Nausea & Vomiting🤢 Flashcards
Types of Emesis
Acute: N&V experienced during the first 24-hour period immediately after chemotherapy administration
Delayed: N&V that occurs more than 24 hours after chemotherapy and may continue for up to 6 or 7 days after chemotherapy.
Anticipatory: N&V that occurs prior to the beginning of a new cycle of chemotherapy. It is either a learned response following chemotherapy induced N& on a previous cycle or an anxlety response. It is most common after 3 to 4 cycles of chemotherapy with very badly controlled acute or delayed symptoms.
Breakthrough: Development of symptoms (nausea or vomiting), despite standard anti-emetic therapy, which require treatment with an additional pharmacological agent
Refractory: Patients who have failed on both standard and rescue medication
Grades
Nausea:
1
Loss of appetite without alteratio nin eating habits
2
Oral intake decreased without significant weight loss, dehydration or malnutrition
3
Inadequate oral caloric or fluid
Intake;
tube feedings, TPN or hospitalization indicated
Vomiting:
1
1-2 episodes (separated by 5 mins in 24hrs)
2
3 - 5 episodes
episodes (separated by 5 minutes) in 24hrs
3
>=6 episodes (separated by 5
minutes) in 24 hrs; tube feeding, TPN or hospitalization
Indicated
4
Life-threatening consequences;
urgent intervention indicated
5
Death
N&V mechanism
CTZ in vomiting centre in medulla not protected by BBB (chemoreceptor trigger zone)
Location: Area postrema in the medulla, outside the blood-brain barrier (BBB).
Can be stimulated by circulating toxins / drugs
Trigger mechanism:
Toxins, drugs, or metabolic changes activate receptors in the CTZ, such as:
5-HT3 receptors (serotonin): Activated by chemotherapy, GI irritation, or toxins.
D2 receptors (dopamine): Stimulated by drugs like opioids or metabolic disturbances.
NK1 receptors (neurokinin-1): Activated by substance P, often in delayed nausea.
Eg gastric irritation in gut wall stimulates 5HT3
Contains dopamine receptors > dopamine antagonists reduce nausea & vomiting associated with the drugs
eg 5HT3 antagonists (antiemetic)
FLIE score
Functional living index emisis score
Higher the better
Better QOL
Without chemotherapy induced NV, patients have better functional living
