficient
  • Dimensional stability
  • Tolerates physical sterilisation methods
  • Ease of fabrication (cost)
  • Non-permeable
  • Radiopaque
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47
Q

Describe the ideal chemical properties of IV cannula materials

A
  • Absence of leachable additives
  • Stable during storage
  • Stable on chemical sterilisation
  • Stable on implantation (non-biodegradable)
  • Permits adhesives in fabrication
  • Accepts surface coatings
  • Compatibility with chemical compounds and solvents
  • MRI compatible
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48
Q

What is the most commonly used cannula material?

A

Teflon

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49
Q

Describe the importance of cannula tip shape

A
  • Shape of tip can reduce endothelial trauma

- Rounded preferable to square cut or bevel ended

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50
Q

What size cannula is best for small patients?

A

22G for rabbits and small cats

51
Q

What size cannula is best for most patients (esp. cephalic access)?

A

20G

52
Q

What size cannula is best for dogs over 20kg?

A

18G, in very large dogs may use 16-14G

53
Q

What is the importance of cannula size?

A
  • Want biggest size possible
  • Flow through catheter is dependent on internal diameter and inversely proportional to the length of the catheter
  • Flow through catheter inversely proportional to viscosity of the fluids
  • If halve the size of the cannula, reduce flow rate 16 times
54
Q

Name the different designs of cannula

A
  • Butterfly
  • Vascular access ports
  • Intraosseous
  • Subcutaneous
55
Q

Describe Butterfly cannulas

A
  • Difficult to secure without damaging vessel
  • Useful for sampling
  • 27-14G, 1.6-3.2 cm long
  • Metal cannula, wings, attached to extension set
  • Useful for drianing pneumo, pyo and haemothorax in small animals
56
Q

Describe vascular access port cannulas

A
  • Implanted under skin attached to bone
  • Directly into vein
  • Good for repeat doses e.g. fluids for cats in renal failure, chemotherapy
57
Q

List the different types of intraosseous catheter

A
  • 16-20G bone marrow needle
  • Cook intraosseous needle
  • 20Gx3.75cm spinal needle (cats and puppies)
  • 18-25G hypodermic needle for neonates nad birds
58
Q

Describe the use of intraosseous catheters

A
  • Good for patients with inaccessible peripheral vessels
  • Patietns in circulatory collapse needing fluids, blood products or drugs
  • Quick access via bone marrow sinusoids and medullary venous channels
  • Rapid delivery of fluids to neonates, small animals and birds
  • Local anaesthetic over bone
  • Can administer everything except cytotoxic drugs
59
Q

What sites are commonly used for intraosseous administration of drugs or fluids?

A
  • Intertroachanteric fossa of femur
  • Tibial tuberosity
  • Greater trochanter of humerus
  • Wing of ileum
60
Q

Describe the use of Subcutaneous cannulas

A
  • No longer used much as subcut fluids are minimally useful

- Can be implanted under skin

61
Q

What is the function of multilumen cannulae?

A
  • Can administer drugs and take blood from different attachments on a single cannula
  • Outlets along different parts along cannula so drugs administered are not mixed with blood taken for sampling
62
Q

List the common veins used for cannula placement

A
  • Cephalic
  • Saphenous
  • Jugular
  • Auricular
63
Q

Describe placement of a cannula in the cephalic vein

A
  • Most common for dogs and cats
  • Also rabbits, horses and cows
  • Accessory cephalic that joins 3rd of way between carpus and elbow, avoid this and use dorsal cephalic
  • Start distally so can move proximally if goes wrong
64
Q

Describe the placement of a saphenous cannula

A
  • Requires more assistance, restrain in lateral
  • Medial or lateral can be used
  • Use vein on caudal aspect of leg as it ascends
  • Medial easier for cat and non-fat dog (straighter)
  • Easy to see
  • Well tolerated long term
  • Swelling common, not a problem if placed aseptically
65
Q

Describe the placement of a jugular cannula

A
  • Dogs, horses
  • Right is straighter in dogs
  • Useful for long term therapy and regular sampling
  • Well tolerated
  • Multilumen cannulae can be used (Seldinger technique to place cannula)
66
Q

Describe the placement of an auricular cannula

A
  • Animals with large floppy ears e.g. rabbits, dogs, ruminants
  • Runs very lateral on the ear
  • EMLA cream (lidocaine and prilocaine) can help reduce discomfort
67
Q

Describe the preparation of a site for the placement of a cannula

A
  • Clip (or cut hair with scissors, or part hair)
  • Surgical scrub
  • Alcohol
  • Ensure sufficient contact time of disinfecting agents
  • Dry hair prior to cannulation so tape will stick
68
Q

Describe how to secure a cannula

A

Secure with tape underneath and on top, then use vet wrap or soft wrap on top

69
Q

Describe the monitoring of cannulas

A
  • Check regularly, flush every 6 hours with heparinised saline
  • Normal cannulae can be maintained for up to 3 days (1 day more if looks very good)
  • Swab ports prior to injection
  • Replace giving sets, bungs, and T ports after 3 days even where are not changing cannula
  • Must be unwrapped and inspected every day
70
Q

What complications can arise from placing a cannula?

A
  • Extravasation
  • Thrombosis
  • Thrombophlebitis
  • Infection
  • Emboli
  • Exsanguination
  • Haematoma/abscess following IV infusion
71
Q

Describe thrombophlebitis

A
  • Inflammation of vein
  • Seen as swelling in neck and jaw of horse, remove cannula, pack site and use ice, raise head, administer systemic and topic anti-inflammatories, antibiotics following culture, heparin and vasodilators may also be used
72
Q

Outline treatment following infection at site of cannula

A
  • Remove
  • Sample and do culture and sensitivity
  • Antibiotics may be needed
73
Q

How can anaesthetic agents be administered?

A
  • IM
  • IV
  • IP
  • Subcut (rare)
  • Induction chamber/mask
  • Immersion/contact (fish))
74
Q

List the groups of injectable anaesthetic agents used in veterinary species

A
  • Propofol
  • Thiobarbiturates
  • Oxybarbiturates
  • Injectable steroid anaesthetics (saffan, no longer in UK)
  • Dissociative agents
  • Imidazole anaesthetics (etomidate, not licensed)
75
Q

Name the thiobarbiturate used in veterinary species

A

Thiopentone sodium

76
Q

Name the oxybarbiturate used in veterinary species

A

Pentobarbitone

77
Q

Describe the anaesthetic induction in horses

A
  • Usually IV
  • In foals can use inhalants or nasotracheal intubation and gas
  • Ketamine or guaifenesin common used
78
Q

How is anaesthesia maintained in horses?

A
  • Incremental “top ups” IV
  • TIVA
  • Inhalation agents
79
Q

Outline the use of ketamine as an induction agent in horses

A
  • Combined with other drugs
  • Eyes remain open and central
  • Less cumulative vs thiopentone
  • Can be used as “top ups”
  • Often used in combination with acepromazine, alpha2 agonists, BZDs or guaifnesin
80
Q

Outline the use of guaifenesin as an induction agent in horses

A
  • GGE
  • Centrally acting muscle relaxant
  • Infused immediately prior to induction until horse is ataxic, and as part of TIVA
  • Not licensed
  • Can be used alone in foals but only as a combination in adults
81
Q

What alternatives to guaifenesin can be used in horses?

A
  • BZDs
  • Midazolam
  • Diazepam (zolazepam)
82
Q

Describe the induction of anaesthesia in ruminants

A
  • Many procedures performed standing
  • Induction usually IV (calves can be mask induced)
  • Some cows may drink chloral hydrate
  • Ketamine and alpha2 agonists mostly used
83
Q

Describe the induction of anaesthesia in pigs

A
  • Can be administered deep IM, IV, or mask
  • Ketamine, alfazalone and propofol used
  • Ketamine combinations
  • Some risk of malignant hyperthermia
84
Q

Describe the intubation of pigs

A
  • Challenging as mouth does not open wide
  • Trachea changes direction by 90degrees twice
  • Smaller tubes required vs equivalent weight dog
85
Q

Describe the principles of anaesthesia in exotic species

A
  • Same general principles as for other species
  • Few pieces of specialised equipment required
  • Easily stressed
  • Need to weigh accurately
  • Have an increased surface area:bodyweight ratio so will lose heat quickly
  • Risk of hyper or hypothermia
86
Q

Describe the induction of anaesthesia in rabbits

A
  • Higher risk
  • IV, IM, SC, mask
  • Pre-oxygenate
  • Fentanyl/fluanisoe recipes or alfaxalone IV are licensed, ketamine +medetomidine and opioid (butorphanol or buprenorphine) IM or IV, or BZD+opioid followed 15 mins later by alfaxalone or propofol
87
Q

Explain why there is a higher risk of anaesthesia in rabbits than other species

A
  • Hypothermia
  • Prolonged recovery
  • Some protocols can lead to GI disturbances
  • difficult intubation
  • Respiratory obstruction leading to cyanosis
88
Q

Describe the induction of anaesthesia in birds

A
  • Inhalant e.g. isoflurane in oxygen
  • Apnoea common so intubate (Cole tube)
  • Air sac cannulation also possible
89
Q

Outline the risks in anaesthesia of birds

A
  • Hide illness well
  • High metabolism so conditions change quickly
  • Easily become hypoglycaemic so do not fast for too long
  • Care with changing body position (need to do this slowly)
  • Cannot ventilate when in sternal recumbency
90
Q

Outline the principles of anaesthesia in reptiles

A
  • Challenging
  • Blood shunting can make gas induction/maintenance impossible
  • Heart rate stays stable regardless of anaesthetic plane
  • Respiration abolished at surgical planes so IPPV needed
  • Chelonia esp difficult to induce with gas
  • Venous access difficult
  • Reptiles respond slowly to changes in gas concentration
  • Use toe, tail pinch and tongue retraction to assess anaesthetic level
  • Avoid sudden changes in body position
91
Q

What are the methods administration of induction agents in reptiles?

A
  • IV
  • Intraosseous
  • Gas (complicated due to blood shunting)
92
Q

What drugs are used in the anaesthesia of reptiles?

A
  • Popfol
  • Alfaxalone
  • Analgesia with butorphanol +/- NSAID (also buprenorphine in some)
93
Q

Describe the anaesthesia of lizards

A
  • Inhalant, IV (ventral coccygeal veins)
  • Always intubate
  • IPPV provided 1-2x/minute
94
Q

Describe the anaesthesia of chelonians

A
  • Fluid therapy beneficical (oral, IV, intracoelomic, epicoelomic, intraosseous)
  • Anaesthesia via inhalant, injectable +inhalant, injectable “top ups”
  • Oxygen advised
  • Anaesthesia usually well tolerated
  • Intubation easy, use T piece circuit to deliver O2 and iso/sevo, IPPV
95
Q

Describe the anaesthesia of snakes

A
  • Fluid therapy advised (SC, intracoelomic)
  • Anaesthesia via injectables or mask with inhalant (better for very sick snakes)
  • Can be intubated and anaesthesia maintained using inhalants
  • IPPV 4x/minute
96
Q

How is blood sampled from snakes?

A

Cardiocentesis or tail vein

97
Q

Describe the anaesthesia of fish and amphibians

A
  • MS-222 (tricaine methane sulphonate, 1:2500 dilution in sterile water)
  • Some species may require injectable techniques
  • Make solution from powder
  • Effects are cumulative so remove from solution once anaesthetised
  • Short procedures only require patient to be kept moist, longer procedures require oxygenated water to be passed over gills +/- anaesthetic solution
98
Q

What drugs are used in the anaesthesia of amphibians?

A
  • Phenoxyethanol
  • Benzocaine (in acetone)
  • Ketamine IM
  • Bubble isoflurane or halothane through water
  • Isoflurane in KY jelly
  • Clove oil (eugenol)
99
Q

What are the ideal properties of an injectable induction agent?

A
  • Water soluble
  • Long shelf life and stable when exposed to light
  • Small volume required
  • No local toxicity
  • No effect on organ function
  • Minimal individual variation
  • Safe therapeutic ratio
  • Onset within one vein to brain circulation time
  • Short duration of action
  • Non-toxic metabolites
  • No histamine release
100
Q

Describe the formulation of propofol

A
  • Alkyl phenol, white emulsion, 10mg/ml

- Contains soyabean glycerol, egg lecithin, no preservative and NaOH so short shelf life once open

101
Q

Describe the pharmacokinetics of propofol

A
  • Rapid onset due to rapid uptake by CNS
  • Short period of unconsciousness (5-8 min)
  • Lipophilic (large VD)
  • Rapid smooth emergence due to redistribution away from vessel rich areas and efficient metabolism
  • Metabolites are inactive
  • Repeat administration produces deeper plane of anaesthesia but also extends eradication phase
  • Suitable for TIVA
102
Q

Describe the clinical properties of propofol

A
  • Respiratory depression (apnoea)
  • Cardiovascular depression
  • Rapid and smooth recovery
  • Adequate muscle relaxation
  • Good anticonvulsant
  • Non irritant
  • descreases intracranial pressure
  • May cause paddling following administration
  • Dose depends on premed
103
Q

Outline the side effects and contraindications of propofol

A
  • Avoid in shock or sepsis
  • Decrease dose in old dogs and cats (give to effect)
  • Pawing and sneezing in cats due to histamine release
  • Can be diluted with 5% dextrose (not saline)
104
Q

Describe the principles of using thiobarbiturate induction agents

A
  • Give to effect
  • Dose depends on premedication
  • Slow injection in sick patients
  • Used in horses when are moving dangerously on operating table
105
Q

Describe thiobarbiturate induction agents

A
  • Sodium salt powder
  • Highly lipid soluble
  • Very alkaline solution (pH 14)
  • Difficult to source
  • No longer licensed in dogs, cats and horses
  • Mainly used in horses
106
Q

Describe the side effects of anaesthetic induction with thiobarbiturates

A
  • Rapid loss of consciousness
  • Respiratory depression
  • Cardiovascular depression
  • Peripheral vasodilation
107
Q

Describe the pharmacodynamics of thiobarbiturates

A
  • Highly protein bound, displaced by other drugs e.g. flunixin, phenylbutazone
  • Unionised fraction penetrates cells so pH can affect response
  • Plasma protein concentration important
  • Crosses placenta
  • Metabolised in liver
  • Prolonged recovery (hours) in sighthounds
108
Q

Describe oxybarbiturate induction agents

A
  • Similar to thiopentone in structure
  • Slower onset of action vs thiopentone
  • Plasma protein binding less, less lipid soluble
  • Slow recovery, difficult to source
  • CVS and respiratory depression, irritant, poor
  • No longer available
109
Q

Name the injectable steroid anaesthetics

A
  • Saffan (no longer available in UK)
  • Alfaxalone/alphadonolne
  • Solubilised by Cremaphor
110
Q

What are the contraindications for injectable steroid anaesthetics?

A
  • Formulations with Cremaphor not used in dogs or cats as causes massive histamine release, anaphylaxis in some cats
  • Avoided in atopic/airway cases
111
Q

Describe the formulation of injectable steroid anaesthetics used in cats and dogs

A
  • No Cremaphor, instead use 2-hydroxypropyl beta-cyclodextrin HPBCD
  • ## Alfaxan
112
Q

Describe the pharmacokinetics and dynamics of alfaxan

A
  • Short plasma elimination half life, cleared from body quickly
  • Can be given as repeated boluses or TIVA
  • Premed prefereable: induction is smooth but recovery worse than propofol
113
Q

Describe the mechanism of action of injectable steroid anaesthetics

A

Activates GABA inhibitory receptors

114
Q

Describe the clinical properties of ketamine anaesthetic induction

A
  • Rpaid induction
  • Mixed respiratory effects
  • Good analgesia
  • Cardiovascular effects depend on dose but generally good at maintaining cardiac output
  • Muscle tone increased
  • Salivation and lacrimation increased
  • Do not appear anaesthetised
115
Q

Describe the chemical properties of ketamine

A
  • Weak organic base pH 3.5

- Can be administered IV, IM, SV, IP, PO, epidural

116
Q

Outline the useage of ketamine as an anaestehtic induction agent

A
  • Can be combined with BZDs, alpha2 agonists, acepromazine and opioids
  • Versatile induction agent
  • Invariably needs to be combined with something
117
Q

Outline the effects of ketamine in horses

A
  • CVS and respiratory depression

- No analgesia

118
Q

Given an example of a ketamine alternative

A
  • Zoletil
  • 250mg tiletamine and 250mg zolazepam as powder per vial
  • Indicated for dog and cat general anaesthesia
119
Q

Describe etomidate

A
  • Not commonly used in UK
  • Imidazole derivative
  • Induction agent for trauma, C section, CSF, shock and neurosurgery
  • HR, ABP, CO remain stable
  • Myoclonus, phlebitis and pain may occur on injection
  • Addisonian crises where there is no adrenal function
  • Available as propylene glycol or emulsion formulations
120
Q

Describe the side effects of propofol

A
  • Rigidity, twitching
  • apnoea
  • Profound bradycardia
  • Care in hypoproteinaemia
  • Heinz body anaemia in cats
  • Pain on injection
  • Local reaction
121
Q

Describe the contraindications for use of thiopentone induction agents

A
  • Fractious animals without secure IV access as contact with skin causes sloughing
  • Hypoproteinaemic patietns
  • Worsen CSF, arrhythmias
  • Liver disease (metabolised by liver)
  • Renal disease (increases K, worsen arrhythmias)
  • Anaemia, hypovolaemia
  • Hypotheyroid, hypoadrenocortic patients (hypotension difficult to control)
122
Q

Describe the side effects of steroid anaesthetic induction agents

A
  • Poor recovery with alfaxalone
  • Occasional apnoea seen
  • If disturbed during recovery can cause excitement
123
Q

Describe the side effects of ketamine induction use

A
  • Stormy recovery if disturbed or not adequately premedicated
  • Depth assessment different (eyes open)
  • Corneal drying
  • Vomiting common with A2A combinations, avoid in patients with GI obstruction
  • Avoid in patients with increased intracranial pressure, ocular surgery, fever, hyperthyroid
  • Pupils may be asymmetric, does not lead to ventromedial rotation of eye

CPS (13 decks)

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