Complications in Anaesthesia

Question 1

First 3 steps in case of change in heart rate under anaesthetic

Answer 1

1. Consider what is normal for that animal from pre-op results
2. Consider if it is causing a problems with perfusion & oxygen delivery- check SPO2% and ABP to decide
3. Consider what might be causing it

Question 2

Causes of reduced heart rate (bradycardia) under anaesthetic

Answer 2

Drugs
Toxaemia (endogenous/exogenous)
High Vagal tone
Heart problem
Hypoxia

Question 3

Drugs that cause bradycardia during anaesthesia

Answer 3

Volatile agents
alpha 2 agonists
Induction agent
Opioids

Question 4

Toxaemia that causes bradycardia

Answer 4

hyperkalaemia (high potassium)
e.g in blocked patient

Question 5

Why does vagal tone affect bradycardia

Answer 5

Vagal tone could be increased by the operation e.g. in gut or eye- think if anatomy of vagus

Question 6

How to treat alpah-2 induced bradycardia

Answer 6

Atipamezole

Question 7

Drugs to treat bradycardia

Answer 7

Anticholinergics- Atropine! or Glycopyrate

Question 8

Causes of tachycardia

Answer 8

Sympathetic Stimulation ‘too light’
PaCO2 (high), PaO2 (low), pH abnormalities
CNS disturbances
Low ABP or cardiac disease
Drugs

Question 9

Drugs causing tachycardia

Answer 9

Anticholinergics, Ketamine,

Question 10

How to increase depth of aesthetic in tachycardic patient

Answer 10

Increase volatile agent, give IV opioid, lidocaine or propanolol

Question 11

Most common causes of ectopic beats

Answer 11

Stress (circulating catecholamines)
Hypoxia or hypercapnia
Hypovolaemia or hypotension
Anaesthetic drugs
Myocardial inflammation or stimulation
Trauma
CHF or HCM (hypertrophic cardiac myopathy)
Major organ dz e.g. intracranial dz

Question 12

First checks for hypotensive animal under anaesthetic

Answer 12

Check equipment (cuff size, transducer, fluid line)
Check urine production- gives crude estimate of blood flow through kidneys

Question 13

Most common causes of hypotension

Answer 13

Anaesthetic drugs- isoflurane
Hypovolaemia and haemorrhage
Cardiac insufficiency

Question 14

How to improve hypotension in anaesthesia

Answer 14

Check patient and attempt to determine cause
Reduce volatile/ inhalation agent (TIVA/PIVA)
Increase IVFT
Check urine output if possible
Consider inotrope/vasopressor

Question 15

Drugs to consider with hypotension in anaesthesia

Answer 15

Dobutamine (inotrope), Norepinephrine (vasopressor)