Nausea and Vomiting

Question 1

List the clinical signs of significant dehydration. (5)

Answer 1

1. Postural perfusion changes inc. tachycardia, hypotension, dizziness
2. Decreased sweating and urination
3. Poor skin turgor, dry mouth, dry tongue
4. Fatigue and altered consciousness
5. Evidence of poor fluid intake compared to fluid loss

Question 2

Undifferentiated nausea may include… (4)

Answer 2

• Secondary to CCP
• Secondary to opioid analgesia
• Secondary to cytotoxic drugs or radiotherapy
• Severe gastroenteritis

Question 3

What is the non-antiemetic option that may alleviate nausea?

Answer 3

IV Fluids should be considered, unless clinically C/I (Hx of cardiac/renal failure).

Question 4

What is the preferred treatment for N+V in the dehydrated pregnant patient?

Answer 4

Normal Saline.
Ondansetron may be considered based on severity/transport times.
Stemetil is contraindicated.

Question 5

How is ODT Ondansetron given?

Answer 5

Dissolves on tongue in a few seconds, then swallowed normally.

Question 6

What routes and doses can Ondansetron be given?

Answer 6

1. ODT - 4mg, rpt 4mg
2. IV - 8mg, no rpt
3. IM - 4mg, if severe can administer a second 4mg dose

Question 7

What is the relationship between Ondansetron and Tramadol?

Answer 7

Ondansetron is an antagonist at the same active receptor site. Ondans admin may reduce the effectiveness of the analgesia, and is therefore not the preferred option in pts suffering N+V post-Tramadol admin.

Question 8

What is the relationship between Ondansetron and Long QT Syndrome?

Answer 8

Low-level evidence suggests that Ondansetron can prolong the QT interval with subsequent risk of VT.

Question 9

What are the 6 indications for antiemetics?

Answer 9

1. Undifferentiated nausea and vomiting
2. Potential for motion sickness
3. Planned aeromedical evacuation
4. Vertigo
5. Awake, spinally immobilised patients
6. Eye trauma (eg. hyphema, penetrating eye injury)

Question 10

How is undifferentiated nausea and vomiting managed?

Answer 10

Ondansetron 4mg ODT, rpt 4mg after 5-10 mins if symptoms persist.
If IV in situ - 8mg IV Ondansetron

If known allergy to Ondansetron and pt ≥21 then:
12.5mg Prochlorperazine

Question 11

What are the 2 separate indications for treating dehydrated patients, and how are they managed?

Answer 11

1. Less than adequate perfusion
   - Consider NS up to 40ml/kg, consult for further fluid.
   If consult unavailable, admin a further 20ml/kg
   Titrate to response.
2. Adequate perfusion but significant dehydration
   - Consider NS 20ml/kg over 30mins

Question 12

What 3 indications fall under the Vestibular Nausea category, and how is it managed?

Answer 12

1. Potential for motion sickness
2. Planned aeromedical evacuation
3. Vertigo

If pt ≥21, Prochlorperazine 12.5mg
If pt <21, Ondansetron as per IV/ODT guidelines

Question 13

Which 2 indications fall under the Prophylaxis For category, and how is it managed?

Answer 13

1. Awake, spinally immobilised pt
2. Eye injuries

Ondansetron as per IV/ODT guidelines
If known allergy to Ondansetron and pt ≥21 then:
12.5mg Prochlorperazine