Week 2 PONV (everything) Flashcards
2 intraop factors that influence PONV
type of surgery and duration of surgery
what 3 surgeries have the high incidence of PONV
cholecystectomy, gynecological and lap surgeries
how would increasing surgical time (duration) by 30 minutes effect the risk for PONV?
increasing surgical duration increases risk of PONV by 60%
what inhaled anesthetic increases the risk for PONV?
Nitrous Oxide:
avoiding NO significantly decreases vomiting in Lap procedures and PONV
Nitrous oxide’s association with PONV is suggested to be due to what 3 factors?
Simulation of sympathetic system with catecholamine release
Middle ear pressure changes stimulating the vestibular system
Increased abdominal distension. This is from the exchange of Nitrous oxide and nitrogen in gas introduced into GI tract by mask ventilation
effect of Ether and Cyclopropane on PONV
Ether and Cyclopropane cause higher PONV d/t increase in endogenous catecholamines
effect of volatile gases on PONV in the early stage (0-2hr) vs delayed stage (2-24hr) of surgery
Volatiles gases were primary cause of early PONV (0-2 hours)
Volatile gases have no impact on delayed PONV (2-24 hours)
which volatile anesthetics are asociated with a lower risk for PONV
Sevoflurane, Enflurane, Desflurane, and Halothane
all but Ether and Cyclopropane: Iso was not mentioned
effect of volatile gases on PONV depends on what?
the effect is dose dependent
Etomidates effect on PONV
Continuous infusion markedly increases post-op emesis
why does ketamine increase the risk for PONV
related to release of endogenous catecholamine release:
ketamine causes hallucinations, vivid dreams and increased risk for PONV
Of Barbiturates, Nitrous Oxide and Ketamine which has a higher risk for PONV
Ketamine
how does Propofol effect PONV
reduces the risk
Nitrous-Opioid-Relaxant technique: how does it effect PONV
increases the incident of PONV d/t directly stimulating the CTZ
MOA of opioids contribution to increased risk for PONV.
Emesis caused by stimulation of opioid receptors in the CTZ.
Using intraoperative opioids shows a weak contribution to PONV.
DOSE DEPENDENT EFFECT
Do neuromuscular reversal agents increase risk for PONV?
it is unknown/uncertain
regional vs general anesthesia: what is the risk for PONV
GA is 9x more likely to cause PONV compared to Regional
do central neuraxial blocks or peripheral blocks cause a greater risk for emesis?
central neuraxial blocks
why is Emesis with central neuraxial blocks greater than with peripheral blocks
d/t SNS block contributing to postural hypotension induced N/V
what would decrease the risk for nausea with epidurals
nausea is less with lipid soluble opioids such as fentanyl and sufentanil
why does using lipid soluble opioids in epidurals decrease the risk for nausea
d/t less rostral spread from lumbar epidural injection site to CTZ and vomiting center than the less lipid soluble such as morphine
what type of pain is more commonly related to PONV
visceral or pelvic pain
how does movement or transport effect PONV
Sudden motion, changes in position, and/or transport from PACU to patient floor can precipitate n/v after receiving opioids
during what point in the surgical process would we use Non steroidals and why do we use them
used perioperatively to reduce need for opioids
what is no longer recommended for PONV prevention
supplemental O2
Genes/receptors regarded as r/t PONV or opioid induced N/V:
8
5-HT3
D - Dopamine type 2
A - Alpha-2 adrenoceptor
M - Muscarinic type-3
C - Catechol-o-methyl transferase
A - Adenosine triphosphate (binding cassette subfamily B member)
U - Uridine 5’-diphospho-glucuronosyltransferae
C - Cytochrome P450 superfamily enzyme
*5 DAM CAUC (s)
5 Primary Afferent Pathways involved in vomiting stimulation:
- Chemoreceptor Trigger Zone (CTZ)
- Vagal mucosal pathway in the GI system
- Neuronal Pathways from the Vestibular system (Inner ear)
- Reflex afferent pathways from the cerebral cortex
- Midbrain afferents
Stimulation of the afferent pathways stimulating vomiting can be activated by four receptor types:
- Cholinergic (muscarinic)
- Dopaminergic
- Histaminergic
- serotonergic
Vomiting center is located within:
the reticular formation of the brainstem
Flood says medulla oblongata and consists of nucleus of the tractus solitaires and parts of the reticular formation
The vomiting center received afferent inputs from
the 5 afferent pathways
Efferent signals are directed to the following nerves:
Flood states V, Vii, IX, X, Xii
Glossopharyngeal Hypoglossal Trigeminal Accessory Spinal segmental
the gut, oropharynx, movement, pain, hypoxemia, and hypotension can all do what
stimulate the vomiting center
CTZ is located
Outside the BBB
What has contact with CSF and allows substances in blood and CSF to interact.
CTZ
Toxins and/or drugs in the blood can stimulate the CTZ causing ____ .
This stimulation may send :
Cause: N/V
Send: emetogenic triggers to the vomiting center activating the vomiting reflex
emetogenic triggers to the vomiting center activating
the vomiting reflex
Vomiting is associated with marked vagal and sympathetic activity causing:
Sweating
Bradycardia
Pallor
PONV is influenced by multiple factors that are r/t:
Patient
Surgery
Anesthesia
PONV Risk Factors:
- Women
- Previous history motion sickness or PONV from previous surgeries
- Nonsmokers
- < 50 years of age is a significant factor
strongest predictive factor for PONV
Women>men
flood: because of the effects of progesterone/estrogen on the CTZ or Vomiting center
patient/factor that decreases PONV due to gradual desensitization of the CTZ
Smokers
recent studies demonstrate that this is NOT a factor in pt PONV factors:
BMI is not a factor
Factors of Delayed Gastric Emptying:
MD Hypothyroidism Pregnancy Increased ICP Swallowing blood Full stomach
Corticosteroids
Methylprednisolone what is this effective for
late PONV prevention
haloperidol antiemetic dose and side effects
<2mg reduces the risk of side effects and QT prolongation. Not FDA approved.
droperidol - receptors
relatively selective D2 receptor antagonist
why was droperidol stopped in 2001
black box warning related to CV events- QT prolongation
what did the recent meta analysis demonstrate for droperidol
low doses <1mg or 15mcg/kg IV has significant antiemetic efficacy with low risk of adverse reactions
perphenazine used for
to treat schizophrenia and n/v
chlorpromazine works on which receptor
d2 receptor antagonist at CTZ
what can chlorpromazine cause
severe sedation
what does chlorpromazine treat
schizophrenia mental illness behavioral disorders tetanus blood disorders such as porphyria severe n/v
Propofol- other than sedation what can we use propofol for
Used in TIVA can reduce baseline risk of PONV
Alpha-2-agonists- has what two effects
Has direct antiemetic effect along with opioid sparing effect
Clonidine and Dexmedetomidine- how long do their anti nausea effects last?
demonstrated a significant but weak and short lived antinausea effect (meta-analysis)
IV Fluids are these effective for PONV
Effective for reducing the baseline risk for PONV.
midazolam how much do we give and when do we give it
2mg
30 min before end of surgery is as effective as zofran 4mg
2mg 30 min before end of surgery is more effective against PONV than 35mcg/kg premedication
gabapentin- how much do we give 2 hrs prior to surgery
600mg 2 hrs prior to surgery effectively decreases PONV
if we want to gabapentin 1 hour before surgery how much do we give
adding “this med” to gabapentin is better for PONV than either drug alone
800mg PO -as effective as dexamethasone 9mg IV
yet the combination of gabapentin and dexmethasone is better than either drug given alone
mirtazepine (remeron) - type and class
antidepressant
specific serotonergic and noradrenergic antidepressant
Strategies that do not work for antiemetic drugs
Music therapy Isopropyl alcohol inhalation Intraoperative gastric decompression The proton pump inhibitor esomeprazole (Nexium) Ginger root Nicotine patch to nonsmokers Cannabinoids
Sister Anna Has Double Nausea
receptor antagonism
serotonin (5-hydroxytryptamine subtype 3 ) antagonist
anticholinergics/antimuscarinics (M)
Histamine H1 antagonist
Dopamine (D2) antagonist
Neurokinin 1 antagonist
anticholinergics antimuscarinics drug example
scopolamine
histamine H1 antagonist example
promethazine perphenazine dimenhydrinate diphenhydramine meclizine chlorpromazine
dopamine d2 antagonist examples
domperidone chlorpromazine metoclopramide droperidol haloperidol
neurokinin 1 antagonist example
aprepirant
cospitant
rolapitant
serotonin (5-hydroxytryptamine subtype 3 ) antagonist
*they all have the same ending except for one!
ondansetron granisetron dolasetron ramosetron palonosetron tropisetron corticosteroid
Shaikh, S., Nagarekha, D., Hegade, G., & Marutheesh, M. (2016). Postoperative nausea and vomiting: A simple yet complex problem. Anesthesia Essays Resources, 10(3). 388-396.
…
What type of drug is ondansetron and dolasertron?
5-HT3
Zofran dose should not exceed what mg according to the FDA and for what reason?
FDA recommends that a single dose should not exceed 16 mg d/t risk of QT prolongation.
What med was banned by the FDA in 2010 in use for chemotherapy-induced N/V in adults and children d/t concerns of QT prolongation and torsade’s de pointes?
Dolasetron
of the drugs in the group 5-HT3, which drug is the most used by anesthesia (and perhaps in the hospital)
Zofran
How do Anticholinergic/ Antimuscarinic induce antiemetic effects?
Blocks muscarinic receptors in the cerebral cortex and pons.
How does Transdermal Scopolamine work?
Competitive inhibitor at postganglionic muscarinic receptors in the PNS and acts directly on the CNS by antagonizing cholinergic transmission in the vestibular nuclei.
How do histamine receptor antagonist work?
Blocks acetylcholine receptors in the vestibular apparatus and histamine receptors in the nucleus tractus solitaries.
What are three examples of Histamine receptor antagonists?
Dimenhydrinate (Dramamine)
Meclizine: Has longer during of PONV effect than ondansetron
Promethazine
What drug is a Dopamine antagonist?
Reglan
What all receptors does Reglan block? (3 answers)
Metoclopramide: Strong D2-receptor antagonist and blocks H1 and 5-HT3 receptors as well.
True or false:
reglan increases duodenal peristalsis?
True
What drug matches the description below:
Enhances 5-HT4 receptors and upper GI tract motility to promote gastric emptying without affecting gastric, biliary, and pancreatic secretion.
Reglan (dopamine - antagonist)
Is Reglan known as a strong or weak antiemetic?
weak antiemetic, it works mostly to increase gastric emptying. (think of it’s antiemetic abilities as a happy side effect)
Will you use Reglan with opioid use or not?
You can use reglan with opioid use, because with opioids you have delayed emptying of the stomach and by using reglan you Increases GE sphincter tone an decreases pyloric sphincter tone to prevent delayed emptying associated with opioid use.
What are Neurokinin-1 Receptor Antagonists?
New group of drugs used for PONV thought to prevent both acute and delayed emesis.
Where does Neurokinin- 1 receptor antagonist work at physiologically?
Act mainly at nucleus tractus solitaries and areas of reticular formation blocking NK-1 receptors.
Is Neurokinin-1 Receptor Antagonists more effective at inhibiting nausea or emesis?
Emesis
Aprepitant is a Neurokinin-1 Receptor Antagonists, what is the name of the PO version and the IV version?
Emend [PO], Cinvanti [IV]
What is the half life of Aprepitant Emend [PO], Cinvanti [IV] ?
40 hours
What drug is more effective than zofran for preventing vomiting at 24 and 48 hour after surgery and in reducing nausea severity in the first 48 hours after surgery?
Aprepitant Emend [PO], Cinvanti [IV]
Two meds listed in the power point that are Neurokinin-1 Receptor Antagonists, not approved for use yet? (who knows what he will test over lol)
Cospitant and Rolapitant
