Hyperemesis with Ketosis

Hyperemesis with ketosis is hyperemesis gravidarum in which prolonged vomiting and starvation produce ketones in the blood and urine, with a mild metabolic acidosis. It results from raised hCG and inadequate intake. It matters because ketosis worsens nausea, signals starvation and can progress to nutritional deficiency and Wernicke encephalopathy.

• Ketonuria of 2 plus or more is typical.
• Risk factors: previous hyperemesis, first pregnancy, multiple pregnancy, molar pregnancy.
• Responds to fluids and glucose with thiamine.

Women vomit repeatedly, are weak and drowsy, have weight loss above 5 percent, dry mucosa, tachycardia and ketotic breath.

• Smell of ketones.
• Low urine output.
• Differential diagnosis: diabetic ketoacidosis, gastroenteritis, urinary tract infection, hepatitis, thyrotoxicosis, pancreatitis, Addison disease.
• Complications: dehydration, acute kidney injury, Wernicke encephalopathy, metabolic acidosis, venous thrombosis, malnutrition.

The approach is to confirm ketosis and exclude diabetic ketoacidosis and other causes.

• Urine dipstick for ketones (2 plus or more), glucose and infection.
• Capillary glucose to exclude diabetic ketoacidosis; venous blood gas where available (bicarbonate below 18 mmol/L).
• Electrolytes, urea, creatinine, liver enzymes, TSH, free T4.
• Weight on admission; ultrasound for viability, multiple pregnancy or molar pregnancy.

The principle is rehydration, thiamine, glucose and antiemetics.

• Supportive: admit; intake and output chart; daily weight; small frequent meals when tolerated; treat vomiting early.
• Pharmacological: thiamine 100 mg IV daily for 3 days before dextrose; sodium chloride 0.9 percent 1 litre IV over 1 to 2 hours, then dextrose 5 percent in sodium chloride 0.9 percent 1 litre over 6 hours with potassium chloride 20 mmol per litre; metoclopramide 10 mg IV 8-hourly (maximum 5 days); promethazine 12.5 to 25 mg IV or IM 8-hourly (maximum 100 mg daily); ondansetron 4 mg IV 8-hourly if others fail; hydrocortisone 100 mg IV 12-hourly for refractory cases then prednisolone 40 mg oral daily tapered over 2 weeks; enoxaparin 40 mg subcutaneous daily for admission above 3 days.
• Procedures: none.
• Special groups: women with diabetes use insulin with careful glucose monitoring and treat diabetic ketoacidosis as an emergency.
• Red flags: confusion, ataxia, nystagmus, persistent vomiting for more than 48 hours, ketonuria persisting despite fluids, glucose above 11 mmol/L.
• Follow-up: repeat urine ketones daily; discharge when ketones clear and oral intake is adequate; review weekly; weigh at each visit.