Causes of Vomiting
Where is the vomiting center?
Lateral Ventricular Medulla or Nucleus Tracts Solitarius.
List the types of anesthesia in most to least likely to induce PONV: Regional, TIVA, General
Most to least: general, TIVA, regional
This combination of classes is considered the gold standard for preventing PONV.
5-HT3 (ondansetron) and Corticosteroid (Dexamethasone)
What should you do in the event of needing a "rescue treatment" for PONV?
Give an antiemetic from a different class than the prophylactic drug.
What should you do in the event of needing a "rescue treatment" for PONV?
Give an antiemetic from a different class than the prophylactic drug.
What unique characteristic allows the CTZ to respond to emetogenic drugs, chemicals and toxins, and radiation or uremia?
CTZ is located outside the blood brain barrier.
Which medication classes should be avoided in patients with Parkinsons disease? Give 2 examples of these medications.
Butyrophenones or D2 receptor antagonist and substituted benzamindes. Droperidol (inapsine) and Metoclopramide (Reglan)
What are the contraindications for using Metoclopramide?
Peds, Pheochromocytoma, Bowel Obstruction, Parkinson's disease
When should ondansetron be administered during the case and what dose has been disproven to be more effective?
Textbook answer to give toward the end of the case, but clinician decision. 8 mg not shown to be more effective than 4 mg.
Which 5 receptors are stimulated in the CTZ?
D2, 5-HT3, Opioid, Histamine, and Neurokinin-1.
Name the appropriate number of risk factors that could potential indicate a an incidence of PONV of 61%. Give an example of these factors.
3 risk factors: Female, HX motion sickness, Non smoker
This medication exerts its clinical effects in the vestibular nuclei and reticular formation at muscarinic receptors.
Scopolamine patch.
This medication requires what type of monitoring related to its FDA black box warning.
Droperidol has a black box warning for prolonged QT. Monitor ECG in preop and 2-3 hours after administration.
Name 3 negative implications PONV can cause.
Damage to the surgical site, Delayed PACU, patient dissatisfaction.
What type of response does stimulation of H1 and M receptors cause and where are these receptors located?
Motion sickness related nausea, receptors are located in the vestibular region.
Which 3 types of surgery has the greatest risk for inducing nausea?
Cholecystectomy, Laparoscopic, Gynecologic.
This medication targets antagonist D2 receptors, mild anticholinergic and antihistaminergic properties and can be given IV or rectally.
Promethazine (Phenergan)
Which 5-HT3 antagonist has a half life double that of ondansetron and its active metabolite is responsible for the antiemetic effect?
Dolasetron (Anzemet)
What is the proper use of a Scopolamine patch ie when should it be applied, removed, and how much is administered per hour.
Applied 1-4 hours before preop, ideally the night before. Remove 24-72 hours after SX. 5 mcg/hr.
Which neurotransmitter is impacted with use of a muscarinic antagonist? Is this neurotransmitter excitatory or inhibitory in the GI system.
Acetylcholine, inhibitory in the GI system.
The avoidance of which medications/treatment modalities can decrease the risk of inducing nausea?
Avoid general, halogenated agents, nitrous oxide, opioids, etomidate and neostigmine.
This medication features allosteric binding of its receptor resulting in its extra long lasting antiemetic effects.
Palonosetron (Aloxi)
Which medication is the only FDA approved medication for rescue PONV treatment? What is its MOA?
Amisulpride (Barhemsys). D2 and D3 blocker.
What fluid rate is recommended to possibly decrease the incidence of PONV?
15-40 ml/kg