CAL - Care of the anaesthetised patient

Question 1

List 3 reasons why we should give IV fluids to animals undergoing anaesthesia.

Answer 1

1. to maintain an open vein
2. to compensate for ‘relative hypovolaemia’
3. to replace blood losess.

Question 2

Define CSL (crystalloid fluid)

Answer 2

Compound Sodium Lactate (isotonic and balanced - contains electrolytes in similar concentrations to plasma)

Question 3

List 6 causes of tachycardia in an anaesthetised animal

Answer 3

• inadequate anaesthesia
• hypovolaemia/ hypotension
• hypercapnia
• hypoxaemia
• hyperthermia
• tachyarrhythmia

Question 4

How might we be able to distinguish between a tachycardia caused by anaesthesia being ‘too light’ and that caused by hypovolaemia?

Answer 4

1. has the animal bled into a body cavity
2. estimate volume of blood loss
3. measure BP

Question 5

What is suggested if pulse rate and BP increase in parallel leading to tachycardia?

Answer 5

the level of analgesia is inadequate

Question 6

What is suggested if pulse rate increases as BP decreases?

Answer 6

hypovolaemia much more likely than inadequate anaesthesia.

Question 7

Define 2nd degree AV block

Answer 7

some P-waves are not followed by QRS complexes

Question 8

What is a side effect of medetomidine pre-meds?

Answer 8

2nd degree AV block (medetomidine causes an initial hypertension due to vasoconstriction but there is a baroreflex mediated reduction in HR. Even if BP is normal., HR < 40bpm needs to be treated.)

Question 9

What is the risk of giving atropine soon after medetomidine?

Answer 9

severe hypertension

Question 10

What is the best way to antagonise medetomidine?

Answer 10

atipamezole

Question 11

What is the most appropriate treatment for hypotension? 3

Answer 11

reducing amount of anaesthetic delivered, giving crystalloid fluid bolus up to 10ml/kg, consider positive inotrope (e.g. dopamine or dobutamine) if no response.

Question 12

What is the most appropriate treatment for hypercapnia?

Answer 12

treat by ventilation of the lungs – IPPV.

Question 13

What is the most appropriate treatment for hypoxaemia? 3

Answer 13

increase FiO2 if possible, check BP and treat if low, IPPV.

Question 14

What is the most appropriate treatment for ventricular tachycardia? 3

Answer 14

if sustained and associated with haemodynamic compromise (i.e. low BP) should be treated with lidocaine, bolus of 1.5mg/kg IV followed by CRI given IV of 50mcg/kg/min

Question 15

What is the first line of treatment for sinus bradycardia?

Answer 15

atropine (or glycopyrrolate

Question 16

What is the first line of treatment for sinus bradycardia that is a baroreflex response to hypertension (e.g. after administration of medetomidine)?

Answer 16

atropine is not indicated therefore glycopyrrolate instead

Question 17

Name a commonly used colloid for blood loss between 10-25% of total volume

Answer 17

Voluven (tetrastarch)