25. Nausea/Vomiting Flashcards
3 phases of nausea/emesis
Nausea
Retching
Emesis
Ruminating defn
Confused with emesis but non forcing, dribbling of stomach contents out, maybe swallowed
Ruminating defn
Confused with emesis but non forcing, dribbling of stomach contents out, maybe swallowed
What is the CNS sequence of vomiting?
Vomiting centre is coordinated by medulla
Activation of muscarjnic receptors triggers vomiting center
Four main triggers: GI itself (main stomach, duod , outside main GI tract (biliary), CNS, chemoreceptor trigger zone in postrema of fourth ventricle
Efferent effects Through vagus, phrenic and spinal nerves
What 4 receptors are required to hit for anti nausea meds?
Histamine
Dopamine
Serotonin
Cholinergic
Acute vs chronic emesis timeline
<1 week
> 4 weeks
Cyclic emesis defn
Distinct episodes with asymptomatic period
Cyclic emesis defn
Distinct episodes with asymptomatic period
DDX vomiting
V- vestibular or vascular (MI)
Obstruction - sbo
Metabolic - DKA
Infection/infalmmatin - Crohn’s/ibd, gastritis, pancreatitis, biliary cause, PUD
CNS - CO,
Iatrogenic/ingestion
Neoplasm
Gravardum (pregnancy, cannabis etc) or GU- torsion!!
DDX Bright red blood vomit
PUD
gastritis
varices (esophageal)
aortoenteric fistula
esophageal rupture
duodenal or gastric tumor
mallory weiss tear
dieulafoy lesion
FB
DDX coffee ground emesis
PUD
gastritis
esophageal varices
duod or gastric tumor
MalloryWeiss syndrome
Vomiting undigested food -ddx 4
gasttric outlet obstruction
achalasia
esophageal stricture
fb
Vomiting feces or adult bilious emesis - 2ddx
small or large bowel obstructions
Rome IV criteria for cannabinoid hyperemesis syndrome: criteria
- stereotypical episodic emesis (meets defn of cyclic)
- presentation after prolonged, excessive cannabis use
- relief of emesis episodes by sustained cessation of canabis
Criteria need last 3 mo fulfilled with at least 6 mo pre dx
May feel better after prolonged hot bath or shower
PE of emesis: head to toe
vitals, fluid status
HENENT: nystagmus, oral exam if bulimia
abdo exam
neuro exam if concern for central
Ancillary testing for emesis
chem 7
lipase
LFT and ammonia
serum drug - asa, acetaminophen, vpa, carbamazepine, phenobarbital
blood gas/bhb if dka
bcg
urinalysis
POCUS
abdo ct +/- head ct
When is an abdo xray useful?
air under diaphragm
FB
Boerhaave syndrome: for pneumomediastinum
What receptor does ondansetron treat?
serotonin antagonist
Ondansetron ecg risk?
prolonged qt –> torsades
Name 6 possible sequelae of emesis
Hypovolemia
Metabolic alkalosis
Hypokalemia
Mallory weiss tear
booerhave syndrome
aspiration pneumonitis and pneumonia
What is the mechanism of metoclopramide?
prokinetic agent useful for gastroparesis and dysmotility order
dopamine and serotonin antagonist
How does haloperidol work for nausea?
Dopamine antagonist
What is the mechanism of prometahzine and dimenhydrinate in antinausea?
antihistamine H1 receptor
What is the mechanism of prochlorperazine in nausea/emesis?
dopamine antagonist
