Post-Op Nausea and Vomiting

Question 1

What % of post-op patients are affected by N&v in the first 24-48 hours post surgery?

Answer 1

20-30%

Question 2

What are the consequences of PONV?

Answer 2

• Increased anxiety for future surgical procedures
• Increased recovery time and hospital stay
• Aspiration pneumonia
• Incisional hernia or suture dehiscence
• Bleeding
• Oesophageal rupture
• Metabolic alkalosis

Question 3

What can the risk factors for PONV be divided into?

Answer 3

• Patient factors
• Surgical factors
• Anaesthetic factors

Question 4

What are the patient risk factors for PONV?

Answer 4

• Female
• Younger age
• Previous PONV or motion sickness
• Use of opioid analgesics
• Non-smoker

Question 5

What are the surgical risk factors for PONV?

Answer 5

• Intra-abdominal laparoscopic surgery
• Intracranial or middle ear surgery
• Squint surgery
• Gynaecological surgery, especially ovarian
• Prolonged operative times
• Poor pain control post-op

Question 6

What are the anaesthetic risk factors for PONV?

Answer 6

• Opiate analgesia or spinal anaesthesia
• Inhalational agents
• Prolonged anaesthetic time
• Intraoperative dehydration or bleeding
• Overuse of bag and mask ventilation

Question 7

What is the first priority when assessing a patient with PONV?

Answer 7

Ensuring they are safe and stable - if any doubt, ABCDE approach should be taken

Question 8

What is there a risk of with PONV when the patient is drowsy?

Answer 8

Aspiration

Question 9

How can aspiration caused by PONV be avoided?

Answer 9

• Careful airway assessment

- Protection with NG tube if required

Question 10

What questions should be asked when assessing a patient with PONV?

Answer 10

• What was the operation? Is it likely to cause PONV?
• Which anaesthetic agents/post-op drugs have been used
• Are there any other factors contributing to the nausea?
• Which anti-emetic therapy would suit this patient best

Question 11

What are the alternative causes of N&V in post-op patient?

Answer 11

• Infection
• GI causes
• Metabolic causes
• Medication
• CNS causes
• Psychiatric causes

Question 12

What are the GI causes of post-op N&V?

Answer 12

• Post-op ileus

- Bowel obstruction

Question 13

What are the metabolic causes of post-op N&V?

Answer 13

• Hypercalcaemia
• Uraemia
• DKA

Question 14

What medications can cause post-op N&V?

Answer 14

• Antibiotics

- Opioids

Question 15

What are the CNS causes of post-op N&V?

Answer 15

• Raised ICP

Question 16

What are the psychiatric causes of post-op N&V?

Answer 16

Anxiety

Question 17

What can the management of PONV be divided into?

Answer 17

• Prophylactic
• Conservative
• Pharmacological

Question 18

What are the prophylactic measures for PONV?

Answer 18

• Anaesthetic measures
• Prophylactic anti-emetic therapy
• Dexamethasone at induction of anaesthesia

Question 19

What anaesthetic measures can be taken to reduce PONV?

Answer 19

• Reduce opiates
• Reduce volatile gases
• Avoid spinal anaesthetics

Question 20

What are the conservative management options for PONV?

Answer 20

• Adequate fluid hydration
• Adequate analgesia
• Ensure no obstructive cause

Question 21

What is important to do when using drugs to manage PONV?

Answer 21

Ensure choice of anti-emetic is considered by the likely cause of nausea

Question 22

What is often more effective in the drug treatment of PONV?

Answer 22

Multi-modal therapy

Question 23

What anti-emetic should be used for patients with impaired gastric emptying or gastric stasis?

Answer 23

Prokinetic agent, such as metaclopramide or domperidone (unless bowel obstruction suspected)

Question 24

What anti-emetic can be given in patients with bowel obstruction?

Answer 24

Hyoscine (reduces secretions and subsequent N&V)

Question 25

What anti-emetic should be used for patients with a suspected metabolic or biochemical imbalance?

Answer 25

Metoclopramide

Question 26

What anti-emetic should be used for patients with opioid-induced N&V?

Answer 26

• Ondansteron

- Cyclizine