Pre-anaesthetic Medications - FF Article Flashcards
What are the aims of pre-anaesthetic medications?
To quieten or immobilize the patient, reduce stress, allow cat-friendly handling, reduce other anaesthetic doses, contribute to analgesia and recovery.
Why are combinations of drugs used for pre-anaesthesia?
No single drug provides all desired qualities; combinations minimize side effects and ensure smooth recovery.
What are the common drugs used for pre-anaesthesia?
Phenothiazines (e.g., acepromazine), alpha2 agonists (e.g., medetomidine), benzodiazepines (e.g., diazepam), opioids, ketamine, alfaxalone.
How does acepromazine work?
Acepromazine is a dopamine receptor antagonist providing calming effects, but it lacks analgesic properties and can cause hypotension.
What are the side effects of acepromazine?
Peripheral vasodilation leading to hypotension and hypothermia, especially in patients with hypovolaemia or dehydration.
How do alpha2 agonists work?
They provide sedation, muscle relaxation, and analgesia, but can cause bradycardia, arrhythmias, and reduced cardiac output.
What is a key point when using alpha2 agonists?
They significantly reduce the dose of induction and inhalation agents for anaesthesia maintenance.
What are the side effects of alpha2 agonists?
Bradycardia, arrhythmias, reduced cardiac output, peripheral vasoconstriction, vomiting, reduced gut motility, diuresis, hyperglycaemia.
What are benzodiazepines used for in pre-anaesthesia?
Benzodiazepines provide anxiolysis, mild sedation, and muscle relaxation but no analgesia; they have minimal cardiovascular effects.
What are the risks of using ketamine in cats?
Ketamine can increase intraocular and intracranial pressure and cause excitability during recovery.
How is alfaxalone used in cats?
Alfaxalone provides sedation at lower doses, often combined with opioids or benzodiazepines to improve muscle relaxation and minimize twitching.
What are opioids used for in pre-anaesthetic medications?
Opioids provide analgesia, improve sedation, and vary in duration and strength depending on the type (e.g., butorphanol, buprenorphine).
What combination of drugs is commonly used for sedation?
A combination of alpha2 agonist, an opioid, and ketamine provides profound sedation and is often used for neutering cats.
What is Zoletil and how is it used?
Zoletil is a combination of zolazepam and tiletamine used for sedation and general anaesthesia, contraindicated in patients with cardiac or respiratory disease.
