Overview
Acute Nausea and Vomiting
Quick Reference
Critical Alerts
- Vomiting may be symptom of serious illness: ACS, DKA, bowel obstruction, increased ICP
- Assess hydration status: Priority
- Bilious or feculent vomiting = Obstruction: Emergent imaging
- Coffee-ground or bloody vomiting = GI bleed: Resuscitate, GI consult
- Antiemetics are symptomatic treatment: Address underlying cause
- Pregnancy test in women of childbearing age: Rule out pregnancy
Life-Threatening Causes
| Cause | Key Features |
|---|---|
| Bowel obstruction | Distension, bilious vomiting, no flatus |
| Acute MI (inferior) | Chest pain, diaphoresis, ECG changes |
| DKA/HHS | Hyperglycemia, altered mental status |
| Increased ICP | Headache, altered consciousness, papilledema |
| Toxin ingestion | Exposure history |
| Addisonian crisis | Hypotension, hyponatremia, hyperkalemia |
Emergency Treatments
| Drug | Dose | Notes |
|---|---|---|
| Ondansetron | 4-8 mg IV/PO | First-line; serotonin antagonist |
| Metoclopramide | 10-20 mg IV | Prokinetic; avoid in obstruction |
| Prochlorperazine | 10 mg IV | Also treats migraine |
| Promethazine | 25 mg IV/IM | Sedating |
| Dexamethasone | 4-10 mg IV | Adjunct for refractory nausea |
Definition
Overview
Nausea and vomiting are among the most common complaints in the ED. While usually due to benign causes (viral gastroenteritis, medication side effects), they can also be symptoms of serious conditions. ED management involves ruling out life-threatening causes, correcting dehydration, providing symptomatic relief, and treating the underlying cause.
Classification
By Duration:
| Type | Duration |
|---|---|
| Acute | <1 week |
| Chronic | > month |
By Mechanism:
| Type | Examples |
|---|---|
| CNS-mediated | Increased ICP, vestibular, migraine |
| GI | Obstruction, gastroenteritis, pancreatitis |
| Metabolic | DKA, uremia, adrenal insufficiency |
| Toxic | Medications, alcohol, drugs |
| Pregnancy | Hyperemesis gravidarum |
Epidemiology
- Very common ED complaint
- Multiple potential causes: GI, CNS, metabolic, toxic, pregnancy
Pathophysiology
Vomiting Reflex
Vomiting Center (Medulla):
- Receives input from multiple sources
- Coordinates vomiting response
Input Sources:
| Source | Stimuli |
|---|---|
| Chemoreceptor trigger zone (CTZ) | Drugs, toxins, metabolic abnormalities |
| GI tract | Distension, inflammation, obstruction |
| Vestibular system | Motion, labyrinthitis |
| CNS | Increased ICP, migraine |
| Cortex | Anticipatory nausea, psychological |
Clinical Presentation
Symptoms
| Feature | Significance |
|---|---|
| Nausea | Unpleasant sensation preceding vomiting |
| Vomiting | Forceful expulsion of gastric contents |
| Retching | Involuntary contractions without expulsion |
| Associated abdominal pain | GI cause |
| Associated headache | CNS cause |
| Vertigo | Vestibular cause |
Vomitus Characteristics
| Type | Significance |
|---|---|
| Undigested food | Gastric outlet obstruction, gastroparesis |
| Bilious (green/yellow) | Obstruction distal to ampulla |
| Feculent | Distal bowel obstruction |
| Coffee-ground/Bloody | Upper GI bleeding |
History
Key Questions:
Physical Examination
Assess Hydration:
| Finding | Significance |
|---|---|
| Dry mucous membranes | Dehydration |
| Decreased skin turgor | Dehydration |
| Tachycardia | Dehydration or other cause |
| Hypotension | Severe dehydration or serious illness |
| Orthostatic changes | Hypovolemia |
Abdominal Exam:
| Finding | Significance |
|---|---|
| Distension | Obstruction |
| Tenderness | Peritonitis, pancreatitis |
| High-pitched bowel sounds | Early obstruction |
| Absent bowel sounds | Ileus, late obstruction |
| Surgical scars | Adhesions, obstruction risk |
Neurological Exam:
| Finding | Significance |
|---|---|
| Papilledema | Increased ICP |
| Focal deficits | CNS lesion |
| Nystagmus | Vestibular disorder |
| Altered mental status | Metabolic, toxic, CNS |
Onset, duration, frequency
Common presentation.
Vomitus appearance (bilious, bloody)
Common presentation.
Associated symptoms (pain, diarrhea, fever, headache)
Common presentation.
Medications (opioids, chemotherapy, new meds)
Common presentation.
Pregnancy possibility
Common presentation.
Last menstrual period
Common presentation.
Recent meals (food poisoning)
Common presentation.
Travel history
Common presentation.
Alcohol or drug use
Common presentation.
Diabetes, renal disease
Common presentation.
Red Flags
Serious Causes to Exclude
| Finding | Concern | Action |
|---|---|---|
| Bilious or feculent vomiting | Bowel obstruction | Imaging, NG tube, surgery consult |
| Bloody or coffee-ground | GI bleeding | Resuscitate, GI consult |
| Severe headache | Increased ICP, SAH | CT head |
| Altered mental status | CNS, metabolic | BMP, CT, toxicology |
| Severe abdominal pain | Surgical abdomen | Imaging, surgery consult |
| Chest pain | ACS | ECG, troponin |
| Hypotension | Shock, adrenal crisis | Resuscitate |
| Pregnancy + severe vomiting | Hyperemesis, ectopic | HCG, ultrasound |
Differential Diagnosis
Common Causes
| Category | Examples |
|---|---|
| GI | Gastroenteritis, pancreatitis, cholecystitis, hepatitis, obstruction |
| CNS | Migraine, increased ICP, vestibular neuritis, labyrinthitis |
| Metabolic | DKA, uremia, hyponatremia, adrenal insufficiency |
| Toxic | Medications, alcohol, food poisoning |
| Pregnancy | Morning sickness, hyperemesis gravidarum |
| Cardiac | Inferior MI |
| Psychiatric | Eating disorders, cyclic vomiting syndrome |
Diagnostic Approach
Laboratory Studies
| Test | Indication |
|---|---|
| BMP | Electrolytes, renal function, glucose |
| CBC | Infection, anemia |
| Lipase | Pancreatitis |
| LFTs | Hepatobiliary disease |
| Urinalysis | UTI, DKA |
| HCG | All women of childbearing age |
| Troponin | If cardiac suspected |
| Drug screen | If toxic ingestion suspected |
Imaging
| Modality | Indication |
|---|---|
| Abdominal X-ray | Obstruction (air-fluid levels) |
| CT abdomen | Obstruction, pancreatitis, other surgical causes |
| CT head | Altered mental status, severe headache |
| Ultrasound | RUQ (cholecystitis), pregnancy |
Other Studies
| Study | Indication |
|---|---|
| ECG | Older patients, cardiac risk factors |
| LP | After CT if meningitis/SAH suspected |
Treatment
Principles
- Rule out serious causes: Red flags guide workup
- Correct dehydration: IV or oral fluids
- Antiemetics for symptomatic relief
- Treat underlying cause
Rehydration
Mild-Moderate:
- Oral rehydration (small, frequent sips)
Moderate-Severe:
- IV fluids: NS or LR
Antiemetics
First-Line: Ondansetron (5-HT3 Antagonist):
| Route | Dose |
|---|---|
| IV | 4-8 mg |
| PO/ODT | 4-8 mg |
| IM | 4 mg |
Dopamine Antagonists:
| Drug | Dose | Notes |
|---|---|---|
| Metoclopramide | 10-20 mg IV | Prokinetic; avoid in obstruction, EPS risk |
| Prochlorperazine | 10 mg IV | Also treats migraine |
| Promethazine | 25 mg IV/IM | Sedating; avoid in elderly |
| Droperidol | 0.625-1.25 mg IV | QT prolongation risk |
Antihistamines:
| Drug | Dose | Notes |
|---|---|---|
| Diphenhydramine | 25-50 mg IV | Vestibular, motion sickness |
| Meclizine | 25-50 mg PO | Vestibular |
| Dimenhydrinate | 50 mg IV | Motion sickness |
Adjuncts:
| Drug | Dose | Notes |
|---|---|---|
| Dexamethasone | 4-10 mg IV | Refractory nausea, chemotherapy-induced |
| Lorazepam | 0.5-2 mg IV | Anticipatory nausea |
Specific Treatments
Bowel Obstruction:
- NPO, NG tube, IV fluids, surgery consult
GI Bleeding:
- IV PPI, GI consult, blood products if needed
DKA/Metabolic:
- Treat underlying condition
Pregnancy:
- Ondansetron safe; pyridoxine + doxylamine for mild
Disposition
Discharge Criteria
- Hydration restored
- Able to tolerate oral fluids
- No red flags
- Underlying cause addressed or benign
- Follow-up arranged
Admission Criteria
- Severe dehydration
- Unable to tolerate oral intake
- Electrolyte abnormalities (hypokalemia, etc.)
- Bowel obstruction or surgical cause
- Serious underlying illness (DKA, MI, SAH)
- Hyperemesis gravidarum requiring IV therapy
Follow-Up
| Situation | Follow-Up |
|---|---|
| Gastroenteritis | PCP if not improved in 2-3 days |
| New medication-related | PCP for medication adjustment |
| Pregnancy | OB follow-up |
Patient Education
Condition Explanation
- "Nausea and vomiting can be caused by many things, most commonly stomach bugs or medication side effects."
- "Staying hydrated is the most important part of treatment."
- "There are medications to help with the nausea."
Home Care
- Sip clear fluids frequently
- Avoid solid food until vomiting stops
- Gradually reintroduce bland foods
- Avoid spicy, fatty, or acidic foods
- Take anti-nausea medication as prescribed
Warning Signs to Return
- Unable to keep down any fluids for >12 hours
- Blood in vomit
- Severe abdominal pain
- High fever
- Confusion or altered mental status
- Signs of dehydration (dizziness, dark urine, no urination)
Special Populations
Pregnancy
- Ondansetron is generally considered safe
- Pyridoxine (vitamin B6) + doxylamine for mild
- Rule out hyperemesis gravidarum
Elderly
- Higher risk of dehydration
- Higher risk of serious cause (MI, stroke, obstruction)
- Avoid promethazine (sedation, EPS)
Post-Operative
- Ileus common
- PONV (post-operative nausea/vomiting) responds to ondansetron
Chemotherapy
- Pre-treat with antiemetics
- 5-HT3 antagonists + dexamethasone + NK1 antagonist
Quality Metrics
Performance Indicators
| Metric | Target | Rationale |
|---|---|---|
| Pregnancy test in women of childbearing age | 100% | Rule out pregnancy |
| Hydration assessed | 100% | Priority |
| Red flag assessment | 100% | Identify serious causes |
| Antiemetic given | >0% | Symptomatic relief |
Documentation Requirements
- Vomitus characteristics
- Hydration status
- Red flag assessment
- Pregnancy test result (if applicable)
- Treatment and response
- Discharge instructions
Key Clinical Pearls
Diagnostic Pearls
- Bilious vomiting = Obstruction below ampulla: CT, surgery
- Bloody/Coffee-ground = GI bleed: Resuscitate, GI consult
- Pregnancy test in all women of childbearing age
- Inferior MI can present with nausea/vomiting: Get ECG
- Severe headache + vomiting = Increased ICP: CT head
- Altered mental status + vomiting = DKA, toxins, CNS
Treatment Pearls
- Ondansetron is first-line: Safe, effective
- Metoclopramide is prokinetic: Avoid in obstruction
- Prochlorperazine also helps migraine
- Diphenhydramine for vestibular causes
- Dexamethasone for refractory nausea
- Rehydration is key: IV or oral
Disposition Pearls
- Most gastroenteritis can be discharged: Once hydrated
- Admit for obstruction, bleeding, metabolic causes
- Follow-up if not improving in 2-3 days
- Educate on hydration and warning signs
References
- Scorza K, et al. Evaluation of Nausea and Vomiting. Am Fam Physician. 2007;76(1):76-84.
- Quigley EM, et al. AGA technical review on nausea and vomiting. Gastroenterology. 2001;120(1):263-286.
- Hasler WL, et al. Nausea, Vomiting, and Indigestion. In: Harrison's Principles of Internal Medicine. 21st ed. 2022.
- Hesketh PJ. Chemotherapy-induced nausea and vomiting. N Engl J Med. 2008;358(23):2482-2494.
- ACOG Practice Bulletin. Nausea and vomiting of pregnancy. Obstet Gynecol. 2018;131(1):e15-e30.
- Committee on Practice Bulletins. Hyperemesis gravidarum. Obstet Gynecol. 2018.
- NICE Guidelines. Nausea and vomiting in adults: management. 2021.
- UpToDate. Approach to the adult with nausea and vomiting. 2024.