From the Guidelines
To determine the underlying cause of nausea and vomiting, a combination of diagnostic tests such as blood tests, urine tests, imaging studies, upper endoscopy, and gastric emptying studies can be recommended. The choice of test depends on the patient's medical history, physical examination findings, and the pattern of their symptoms 1.
Diagnostic Approach
- Blood tests can check for infections, electrolyte imbalances, or liver problems
- Urine tests may detect pregnancy or urinary tract infections
- Imaging studies like abdominal X-rays, ultrasound, or CT scans can identify structural abnormalities
- For digestive issues, an upper endoscopy allows direct visualization of the esophagus, stomach, and small intestine
- Gastric emptying studies, such as gastric emptying scintigraphy of a radiolabeled solid meal, can assess how quickly food leaves the stomach, which is particularly useful in diagnosing gastroparesis 1
Considerations
- If nausea and vomiting persist, it's essential to reassess the cause and consider alternative diagnoses or treatments, including opioid rotation or the addition of antiemetic agents 1
- In cases of chemotherapy-induced nausea and vomiting, management should follow established guidelines, which may include the use of serotonin receptor antagonists, dopamine receptor antagonists, or other antiemetic agents 1
- For persistent nausea and vomiting, a multidisciplinary approach, including palliative care, may be necessary to improve the patient's quality of life 1
From the Research
Diagnostic Tests for Nausea and Vomiting
To determine the cause of nausea and vomiting, several tests can be performed, including:
- Urinalysis
- Urine pregnancy testing
- Complete blood count
- Comprehensive metabolic panel
- Amylase and lipase levels
- Thyroid-stimulating hormone level
- Stool studies with cultures 2
- Imaging studies such as abdominal radiography, ultrasonography, and computed tomography 2
- Computed tomography of the head if an acute intracranial process is suspected 2
- Esophagogastroduodenoscopy for patients with risk factors for gastric malignancies or alarm symptoms 2
- Gastric emptying study if gastroparesis is suspected 2
Laboratory Tests
Laboratory tests such as basic metabolic panel can help identify electrolyte abnormalities and kidney disorders that may be contributing to nausea and vomiting 3.
- Electrolytes such as potassium and chloride
- Blood urea nitrogen and creatinine to assess renal function and acid-base homeostasis 3
Approach to Diagnosis
A practical 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, severity of symptoms, and physical examination findings to formulate a differential diagnosis and to guide evaluation
- Directing treatment on the basis of knowledge of neurotransmitters and receptors involved in the emetic pathways 4