July 12, 2007 — In a review article in the July 1 issue of American Family Physician, Keith Scorza, MD, and colleagues from the Dewitt Army Community Hospital in Fort Belvoir, Virginia, describe an approach to evaluating common causes of nausea and vomiting and briefly review treatment options.

According to the authors, the significant causes of nausea and vomiting include iatrogenic causes, toxicity, infectious causes, gastrointestinal disorders, and central nervous system or psychiatric conditions.

Among iatrogenic causes, chemotherapeutic agents are the most well known. Infectious and toxic causes are usually self-limiting and include viral gastroenteritis as well as bacteria and their toxins. Gastrointestinal disorders are often caused by an inflammatory process, such as appendicitis, cholecystitis, or pancreatitis, or may be caused by obstruction or motility problems. Central nervous system or psychiatric causes include increases in intracranial pressure, migraine, and emotional or physical stressors.

"Pregnancy is the most common endocrinologic cause of nausea and vomiting and must be considered in any woman of childbearing age," the authors point out.

The authors review the 3-step process for evaluating nausea and vomiting recommended by the American Gastroenterological Association. The 3 recommended steps are as follows:

• Recognize and correct symptoms, such as dehydration or electrolyte abnormalities.
  
  
• Try to identify the underlying cause and provide specific therapy.
  
  
• Use empiric therapy if no cause can be identified.

"Diagnostic tests should be ordered only when based on clinical suspicion," the authors suggest. "Most of the time, a history and physical examination can identify the cause. If all organic, gastrointestinal, and central causes of nausea and vomiting have been explored, psychogenic vomiting should be considered," they add. A detailed algorithm for the evaluation of nausea and vomiting adapted from an American Gastroenterological Association medical position statement on nausea and vomiting is provided in the article.

With respect to treatment, the primary goal is "a careful assessment of fluid and electrolyte status with appropriate replacement," Dr. Scorza and colleagues suggest. A low-fat or liquid diet may be prescribed. Targeted therapy should be given when a specific cause is identified, but empiric therapy should be administered in the event that the cause remains unknown. "It is reasonable to begin with a trial of a phenothiazine, such as prochlorperazine."

Therapies for known etiologies of nausea and vomiting include the following:

• ondansetron/dexamethasone for acute chemotherapy-induced nausea and vomiting and metoclopramide/dexamethasone for delayed chemotherapy-induced nausea and vomiting;
  
  
• tricyclic antidepressants for adults with cyclic vomiting syndrome;
  
  
• supportive treatment and possible gastric pacing for gastroparesis; and
  
  
• droperidol/dexamethasone or ondansetron for postoperative nausea and vomiting.

During pregnancy, prochlorperazine, chlorpromazine, metoclopramide, and methylprednisolone are recommended for hyperemesis gravidarum; meclizine, promethazine, electrolyte replacement, and thiamine supplementation are recommended for morning sickness.

Am Fam Physician. 2007;76:76-84.

Clinical Context

Study Highlights

• The American Gastroenterological Association suggests a 3-step approach to the initial evaluation of nausea and vomiting.
• The first step is to recognize and correct any consequences of the symptoms, such as dehydration and electrolyte abnormalities.
• The second step is to try to identify the underlying cause and provide specific therapies:
  • The cause of most acute nausea and vomiting can be determined from the history and physical examination; diagnostic tests should be ordered based on clinical suspicion.
  • Symptom duration should be determined because the differential diagnoses for acute symptoms and chronic symptoms differ.
  • The physical examination should focus on signs of dehydration, evaluation of skin turgor and mucous membranes, and observation for hypotension or orthostatic changes. Abdominal and neurologic examinations should also be performed.
  • The presence of abdominal pain usually suggests an organic cause; the location, severity, and timing of pain may indicate a specific etiology.
  • Warning signs such as chest pain, severe abdominal pain, central nervous system symptoms, and fever; a history of immunosuppression, hypotension, or severe dehydration; or older age should prompt immediate evaluation.
  • There are no diagnostic tests specific to determining the etiologies of nausea and vomiting; tests should be directed based on history and physical examination.
  • A pregnancy test should be performed in any woman of childbearing age and is needed before radiography.
  • Proximal mucosal lesions and obstructions may be detected by esophagogastroduodenoscopy or upper gastrointestinal radiography; computed tomography may soon be the method of choice for detecting intestinal obstructions.
  • If no diagnosis is determined after initial evaluation, gastric motility studies (eg, gastric emptying scintigraphy, cutaneous electrogastrography, and antroduodenal manometry) may be considered.
• The third step, if no etiology can be determined, is to use empiric therapy and treat symptoms.
  • Medications that may be beneficial include phenothiazines (eg, prochlorperazine), prokinetic agents (eg, metoclopramide), and serotonin antagonists (eg, ondansetron).
  • Trials determining the specific effectiveness of medication for nausea and vomiting are limited; therefore, a trial of any medication may be reasonable on an individual basis.

Pearls for Practice

• Nausea and vomiting are usually caused by the following: iatrogenic, toxic, and infectious causes; gastrointestinal disorders; and central nervous system or psychiatric conditions.
• The American Gastroenterological Association suggests a 3-step approach to the initial evaluation of nausea and vomiting: recognizing and correcting any consequences of the symptoms, trying to identify the underlying cause and providing specific therapies, and using empiric therapy and treating symptoms.

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