Antiemetics/Aspiration Prophylaxis Flashcards
(74 cards)
1
Q
What is PONV?
A
- postop nausea/vomiting
- N/V within 24 hours of surgery
2
Q
What are the highest complaints and leading cause of unanticipated hospital admission after outpatient surgery?
A
- pain
- PONV
3
Q
PONV occurs in _____% of patients without prophylaxis after general anesthesia
A
40%
4
Q
PONV occurs in _____% of HIGH RISK patients without prophylaxis
A
80%
5
Q
What are some patient risk factors for PONV?
A
- female (strongest indicator)
- nonsmoker
- hx of PONV or motion sickness
6
Q
What are some surgical risk factors for PONV?
A
- longer procedures
- GYN procedures
- larparoscopic procedures
- ENT procedures
- breast/plastics procedures
7
Q
What are anesthetic risk factors for PONV?
A
- inhalational agents
- nitrous (esp in women under 35yo)
- neostigmine
- opioids
8
Q
What is the difference in PONV between kids and adults?
A
- kids: weak association with age
- adults: risk decreases with age
9
Q
What is the greatest association to PONV in children?
A
the surgical procedure
- hernia; tonsils/adenoids; strabismus sx; male genitalia
10
Q
What factors is PONV associated with?
A
- dehydration
- electrolyte imbalance
- wound dehiscence
- bleeding
- airway compliance
- UNPLANNED ADMISSIONS
- PATIENT DISCOMFORT
11
Q
What type of approach should we consider when preventing PONV?
A
multimodal approach
12
Q
When is scopalamine used?
A
- prevent motion induced nausea
- PONV
- trauma patients
- motion sickness from simulation of vestibular apparatus
13
Q
What agents increase vestibular sensitivity to motion?
A
- opioids
- morphine
14
Q
How is scopalamine administered?
A
transdermally
15
Q
What are the effects of administering scopalamine transdermally?
A
- sustained plasma concentration
- less sedation
- drying of secretions
- cycloplegia (paralysis of ciliary muscle of the eye; dilation of pupil and paralysis of accommodation)
16
Q
What is cycloplegia and what agent cause produce this as a side effect?
A
- paralysis of ciliary muscle of the eye; dilation of the pupil and paralysis of accommodation
- transdermal scopalamine can cause this
17
Q
What is the mechanism of action of ondansetron?
A
selective 5-HT3 receptor antagonist in the GI tract and chemoreceptor trigger zone
18
Q
When is ondansetron used?
A
- preventative and rescue treatment for N/V; used in chemo
- lots of debate on when to give it
18
Q
What are some side effects of ondansetron?
A
- headaches
- diarrhea
18
Q
Ondansetron Dosing
A
4 mg IV
18
Q
Ondansetron duration
A
4-6 hours
19
Q
What is a potential cardiac effect with ondansetron?
A
prolonged QT interval (can lead to torsades)
20
Q
How is ondansetron extensively metabolized?
A
hepatic metabolism
21
Q
T/F: ondansetron use in OB is questionable
A
true
22
What is dexamethasone used for?
- N/V prevention
- ENT
- traumatic intubations
- lower surgical inflammation
23
What class of drug is dexamethasone?
corticosteroid
24
What are the side effects of dexamethasone?
- gential itching/burning (give to patient while asleep, not awake!!)
- hyperglycemia (however new studies say no)
25
Careful use with dexamethasone in ________ because of hyperglycemia
diabetics
- they can potentially have wound healing issues
26
Dexamethesone Dosing
4 - 12 mg on induction
27
Dexamethasone duration
24 hours
28
Dexamethasone can be used in combination with ____________
antiemetics
29
What is the mechanism of action of dexamethasone?
- mechanism is actually unclear
- may centrally inhibit prostaglandin synthesis and control endorphin release
30
What is the trade name of ondansetron?
Zofran
31
What is the trade name of dexamethasone?
Decadron
32
What is the trade name of promethazine?
Phenergan
33
Which antiemetic is no longer on US formulary?
IV phenergan (promethazine)
34
What is promethazine used for?
- N/V
- anxiety
35
What are the side effects of promethazine?
- sedation
- potentiates sedative effects of benzos and opioids (C section)
- hypotension
- extrapyramidal symptoms (Akathisia)
36
Promethazine Dosing
12.5 - 25 mg IV
- DILUTED and given SLOWLY
37
Promethazine onset and duration
Onset: 3-5 min
Duration: 4-6 hours
38
Promethazine is considered a ___________________ due to sedation potential
first-generation H1 receptor antagonist
39
What class is promethazine under?
- phenothiazine
40
What are the mechanisms of action of promethazine?
- H1 receptor antagonist (antihistamine)
- anticholinergic action (motion sickness)
- D2 antagonist in chemoreceptor trigger zone
41
What two factors are associated with pulmonary complications of aspiration?
- volume of gastric acid contents
- acidity of aspirated gastric contents
42
What is the trade name of metoclopramide?
Reglan
43
Metoclopramide is considered a gastrointestinal ____________
gastrointestinal prokinetic
44
How does metoclopramide work?
- increases LES tone
- enhances repsonse to ACh in upper GI tract to enhance gastric motility and accelerate gastric emptying, thus reducing gastric volume
45
Where does the antiemetic action of metoclopramide come from?
antagonism dopamine-agonist effects in the chemoreceptor trigger zone
46
What action does metaclopramide have on the CNS?
inhibition of dopamine receptors within the CNS (crosses the BBB)
47
What are the side effects of metaclopramide?
- sedation
- restlessness
- extrapyramidal symptoms (tardive dyskinesia)
48
When is metaclopramide contraindicated?
- bowel obstruction
- Parkinson's disease
- restless let syndrome
- movement dysorders related to dopamine inhibition or depletion
49
What is metaclopramide used for?
- preop for aspiration prophylaxis
- treatment of diabetic gastroparesis
- GERD
- OB
50
T/F: Metaclopramide alters gastric fluid pH
false
- metaclopramide does NOT alter gastric fluid pH
51
Metaclopramide Dosing
5-10 mg IV in preop
52
Metaclopramide onset and duration
Onset: 1-3 min
Duration: 1-2 hours
53
Metaclopramide has potential for _____________ syndrome
Neuroleptic Malignant Syndrome
54
What is neuroleptic malignant syndrome?
55
How is neuroletpic malignant syndrome treated?
56
What other syndrome is neuroleptic malignant syndrome similar to?
57
What are the five hyperthermic toxidromes that can occur in anesthesia?
- sympathomimetic
- anticholinergic
- serotonin syndrome
- neuroleptic malignant
- malignant hyperthermia
58
What drug class does famotidine fall under?
H2 receptor antagonist
59
What is the trade name of famotidine?
Pepcid
60
How does famotidine work?
- inhibits gastric acid secretion/fluid volume
- raises gastric pH
61
Why would famotidine be given in anesthesia?
given in preop to decrease risk of pulmonary aspiration in risk patients
62
Famotidine Dose
20 mg IV
63
Famotidine onset
Onset: 30 min - 1 hour
64
What is the trade name of hydroxyzine?
Vistaril
65
What is the mechanism of action of hydroxyzine?
- blocks ACh in the vestibular apparatus
- blocks H1 receptors in the solitary tract
66
What drug class does hydroxyzine fall under?
antihistamine
67
When is hydroxyzine used?
- PONV
- pruritus (pregnancy)
- antianxiety
68
What are the side effects of hydroxyzine?
- sedation
- pain on injection
69
Hydroxyzine Dosing
- 25 mg IV mixed with Ephedrine
- 25 mg IM 20 min before the end of surgery
70
What cases should we be careful in with hydroxyzine use?
hypertension
71
T/F: there is a current national shortage of hydroxyzine
true
