PONV Flashcards
Risk Factors for Adults: Patient specific
Main 4?
Female
Non-smokers
History of PONV
History of motion sickness
-Delayed gastric emptying
-Preoperative anxiety
PONV = ___% of pt
Peaks at ____ hrs
Persist for ____hrs
Intractable vomit = ____%
Most common patient complaint
**Overall incidence: 20-30% up to 80%*
Intractable vomiting: 0.1%
Peaks 6 hrs postop
Persists 24-48 hours
Risk factors for Adults: Anesthesia/PACU
Surgical risk factors for PONV?
–> What meds?
–> Surgery?
-Volatiles
-Nitrous oxide
-*Intra/Postop opioids
-Neostigmine
-Preanesthetic medication (ketamine/etomidate)
-Gastric distention
-Longer duration of anesthesia
-Mandatory po fluids before discharge
What surgeries are high risk for PONV? (5)
High-risk surgery
1. Laparoscopy (belly)
2. Laparotomy Ileius
3. Ear, nose, throat surgery (ENT)
4. Neurosurgery
5. Breast, strabismus, or plastic surgery
**Belly, ENT, girlies
PEDATRICS PONV
What high risk surgeries (5)?
How does Peds N/V compare to adult?
-Increases with age until puberty
-Male = female
-Vomiting 2x more than adults
- Adenotonsillectomy (ENT bleeding)
- Strabismus repair
- Hernia repair
- Orchiopexy (fix undescended testicle)
- Penile surgery
Some general causes for PONV?
- Hypotension
- Hypoxemia
- Elevated ICP
- Gastric bleeding
- Hypoglycemia
Strategies to reduce PONV??
Sedation?
Induction?
Opioids? Alternatives?
Anes? Gas?
Avoid (2):
Nursing protocol?
Regional/ TIVA Prop > General Anes
Intraop
-Supplemental O2
-Adequate Hydration
-Propofol for induction and maintenance
-Avoid nitrous
-Minimize neostigmine
Minimize opioids
-Infiltrate surgical wound with LA
-Non-steroidals
-Minimize motion, early ambulation
Nitrous ___%+ is associated with PONV
Nitrous 50% or 0.5 MAC or greater
Less than 50% ehh maybe ok
Things to do instead of opioids?
Single dose of morphine associated with…PONV doesn’t matter the dose
TO DO: Regional nerve blocks, high dose acetaminophen, wound infiltration with LA, gabapentin, COX2
Reversal of NMBD
How does neostigme/anti-cholinergics cause N/V??
What does of neostigmine??
>__mg?
MINIMIZE NEOSTIGME
Anticholinesterases: muscarinic actions on GI
** Dose related (> 2.5mg of neostigmine) **
Atropine effect on PONV?
´Atropine reduces PONV
-Give NMBD that aren’t reversed…. Bc the reversal of NMBD cause N/V like neostigme. Can use LMA or intubate with NMBD (depending on case)
Isopropyl alcohol?
Adequate pre-hydration? How much?
Chewing gum?
Ginger?
Carbohydrate loading?
Peppermint?
-Adequate pre-hydration= 10-30 ml/kg
-Isopropyl alcohol (aromatherapy) : 50% reduction in nausea
Chewing gum :D
´ Potential improvement in nausea; stimulates motility
Questionable:
´ Ginger = No significant reduction
Carbohydrate loading =Overall questionable
Peppermint aromatherapy : not effective
Acupuncture/ Acupressure
Stimulates ____?
How does it work? (3)
Better at inhib N or V?
P 6 stimulation:
1.). Hypophyseal secretion of beta-endorphins
2.) Subsequent inhibition of CTZ
3. ) Decreases acid secretion
Better at inhibiting nausea than vomiting
Short, effective early
Recepters that can cause N/V:
BBB?
(8)
Chemo receptor has NO BBB!
Receptors:
´ Dopamine
´ Serotonin
´ 5-HT3
´
´ Histamine
´ Muscarinic
´ Neurokinin-1?
-Opioid
-Cannabinoid?
Emetic Center located ____________.
Direct/indirect? via ____?
Incoming stimuli acts at:
1.)
2.)
3.)
4.) –> 2 areas, what CN
Located in lateral reticular formation of brainstem
Indirect via AFFERENT incoming stimuli input to:
(afferent input)
1. Pharynx
2. GI tract (lack of gastric emptying/ distention)
3. Mediastinum
4. Afferent nerves from higher brain centers
–>CTZ from area postrema
–>Vestibular portion of 8th CN
Predicting PONV: Apfel score
Risk: Surgeries?
Predictors:
´ 0 risk factors: %
´ 1 risk factor: %
´ 2 risk factors: %
´ 3 risk factors: %
´ 4 risk factors: %
RISK:
-General anesthesia
-High risk: breast, dental, ENT, lap BTL
Predictors:
-Female,
-hx of PONV
-Postop opioids
-Nonsmoker
´ 0 risk factors: 10%
´ 1 risk factor: 20%
´ 2 risk factors: 39% * prophylaxis indicated here at 2 factors
´ 3 risk factors: 60 %
´ 4 risk factors: 79%
Issues from N/V
- Tension on suture lines –> Wound dehiscence
- Aspiration
- Dehydration and electrolyte imbalance
- Increased intracranial and intraocular pressure
- Prolonged PACU
- Unanticipated admissions
- Increased cost of care
- Increased use of personnel and resources
What is the gold standards?
***No single drug is gold standard
´ *Patients should not receive the same drug for prophylaxis and treatment
***Work on identifying and preventing as treating is +/- effective
Anti-dopaminergics
S/E??
Works as: (3)
Subtypes:
1. Butyrophenones
2. Phenothiazines
Dopamine receptor antagonists are
1.) Anti-emetic
2.) Antipsychotic
3.) Neuroleptic
Can cause neuro s/e: drowsiness, sedation, EPS effects
Anti-dopaminergics
- Butyrophenones SUBTYPE “-ridol”
Example 1: Haloperidol
Route?
PONV?
Example 2: Droperiodl
Dose?
Effective as _____.
More effective with ____
S/E: <3
BLACK BOX (2):
1.)
2.)
Haloperidol
- Not really approved for PONV
-Not approved for IV use, giving IM slows onset…
Droperidol
-never > 0.625 mg!
-As effective as Ondansetron 4mg
-With metoclopramide 10mg more effective
´ Weak alpha blocker…hypotension
Black box (BAD):
1. torsades de pointes (polymorphic v-tach)
2. sudden death
Anti-dopaminergics
2. Phenothiazines
“-azine”
Prochlorperazine
Chlorpromazine
Promethazine (Phenergan)
-Dose:
-Antagonizes what receptors? (4)
-S/E???
-BLACK BOX: (2)
Promethazine (Phenergan)
´ 12.5-25 mg
Also antagonize:
1. Dopaminergic
2. Alpha adrenergic
3. Histamine
4. Muscarinic cholinergic receptors
Sedation, hypotension, EPS
Black box (BAD)
-tissue damage;
-respiratory arrest < 2 y/0
Anticholinergics:
Scopalamine
PATCH DOSE:
LEAVE ON FOR: ____hrs
Works by:
S/E: !!
1.5 mg transdermal patch
´ leave in place 48-72 hours (2-3 days)
–>Blocks acetylcholine
–>Causes drowsiness, dry mouth, dizziness
place where there is thin skin
5HT3 antagonists
-Dolasetron (Anzemet)
-Granisetron (Kytril)
-Palonosetron
Ondansetron (Zofran)
Dose??
WHEN TO GIVE???
4mg within 15-20 of surgery end
(want it to last when pt are awake!!)
´data unclear on 4mg vs. 8m
Steroids:
Dexamethasone
USES:
1.)
2.)
S/E?
Dose??
WHEN TO GIVE???
1.) Decrease postop pain and edema
2.) Anti-inflammatory reaction
Not useful for rescue
´No adverse side effects
´Hyperglycemia
´Dose: 4mg as effective as 8mg (airway swell give more)
Given during/just after induction
