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.
Vomiting is the final part of a sequence of events coordinated by the emetic center located in the medulla. The emetic center can be activated by afferent neural pathways from digestive (eg, pharynx, stomach, small bowel) and nondigestive (eg, heart, testes) organs, the chemoreceptor trigger zone located in the area postrema on the floor of the 4th ventricle (containing dopamine and serotonin receptors), and other central nervous system centers (eg, brain stem, vestibular system).
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 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 Intestinal Obstruction Intestinal obstruction is significant mechanical impairment or complete arrest of the passage of contents through the intestine due to pathology that causes blockage of the bowel. Symptoms include... read more ). Bilious vomiting indicates a high intestinal obstruction and, especially in an infant, requires immediate evaluation.
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:
Other important causes in infants and neonates include the following:
Intestinal obstruction (eg, meconium ileus Meconium Ileus Meconium ileus is obstruction of the terminal ileum by abnormally tenacious meconium; it most often occurs in neonates with cystic fibrosis. Meconium ileus accounts for up to 33% of neonatal... read more , volvulus, intestinal atresia, stenosis)
Less common causes of recurrent vomiting include sepsis Neonatal Sepsis Neonatal sepsis is invasive infection, usually bacterial, occurring during the neonatal period. Signs are multiple, nonspecific, and include diminished spontaneous activity, less vigorous sucking... read more and food intolerance. Metabolic disorders Introduction to Inherited Disorders of Metabolism Most inherited disorders of metabolism (also called inborn errors of metabolism) are caused by mutations in genes that code for enzymes; enzyme deficiency or inactivity leads to Accumulation... read more (eg, urea cycle disorders Urea Cycle Disorders Urea cycle disorders are characterized by hyperammonemia under catabolic or protein-loading conditions. There are many types of urea cycle and related disorders (see the table) as well as many... read more , organic acidemias) are uncommon but can manifest with vomiting.
The most common cause is
Nongastrointestinal infections may cause a few episodes of vomiting. Other causes to consider include serious infection (eg, meningitis Overview of Meningitis Meningitis is inflammation of the meninges and subarachnoid space. It may result from infections, other disorders, or reactions to drugs. Severity and acuity vary. Findings typically include... read more , pyelonephritis), acute abdomen (eg, appendicitis Appendicitis Appendicitis is acute inflammation of the vermiform appendix, typically resulting in abdominal pain, anorexia, and abdominal tenderness. Diagnosis is clinical, often supplemented by CT or ultrasonography... read more ), increased intracranial pressure secondary to a space-occupying lesion (eg, caused by trauma or tumor), and cyclic vomiting Etiology Nausea, the unpleasant feeling of needing to vomit, represents awareness of afferent stimuli (including increased parasympathetic tone) to the medullary vomiting center. Vomiting is the forceful... read more .
In adolescents, causes of vomiting also include pregnancy Contraception and Adolescent Pregnancy Many adolescents engage in sexual activity but may not be fully informed about contraception, pregnancy, and sexually transmitted infections, including hepatitis C and HIV infection. Impulsivity... read more , eating disorders Introduction to Eating Disorders Eating disorders involve a persistent disturbance of eating or of behavior related to eating that Alters consumption or absorption of food Significantly impairs physical health and/or psychosocial... read more , and toxic ingestions (eg, acetaminophen Acetaminophen Poisoning Acetaminophen poisoning can cause gastroenteritis within hours and hepatotoxicity 1 to 3 days after ingestion. Severity of hepatotoxicity after a single acute overdose is predicted by serum... read more , iron Iron Poisoning Iron poisoning is a leading cause of poisoning deaths in children. Symptoms begin with acute gastroenteritis, followed by a quiescent period, then shock and liver failure. Diagnosis is by measuring... read more , ethanol).
Evaluation includes assessment of severity (eg, presence of dehydration, surgical or other life-threatening disorder) and diagnosis of cause.
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.
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).
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.
The following findings are of particular concern:
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 Intestinal Obstruction Intestinal obstruction is significant mechanical impairment or complete arrest of the passage of contents through the intestine due to pathology that causes blockage of the bowel. Symptoms include... read more 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 Intussusception Intussusception is telescoping of one portion of the intestine (intussusceptum) into an adjacent segment (intussuscipiens), causing intestinal obstruction and sometimes intestinal ischemia.... read more .
A child or adolescent with fever, nuchal rigidity, and photophobia should be evaluated for meningitis Overview of Meningitis Meningitis is inflammation of the meninges and subarachnoid space. It may result from infections, other disorders, or reactions to drugs. Severity and acuity vary. Findings typically include... read more .
A child or adolescent with fever and abdominal pain followed by vomiting, anorexia, and decreased bowel sounds should be evaluated for appendicitis Appendicitis Appendicitis is acute inflammation of the vermiform appendix, typically resulting in abdominal pain, anorexia, and abdominal tenderness. Diagnosis is clinical, often supplemented by CT or ultrasonography... read more .
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 Some Causes of Vomiting in Infants, Children, and Adolescents ).
In infants, irritability, choking, and respiratory signs (eg, stridor) may be manifestations of gastroesophageal reflux Gastroesophageal Reflux in Infants Gastroesophageal reflux is the movement of gastric contents into the esophagus. Gastroesophageal reflux disease (GERD) is reflux that causes complications such as irritability, respiratory problems... read more . 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 Hirschsprung Disease Hirschsprung disease is a congenital anomaly of innervation of the lower intestine, usually limited to the colon, resulting in partial or total functional obstruction. Symptoms are obstipation... read more or intestinal stenosis.
In children and adolescents, fever suggests infection; the combination of vomiting and diarrhea suggests acute gastroenteritis Overview of Gastroenteritis Gastroenteritis is inflammation of the lining of the stomach and small and large intestines. Most cases are infectious, although gastroenteritis may occur after ingestion of drugs and chemical... read more . Lesions on fingers and erosion of tooth enamel or an adolescent unconcerned about weight loss or with distorted body image suggests an eating disorder Introduction to Eating Disorders Eating disorders involve a persistent disturbance of eating or of behavior related to eating that Alters consumption or absorption of food Significantly impairs physical health and/or psychosocial... read more . Morning nausea and vomiting, amenorrhea, and possibly weight gain suggest pregnancy Contraception and Adolescent Pregnancy Many adolescents engage in sexual activity but may not be fully informed about contraception, pregnancy, and sexually transmitted infections, including hepatitis C and HIV infection. Impulsivity... read more . Vomiting that has occurred in the past and is episodic, short-lived, and has no other accompanying symptoms suggests cyclic vomiting Etiology Nausea, the unpleasant feeling of needing to vomit, represents awareness of afferent stimuli (including increased parasympathetic tone) to the medullary vomiting center. Vomiting is the forceful... read more .
Testing should be directed by suspected causative disorders ( see Table: Some Causes of Vomiting in Infants, Children, and Adolescents 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, serum electrolytes should be measured.
Treatment of nausea and vomiting is targeted at the causative disorder. Rehydration Treatment Dehydration is significant depletion of body water and, to varying degrees, electrolytes. Symptoms and signs include thirst, lethargy, dry mucosa, decreased urine output, and, as the degree... read more 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: For children > 2 years, 0.25 to 1 mg/kg (maximum 25 mg) orally, IM, IV, or rectally every 4 to 6 hours
Prochlorperazine: For children > 2 years and weighing 9 to 13 kg, 2.5 mg orally every 12 to 24 hours; for those 13 to 18 kg, 2.5 mg orally every 8 to 12 hours; for those 18 to 39 kg, 2.5 mg orally every 8 hours; for those > 39 kg, 5 to 10 mg orally every 6 to 8 hours
Metoclopramide: 0.1 mg/kg orally or IV every 6 hours (maximum 10 mg/dose)
Ondansetron: 0.15 mg/kg (maximum 8 mg) IV every 8 hours or, if the oral form is used, for children 2 to 4 years, 2 mg every 8 hours; for those 4 to 11 years, 4 mg every 8 hours; for those ≥ 12 years, 8 mg every 8 hours
Promethazine is an H1 receptor blocker (antihistamine) that inhibits the emetic center response to peripheral stimulants. The most common adverse effects are respiratory depression, sedation, dizziness, anxiety, blurred vision, dry mouth, impotence, and constipation; the drug is contraindicated in children < 2 years. Therapeutic doses of promethazine can cause extrapyramidal adverse effects, including torticollis.
Prochlorperazine is a weak dopamine receptor blocker that depresses the chemoreceptor trigger zone. Drowsiness, dizziness, anxiety, strange dreams, insomnia, galactorrhea, akathisia, and dystonia are the most common adverse effects.
Metoclopramide is a dopamine receptor antagonist that acts both centrally and peripherally by increasing gastric motility and decreasing afferent impulses to the chemoreceptor trigger zone. Drowsiness, dizziness, agitation, headache, diarrhea, akathisia, and dystonia are the most common adverse effects.
Ondansetron is a selective serotonin (5-HT3) receptor blocker that inhibits the initiation of the vomiting reflex in the periphery. A single dose of ondansetron is safe and effective in children who have acute gastroenteritis and do not respond to oral rehydration therapy Oral Rehydration Oral fluid therapy is effective, safe, convenient, and inexpensive compared with IV therapy. Oral fluid therapy is recommended by the American Academy of Pediatrics and the World Health Organization... read more (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.
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.