general anaesthetics Flashcards
(100 cards)
1
Q
whats analgesia
A
a lack of pain sensation
2
Q
whats anaesthesia
A
lack of sensation, total loss of motoric activity
- local
- general
3
Q
whats local anaesthesia
A
without loss of conscious
4
Q
whats general anaesthesia
A
total loss of consciousness
5
Q
how many stages are there to general anaesthesia
A
- stage 1
- stage2
- stage 3
- stage 4
6
Q
describe stage 1 of general anaesthesia
A
disordered consciousness - induction
7
Q
describe stage 2 of general anaesthesia
A
excitment
8
Q
what happens in stage 3 of general anaesthesia
A
surgical anaesthesia - unconsciousness, amnesia, immobility, unresponsive to surgical stimulation
9
Q
what happens in stage 4 of general anaesthesia
A
overdose
10
Q
what types of anaesthetics do we use for induction
A
injectable anaesthetics
11
Q
what types of anaesthetics do we use for maintenance
A
inhalational anaesthetics
12
Q
injectable anaesthetics
A
- barbiturates
- propofol
- imidazole anaesthetics
- steroid anaesthetics
- NMDAr antagonists
13
Q
inhalational anaesthetics
A
- halothane
- isoflurane
- sevoflurane
- dinitrogen monoxide
- desflurane
- methoxyflurane
14
Q
barbiturates for use as injectable anaesthetics
A
- pentobarbital
- methohexital
- hexobarbital
- thiopental
- thiamylal
- venobarbital
15
Q
steroid anaesthetics for use as injectable anaesthetics
A
-alfadolone and alfaxolone in combo
16
Q
imidazoles for use as injectable anaesthetics
A
- etomidate
- medomidate
17
Q
dissociative injectable anaesthetics
A
- ketamine
- tiletamine
18
Q
properties of an ideal injectable anaesthetic
A
- water and lipid soluble
- sufficiently potent
- good analgesic activity
- muscle relaxation
- non irritant to tissue
- rapid and safe induction and recovery
- limited effect on vital fnctions
- high TI
- not have direct reno and hepatotoxicity
- rapid metabolism
- no chemical or pharmacological incompatability
- pharmacological antagonist
19
Q
barbiturates mechanism of action
A
- GABA bariturate receptor complex allosteric activator
- decr in Ca accumulation -> inhibit release of NTs, stabilisation of membranes
20
Q
barbiturates pharmacological effects
A
CNS, circulation, resp - slight overdosing can lead to resp and cardio inhibition
21
Q
barbiturates duration of action for anaesthesia
A
short or ultra short acting
22
Q
barbiturates application
A
only IV, effective and harmless
23
Q
short acting barbiturates duration
A
15-60 mins
24
Q
ultra short acting barbiturates duration
A
5-8mins
25
short and ultra short acting barbiturates distribution
- fast - complete, blood brain barrier
- placenta -> fetus -> pronounced side effect
- redistribution
- accumulation -> no readministration
26
ultra short acting barbiturates indication
- induction, general anaesthesia, no analgesia
- convulsive state, epilepsy
- euthanasia
27
ultra short acting barbiturates contra indications
- younger age, under 2 months
| - diminished cardiac output
28
ultra short acting barbiturates therapeutic index
small
29
ultra short acting barbiturates side effects
- resp depression - neonates
- cardio depression
- tissue irritation
- pre/postnarcotic excitations
30
which breed of dog are oversensitive to barbiturates
greyhounds - no fatty tissue, 2nd distribution not possible, try to completely avoid use in greyhounds
31
ultra short acting barbiturates
- thiopental
- metohexital
- hexobarbital
- pentobarbital
- thiamylal
32
propofol pharmacological effects
- unconscioussness
- muscle relaxation good
- analgesia not pronounced - combo with opioids
33
propofol duration
IV 30-45mins
34
propofol distribution
fast - complete, blood brain barrier, placenta
35
propofol metabolism
quick hepatic and extrahepatic metabolism - in liver failure administration is safe
36
propofol elimination
in urine in the form of metabolites, mainly as gluronide conjugate or other inactive forms
37
propofol indications
- induction and maintainance general anaesthesia
- TIVA with opioids
- convulsions, epileptic seizure
38
propofol contraindications
cardiac, respiratory, renal, hepatic impairment
39
propofol side effects
- transcient apnoea during induction
- cardiovascular depression
- vomiting, excitation during recovery
- allergy septicaemias
- increased ICP and ocular pressure
40
propofol proprietary products
- narcofol inj
- vetofol inj
- frescofol inj
- diprivan inj
41
etomidate anaesthetics receptor
GABAa
42
etomidate pharmacological effect
- unconsciousness
- muscle relaxation good
- analgesia not pronounced - combo
43
etomidate duration
up to 10-20mins
44
etomidate distribution
fast - complete, blood brain barrier, placenta
45
whats wake up like under etomidate
quick wake up and excitation
46
etomidate indication
- induction before inhalational anaesthesia
| - combo - opioids, short procedure
47
etomidate side effects
- severe tissue irritation - only IV
- resp depression
- cardiovascular depression none
- adrenocortical suppression - 2-3hr - no cont inf
- pre/post narcotic excitation - frequent and violent
48
etomidate therapeutic index
broad
49
metomidate most commonly used species
pigs
50
metomidate is an anaglogue of what
etomidate
51
metomidate analgesic effect
moderate, better in combo with azaperone
52
is metomidate acidic or basic
highly acidic, can only be injected into large veins
53
are excitations common with metomidate
frequent, pre and post anaesthetic
54
whats cardio depression like with metomidate
moderate
55
possible side effects metomidate in horses
tremors, convulsions
56
steroid anaesthetics fixed combo
alphaxalone+alfadolone = althesin, when used in fixed combo they have a common name
57
althesin pharmacological effect
- unconscioussness
- muscle relaxation good
- analgesia not pronounced - combo with opioid
58
althesin onset
IV 30mins, IM 5-10mins
59
althesin duration
up to 10-30mins
60
althesin metabolism
quick metabolism, no accumulation -> readministration
61
althesin recovery
quick
62
althesin therapeutic index
broad
63
althesin side effects
- cardio depression - hypotension, neg ionotropic
- histamine release - allergy
- postnarcotic excitation - stimulation during recovery
64
althesin licensed products
- cremofor - cat, shock in dogs bc of intensive histamine release
- cyclodextrine - dog and cat
65
ketamine proprietary products
- bioketan inj
- CP-ketamin inj
- narketan inj
- calypsol inj
66
tiletamine proprietary products
zoletil inj
67
ketamine indications
-anaesthesia in combo, inductions and maintainance
68
ketamine contraindications
sole use in horses and dogs, hepatic and or liver impairment, late pregnancy
69
ketamine side effects
- catalepsy like condition
- increased sympathetic nervous system tone
- increased cardiac output, heart rate, blood pressure, arrythmias
- mild resp depression, tidal volume slightly incr
- salivation
- pre/postanaesthetic excitations, convulsions
- incr ICP/eye pressure
- hallucinations -> missuse, dependancy
70
in which species can ketamine only be used in combo
horses and dogs
| eg opioids, alpha2-agonists, benzodiazepines etc
71
zoletil how does it come prepared
freshly dissolved in water, saline or 5% dextrose - 14 days if stored in a refrigerator
72
zoletil onset
very fast onset of unconsciousness, 2-5min
73
zoletil side effects
- incr sympathetic tone -> tachycardia, arrythmias, hyperthermia, incr ICP
- dose dependant resp depression
- pain response when drug given by IM or SC
74
types of combined anaesthesia
- balanced anaesthesia
- total intravenous anaesthesia
- neuroleptanalgesia
- ataranalgesia
75
whats balanced anaesthesia
combo of antimuscarinics, sedatives, opioids, anaesthetics and muscle relaxants
76
balanced anaesthesia effects
- safe and deep anaesthesia
- pain control
- less side effects
- relaxed body
- smooth recovery
77
whats TIVA, total intravenous anaesthesia
combo of agents given exclusively by the intravenous route without the use of inhalation agents
78
whats neuroleptanalgesia
tranquiliser and opioids, a state of sedation combined with analgesia
79
whats ataranalgesia
benzodiazepine or opioid and ketamine -> zoletile A.U.V
80
advantages of neuroleptanagesia
- less amount of sedative, safer
| - prior anaesthesia - induction safer, analgesia more pronounced
81
examples of combos used for neuroleptanalgesia
- etorphine, acepromazine
- butorphanol, acepromazine
- fentanyl, fluanisone
- fentanyl, droperidol
82
physiological signs of neuroleptanalgesia in dogs
- pupil myosis
- circulation - mild bradycardia and hypotension
- musculature - usuay relaxation
- respiration - depression
83
physiological signs of neuroleptanalgesia in horses
- pupil - mydriasis
- circulation - prolonged tachycardia, hypotension, transcient hypertension + incr hematocrit
- muscles - incr muscle tone, forelimbs ext, hindlimbs flex
- resp - depression
84
groups of inhalational anaesthetics
organic and inorganic
85
organic types of inhalational anaesthetics
non halogenated and halogenated
86
halogenated inhalational anaesthetics
- chloroform
- halothane
- isoflurane
- desflurane
- sevoflurane
- methyoxyflurane
87
non halogenated inhalational anaesthetics
diethyl ether
88
criteria for efficacy of inhalational anaesthetics
- good vaporisation
- good blood gas distribution
- lipid solubility, good oil; gas distribution
89
whats the MAC
minimum alveolar conc
90
halothane side effects
- teratogenic, carcinogenic, hepatotxic, arrhythmogenic,
- sensitivity to catecholamines incr
- ADH level incr
- EU bans therapeutic use
91
isoflurane, svoflurane indications
induction and maintainance of general anaesthesia
92
isoflurane, sevoflurane contra-indications
younger age, pregnant, lactating animals, susceptibility to malignant hyperthermia
93
isoflurane, sevoflurane side effects
- cardio and resp depression
- cardiac arrhytmias
- malignant hyperthermia
- nephrotoxicity
94
isoflurane dose induction
3-5%
95
isoflurane maintainance dose
1.5-3%
96
sevoflurane induction dose
5-7%
97
sevoflurane maintainance dose
3.3-3.8%
98
desflurane side effects
more common than others
- resp tract irritation
- tachyacardia
99
which group of animals should methoxyflurane not be used in
reptiles, risk of nephrotoxicity
100
methoxyflurane is preferred to be used when
maintainence
