Summer 25 - PONV Flashcards
(27 cards)
What is the definition of nausea?
A subjective, unpleasant sensation in the epigastrium and throat that creates an urge to vomit.
Define vomiting.
The forceful expulsion of upper GI contents via the mouth, caused by sustained abdominal muscle contraction.
What is retching?
Rhythmic contractions of respiratory, abdominal, and diaphragmatic muscles without expulsion of gastric contents.
Where is the Chemoreceptor Trigger Zone (CTZ) located?
In the area postrema.
What is the role of the Emetic Center?
Coordinates vomiting response.
What nerve conveys signals from the GI tract to the emetic center?
Vagus nerve.
Which cranial nerve is implicated in motion sickness?
CN VIII (Vestibular system).
List the neurotransmitter systems and receptors involved in emesis.
- 5-HT₃ (Serotonin)
- D₂ (Dopamine)
- H₁ (Histamine)
- Muscarinic (M₁) (Acetylcholine)
Name some common stimuli triggering emesis.
- Drugs (Cisplatin, nitrogen mustard, digoxin, opioids)
- Motion/Vestibular input
- GI tract distension and irritation
- Pharynx gag reflex stimulation
- Higher centers (vision, taste, emotion)
- N₂O
What factors increase the risk of PONV related to patient-specific factors?
- Female sex
- Young age
- Non-smoker
- Obesity
- History of motion sickness or PONV
What surgical-related factors contribute to PONV?
- Type and duration of surgery
- Intra-abdominal procedures
What anesthetic-related factors increase the risk of PONV?
- Use of volatile agents
- Nitrous oxide
- Opioid use
- Prolonged anesthesia duration
What are the primary patient-related risk factors for PONV?
- Age
- Sex
- Obesity
- Nonsmoking status
- History of PONV or motion sickness
- Anxiety
- Delayed gastric emptying
Which surgical categories promote PONV?
- Gonadal/Reproductive
- Abdominal
- Oculo-gyric
- Pharyngeal
What is the effect of benzodiazepines on PONV risk?
They reduce PONV risk.
True or False: General anesthesia has a higher PONV risk than major regional anesthesia.
True.
What is the incidence of PONV with general anesthesia?
25–30%.
What are the consequences of PONV?
- Patient discomfort
- Functional impairment
- Increased healthcare cost
- Wound complications
- Pulmonary risk
- Physiologic derangements
What is the total risk score that indicates prophylactic antiemetics should be used?
≥ 3 points.
Fill in the blank: The drug Aprepitant is an approved _______ antagonist.
NK-1
What is the mechanism of 5-HT₃ receptor antagonists?
They are the only serotonin receptor that is a ligand-gated cation channel.
What is the risk associated with high doses of 5-HT₃ receptor antagonists?
QT Prolongation.
What is the clinical implication of CYP2D6 ultrarapid metabolizers?
Higher risk of PONV despite standard dosing.
What is Scuderi’s Multimodal Therapy?
A comprehensive strategy targeting multiple emetogenic pathways.