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Flashcards in PONV Deck (53)
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1
Q

5 Primary afferent pathways involved in vomiting stimulation:

A

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

2
Q

Stimulation of the afferent pathways stimulating vomiting can be activated by four receptor types

A

Cholinergic (muscarinic)
Dopaminergic
Histaminergic
serotonergic

3
Q

Vomiting center is located

A

It is located within the reticular formation of the brainstem

4
Q

Vomiting center can also be stimulated by

A

gut, oropharynx, movement, pain, hypoxemia, and hypotension

5
Q

Efferent signals are directed to the following nerves:

A
Glossopharyngeal (IX)
Hypoglossal (XII)
Trigeminal (V)
Accessory(XI)
Spinal segmental
Flood states  V, VII, IX, X, XII
6
Q

Outside the BBB
Has contact with CSF and allows substances in blood and CSF to interact.
Toxins and/or drugs in the blood can stimulate the____causing n/v
This stimulation may send emetogenic triggers to the vomiting center activating the vomiting reflex

A

CTZ

7
Q

Vomiting is associated with marked vagal and sympathetic activity causing:

A

Sweating
Pallor
Bradycardia

8
Q

PONV is influenced by multiple factors that are r/t:

A

Patient
Surgery
Anesthesia

9
Q

PONV: PATIENT FACTORS

A

Sex: Women > Men (strongest predictive factor)
Motion Sickness: Previous history motion sickness or PONV from previous surgeries
Smoking: Nonsmokers > Smokers due to gradual desensitization of the CTZ
Age: < 50 years of age is a significant factor
Obesity: recent studies demonstrate BMI is not a factor
Delayed Gastric Emptying:
MD
Hypothyroidism
Pregnancy
Increased ICP
Swallowing blood
Full stomach

10
Q

PONV:
PRE-OP AND INTRA-OP FACTORS
Surgical: ______________
During Surgery: _______________

A

Surgical: Type of surgery: cholecystectomy, gynecological and lap surgeries have high incidents of PONV
During Surgery: Long duration; Increasing by surgery time by 30 minutes may increase PONV risk by 60%

11
Q

Significant decrease in vomiting when avoided in lap procedures.

A

Nitrous oxide

12
Q

_________ and ________ cause higher PONV d/t increase in endogenous catecholamines

A

Ether and Cyclopropane

13
Q

_________, _______, _______, ______. and _______ are associated with lesser degree of PONV

A

Sevoflurane, Enflurane, Desflurane, and Halothane

14
Q

Continuous infusion markedly increases post-op emesis

A

Etomidate

15
Q

When used for induction, its been known to delay D/C d/t vivid dreams, hallucinations, and higher incidence of PONV (20 to endogenous catecholamine release) when compared to giving barbiturates and nitrous oxide

A

Ketamine

16
Q

reduced PONV

A

Propofol

17
Q

increase incident of PONV d/t directly stimulating the CTZ

A

Nitrous-Opioid-relaxant technique

18
Q

Emesis caused by stimulation of opioid receptors in the CTZ. Using intraoperative ______ shows a weak contribution to PONV

A

opioids

19
Q

Incidence of PONV is uncertain

A

Neuromuscular Reversal Agents

20
Q

Risk for PONV is 9 times less than with ______than with general anesthesia

A

regional

21
Q

Nausea after epidural may be less with ______ ________ opioids such as _______ and ________d/t less rostral spread from lumbar epidural injection site to CTZ and vomiting center than the less lipid soluble such as morphine

A

lipid soluble, fentanyl and sufentanil

22
Q

______ or _____ is common cause of post op emesis

A

Visceral or pelvic pain

23
Q

Sudden motion, changes in position, and/or transport from PACU to patient floor can precipitate n/v after receiving ______

A

opioids

24
Q

Post-op opioids ______ risk for PONV in dose dependent manners. This effect can last as long as opioids are used in the post op period

A

increase

25
Q

________ can be used perioperatively to reduce need for opioids.

A

Non-steroidal

26
Q

__________ is no longer recommended for PONV prevention

A

Supplemental O2

27
Q

Genes/receptors regarded as r/t PONV or opioid induced N/V:

A
5-HT3
Muscarinic type-3
Dopamine type 2
Catechol-o-methyl transferase
Alpha-2 adrenoceptor
Adenosine triphosphate binding cassette subfamily B member
Cytochrome P450 superfamily enzyme
Uridine 5’-diphospho-glucuronosyltransferae
28
Q

5-hydroxytryptamine subtype 3 receptor antagonists:

A
Ondansetron
Dolasetron (ban d/t concerns of QT prolongation and torsade's de pointes)
29
Q

Blocks muscarinic receptors in the cerebral cortex and pons to induce antiemetic effects

A

Anticholinergic/Antimuscarinic

Transdermal Scopolamine

30
Q

Histamine Receptor Antagonists: Blocks acetylcholine receptors in the vestibular apparatus and histamine receptors in the nucleus tractus solitaries

A

Dimenhydrinate (Dramamine)
Meclizine: Has longer during of PONV effect than ondansetron
Promethazine

31
Q

Dopamine Antagonist:

A

Metoclopramide: Strong D2-receptor antagonist and blocks H1 and 5-HT3 receptors as well.

32
Q

Neurokinin-1 Receptor Antagonists: New group of drugs used for PONV thought to prevent both acute and delayed emesis. Act mainly at nucleus tractus solitaries and areas of reticular formation blocking NK-1 receptors. More effective in inhibiting emesis than nausea.

A

Aprepitant (Emend [PO], Cinvanti [IV]):

33
Q

Aprepitant (Emend [PO], Cinvanti [IV]): NK-1 receptor antagonist with a ____hours half life. Significantly more effective than ondansetron for preventing vomiting at 24 and 48 hour after surgery and in reducing nausea severity in the first 48 hours after surgery

A

40

34
Q

Blocks synthesis of prostaglandins which sensitized nerves to other commonly involved neurotransmitters in emesis control.
May have central effect by antagonizing 5-HT3 receptors or corticosteroid receptors in the nucleus tractus solitaries

A

Corticosteroids:
Dexamethasone:

35
Q

effective for late PONV prevention

A

Methylprednisolone:

36
Q

Butryphenones

A

Droperidol

Haldol

37
Q

Relatively selective D2 receptor antagonist. Use was stopped in 2001 due to black box warning related to CV events. A recent meta-analysis demonstrated at low doses of <1 mg or 15 mcg/kg IV there is significant antiemetic efficacy with low risk of adverse reactions.

A

Droperidol

38
Q

Haldol

A

< 2 mg reduces the risk of side effects and QT prolongation. Not DFA approved

39
Q

Phenothiazines

A

Perphenazine

Chlorpromazine

40
Q

Used to treat schizophrenia and n/v

A

Perphenazine

41
Q

a D2 receptor antagonist at CTZ. May treat schizophrenia; used to treat mental illness, behavioral disorders, tetanus, blood disorders such as porphyria and severe n/v. Severe sedation

A

Chlorpromazine

42
Q

Used in TIVA can reduce baseline risk of PONV

A

Propofol

43
Q

Has direct antiemetic effect along with opioid sparing effect. Clonidine and Dexmedetomidine (alpha-2-adrenceptor agonists) demonstrated a significant but weak and short lived antinausea effect (meta-analysis)

A

Alpha-2-agonists

44
Q

Antidepressant (specific serotonergic an noradrenergic antidepressant). The combination of _______30 mg PO and dexamethasone 8 mg decreases incidence of late PONV > 50%.

A

mirtazapine (remeron)

45
Q

_____600 mg 2 hours prior to surgery effectively decreases PONV. An hour before surgery ________ 800 mg PO is as effective as dexamethasone 9 mg IV and the combination is better than either drug given alone

A

Gabapentin

46
Q

_______: 2 mg 30 before end of surgery is as effective as ondansetron 4 mg. 2 mg 30 min before end of surgery is more effective against PONV than 35 mcg/kg premedication

A

Midazolam

47
Q

Effective for reducing the baseline risk for PONV.

A

IV Fluids:

48
Q

Strategies that do not work:

A
Music therapy
Isopropyl alcohol inhalation
Intraoperative gastric decompression
The proton pump inhibitor esomeprazole (Nexium)
Ginger root
Nicotine patch to nonsmokers
Cannabinoids
49
Q

Serotonin (5-hydroxytryyptamine subtype 3) antagoist examples

A

ondansetron, granisetron, dolasetron, ramosetron, palonsetron, tropistron, corticosteroids

50
Q

Antcholinergics. antimuscarinics (M)

A

Scopolamine

51
Q

Histamine (H1) antagonist

A

promethazine, perphenazine, dimenhdrinate, diphenhydramine, meclizine, chlorpromazine

52
Q

Dopamine (D2) antagonist

A

Domperidone, chlorpromazine, metoclopramide, drperidol, haloperidol

53
Q

Neurokinin-I antagonist

A

Apreitant, cospitant, rolapitant