What is the appropriate workup for vomiting in adults?

From the Guidelines

The workup for vomiting in adults should begin with a thorough history and physical examination to identify potential causes, and treatment should include antiemetics, such as olanzapine, in addition to standard antiemetic regimens for patients who experience nausea or vomiting despite optimal prophylaxis 1. The initial evaluation should include assessment of hydration status, vital signs, and abdominal examination. Laboratory tests typically include complete blood count, comprehensive metabolic panel, amylase, lipase, and urinalysis. If the patient has severe or persistent symptoms, additional testing may include abdominal imaging (X-ray, ultrasound, or CT scan depending on suspected etiology) and possibly upper endoscopy. For patients with concerning neurological symptoms, head CT may be warranted to rule out increased intracranial pressure. Specific testing should be guided by clinical suspicion - for example, pregnancy testing in women of childbearing age, stool studies if infectious gastroenteritis is suspected, or thyroid function tests if metabolic causes are considered. Treatment should address the underlying cause while providing supportive care including antiemetics (such as ondansetron 4-8mg every 8 hours), IV fluids for dehydration, and correction of electrolyte abnormalities 1. This systematic approach helps identify serious conditions requiring urgent intervention while providing symptomatic relief during the diagnostic process. Key considerations in the management of vomiting in adults include:

• Identifying and treating the underlying cause
• Providing supportive care with antiemetics and IV fluids
• Monitoring for potential complications, such as dehydration and electrolyte imbalances
• Avoiding medications that may worsen symptoms or increase the risk of complications, such as antimotility agents in patients with infectious diarrhea 1.

From the FDA Drug Label

The provided drug labels do not directly address the workup for vomiting in adults.

The FDA drug label does not answer the question.

From the Research

Evaluation of Nausea and Vomiting in Adults

• Nausea and vomiting are common symptoms that can reduce quality of life and indicate life-threatening illness 2
• Acute nausea and vomiting last up to 7 days, while chronic nausea and vomiting last 4 weeks or longer 2
• Typical causes of acute nausea and vomiting include gastroenteritis, foodborne illness, acute migraine headaches, vestibular disturbances, early pregnancy, and adverse effects of medication 2

Diagnostic Approach

• A careful history of related factors is essential to guide the initial evaluation and narrow the differential diagnosis 2
• Factors to consider include associated symptoms, timing of onset and duration of symptoms, exacerbating or relieving factors, alarm symptoms, medication and substance use, relationship with recent food ingestion, and comorbidities 2
• A 5-step approach to the clinical evaluation and treatment of nausea and vomiting includes defining what the patient means by nausea and vomiting, determining whether symptoms are acute or chronic, considering medication or toxin adverse effects, using the patient's presentation to formulate a differential diagnosis, and directing treatment based on knowledge of neurotransmitters and receptors involved in the emetic pathways 3

Treatment Options

• Nonpharmacologic management options include fluid and electrolyte replacement, small, frequent meals, and avoidance of trigger foods 2
• Antiemetic drugs, such as ondansetron and metoclopramide, can effectively reduce symptoms of acute nausea and vomiting 2, 4, 5
• Chronic symptoms are often more challenging to treat, and treatment should be based on a thoughtful discussion of benefits, side effects, and costs 6
• A validated treatment algorithm for chronic nausea and vomiting does not exist, and treatment should be individualized based on the underlying cause of symptoms 6

Comparison of Antiemetic Drugs

• Ondansetron and metoclopramide have been compared in several studies, with ondansetron showing greater efficacy in some cases 4, 5
• A study comparing ondansetron with metoclopramide in the prophylaxis of chemotherapy-induced nausea and vomiting found ondansetron to be more effective 5
• However, another study found similar reductions in nausea severity for ondansetron, metoclopramide, and placebo in adult emergency department patients with undifferentiated nausea and vomiting 4