What are the management options for hyperemesis?

Management of Hyperemesis

The management of hyperemesis should follow a stepwise approach beginning with fluid resuscitation, electrolyte replacement, and thiamine supplementation, followed by antiemetic therapy with medications such as ondansetron, metoclopramide, or promethazine, with corticosteroids reserved for refractory cases. 1

Definition and Assessment

• Hyperemesis gravidarum is characterized by persistent vomiting, weight loss ≥5% of pre-pregnancy weight, dehydration, and ketonuria, affecting 0.3-2% of pregnancies 1
• Assessment should include evaluation for weight loss, signs of dehydration, and laboratory tests including electrolytes, liver function tests, and urinalysis for ketonuria 1
• Severity can be assessed using the Pregnancy-Unique Quantification of Emesis (PUQE) score 1
• Differential diagnosis should rule out other causes of nausea and vomiting such as urinary tract infection, thyrotoxicosis, and gastrointestinal disorders 2

First-Line Management

• Immediate intravenous fluid resuscitation to correct dehydration, which often improves associated symptoms and laboratory abnormalities 1
• Thiamine supplementation (vitamin B1) to prevent Wernicke's encephalopathy, a serious neurological complication 1
• Electrolyte replacement with particular attention to potassium and magnesium levels 1
• First-line antiemetics include:
  • Vitamin B6 (pyridoxine) combined with doxylamine 1, 3
  • Metoclopramide (category A) 2
  • Promethazine (category C) 2

Non-Pharmacological Interventions

• Dietary modifications including small, frequent, bland meals, high-protein, low-fat meals, and avoidance of specific food triggers 1
• Ginger has shown benefit in some studies 2
• Evidence is mixed regarding acupressure and acupuncture 2

Second-Line Pharmacological Management

• Ondansetron (5-HT3 antagonist) is commonly used and has a favorable pregnancy safety profile 1, 3
  • Monitor for QT interval prolongation, especially in patients with electrolyte abnormalities 1
• Prochlorperazine (category C) can be used when first-line agents fail 2
• For breakthrough emesis, the general principle is to give an additional agent from a different drug class 4
  • Consider around-the-clock administration rather than PRN dosing 4
  • The oral route may not be feasible; rectal or IV therapy is often required 4

Refractory Cases

• Corticosteroids (prednisolone, category A) may be effective in refractory cases 2
• Alternative pharmacotherapeutics to consider include:
  • Mirtazapine, which has antidepressant, anxiolytic, antiemetic, and appetite-stimulating effects 5, 6
  • Olanzapine has shown value for preventing delayed and refractory emesis and nausea 4, 6
    • Use with caution in elderly patients due to risks of dementia-related psychosis, type II diabetes, and hyperglycemia 4
  • Gabapentin may be considered in refractory cases 6
• Enteral or parenteral nutrition support may be necessary in severe cases with prolonged inability to maintain oral intake and ongoing weight loss 1, 6

Monitoring and Follow-up

• Regular assessment of hydration status and electrolyte balance 1
• Ongoing evaluation of symptom control using PUQE score 1
• Fetal growth monitoring, especially if there is insufficient gestational weight gain 1
• Before administering the next cycle of chemotherapy (in oncology patients with hyperemesis), reassess both the day 1 and postchemotherapy antiemetic regimen that failed during the present cycle 4

Special Considerations

• In pregnancy, hyperemesis typically resolves by week 16-20 in most cases, though 10% may experience symptoms throughout pregnancy 1
• High recurrence risk (40-92%) in subsequent pregnancies should be discussed with patients 1
• For patients with adjustable gastric bands, deflation may be necessary to prevent band slippage and nutrient deficiencies 1
• In twin pregnancies, more intensive monitoring may be required 7

Complications to Monitor

• Electrolyte imbalances, particularly hypokalemia 1
• Liver function abnormalities (approximately 50% of patients will have abnormal AST and ALT) 1
• Nutritional deficiencies, especially thiamine 1
• Decreased quality of life and secondary depression 2