6. Nausea and Vomiting Flashcards
What is nausea?
An inclination to vomit or a feeling in the throat or epigastric region alerting the individual that vomiting is imminent.
What is vomiting/emesis?
The ejection or expulsion of gastric contents through the mouth - often a forceful event.
What is the dynamic threshold?
An ever-changing point at which an individual experiences nausea.
What is regurgitation?
gastric or esophageal contents rise to the pharynx because of pressure differences caused by an incomplete lower esophageal sphincter, for example.
What is retching?
labored movement of abdominal and thoracic muscles before vomiting
What are the clinical consequences of vomiting?
- dehydration
- aspiration
- electrolyte or acid/base imbalance
- Mallory-Weiss Syndrome
Vomiting is controlled via central emesis in the __-____ _____.
mid-brain stem
What are the receptors involved with visceral stimulation?
serotonin and dopamine
What are the receptors involved with vestibular stimulation?
histamine and acetylcholine
What are the receptors involved with CTZ stimulation?
serotonin, dopamine, and substance P
What is the result of visceral stimulation?
GI tract upset
What is the result of vestibular stimulation?
motion sickness
What is the result of CTZ stimulation?
vomiting
What autonomic nervous system symptoms are present?
- sweating
- pale
- hyper-salivation
- high BP
- tachycardia
- decreased gastric motility
What endocrine system symptoms are present?
increased vasopressin (ADH) level
What GI system symptoms are present?
gastric dysrhythmias
When should you refer patients to seek other help?
- severe dehydration
- protracted vomiting (> 1-2 days)
- infants or frail elderly
- severe headache
- recent head injury
- blood in vomit
- severe abdominal pain
- ingestion
- AMS
What symptomatic anomalies need to be corrected?
- electrolyte abnormalities
- dehydration
- malnutrition
What recommendation should be given to a patient with mild symptoms and no alarm signs?
- dietary modification
- symptomatic therapy with antiemetic or prokinetic
What recommendation should be given to a patient with significant symptoms +/- warning signs or complications?
- initiate symptomatic medication
- lab testing
- plain abdominal films
- upper endoscopy
If no diagnosis is determined in a patient with significant symptoms +/- warning signs or complications, what are the next steps?
consider
- gastric scintigraphy
- electrogastrography
If a patient with significant symptoms +/- warning signs or complications has abnormal gastric scintigraphy or electrogastrography results, what is the next step?
- prokinetic therapy
- consider cause of gastroparesis
What is the mechanism of action of ondansetron (Zofran)?
- primarily block central serotonin receptors in the CTZ
- also block peripheral receptors in vagal and spinal afferent nerves
In what formulations is ondansetron available?
PO (IR and orally disintegrating tablet)
solution
IV
