Download nausea and vomiting

CHAMP: Bedside Teaching
PALLIATION OF NON-PAIN SYMPTOMS:
NAUSEA AND VOMITING
Deon Cox-Hayley DO, Stacie Levine MD
Teaching Trigger:
You encounter a patient who is complaining of nausea and/or vomiting.
Clinical Question #1: What triggers nausea and vomiting?
Teaching Points:
1. The vomiting center (VC), located in the medulla, controls the act of vomiting.
2. The VC receives input from:
Chemoreceptor Trigger Zone (in area postrema in fourth ventricle)
D2 (dopamine) and 5-HT3 receptors stimulated by:
-metabolic products (uremia, diabetic acidosis)
-chemotherapeutic agents
-irradiation
a)
Cerebral Cortex
-Cortical: psychological (anticipatory vomiting)
-Limbic: tastes, smells
-Increased intracranial pressure
-Conditioned vomiting
b)
Vestibular Apparatus: H1 and Achm receptors
-motion, position
c)
Vagus nerve and gastrointestinal tract
5-HT3 receptor stimulated by:
-myocardial infarction, drugs, bacterial toxins, irritation, chemotherapy,
metastatic disease to GI tract, bowel obstruction, gastric distension
d)
Clinical Question #2: What are appropriate treatments?
Teaching Point:
Treat based on underlying etiologies and receptors involved:
Class
Dopamine
Antagonist
Drug
Chlorpromazine
Prochlorperazine
Metoclopromide
Haloperidol
Fluphenazine
Anticholinergic
Scopolamine
Hydroxyzine
H1 antihistamine
Diphenhydramine
Dimenhydrinate
Promethazine
Hydroxyzine
Ondansetron
Granisetron
Dexamethasone
Methylprednisolone
Dronabinol
Nabilone
Lorazepam
5-HT1
Steroids
Cannibinoids
Benzodiazepines
Principal Action
CTZ/Vomiting
Center
CTZ
CTZ/GI
cholinergic
CTZ
CTZ
Vestibular,
Vomiting Center
Periphery, GI tract
Vomiting Center,
Vestibular
UGI tract,
vomiting center
UGI tract/? CNS
Not known
Vomiting Center
Vomiting Center
Adjunctive
**Refractory nausea/vomiting may require a combination of anti-emetics that work at
different receptors