Ex: 6 - Nausea/Vomiting (68) Flashcards
Nausea
Sickness at the stomach; an inclination to vomit
Vomiting
The ejection of matter forcibly from the stomach through the esophagus and mouth
Retching (arcadas)
Making movements of vomiting w/o effect
What are other symptoms associated with nausea and vomiting
Pallor
Tachycardia
Diaphoresis
Etiology of nausea and vomiting: GI disorders
Influenza
-Intestinal pathogen
-food poisoning
Ulcers; GERD
Pancreatitis
Cholecystitis
Obstruction
Tumors
DM gasteoparesis
Etiology of nausea and vomiting: CNS disorders
Anxiety tumors HA
Etiology of nausea and vomiting: Pain
Acute or chronic
Etiology of nausea and vomiting: Excessive intake of just about anything… pregnancy
Intake:
Man vs Food
Alcohol
Pregnancy
-80% of pregnant women
Treatment-induced causes of nausea and vomiting
Cancer chemotherapy
-Varies with agent and dose
Radiation therapy
-CNS and abdominal
Anesthesia (~30%)
-Varies greatly with type
NV associated w/procedures
-Especially abdominal
Drug-induced causes of NC cont: Anti-neoplastic agents
Opioids
Aspirin, NSAIDs, etc
Iron
Some antibiotics
-Tetracycline; erythromycin
Estrogens
-High doses
Anti-parkinson meds
SSRIs
Complications of NV
Patient discomfort
Dehydration (K+, Na+, Cl-)
Malnutrition
Aspiration Pneumonia
Anxiety; anticipatory NV
Compromise therapy
Decreased QOL
Assessment of NV
Number of episodes
Onset
Duration of symptoms
Evidence of dehydration
Severity of nausea
-Visual analog scale
0-10
Questions to ask patients:
How long have you had NV?
What color
How often
Is the vomiting related to eating?
-If so, what foods/ and how soon after eating
-Do you have nausea w/o vomiting?
Is the NV associated with…
-Abdominal pain
-Constipation
-Diarrhea
-A loss of appetite
-A change in color of your stool
-A change in color of your urine
-Fever
-Chest pain
-HA
-Hearing loss
Pathophysiology of NV
Cortex
-Sensory input
-Anxiety and memory
-Meningeal irritation
-Increased ICP
CTZ
-Drugs, metabolic
Dorsal vagal complex
Multiple receptors
GI
-Serotonin release from mucosal enterochromaffin cells
-obstruction
-stasis
-inflammation
Vestibular
-Motion
-CNS lesions
-Opioids
-aggravates most nausea
when we have agents that impact receptors at multiple places, tend to be more efficacious
Patho of NV cont: Site of drug action
Dopamine receptors [D2]
Histamine receptors [H1 and H2]
Muscarinic - cholinergic receptors [M1]
Serotonin receptors [5-HT3]
Neurokinin receptors [NK-1]
Often use antihistamines/antimuscarinics to treat NV
Non-pcol management of NV
First steps
-Determine the cause
-Put the gut to rest
-clear liquid diet
-IV hydration
Dietary
-Avoid fatty, fried, sweet and spicy foods
-eat food that is cold or at room temp
Non-pharmacologic therapy
Physical
-Avoid unpleasant sights, sounds, and odors that may aggravate NV
-Fresh air
-Avoid sudden movements
-Dim lights
-acupressure
-3 fingers above the wrist
-Pregnancy
-Chemotherapy
Nerve stimulation therapy
ReliefBand
-helps the stomach return to a normal rhythm of 3 cycles/min
-Adjustable settings on 2 day and 5 day devices
Drug therapy: Antihistamines - Anticholinergics
Meclizine; Dimenhydramine; Scopolamine
MOA:
-Block histamine and or muscarinic receptors in the CTZ and NTS centers
-Interrupt visceral afferent pathways
Side effects: drowsiness, sedation, dry mouth, constipation, blurred vision
Overall, role is limited for moderate to severe NV
Drug therapy - Phenothiazines
-Prochlorperazine
-Promethazine
-Chlorpromazine
MOA
-Dopamine inhibition at CTZ
-Comparison of phenothiazines
-Std of care prior to 5-HT3 antagonists
SE
-Dizziness, sedation, dry mouth, hypotension, EPS (abnormal movements that occur when dopamine receptors stimulated)
Drug therapy - Serotonin Antagonists
Ondansetron
Granisetron
Palonosetron
Dolasetron
MOA
-Serotonin inhibition at CTZ, VC, and GI tract
Side effects:
-Mild HA; Dizziness; fatigue; constipation
-Recent concern about QT prolongation
Advantages/Disadvantages of various Serotonin antagonists
Ondansetron
-Multiple dosage forms; including ODT
-Generic/lower cost <$10 tx course
Granisteron
-Multiple dosage forms: patch; LA injection
-Generic/lower cost <$10 tx course
Dolasetron
-PO only
-$$$
Palonsetron
-Longest DOA - t 1/2 = 40hrs
Brand only, $$$
No PO dosage form
No suppository dosage forms
Drug therapt: Neuokinin-1 antagonists
Will not see as much, primarily used for chemotherapy induced NV (CINV)
Aprepitant; Fosaprepitant; Rolapitant
MOA
-Neurokinin receptor inhibition at CTZ, VC, and GI tract
Side effects
-Fatigue; hiccups; constipation; decreased appetite
Drug therapy - others
Butyrophenones:
Haloperidol; Droperidol
MOA: Dopamine inhibition at CTZ
Black box Warning: risk of EKG abnormalities - Rarely used
Metoclopramide
-MOA: Dopamine inhibition at CTZ
-Serotonin inhibition at CTZ, VC and Gi tract (high dose)
EPS at high dose (Give with benadryl)
Corticosteroids (Dexamethasone)
MOA: inhibition of cortical input into vomiting center?
Enhances the efficacy of any other antiemetics
Cannabinoids
-MOA: Binds with cannabinoid or CB1 receptors in the brain
Side effects: sedation, dry mouth, euphoria, dysphoria; facial flushing, visual changes
Importance of Route of Admin in the Tx of NV
Route of admin:
-Po tablet
-ODT tablet
-PR
-IV
-IM
Tx of motion sickness
Very common
-1/3 of population very susceptible
1/3 susceptible with rough conditions
1/3 susceptible with extreme conditions
-Peak age 12-21 years
Prevention
Treatment of Motion sickness:
Scopolamine (Transderm-Scop)
-Apply patch before needed
-Duration = 72 hours
Dimenhydrinate 50mg
-Dramamine
-Oral (30-60 min before needed)
Meclizine 25 mg
-Bonine; Dramamine less drowsy
-zentrip
-Oral (30-60 min before needed)
Tx of NV secondary gastroenteritis or pain
VERY COMMON
-Treat symptoms while treating the Cause
-Ondansetron 4-8mg IV/ODT/PO q8-12 hours prn
-Promethazine 12.5 -25mg IV/IM/PO q4-6 hrs prn
Post Operative NV
Very common with older inhaled agents
-Patients with multiple risk factors are at highest risk for PONV
Most common complication associated w/ambulatory surgery (30-50%)
Prevention
Risk factors for PONV
Patient-specific factors
-F > M
-Non-smoking status
-HX of PONV
-hx of motion sickness
Anesthetic risk factors
-Intra-operative use of volatile anesthetics
-less with propofol
-Use of nitrous oxide
-Type of surgery
-Laparoscopy
-Craniotomy
-ENT
Tx of PONV chart
Risk:
Low
-1-2 risk factors
Prophylaxis:
-No tx necessary
Risk: Moderate to high
2+ risk factors
Prophylaxis:
-Tx with 1 or 2 agents
-Only1 agent if propofol is used
-5-HT3 antagonists are DOC
-All classes can be used
Drugs administered at end of procedure
Risk: Highest
-3 or more esp. if prior hx of PONV
-Always use 2 agents
-5-HT3 + metoclopramide or aprepitant
Risk: Breakthrough
Prophylaxis:
-Use an agent from a different class if within 6 hours of original dose
-Amisulpride (Barhemsys)
Treatment of PONV
Aprepitant (Emend)
-40 mg orally 1 to 3 hours prior to induction of anesthesia
-May be superior to ondansetron 4mg at both 24 and 48 hrs post-op
-Data in trials was not statistically significant
Amisulpride (Barhemysys)
-5-10 mg IV infused over 1-2 minutes
-Selective dopamine-2 and dopamine -3 antagonist
-Not indicated for prophylaxis
-has been associated with QT prolongation
Monitoring antiemtic therapy
Efficacy
-Volume
-Frequency and duration
-Nausea rating
-Ability to eat
-PRN doses of anti-emetic agents
-QOL ratings
Toxicity
-Sedation/drowsiness
-Dizziness
-Diarrhea
-HA
-Anticholinergic SE
-EPS
