Lecture 5 Preanesthetic Medications and Induction Agents part 2 Flashcards
1
Q
- What are the Alpha-2 agonists used in horses
- What are the reversal agents?
A
- Alpha-2 agonists - Horses:
- Xylazine
- Detomidine
- Romifidine
- Reversal agents:
- yohimbine
- tolazoline
2
Q
- What are the benzodiazepines used for sedative/ tranquilizer abilities?
- What is the reversal agent?
A
- Benzodiazepines:
- Diazepam
- Midazolam
- Reversible with flumazenil
3
Q
- What type of animals do you use benzodiazepines to sedate?
- Which don’t you use them in and why?
A
- Sedation more profound in:
- Sedation more profound in pediatric (<3mos.)
- geriatric,
- critical patients
- Small ruminants,
- Neonatal foals
- Don’t:
- young, healthy dogs, cats
- Causes paradoxical excitement, hyperresponsiveness
4
Q
How do Benzodiazepines (•Diazepam, Midazolam) effect:
- Cardiovascular system?
- Respiratory?
- Analgesia?
- Other side effects/ uses?
A
- Mild cardiovascular effects
- Enhances respiratory depression of other drugs
- No analgesia
- Muscle relaxation, Anticonvulsant effects
5
Q
Diazepam contains propylene glycol, why do we care?
A
Pain on injection, not well absorbed, toxicity at high doses (seizure txt)
6
Q
What are the uses for midazolam?
A
- Used with opioid for pre-med for very young (<3 mos.), geriatric, sick, dogs
- 0.1- 0.2 mg/kg IM or IV
- Induction adjunct => ↓ Propofol induction dose
7
Q
What drug possibly has amnesic properties?
A
Midazolam
8
Q
What are some benefits of using Anti-cholinergics as premeds?
A
- ↓ vagal effects, salivary secretions
- Modern inhalants not as irritating to respiratory tract so not used as much for this reason
- Still used to counter vagal effects of anesthetic drugs
9
Q
- Does atropine cross the blood brain barrier/ placenta?
- What is the onset of action?
- Duration of action?
- Side effects?
A
- Crosses BBB/placenta
- Onset of action (minutes): 5 IM, 1 IV
- DOA: 60-90 minutes
- Side effects: sinus tachycardia, 2° A-V block
10
Q
- Does Glycopyrrolate cross the blood brain barrier/ placenta?
- What is the onset of action?
- Duration of action?
A
- Does not cross BBB/placenta
- Onset of action: 3 – 5 minutes
- DOA: 2-4 hours
11
Q
What are the side effects of glycopyrrolate?
A
- Side effects: sinus tachycardia, 2° A-V block => ↑ with IV administration
- A-V block – wait, give additional dose
- Sinus tachycardia – self-limiting
- Caution in geriatric or cardiac disease
- Avoid in LA (GI statsis)
12
Q
What is Guaifenesin (GG) used for?
A
- Central muscle relaxant (replaced succinylcholine to ‘cast’ horses)
- Action similar to benzodiazepine
- Adjunct for induction in horses, large ruminants, camelids
- Maintenance for total intra-venous anesthesia (TIVA)
- Triple Drip => GG + xylazine + ketamine
13
Q
What are disadvantages of using Guaifenesin
A
- Minimal analgesia, hypnotic at large doses
- Do NOT use concentrations >5%
- hemolysis in cattle
- jugular thrombophlebitis in horses
- Large volume of injection (1-2 ml/kg)
- Perivascular injection => sloughing
14
Q
What are the Anesthetic Induction agents used for Dogs & Cats
A
- Propofol
- Alfaxalone
- ketamine/benzodiazepine
- Telazol (tiletamine + zolazepam)
- Etomidate
- Ketamine + Propofol
- Total IM injectable anesthesia
- Dexmedetomidine + opioid + dissociative (ketamine or Telazol)
15
Q
What are the anesthetic induction agents used in:
- Horses
- Large ruminants
- Small ruminants
- Camelids
A
- Horses
- Ketamine + Midazolam +/- GG
- Large Ruminants
- Triple Drip: GG + xylazine + ketamine
- Small Ruminants
- Ketamine + Midazolam
- Ketamine + propofol
- Camelids
- Triple Drip Or Ketamine + Midazolam