What is the initial step and management approach for a patient with ongoing nausea and vomiting?

Evaluation and Management of Ongoing Nausea and Vomiting

The initial workup for ongoing nausea and vomiting should include assessment of potential causes, hydration status, and electrolyte abnormalities, followed by targeted treatment based on the underlying etiology.

Initial Assessment

History

• Duration and pattern of symptoms (acute, chronic, cyclic)
• Associated symptoms (abdominal pain, diarrhea, headache)
• Medication use (opioids, GLP-1 agonists, chemotherapy)
• Recent dietary changes or food intake
• Potential triggers (motion, stress, foods)
• Timing in relation to meals

Physical Examination

• Vital signs (including orthostatics)
• Hydration status (mucous membranes, skin turgor)
• Abdominal examination (tenderness, distension, masses)
• Neurological examination (focal deficits, papilledema)

Initial Laboratory Testing

• Electrolytes, BUN, creatinine
• Liver function tests
• Pregnancy test in women of childbearing age
• Consider lipase if pancreatitis suspected

Common Etiologies to Consider

1. Gastrointestinal causes:

   • Gastroparesis
   • Bowel obstruction
   • Gastritis/PUD
   • GERD

2. Medication-induced:

   • Chemotherapy
   • Opioids
   • GLP-1 receptor agonists
   • Antibiotics

3. Metabolic/Endocrine:

   • Electrolyte abnormalities
   • Uremia
   • Diabetic ketoacidosis
   • Hypercalcemia

4. Central nervous system:

   • Increased intracranial pressure
   • Vestibular disorders
   • Migraines

5. Psychogenic:

   • Anxiety
   • Depression
   • Eating disorders

Management Approach

Immediate Interventions

1. Fluid resuscitation:

   • IV hydration for moderate-severe dehydration
   • Correction of electrolyte abnormalities

2. First-line antiemetics:

   • Dopamine receptor antagonists:
     • Prochlorperazine 5-10 mg PO/IV every 6 hours 1
     • Metoclopramide 10-20 mg PO/IV every 6 hours 2
     • Haloperidol 0.5-2 mg PO/IV every 4-6 hours 2

3. Second-line antiemetics:

   • 5-HT3 receptor antagonists:
     • Ondansetron 8 mg PO/IV every 8 hours 2, 3
   • Corticosteroids:
     • Dexamethasone 4-8 mg daily 2
   • Benzodiazepines:
     • Lorazepam 0.5-1 mg PO/IV every 6 hours 2

Breakthrough Treatment

For persistent nausea and vomiting despite initial treatment:

1. Add medications from different classes:

   • If using dopamine antagonist, add 5-HT3 antagonist 2
   • Consider olanzapine 2.5-5 mg daily for refractory symptoms 2, 3
   • Consider scopolamine transdermal patch for vestibular symptoms 2

2. Optimize administration:

   • Use around-the-clock dosing rather than PRN 2
   • Consider alternative routes (IV, rectal, nasal) if oral route not feasible 2
   • Multiple concurrent agents may be necessary 2

3. Consider cannabinoids:

   • Dronabinol or nabilone for refractory cases 2

Special Considerations

Elderly Patients

• Use lower doses of antiemetics 3, 1
• Monitor for extrapyramidal symptoms with dopamine antagonists
• Use caution with ondansetron and haloperidol due to QT prolongation risk 3

Chemotherapy-Induced Nausea/Vomiting

• Prophylaxis based on emetogenic potential of regimen 2
• Combination therapy with NK1 antagonist, 5-HT3 antagonist, and dexamethasone for high-risk regimens 2

Cyclic Vomiting Syndrome

• Abortive therapy with sumatriptan and antiemetics 2
• Sedation often effective (benzodiazepines, diphenhydramine) 2
• IV fluids and electrolyte replacement during episodes 2

Non-Pharmacological Interventions

1. Dietary modifications:

   • Small, frequent meals
   • Low-fat diet if tolerated
   • Avoid trigger foods
   • Adequate hydration

2. Positioning strategies:

   • Elevate head of bed 6-8 inches
   • Avoid lying flat for 2 hours after meals
   • Avoid meals within 3 hours of bedtime 3

3. Complementary approaches:

   • Acupressure wristbands
   • Ginger supplements
   • Behavioral therapy for anticipatory nausea 2

Monitoring and Follow-up

• Daily assessment of frequency and character of vomiting
• Monitoring of hydration status and electrolytes
• Evaluation of medication effectiveness
• Adjustment of antiemetic regimen based on response

When to Consider Additional Evaluation

• Persistent symptoms despite appropriate management
• Red flag symptoms (hematemesis, severe abdominal pain, focal neurological findings)
• Weight loss or malnutrition
• Concern for mechanical obstruction

In these cases, consider:

• Upper endoscopy
• Abdominal imaging
• Gastric emptying study
• Neuroimaging if CNS etiology suspected