Exam 3 - PONV (Grayson's) Flashcards
When does nausea peak in patients post-op?
How long does nausea/vomiting typically last post-op?
Peak: 6 hours
Persists for 24 - 48 hours
What are the four major inherent (patient-specific) risk factors for PONV?
- Female
- Non-smoker
- PONV history
- History of motion sickness
and others:
-delayed gastric emptying and perioperative anxiety!!
Opioid use not an inherent risk factor.
What is the greatest risk factor of PONV for adults related to anesthesia/PACU?
A. propofol
B. intra/postop opioid use
C. gastric distention
D. neostigmine
B. intraop and postop opioids.
starred on slides, seems like a hint lol
What are some anesthesia/PACU-related PONV risk factors? select 2.
A. use of nitrous and/or volatiles
B. use of sugammadex
C. using NSAIDs or precedex
D. forced PO fluids prior to d/c
E. propofol gtt
F. scopalamine
A. VAA’s + Nitrous
D. Forced PO fluids prior to discharge
also: Neostigmine, Gastric distention, longer duration of anesthesia
What surgeries place a patient at higher risk for development of PONV? select 3.
A. laparotomy/laparoscopy
B. lower leg amputations
C. thoracotomy
D. strabismus correction
E. breast augmentation
F. cardiac valve replacement
A. laparotomy/laparoscopy
D. strabismus
E. breast augmentation
- also: ENT, Neuro, plastic
use TIVA w propofol for these high risk sx!
Which specific pediatric procedures are noted to have a higher incidence of PONV?
- Adenotonsillectomy
- Strabismus repair
- Hernia repair
- Orchiopexy (sx for testicular torsion)
- Penile surgeries
Where is the emetic center of the brain located?
Lateral reticular formation of the brainstem
which no substances directly act on!
Incoming (Afferent) input comes from pharynx, GI tract, mediastinum, and afferent nerves from higher brain centers. What are the 2 higher brain centers that send input to emetic center?
A. area postrema
B. hypoglossal nerve
C. amygdala
D. vestibular portion of CN VIII
E. CN X (vagus)
F. medial lemniscus
A. CTZ (chemoreceptor trigger zone) from area postrema
D. vestibular portion of CN 8 (vestibulocochlear)
T/F: Chemicals and drugs in the blood or CSF can easily go into chemoreceptor trigger zone of the area postrema and trigger N/V.
True. CTZ has no BBB!
No BBB means chemicals and drugs in the blood or CSF can trigger N/V.
select all that apply
What are some receptors are located in the Chemoreceptor Trigger Zone?
A. dopamine
B. epinephrine
C. 5-HT3
D. histamine
E. neurokinin-1
F. alpha
A. Dopamine
C. Serotonin / 5-HT3
D. Histamine
E. Neurokinin-1
also: Opioid, muscarinic, and Cannabinoid
What is true about management of PONV?
A. pts should receive the same drug 2x before trying a different approach
B. prophylaxis is indicated for pts with 3 or more risk factors
C. identify and preventing is more effective than treating PONV once it has occurred
D. you must wait 4 hrs before trying a different drug for treatment of PONV
C. identify and preventing is more effective than treating PONV once it has occurred
What is the gold standard for PONV?
A. ondansetron
B. dexamethasone
C. promethazine
D. aprepitant
E. no single drug is gold standard
E. no single drug is gold standard
What induction drug(s) increase risk of PONV? select 2.
A. atropine
B. ketamine
C. etomidate
D. lidocaine
B. ketamine
C. Etomidate
and volatiles!
USE PROPOFOL FOR INDUCTION AND MAINTANENCE INSTEAD!!!
What inhalational agent is associated with PONV (especially in concentrations greater than 50%)?
Nitrous Oxide
Greater than ____mg of Neostigmine is associated with increased PONV risk.
2.5mg - thought to be muscarinic actions on the GI tract
if you must reverse with neostigmine, what antimuscarinic will you use with it that might reduce PONV risk?
A. scopalamine
B. atropine
C. glycopyrrolate
D. ipratropium
B. atropine
or just use NMB that doesn’t require reversal like sux
How is P-6 compression thought to inhibit nausea? select 2.
A. secretion of beta-endorphins from hypophysis
B. inhibition of beta-endorphins from hypophysis
C. increases acid secretion
D. decreases acid secretion
A. secretion of beta-endorphins from hypophysis
D. decreases acid secretion
P-6 compression → Hypophyseal secretion of β-endorphins → inhibition of CTZ.
What are the 2 subtypes of anti-dopaminergics that are used to treat PONV?
- Butyrophenones (haldol, droperidol)
- Phenothiazines (prochlorperazin, chlorpromazine, promethazine)
What are the side effects of dopamine receptor antagonists? select 2.
A. sedation
B. dry mouth
C. hyperglycemia
D. extrapyramidal symptoms
A. sedation/drowsiness
D. Extrapyramidal symptoms
What 2 drugs are butyrophenones?
- Droperidol (Inapsine)
- Haloperidol (Haldol) - not really used for PONV and its only in IM form
select all that apply
What black box warning exists for Droperidol (Inapsine)?
A. torsades de pointes
B. sudden death
C. tissue necrosis if infiltrated
D. resp arrest in children less than 2 yo
A. Torsades de Pointes
B. sudden death.
What is the absolute MAX dose of droperidol?
0.625mg - apparently as effective as zofran 4mg for PONV
but comes w all the side effects
Droperidol is more effective with which other medication?
A. phenergan 12.5 mg
B. pepcid 20 mg
C. metoclopramide 10 mg
D. dexamethasone 8 mg
C, metoclopramide 10 mg
Droperidol also has some hypotension associated with it because of what property?
A. weak beta blocker
B. strong beta blocker
C. weak alpha blocker
D. alpha 2 agonism
C. weak α blocker
What are the 3 phenothiazines mentioned in class?
Prochlorperazine (Compro)
Chlorpromazine (Thorazine)
Promethazine (Phenergan)
What black box warnings are there for promethazine?
- Tissue damage w infiltration
- Resp arrest for < 2yo’s
What 4 receptors does promethazine (Phenergan) antagonize?
- dopamine
- histamine
- α adrenergic
- muscarinic
What is the dose of promethazine?
12.5 - 25 mg
5HT3 Antagonists (like Zofran) block serotonin receptors on the: select 2.
A. CN VIII
B. CN X
C. CTZ
D. raphe nuclei
B. CN X (vagus nerve)
C. CTZ
Chronic use of 5HT3 antagonists can result in mild elevation of:
A. cholesterol
B. blood pressure
C. liver enzymes
D. BUN/creat
C. liver enzymes
may also cause HA and constipation
When should ondansetron be given?
4mg within 15 - 20 min of surgery end. - so that it peaks about the time they’re waking up in recovery
What anticholinergic is given for PONV prophylaxis?
A. atropine 1 mg
B. clidinium 1.5 mg
C. oxybutynin 5 mg
D. scopalamine 1.5 mg
D. Scopolamine - 1.5mg transdermal patch
caution: can cause drowsiness, dry mouth, dizziness!
What is the best placement of a scopalamine patch based on lecture?
A. upper chest
B. lower abdomen
C. wrist
D. inner malleolus
D. inner malleolus, per Dr Mordecai - “somewhere w/ thin skin”
Dexamethasone is given to decrease post op pain and edema, thanks to its anti-inflammatory effects.
- What dosage is utilized?
- When do you administer?
- 4mg (just as effective as 8mg)
- Given during or right after induction!
How does metoclopramide (Reglan) help with PONV?
A. antagonizes substance P in the CTZ
B. block serotonin receptors in area postrema
C. dopamine-R antagonist which increases LES tone and GI motility
D. depresses neural activity in the NTS and GI activity
C. dopamine receptor antagonist which increases LES tone and GI motility
- not as efficacious as droperidol but also doesn’t have the same risks that droperidol has!
- dose: 10 - 20mg IV with short half life!
Which is the drug that antagonizes substance P in the emetic center?
A. reglan
B. droperidol
C. palonosetron
D. aprepitant
D. Aprepitant:
- also Depresses neural activity of the NTS
- may block afferent messages from enterochromaffin (GI) cells
greater anti-VOMITING than antinausea
What is the dose of Aprepitant (Emend)?
When is it given?
dose: 40mg or 125mg (PO or IV)
Given: 2-3 hours prior to induction
How does propofol prevent/treat PONV in subhypnotic doses?
A. blocks GABA
B. GABA agonism
C. blocks serotonin release
D. alpha 2 agonism
C. Blocks serotonin release in subhypnotic doses (1 cc).
May also inhibit CTZ.
What is the subhypnotic dose of propofol?
16.7 mcg/kg/min or TIVA dose (run it on a pump)
What drug should be readily available when using propofol due to the associated bradycardia?
A. atropine
B. glycopyrrolate
C. epinephrine
D. neostigmine
B. Glycopyrrolate
What non-pharmacological/aromatherapy has been associated with a 50% reduction in nausea?
A. peppermint
B. rosemary
C. isopropyl alcohol
D. lemongrass
C. Isopropyl alcohol - lil alcohol swab
What is considered adequate pre-hydration to prevent PONV?
A. 1 L per patient
B. 5 mL/kg
C. 15 mL/kg
D. 35 mL/kg
C. 15 mL/kg
(or 10-30 mL/kg)
