Anaesthesia for the C-section

Question 1

What ASA might an animal presenting for a C-section be categorised as?

Answer 1

• Could be relatively healthy (III) to moribund (V)

Question 2

In the pregnant animal, GI emptying is delayed and pH is lower due to increased gastrin. What relevance does this have to anaesthesia?

Answer 2

• More likely to have food in the stomach → regurgitation more likely
• Increased gastrin → regurgitation could be more harmful
• Need to reduce likelihood of this: intubate with head elevated and keep head elevated during op

Question 3

Why use local anaesthetics in the pregnant animal?

Answer 3

• To reduce MAC
• To provide analgesia

Question 4

When positioning the dam for surgery, you should tilt her slightly off midline. Why is this?

Answer 4

• To minimise compression on the caudal vena cava and maximise cardiac output

Question 5

When should you provide an NSAID to the dam: pre-op, intra-op or post-op?

Answer 5

• Depends on dam’s state
• If the patient is compromised/there is likely to be hypotension, wait until the end of the procedure as this avoids the kidneys having had a prolonged period of hypotension and exposure to the NSAID
• If in doubt about her status, wait until she is waking up

Question 6

You gave the dam an opioid for analgesia, but her puppies are slow to respond as you deliver them. What can you do?

Answer 6

• Give Naloxone sublingually, IM, IV, PO or via umbilical vein

Question 7

Why should you avoid giving Doxapram to slow puppies/kittens?

Answer 7

• Doxapram is a respiratory stimulant but does cause increased oxygen demand which is the last thing we want
• Be aware that this is done in practice‼️

Question 8

What are the advantages of an inverted L block for C-section?

Answer 8

✅ Easy to perform

✅ Doesn’t affect movement of the cow

✅ Deposits anaesthetic away from the incision site, minimising incisional oedema and haematoma

Question 9

What are the disadvantages of an inverted L block for C-section?

Answer 9

❌ Incomplete analgesia and muscle relaxation to the deeper layer of the abdominal wall

❌ Can be more costly due to large doses required

Question 10

What the the advantages of a proximal paravertebral block for C-section?

Answer 10

✅ Relatively easy to perform in animals that aren’t too obese

✅ Requires far less anaesthetic compared to inverted L block

✅ Provides a degree of peritoneal analgesia

✅ Can tell it has worked as it causes a degree of scoliosis of the spine (this can make closure of the incision more difficult)

Question 11

How do you know your proximal paravertebral nerve block worked?

Answer 11

There is a degree of scoliosis of the spine