Post-Op Nausea and Vomiting Flashcards
What % of post-op patients are affected by N&v in the first 24-48 hours post surgery?
20-30%
What are the consequences of PONV?
- Increased anxiety for future surgical procedures
- Increased recovery time and hospital stay
- Aspiration pneumonia
- Incisional hernia or suture dehiscence
- Bleeding
- Oesophageal rupture
- Metabolic alkalosis
What can the risk factors for PONV be divided into?
- Patient factors
- Surgical factors
- Anaesthetic factors
What are the patient risk factors for PONV?
- Female
- Younger age
- Previous PONV or motion sickness
- Use of opioid analgesics
- Non-smoker
What are the surgical risk factors for PONV?
- Intra-abdominal laparoscopic surgery
- Intracranial or middle ear surgery
- Squint surgery
- Gynaecological surgery, especially ovarian
- Prolonged operative times
- Poor pain control post-op
What are the anaesthetic risk factors for PONV?
- Opiate analgesia or spinal anaesthesia
- Inhalational agents
- Prolonged anaesthetic time
- Intraoperative dehydration or bleeding
- Overuse of bag and mask ventilation
What is the first priority when assessing a patient with PONV?
Ensuring they are safe and stable - if any doubt, ABCDE approach should be taken
What is there a risk of with PONV when the patient is drowsy?
Aspiration
How can aspiration caused by PONV be avoided?
- Careful airway assessment
- Protection with NG tube if required
What questions should be asked when assessing a patient with PONV?
- 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
What are the alternative causes of N&V in post-op patient?
- Infection
- GI causes
- Metabolic causes
- Medication
- CNS causes
- Psychiatric causes
What are the GI causes of post-op N&V?
- Post-op ileus
- Bowel obstruction
What are the metabolic causes of post-op N&V?
- Hypercalcaemia
- Uraemia
- DKA
What medications can cause post-op N&V?
- Antibiotics
- Opioids
What are the CNS causes of post-op N&V?
- Raised ICP
What are the psychiatric causes of post-op N&V?
Anxiety
What can the management of PONV be divided into?
- Prophylactic
- Conservative
- Pharmacological
What are the prophylactic measures for PONV?
- Anaesthetic measures
- Prophylactic anti-emetic therapy
- Dexamethasone at induction of anaesthesia
What anaesthetic measures can be taken to reduce PONV?
- Reduce opiates
- Reduce volatile gases
- Avoid spinal anaesthetics
What are the conservative management options for PONV?
- Adequate fluid hydration
- Adequate analgesia
- Ensure no obstructive cause
What is important to do when using drugs to manage PONV?
Ensure choice of anti-emetic is considered by the likely cause of nausea
What is often more effective in the drug treatment of PONV?
Multi-modal therapy
What anti-emetic should be used for patients with impaired gastric emptying or gastric stasis?
Prokinetic agent, such as metaclopramide or domperidone (unless bowel obstruction suspected)
What anti-emetic can be given in patients with bowel obstruction?
Hyoscine (reduces secretions and subsequent N&V)
What anti-emetic should be used for patients with a suspected metabolic or biochemical imbalance?
Metoclopramide
What anti-emetic should be used for patients with opioid-induced N&V?
- Ondansteron
- Cyclizine
