What is the recommended workup and treatment for a patient with suspected gastroparesis?

Gastroparesis Workup and Treatment

The diagnostic workup for suspected gastroparesis requires gastric emptying scintigraphy of a radiolabeled solid meal as the gold standard test, followed by a treatment approach based on symptom severity and predominant symptom pattern. 1

Diagnostic Workup

Initial Evaluation

• History and physical examination focusing on:
  • Cardinal symptoms: nausea, vomiting, postprandial fullness, early satiety, abdominal pain
  • Physical findings: succussion splash (delayed emptying), right upper quadrant bruit (celiac artery compression), digital ulcers/telangiectasia (scleroderma), ascites/masses (malignancy)
  • Risk factors: diabetes, prior surgeries, viral infections
  • Medication review for drugs that delay gastric emptying

Laboratory Tests

• Complete blood count
• Basic metabolic panel (especially important for diabetic patients)
• Liver function tests
• Thyroid function tests (hypothyroidism can mimic gastroparesis)

Diagnostic Tests

1. Upper endoscopy - First step to rule out mechanical obstruction or structural lesions 1

2. Gastric emptying scintigraphy - Gold standard test 1

   • 4-hour solid meal study (99mTc-labeled egg sandwich)
   • Imaging at 0,1,2, and 4 hours
   • Diagnostic criteria: >10% retention at 4 hours
   • Test should be performed after stopping medications that affect gastric motility for 48-72 hours

3. Alternative diagnostic tests when scintigraphy is unavailable:

   • 13C-octanoate or 13C-Spirulina breath test
   • Wireless motility capsule
   • Antroduodenal manometry (helps differentiate neuropathic from myopathic disorders) 1

Treatment Approach

Classification by Severity

• Mild: 10-15% retention at 4 hours
• Moderate: 15-35% retention at 4 hours
• Severe: >35% retention at 4 hours 1

Dietary Modifications

• Small, frequent meals (5-6 per day)
• Low-fat, low-fiber diet
• Liquid or pureed foods when symptoms are severe
• Avoid carbonated beverages and alcohol

Pharmacologic Treatment

For Nausea/Vomiting Predominant Symptoms:

1. Prokinetic agents:

   • Metoclopramide: 10 mg orally 30 minutes before meals and at bedtime 2
     • Monitor for extrapyramidal side effects
     • Black box warning for tardive dyskinesia with long-term use
   • Erythromycin: 125 mg before meals (alternative prokinetic)

2. Antiemetic agents:

   • Prochlorperazine: 5-10 mg orally every 6 hours as needed
   • Ondansetron: 8 mg every 8-12 hours for refractory nausea
   • Phenothiazines (promethazine, prochlorperazine)

For Abdominal Pain/Discomfort Predominant Symptoms:

• Neuromodulators (tricyclic antidepressants at low doses)
• Avoid opioids as they worsen gastric emptying 1

Management of Refractory Cases

1. Moderate symptoms:

   • Combination therapy with prokinetics and antiemetics
   • Consider cognitive behavioral therapy or hypnotherapy
   • Trial of liquid diet

2. Severe symptoms:

   • Gastric electrical stimulation for refractory nausea/vomiting 1
   • Pyloric interventions (botulinum toxin injection, G-POEM)
   • Enteral feeding via jejunostomy tube for nutritional support
   • Venting gastrostomy for symptom relief

Special Considerations

Diabetic Gastroparesis

• Optimize glycemic control (hyperglycemia worsens gastric emptying)
• Consider insulin regimen adjustments to prevent hypoglycemia

Common Pitfalls to Avoid

1. Performing gastric emptying studies for less than 4 hours (reduces diagnostic accuracy)
2. Failing to exclude mechanical obstruction before diagnosing gastroparesis
3. Not stopping medications that affect gastric emptying before testing
4. Using opioids for pain management (worsens gastric emptying)
5. Overlooking conditions that mimic gastroparesis:
   • Cyclic vomiting syndrome
   • Rumination syndrome
   • Cannabinoid hyperemesis syndrome
   • Functional dyspepsia with normal gastric emptying

By following this systematic approach to diagnosis and treatment, patients with gastroparesis can achieve improved symptom control and quality of life.