Management of Nausea and Vomiting Flashcards Preview

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Flashcards in Management of Nausea and Vomiting Deck (54)
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1
Q

What is nausea?

A

The unpleasant feeling of the need to vomit

2
Q

What may (or may not) nausea be accompanied by?

A

Autonomic symptoms

3
Q

What is vomiting?

A

The forceful expulsion of gastric contents through the mouth

4
Q

What % of patients who undergo chemotherapy experience nausea or vomiting?

A

70-80%

5
Q

What % of patients who undergo chemotherapy experience anticipatory vomiting?

A

10-40%

6
Q

What are the categories of factors that influence the incidence and severity of chemotherapy induced emesis?

A
  • Specific chemotherapeutic drug

- Patient variables

7
Q

What factors about the specific chemotherapeutic drug can influence chemotherapy induced emesis?

A
  • Dose
  • Route
  • Schedule of administration
8
Q

What patient variables increase the risk of chemotherapy induced emesis?

A
  • Young patients

- Women

9
Q

What brainstem sites have key roles in the vomiting reflex pathway?

A
  • Chemoreceptor trigger zone

- Vomiting centre

10
Q

Where is the chemoreceptor trigger zone situated?

A

In the area postrema

11
Q

What is the area postrema?

A

A circumventricular structure at the caudal end of the fourth ventricle

12
Q

Is the area postrema inside or outside the blood brain barrier?

A

Outside

13
Q

What is the result of the area postrema being outside the blood brain barrier?

A

It can respond directly to chemical stimuli in the blood or CSF

14
Q

Where is the vomiting centre found?

A

In the lateral reticular formation of the medulla

15
Q

What is the role of the vomiting centre?

A
  • Co-ordinates the motor mechanisms of vomiting

- Responds to different afferent inputs

16
Q

What afferent inputs does the vomiting centre respond to?

A
  • Vestibular system
  • Periphery (pharynx and GIT)
  • Higher brainstem cortical structure
17
Q

How do chemotherapeutic agents exert their emetic actions?

A

Chemotherapy agents, or their metabolites, can directly activate the medullary chemoreceptor trigger zone or vomiting centre. They can also act peripherally to cause vomiting.

18
Q

What neuroreceptors play a critical role in chemotherapy-induced emesis?

A

Several neurotransmitters, including dopamine receptor type 2 and serotonin type 3 (5-HT3)

19
Q

What can trigger anticipatory vomiting?

A
  • Colour or smell of chemotherapeutic drugs

- Stimuli associated with chemotherapy, such as cues in treatment room or the person administering the chemotherapy

20
Q

What is the mechanism of anticipatory vomiting?

A

The triggers activate higher brain centres and trigger emesis

21
Q

How do chemotherapeutic drugs act peripherally to cause vomiting?

A

They cause cell damage in the GI, releasing serotonin from the enterochromaffin cells of the small intestinal mucosa

22
Q

How does the release of serotonin from damage enterochromaffin cells cause vomiting in chemotherapy?

A

The released serotonin activates 5HT3 receptors on vagal and splanchnic afferent fibres, which then carry sensory signals to the medulla, leading to an emetic response

23
Q

How can you identity the cause of nausea and vomiting clinically?

A

Often, there are common patterns/syndromes

24
Q

What % of patients will have more than 1 cause of N&V?

A

Up to 25%

25
Q

What are the different causes of N&V that lead to different patterns?

A
  • Impaired gastric emptying
  • Chemical/metabolic disturbances
  • Raised ICP
  • Constipation
  • Malignant bowel obstruction
26
Q

What are the clinical features of nausea caused by impaired gastric emptying?

A
  • Epigastric discomfort
  • Reduced appetite/satiety
  • Post-prandial or bloating/audible splash
  • Intermittent vomiting that eases nausea
  • Large volume vomits that may contain food
27
Q

What are the causes impaired gastric emptying in cancer?

A
  • Causes associated with cancer
  • Drugs
  • Gastroenterostomy
  • Autonomic neuropathy
28
Q

What are the causes of impaired gastric emptying associated with the cancer?

A
  • Locally advanced cancer
  • Lymph node enlargement
  • Liver mets
  • Ascites
29
Q

Give 2 examples of drugs that can cause delayed gastric emptying

A
  • Morphine

- Anti-cholinergics

30
Q

What are the clinical features of nausea caused by chemical/metabolic disturbances?

A
  • Persistent nausea, aggravated by the sight and smell of food
  • Nausea unrelieved by vomiting
  • Drowsiness/confusion
31
Q

What are the causes of chemical/metabolic disturbance in cancer?

A
  • Drugs
  • Renal or hepatic failure
  • Hyponatraemia
  • Hypercalcaemia
  • Sepsis
  • Tumour toxins
32
Q

What drugs can cause chemical/metabolic disturbance?

A
  • Opioids
  • Antibiotics
  • SSRIs
  • Digoxin
33
Q

What are the clinical features of nausea caused by raised ICP?

A
  • Nausea worse in morning
  • Projectile vomiting
  • Worse on head movement
  • Headache
34
Q

What are the causes of raised ICP in cancer?

A
  • Cerebral mets
  • Cerebral haemorrhage
  • Meningeal disease
35
Q

What are the clinical features of nausea caused by constipation?

A
  • Nausea and faeculent vomiting

- Abdominal distention

36
Q

What are the causes of constipation in cancer?

A
  • Drugs

- Immobility

37
Q

What are the clinical features of malignant bowel obstruction?

A
  • Intermittent vomits that may relieve nausea
  • Large volume vomits, may be bilious or faeculent
  • Abdominal cramps and altered bowel habit
  • Abdominal distention
  • Visible peristalsis
38
Q

When is malignant bowel obstruction common?

A

In abdominal and pelvic cancer

39
Q

Other than abdominal and pelvic cancer, what are the causes of malignant bowel obstruction?

A
  • Autonomic neuropathy

- Carcinomatosis

40
Q

What is carcinomatosis?

A

dunno might add it in when i have wifi

41
Q

What are the physical consequences of nausea and vomiting?

A
  • Dehydration
  • Malnutrition
  • Anorexia
  • Weight loss
  • Insomnia
42
Q

What are the psychological consequences of nausea and vomiting?

A
  • Anxiety
  • Depression
  • Anger
43
Q

Why should nausea be taken serious?

A

It can be debilitating, and may be more distressing than pain

44
Q

What effect might nausea and vomiting have on compliance?

A

Nausea and vomiting, or fear of, may lead to rejection of potentially curative anti-neoplastic treatment

45
Q

What should be done in order tailor the pharmacological management of N&V?

A

You should identify the likely mechanism causing the N&V, and choose an appropriate drug to block the relevant receptor

46
Q

What drugs can be used for acute emesis (<24 hours) caused by chemotherapy?

A
  • Ondansetron

- Dexamethasone

47
Q

What drugs can be used for delayed emesis (>24 hours) caused by chemotherapy?

A
  • Ondansetron and/or dexamethasone

- Prochlorperazine

48
Q

What drugs can be used for anticipatory vomiting?

A

Lorazepam

49
Q

What drugs can be used for iatrogenic nausea and vomiting, e.g. opiates?

A
  • Metaclopramide

- Haloperidol

50
Q

What drugs can be used for nausea and vomiting caused by gastric irritation, including radiotherapy

A
  • Lansoprazole
  • Ondansteron
  • Prochlorperazine
51
Q

What drug can be used for nausea and vomiting caused by increased ICP?

A

Dexamethasone

52
Q

What drug can be used for nausea and vomiting caused by gastric stasis/subacute bowel obstruction?

A

Metaclopramide

53
Q

What drugs can be used for nausea and vomiting caused by obstruction?

A
  • Cyclizine
  • Haloperidol
  • Dexamethasone
  • Octreotide
54
Q

How can nausea and vomiting with a metabolic cause be managed?

A

Correct the cause