Initial Management of Recurrent Vomiting
The initial management of recurrent vomiting should prioritize immediate assessment of hydration status and red flag signs, followed by fluid resuscitation and administration of antiemetics from different drug classes, with the oral route avoided in favor of intravenous or rectal therapy when vomiting is active. 1
Immediate Assessment Priorities
Assess for red flag signs that require urgent intervention:
- Bilious or bloody vomiting (suggests obstruction or surgical emergency) 2
- Altered sensorium or toxic/septic appearance 2
- Severe dehydration with metabolic acidosis 3
- Abdominal distension or concern for bowel obstruction 1
Obtain initial laboratory evaluation:
- Complete blood count with differential 4
- Serum electrolytes, glucose, bicarbonate 4, 3
- Liver function tests, lipase, urinalysis 4
- Consider serum bicarbonate specifically—levels ≤13 mEq/L predict need for hospitalization 3
Fluid Resuscitation Strategy
For patients with dehydration, initiate rapid IV rehydration:
- Administer 20-30 mL/kg isotonic crystalloid over 1-2 hours 3
- Correct electrolyte abnormalities, particularly hypokalemia and hypomagnesemia 4
- Ensure adequate hydration before attempting oral intake 1
Critical pitfall: Patients with serum bicarbonate ≤13 mEq/L typically require prolonged IV therapy and hospitalization, as 85% will not tolerate oral fluids after initial rehydration 3
Antiemetic Administration
Use non-oral routes during active vomiting:
- The oral route is not feasible during ongoing vomiting; use IV or rectal administration 1
- Administer antiemetics around-the-clock rather than PRN to prevent recurrence 1
First-line antiemetic selection (use agents from different drug classes):
- 5-HT3 antagonists: Ondansetron 0.15 mg/kg IV (maximum 4 mg) or 0.2 mg/kg oral when tolerated 2
- Dopamine antagonists: Metoclopramide, prochlorperazine, or haloperidol 1, 4
- Corticosteroids: Dexamethasone 8-12 mg IV 1
- Benzodiazepines: Lorazepam 0.5-2 mg IV/sublingual every 4-6 hours for anxiety component 1
For refractory vomiting, use multiple concurrent agents:
- Combine medications from different classes with alternating schedules or routes 1
- Consider adding H2 blockers or proton pump inhibitors, as patients may confuse heartburn with nausea 1
Specific Etiologic Considerations
If Cyclic Vomiting Syndrome (CVS) is suspected:
- Recognize stereotypical episodes lasting <7 days with symptom-free intervals 1
- Screen for cannabis use history (Cannabis Hyperemesis Syndrome mimics CVS) 4
- Abortive therapy is most effective during the prodromal phase (before vomiting begins) 1
- Consider prophylactic therapy if ≥4 episodes per year 1
If chemotherapy-related:
- Use triple therapy: aprepitant 125 mg + dexamethasone 12 mg + 5-HT3 antagonist on day 1 1
- Continue aprepitant 80 mg on days 2-3 with dexamethasone 1
If gastroparesis is suspected:
- Metoclopramide is the mainstay as it promotes gastric emptying 4, 5
- Monitor for extrapyramidal symptoms, particularly in young males 4
Critical Management Pitfalls to Avoid
Never administer antiemetics if mechanical bowel obstruction is suspected:
- This can mask progressive ileus and gastric distension 4
- Place nasogastric tube for decompression if bilious vomiting present 2
Monitor for medication-specific complications:
- QTc prolongation with ondansetron, especially when combined with other QT-prolonging agents 4
- Extrapyramidal reactions with dopamine antagonists 4
Avoid repeated imaging or endoscopy:
- One-time upper GI imaging or EGD is sufficient to exclude obstruction 4
- Repeated studies are not indicated unless new symptoms develop 4
Disposition and Follow-up
Discharge criteria after rapid IV rehydration:
- Ability to tolerate oral fluids (1-3 ounces clear liquid without vomiting) 3
- Serum bicarbonate >13 mEq/L predicts successful outpatient management 3
- 85% of appropriately selected patients require no further medical evaluation 3
Admission criteria: