Laboratory Tests and Ancillaries
Nausea & Vomiting_Diagnosis 1Diagnostic tests are done to aid in determining the underlying cause of nausea and vomiting and to assess the effects of nausea and vomiting on a patient. Basic tests include a complete blood count (CBC), erythrocyte sedimentation rate (ESR), urinalysis, serum electrolytes, and standard blood chemistry. Other tests to be done would depend on the diseases being considered: Serum drug levels for possible drug toxicities; pregnancy test; thyroid-stimulating hormone (TSH) levels for possible thyrotoxicosis or Addison’s disease; and fecal occult blood.
Imaging
Imaging tests are usually focused on the abdominal area and are done depending on the etiologies of nausea and vomiting being considered, eg mechanical gut obstruction, perforated viscus, or pancreatobiliary disease. These are abdominal X-rays, barium studies, small bowel enemas, small bowel follow-through exams, endoscopic investigations, computed tomography (CT) scans of the abdomen, and ultrasound examinations.
Tests of Gastric Motor Function
Gastric Emptying Time
Gastric emptying time is relatively accurate, easy, and non-invasive. This may reveal the presence of gastroparesis.
Electrogastrography (EGG)
Nausea & Vomiting_Diagnosis 2
A decrease in or the absence of the expected postprandial increase in the electrogastrography amplitude has been shown to correlate with prolonged gastric emptying time and antral hypomotility.
Antroduodenal Manometry
Antroduodenal manometry may be useful in identifying patients with primary or diffuse motor abnormalities. A normal study may be useful in ruling out dysmotility and pointing the clinical investigation into another direction.