Nausea / Vomiting

Cannot miss / life threats
Cannot miss / life threats
Diagnostic flow — check first
Diagnostic flow — check first
  • Glucose FIRST — DKA/HHS classically present with vomiting.
  • β-hCG in any reproductive-age female before imaging or meds.
  • Vomiting WITHOUT abdominal pain → think CNS, metabolic, cardiac, toxic (CT head (without contrast), ECG, BMP, levels).
  • Bilious or feculent vomiting + distension → obstruction (KUB / CT, NG decompression).
  • Headache / focal deficit → CT head (mass, bleed, hydrocephalus).
  • Older / cardiac risk → ECG + troponin (atypical MI).
  • Chronic cannabis + hot-shower relief → cannabinoid hyperemesis (haloperidol).
Differential diagnosis — checklist
0/30

Check off each diagnosis as you consider it. Tap the name for unique exam, lab/imaging clues, first-line confirmatory test, and management.

GI0/7
CNS0/5
Metabolic / endocrine0/7
Cardiac0/2
Toxic / drug0/6
GU / gyn0/3
Initial ED workup
Bedside0/5
  • Vitals + orthostatics
  • Glucose
  • Pregnancy test
  • ECG if older / cardiac risk
  • Abdominal exam
Labs0/6
  • CBC, BMP, lipase, LFTs
  • VBG + lactate
  • UA
  • β-hCG
  • Acetaminophen / salicylate level if intentional
  • Troponin if cardiac concern
Imaging0/4
  • Plain film for obstruction screen
  • CT abd/pelvis (with IV contrast) if surgical concern
  • RUQ US
  • CT head (without contrast) if neuro signs / red flags
Initial management0/4
  • IV antiemetic (ondansetron 4 mg IV; metoclopramide; haloperidol for cannabis hyperemesis)
  • IV fluids, replace K/Mg
  • NG decompression if obstruction
  • Treat underlying cause
ED next steps
ED next steps
  • Vitals + orthostatics, glucose, ECG (esp. older / cardiac risk), abdominal exam.
  • β-hCG in any reproductive-age female; CT head (without contrast) if focal neuro / red flags.
  • Labs: CBC, BMP, lipase, LFTs, VBG + lactate, UA; tox levels if intentional ingestion.
  • Antiemetic: ondansetron 4 mg IV (or metoclopramide 10 mg IV; haloperidol 2.5 mg IV for cannabinoid hyperemesis).
  • IV crystalloid bolus, replace K⁺/Mg²⁺; NG decompression if obstruction.
  • Treat the underlying cause (insulin for DKA, PCI for MI, surgery for obstruction).
  • Disposition: discharge if tolerating PO + benign workup; admit if surgical, metabolic derangement, or refractory vomiting.
Pearls / pitfalls
Pearls
  • Vomiting without abdominal pain — think CNS, metabolic, cardiac, or toxic.
  • Always get β-hCG in any reproductive-age female with vomiting.
  • Cannabinoid hyperemesis: chronic use + relief with hot showers; haloperidol or capsaicin cream.