Post_op 2

Question 1

What are patient-related factors increasing the risk of post-op nausea and vomiting (adults)?

Answer 1

• female gender
• Hx of motion sickness
• Hx of post-op nausea and vomiting
• non - smoker
• age <50 y

Question 2

What are patient-related factors increasing the risk of post-op nausea and vomiting (children?)?

Answer 2

• age >3 years old
• Hx of post-op N/V (personal of Fx)
• strabismus surgery
• surgery lasting >30 minutes

Question 3

What are medical (iatrogenic) factors that contribute to increased risk of post-op N/V?

Answer 3

• nitrous oxide use
• volatile GA use
• opiate use
• emotogenic procedures (laparosopy, gyneacological, cholecystectomy)

Question 4

How long does it usually take for nausea and vomiting re to anaesthetic use to subside?

Answer 4

usually subsides within 24 horus

Question 5

What anaesthetic agents to use in order to reduce post-op nausea and vomiting if GA is required?

Answer 5

Propofol should be chosen (over a nitrous oxide or volatile agents)

Question 6

Which two parts of the brain have a role in vomiting control? (2)

Answer 6

• Chemoreceptor Trigger Zone (4th ventricle in the brain)
• Vomiting Centre

Question 7

What apart from prophylactic anti-emetic therapy can be used in patients at induction of anaesthesia to reduce the risk of vomiting and nausea?

Answer 7

Dexamethasone at induction

Question 8

What’s the most appropriate anti-emetic treatment for a patient with gastric stasis/ impaired gastric emptying? (2)

Answer 8

Prokinetics:

• metoclopramide -> dopamine antagonist
• domperidone -> dopamine antagonist

*not if bowel obstruction is suspected

Question 9

What anti-emetic is used in patients with bowel obstruction?

Answer 9

Hyoscine (an anti-muscarinic) -> to reduce secretions and subsequent N&V in patients with bowel obstruction

Question 10

What antiemetic to use in case of opioid-induced nausea and vomiting? (2)

Answer 10

• ondansetron -> 5-HT3 receptor antagonist
• cyclizine -> H1 Histamine receptor antagonist