Brainscape's Knowledge GenomeTM

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


See full index

Pharmacology I > Definitions + Injectable anaesthetics > Flashcards

Definitions + Injectable anaesthetics Flashcards

1
Q

Requirements for general anaesthesia.

A

1 - Unconsciousness
2 - Analgesia
3 - Muscle relaxation
4 - No cardiovascular effect

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

What is neuroleptanalgesia and why is it used?

A

Tranquilliser + opiate
(acepromazine) + (morphine/fentanyl)

More superficial state = safer
1 - Superficial sleep
2 - Analgesia
3 - Muscle relaxation

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

What is ataranalgesia?

A

The safest anaesthetic combination, but with the most superficial state.

Benzodiazepine + opiate
(diazepam) + (morphine/fentanyl)

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

Procedure of anaesthesia.

A
  1. Premedication (injectable)
  2. Induction (injectable or inhalational)
  3. Maintenance (usually inhalational, sometimes injectable)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the purpose of premedication?

3

A
  1. Decrease the dose of anaesthetic
  2. Analgesia
  3. Decrease pre- and post-narcotic excitation (because narcotics first inhibit all inhibitory pathways of brain)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Name three groups of sedatives.

A
  • Tranquillisers
  • Benzodiazepines
  • a2-agonists
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name three groups of analgesics.

A
  • Opiates
  • NSAIDs
  • Ketamine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the purpose of induction?

A

Allows for introduction of the tracheal tube for inhalational anaesthetics.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Indication/use of injectable anaesthetics.

4

A
  1. Simple procedures
  2. Induction
  3. Total intravenous anaesthesia (TIVA) (acepromazine+diazepam or propofol+fentanyl)
  4. Animals with seizures (barbiturates, propofol)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the treatment course for convulsions?

4

A
  1. Diazepam
  2. Pentobarbital/phenobarbital
  3. Propofol
  4. Inhalational anaesthetic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name 1 long acting-, 1 short acting-, and 3 ultrashort acting barbiturates.

A

Long acting - Phenobarbital (30-40 min)

Short - Pentobarbital (10-20 min)

Ultrashort - Thiopental, thiamylal, methohexital (5-8 min-)

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

Barbiturate mechanism of action.

A

Agonist of GABAa-recetors → opens Cl- ion channel → hyperpolarisation → inhibition of nerve → sleep

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

Barbiturate pharmacological effects.

4

A
  • unconsciousness
  • muscle relaxation
  • anti-convulsion
  • NO analgesic effect (cannot be used alone)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Barbiturate side effects.

5

A

1) respiratory depression!!! (depress. of CNS resp. centre)
+
2) cardiovascular depression → hypotension
= life-threatening

3) Severe tissue irritant effect (only IV!)
→ must be given slowly IV (20 sec), stop if decreased resp.

4) Pre- and post-narcotic excitation
5) Delayed recovery in greyhounds and slim animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Barbiturate pharmacokinetics.

administration, distribution, metabolism

A

Administration: Only given IV (only inject once!!)

Distribution: Excellent, crosses BBB very quickly

Redistribution! (Leaves brain→blood→muscle+fat→animal wakes up) Animal wakes up due to redistribution, NOT excretion!!
- do not readminister bc muscle+fat already saturated, so all goes to brain (esp. Thiobarbital) Accumulation can last for days.

Metabolism: in liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Barbiturate indication/use.

A

Pentobarbital

  • seizures
  • euthanasia

Thiopental, methohexital (faster elimination, can be readministered)

  • only for induction
  • most often used in horses bc propofol v expensive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Propofol dosage.

alone, continuous infusion, premed

A

Can be readministered

Alone:
Once (high dose)
→ 6-8 mg/kg, 5-10 min duration

Continuous infusion:
→ 0.2-0.4 mg/kg/min

Premed:
+ACP → 4-5 mg/kg
+ medetomidine → 3-4 mg/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Propofol pharmacological effects.

8

A

1) unconsciousness
2) good muscle relaxation
3) Ø analgesia (combined with NSAIDs or opiates)
4) quick and smooth recovery (good dream, infrequent excitation)
5) bronchodilation
6) decreased intracranial pressure (ICP) - imp during head trauma surgery + heat shock
7) decreased intraocular pressure - imp in glaucoma patients
8) anti-convulsive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Propofol side effects.

6

A

1) resp. depression, 2 min. apnea (30-40%) → slow administration to counteract (20 sec)
Doxapram: only resp. stimulant drug

2) negative inotropic → hypotension
3) post-narcotic excitation (acepromazine + diazepam as premed to prevent)
4) septicaemia (bact. in bottle)
5) pancreatitis
6) appetite stimulating (small dosage to treat anorexia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Propofol pharmacokinetics.

adme

A

Administration: IV

Distribution: crosses placenta (not sign. if done within 20 min, freq. used in caesarians)

Metabolism: slower in cats (bc. no glucuronidation)
Total recovery dog: 20 min; cat: 30 min

Excretion: kidney, but also extrahepatic (lung, GI)

21
Q

Propofol indication/use.

4

A

1) Simple surgical intercentions
2) Induction
3) Anti-epileptic
4) TIVA (propofol + fentanyl)

22
Q

Name two imidazoles.

A

Etomidate

Metomidate

23
Q

Imidazole pharmacological effects.

7

A

1) Unconsciousness
2) Muscle relaxation
3) Ø analgesia
4) Short duration 5-10 min
5) Recovery (quick, but less smooth)
6) Decreased ICP
7) Decreased intraocular pressure

24
Q

Imidazole side effects.

5

A

1) Tissue necrosis, only IV administration
2) Negligible cardiovascular effects! (unless high dose)
3) Respiratory depression (give slowly)
4) Pre- and post-narcotic tremors, seizures (prevent by benzodiazepine premed)
5) Adrenocortical suppression! Less cortisol prod. → can’t adapt to stress → serious problem if readministered

25
Q

Name two dissociative anaesthetics

A

Ketamine

Tiletamine

26
Q

Ketamine, tiletamine mechanism of action.

A

Dissociation of association tracts.

NMDA-antagonist: central sensitisation of pain. Ketamine prevents the gradual increase in pain sensation (repeated injury).

27
Q

Ketamine, tiletamine side effects.

7

A

1) Catalepsy (increased muscle tone → increased tremor + convulsions)
Add muscle relaxants to counteract: benzodiazepines, a2-agonists (xylazine)

2) Dyspnoe (labored breathing)

3) Mild stimulant of cardiovascular system
- increased sympathetic tone
- hypertension (useful in shock patients)
- arrhythmias

4) Increased ICP (not for use in head trauma or myelography - staining of spinal cord to see herniated disc during x-ray → propofol used)
5) Increased intraocular pressure (not used for glaucoma)
6) Hypertonia of eyes + jaw (opening mm. are stronger → eyes open. Use lubricant drops. Can bite)
7) Delayed + long recovery (total recovery: 4-5 hrs)

28
Q

Ketamine, tiletamine pharmacological effects.

3

A

1) “Dissociation” → not total unconsciousness
2) Mild anaesthesia (blocks central sensitisation)
3) Ø muscle relaxation

29
Q

What are the effects of barbiturates/propofol, etomidate and ketamine on the cardiovascular system?

A

Barbiturates/propofol:
decrease

Etomidate:
no effect

Ketamine:
increase

30
Q

Which anaesthetic can be used during myelography?

A

Propofol

Because of no increase in ICP

31
Q

Ketamine tiletamine pharmacokinetics.

aame

A

Administration: IV or IM (mild tissue irritation)

Absorption: moderate orally and nasal mucosa

Metabolism:

  • dog: extensively in liver (do NOT use in hep. insuff. → T1/2 longer)
  • cat: minimally in liver

Excretion:

  • dog: kidney
  • cat: immediately eliminated through kidney (do NOT use in kidney insuff.)
32
Q

Which 3 groups can be combined with ketamine or tiletamine?

A

1) a2-agonists (NOT in heart failure patients)
2) benzodiazepines
3) tranquilliser

33
Q

Name the combinations of ketamine/tiletamine and a2-agonists, and their effects.

A

xylazine, medetomidine, detomidine

  • unconscioussness,
  • analgesia
  • muscle relaxation

(used for total anaesthesia)

34
Q

Name the combinations of ketamine/tiletamine and benzodiazepines, and their effects.

A

Diazepam(!), midazolam, zolazepam

  • unconscioussness
  • analgesia
  • muscle relaxation

(used for total anaesthesia. Safest combo)

35
Q

Name the combinations of ketamine/tiletamine and a tranquilliser, and their effects.

A

Acepromazine

  • unconsciousness
  • analgesia
  • Ø muscle relaxation

(safe combo, but not for total anaesthesia)

36
Q

What is the dosage of ketamine?

A

Cats (only treated with ketamine alone)
→ 10-20 mg/kg

Other animals (combo)
→ 5-10 mg/kg

Sub-anaesthetic dose (helps against central sensitisation)
→ 0.5-1 mg/kg

37
Q

Which a2-antagonist is used to wake animal up after anaesthesia w/ ketamine + a2-agonist?

A

Atipamezole

But only given after 30-40 min because ketamine must be metabolised first, otherwise tremors + seizures.

38
Q

Name a drug commonly used in combination with tiletamine.

A

Tieletamine + zolazepam

Safer than ketamine, but more expensive.

39
Q

Name two steroid anaesthetics.

A

Alfaxalon

Alfadolon

40
Q

What is/are the components of Saffan?

A

Alfaxalon + alfadolon (3:1)

only used in cats
older product

41
Q

What is/are the components of Alfaxan?

A

Alfaxalon

newer product

42
Q

Steroid anaesthetic mechanism of action.

A

GABAa-recetors agonist → opens Cl- ion channel → hyperpolarisation → inhibition of nerve → sleep

43
Q

Steroid anaesthetic pharmacological effects.

4

A

1) Total unconscioussness
2) Ø analgesia
3) Muscle relaxation
4) Decrease ICP, cerebral BP and oxygen consumption of brain → good in head trauma

44
Q

Are steroid anaesthetics considered safe?

A

Yes, but not frequently used.

45
Q

“Saffan” side effects.

3

A

1) NOT used in dogs.
Saffan: Cremophor (castor oil) vehicle causes histamine release in dogs.
→ vasodilation, hypotension → shock, death

2) ear oedema, rarely necrosis (cats: less histamine release, not severe)
3) pulmonary oedema (v infrequent in cats)

46
Q

Which drug is always given as premed before “Saffan” anaesthetic, and why?

A

Acepromazine

Because it is a histamine antagonist.

47
Q

“Alfaxan” side effects.

2

A

1) Hypotension

2) Pre- and post-narcotic excitation (premed important)

48
Q

What is the benefit of “Alfaxan”?

A

No histamine release in dogs and cats.

49
Q

Steroid anaesthetic pharmacokinetics.

ADME

A

Administration: IM, IV

Distribution: excellent

Metabolism: liver

Excretion: kidney

Pharmacology I (5 decks)

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