Nausea Diagnosis and Management
Introduction to Nausea
- The differential diagnosis for nausea is extensive and must systematically evaluate gastrointestinal, neurologic, metabolic/endocrine, medication-related, and psychogenic causes, with the initial approach determined by whether symptoms are acute (≤7 days) or chronic (≥4 weeks) 1
Acute Nausea Causes
- Bowel obstruction is a life-threatening cause of acute nausea, characterized by abdominal distention, absent bowel sounds, and colicky pain 1, 2
Chronic Nausea Causes
- Gastroparesis is a gastrointestinal cause of chronic nausea, affecting 20-40% of diabetic patients and 25-40% of functional dyspepsia patients, and is characterized by delayed gastric emptying 1
- Cyclic vomiting syndrome is a gastrointestinal cause of chronic nausea, with a prevalence of ~2% in US adults, and is characterized by stereotypical episodes of acute-onset vomiting lasting <7 days 3, 4
Neurologic Causes
- Central nervous system pathology, including tumors and increased intracranial pressure, can cause nausea 1, 5
Medication-Related Causes
- Opioid-induced nausea occurs in 10-50% of patients receiving opioids 5
- Chemotherapy-induced nausea and vomiting can be managed with antiemetic therapy 6, 7
Diagnostic Evaluation
- Gastric emptying scintigraphy is the best accepted method to diagnose gastroparesis, and must be performed for at least 2 hours 1
- Upper endoscopy can be used to exclude mechanical obstruction, peptic ulcer disease, and malignancy 1
Management
- Ondansetron is the preferred initial agent for pharmacologic management of acute nausea, with a dosing of 4-8 mg orally/sublingual 8
- Combination therapy with benzodiazepine and haloperidol can be used for refractory vomiting 8
- Oral rehydration with small, frequent sips of electrolyte-rich fluids can be used for patients tolerating oral intake 8
- IV fluid therapy with normal saline or lactated Ringer's can be used for patients who cannot tolerate oral intake 8