How to manage intractable vomiting in a patient with sickle cell anemia?

Management of Intractable Vomiting in Sickle Cell Anemia

Intractable vomiting in sickle cell anemia patients should be managed with a stepwise approach using dopamine receptor antagonists as first-line therapy, followed by 5-HT3 antagonists and corticosteroids if needed, while ensuring adequate hydration and investigating underlying causes. 1

Initial Assessment and Management

• Rule out common causes of vomiting in sickle cell patients, including:

  • Medication-induced nausea (check blood levels of medications like digoxin, phenytoin, carbamazepine) 1
  • Severe constipation or fecal impaction 1
  • Gastroparesis 1
  • Central nervous system involvement 1
  • Gastric outlet obstruction from intra-abdominal pathology 1

• Ensure aggressive hydration, as sickle cell patients dehydrate easily due to impaired urinary concentrating ability 2

  • Oral hydration is preferred when possible
  • If oral intake is inadequate, use intravenous fluids (preferably 5% dextrose or 5% dextrose in 25% normal saline rather than normal saline due to hyposthenuria in sickle cell patients) 3
  • Maintain meticulous fluid balance monitoring to prevent overhydration 2

Pharmacologic Management

First-Line Therapy

• Initiate treatment with dopamine receptor antagonists 1:
  • Haloperidol
  • Metoclopramide (5-10 mg PO QID 30 minutes before meals and at bedtime)
  • Prochlorperazine
  • Olanzapine

Second-Line Therapy (If vomiting persists)

• Add a 5-HT3 antagonist (e.g., ondansetron) 1
• Consider adding:
  • Anticholinergic agent (e.g., scopolamine) 1
  • Antihistamine (e.g., meclizine) 1
  • If anxiety contributes to nausea/vomiting, add lorazepam 0.5-1 mg q 4 hr prn 1

Third-Line Therapy (If vomiting still persists)

• Add a corticosteroid (e.g., dexamethasone) 1
• Consider olanzapine if not already tried 1

Refractory Cases

• Consider continuous intravenous or subcutaneous infusions of antiemetics 1
• If patient is on opioids, consider opioid rotation as opioids can contribute to nausea 1

Special Considerations for Sickle Cell Patients

• Monitor oxygen saturation and administer oxygen to keep SpO2 above baseline or 96% (whichever is higher) 2
• Maintain normothermia as hypothermia can lead to shivering and peripheral stasis, which increases sickling 2, 4
• Consider blood transfusion if there is evidence of acute hemolysis, aplastic crisis, or sequestration crisis 5
  • Transfused blood should be Hb S negative, Rh and Kell antigen matched 5
• Evaluate for infection, which can precipitate sickle cell crisis and associated symptoms 6
  • Obtain blood cultures if fever is present 7
  • Initiate antibiotics if temperature reaches ≥38.0°C or if there are signs of sepsis 7

Monitoring and Follow-up

• Regular pain assessment using validated pain scales 2
• Continuous oxygen monitoring until saturation is maintained at baseline in room air 2
• Consider early mobilization when appropriate to prevent complications like deep vein thrombosis 4
• Low threshold for admission to high dependency or intensive care units for patients with severe symptoms or complications 2

Non-Pharmacologic Approaches

• Consider non-pharmacologic therapies such as acupuncture, hypnosis, and cognitive behavioral therapy 1
• Ensure regular assessment by hematology specialists 2

Common Pitfalls to Avoid

• Failing to recognize that vomiting may be part of a broader sickle cell crisis requiring comprehensive management 8
• Using normal saline for hydration, which may worsen hyposthenuria in sickle cell patients 3
• Overlooking the possibility of acute chest syndrome, which can be precipitated by infection and may present with gastrointestinal symptoms 7
• Neglecting thromboprophylaxis in immobilized patients, as sickle cell patients have an increased risk of thrombosis 4