Nausea is the sensation of impending emesis and is frequently accompanied by autonomic changes, such as increased heart rate and salivation. Nausea and vomiting typically occur in sequence; however, they can occur separately (eg, vomiting can occur without preceding nausea as a result of increased intracranial pressure).
Vomiting is uncomfortable and can cause dehydration because fluid is lost and because the ability to rehydrate by drinking is limited.
Pathophysiology
Etiology
The causes of vomiting vary with age and range from relatively benign to potentially life threatening ( see Table: Some Causes of Vomiting in Infants, Children, and Adolescents). Vomiting is a protective mechanism that provides a means to expel potential toxins; however, it can also indicate serious disease (eg, intestinal obstruction). Bilious vomiting indicates a high intestinal obstruction and, especially in an infant, requires immediate evaluation.
Infants
Infants normally spit up small amounts (usually < 5 to 10 mL) during or soon after feedings, often when being burped. Rapid feeding, air swallowing, and overfeeding may be causes, although spitting up occurs even without these factors. Occasional vomiting may also be normal, but repeated vomiting is abnormal.
The most common causes of vomiting in infants and neonates include the following:
Acute viral gastroenteritis
Gastroesophageal reflux disease
Other important causes in infants and neonates include the following:
Intestinal obstruction (eg, meconium ileus, volvulus, intestinal atresia, stenosis)
Intussusception (typically in infants aged 3 to 36 months)
Less common causes of recurrent vomiting include sepsis and food intolerance. Metabolic disorders (eg, , organic acidemias) are uncommon but can manifest with vomiting.
Older children
The most common cause is
Acute viral gastroenteritis
Nongastrointestinal infections may cause a few episodes of vomiting. Other causes to consider include serious infection (eg, meningitis, pyelonephritis), acute abdomen (eg, appendicitis), increased intracranial pressure secondary to a space-occupying lesion (eg, caused by trauma or tumor), and cyclic vomiting.
In adolescents, causes of vomiting also include pregnancy, eating disorders, and toxic ingestions (eg, , ironcannabinoid hyperemesis syndrome).
Evaluation
Evaluation includes assessment of severity (eg, presence of dehydration, surgical or other life-threatening disorder) and diagnosis of cause.
History
History of present illness should determine when vomiting episodes started, frequency, and character of episodes (particularly whether vomiting is projectile, bilious, or small in amount and more consistent with spitting up). Any pattern to the vomiting (eg, after feeding, only with certain foods, primarily in the morning or in recurrent cyclic episodes) should be established. Important associated symptoms include diarrhea (with or without blood), fever, anorexia, and abdominal pain, distention, or both. Stool frequency and consistency and urinary output should be noted. A history of possible ingestions or drug use (particularly including use of cannabinoids) should be elicited.
Review of systems should seek symptoms of causative disorders, including weakness, poor suck, and failure to thrive (metabolic disorders); delay in passage of meconium, abdominal distention, and lethargy (intestinal obstruction); headache, nuchal rigidity, and vision changes (intracranial disorders); food bingeing or signs of distorted body image (eating disorders); missed periods and breast swelling (pregnancy); rashes (eczema or urticaria in food allergies, petechiae in sepsis or meningitis); ear pain or sore throat (focal nongastrointestinal infection); and fever with headache, neck or back pain, or abdominal pain (meningitis, pyelonephritis, or appendicitis).
Past medical history should note history of travel (possible infectious gastroenteritis), any recent head trauma, and unprotected sex (pregnancy).
Physical examination
Vital signs are reviewed for indicators of infection (eg, fever) and volume depletion (eg, tachycardia, hypotension).
During the general examination, signs of distress (eg, lethargy, irritability, inconsolable crying) and signs of weight loss (cachexia) or gain are noted.
Because the abdominal examination may cause discomfort, the physical examination should begin with the head. The head and neck examination should focus on signs of infection (eg, red, bulging tympanic membrane; bulging anterior fontanelle; erythematous tonsils) and dehydration (eg, dry mucous membranes, lack of tears). The neck should be passively flexed to detect resistance or discomfort, suggesting meningeal irritation.
Cardiac examination should note presence of tachycardia (eg, dehydration, fever, distress). Abdominal examination should note distention; presence and quality of bowel sounds (eg, high-pitched, normal, absent); tenderness and any associated guarding, rigidity, or rebound (peritoneal signs); and presence of organomegaly or mass.
The skin and extremities are examined for petechiae or purpura (severe infection) or other rashes (possible viral infection or signs of atopy), jaundice (possible metabolic disorder), and signs of dehydration (eg, poor skin turgor, delayed capillary refill).
Growth parameters and signs of developmental progress should be noted.
Red flags
The following findings are of particular concern:
Bilious emesis
Lethargy or listlessness
Inconsolability and bulging fontanelle in infant
Nuchal rigidity, photophobia, and fever in older child
Peritoneal signs or abdominal distention (surgical abdomen)
Persistent vomiting with poor growth or development
Interpretation of findings
Initial findings help determine severity of diagnosis and need for immediate intervention.
Any neonate or infant with recurrent or bilious (yellow or green) emesis or projectile vomiting most likely has a gastrointestinal obstruction and probably requires surgical intervention.
An infant or young child with colicky abdominal pain, signs of intermittent pain or listlessness, and absent or bloody stools needs to be evaluated for an intussusception.
A child or adolescent with fever, nuchal rigidity, and photophobia should be evaluated for meningitis.
A child or adolescent with fever and abdominal pain followed by vomiting, anorexia, and decreased bowel sounds should be evaluated for appendicitis.
Recent history of head trauma or chronic progressive headaches with morning vomiting and vision changes indicate intracranial hypertension.
Other findings can be interpreted primarily depending on age ( see Table: Some Causes of Vomiting in Infants, Children, and Adolescents).
In infants, irritability, choking, and respiratory signs (eg, stridor) may be manifestations of gastroesophageal reflux. A history of poor development or neurologic manifestations suggests a central nervous system or metabolic disorder. Delayed passage of meconium, later onset of vomiting, or both may indicate Hirschsprung disease or intestinal stenosis.
In children and adolescents, fever suggests infection; the combination of vomiting and diarrhea suggests acute gastroenteritis. Lesions on fingers and erosion of tooth enamel or an adolescent unconcerned about weight loss or with distorted body image suggests an eating disorder. Morning nausea and vomiting, amenorrhea, and possibly weight gain suggest pregnancy. Vomiting that has occurred in the past and is episodic, short-lived, and has no other accompanying symptoms suggests cyclic vomiting.
Testing
Testing should be directed by suspected causative disorders ( see Table: Some Causes of Vomiting in Infants, Children, and Adolescents). Imaging studies are typically done to evaluate abdominal or central nervous system pathology. Various specific blood tests or cultures are done to diagnose inherited metabolic disorders or serious infection.
If dehydration is suspected, or vomiting has been prolonged, serum electrolytes should be measured (See also Pathophysiology of Dehydration in Children.)
Treatment
Treatment of nausea and vomiting is targeted at the causative disorder. Rehydration is important.
Drugs frequently used in adults to decrease nausea and vomiting are used less often in children because the usefulness of treatment has not been proved and because these drugs have potential risks of adverse effects and of masking an underlying condition. However, if nausea or vomiting is severe or unremitting, antiemetic drugs can be used cautiously in children > 2 years. Useful drugs include
promethazine can cause extrapyramidal adverse effects, including torticollis.
ondansetron is safe and effective in children who have acute gastroenteritis and are unable to tolerate oral rehydration therapy (ORT). By facilitating ORT, this drug may prevent the need for IV fluids or, in children given IV fluids, may help prevent hospitalization. Typically, only a single dose is used because repeated doses can cause persistent diarrhea. Other common adverse effects include headache, dizziness, drowsiness, blurred vision, constipation, muscle stiffness, tachycardia, and hallucinations.
Key Points
In general, the most common cause of vomiting is acute viral gastroenteritis.
Associated diarrhea suggests an infectious gastrointestinal cause.
Bilious emesis, bloody stools, or lack of bowel movements suggests an obstructive cause.
Persistent vomiting (especially in an infant) requires immediate evaluation.
