Anaesthesia of the collapsed patent

Question 1

What are the key aspects of anaesthesia of the collasped dog?

Answer 1

• Oxygen always helps (but sometimes not tolerated)
• Often a general anaesthetic is safer than heavy sedation as it ensures a secured airway (ET tube and oxygen), monitoring and control
• Undertake a primary & secondary survey and use the info to inform your anaesthetic plan

Question 2

What devices can help with diagnosis of hypoxemia?
What figures mean that oxygen supplementation is needed?

Answer 2

• Pulse oximeter, & or blood gas analyser
• Visual observation of mucous membrane colour (not very accurate)

Rule of thumb oxygen saturation below 93% and an arterial partial pressure of oxygen below 70 mmHg should prompt oxygen supplementation

Question 3

what premedication and sedation will you avoid in ASA III-V?

Answer 3

As animals become more compromised avoid:
◦ NSAIDs
◦ Alpha 2 agonists
‣ can give a little bit of alpha 2 (dexmedetomidine) as can be antagonised
◦ Acepromazine

Question 4

What can be used for induction in ASA III-V?

What are the key things to remember?

Answer 4

• Propofol or alfaxalone (low end of dose range)
• Propofol or alfaxalone then benzodiazepine then more propofol or alfaxalone
  ◦ (ie co-induction, theory is it might reduce total dose of propofol or alfaxalone…..)
• Ketamine and benzodiazepine
• As animals become more compromised always continue to administer oxygen during induction
• Administer drugs slowly as ‘vein to brain’ time has increased with low cardiac outputs
  ◦ longer for propofol to get from the vein to the brain and therefore the anaesthesia will take longer to occur