Approach to Vomiting

Background

Vomiting is an organized, autonomic response that ultimately results in the forceful expulsion of gastric contents through the mouth.

Vomiting in children is most commonly acute infectious gastroenteritis; however, vomiting is a nonspecific symptom and may be initial presentation of serious medical conditions including infections (meningitis, septicemia, urinary tract infection); anatomical abnormalities (malrotation, obstruction, volvulus) and metabolic disease. Persistent and severe vomiting, if untreated, may result in clinically significant volume depletion and electrolyte disturbances.

Basic anatomy / physiology

Why / How does this occur in children?

Vomiting is a coordinated autonomic response involving neural, hormonal, and muscular responses generated by the reticular formation of the medulla that consists of several scattered groups of neurons. The vomiting response may be triggered by peripheral and central stimuli (see figure 1). In particular, the area postrema in the medulla (unprotected by the blood brain barrier) samples peripheral blood and cerebrospinal fluid and likely causes vomiting associated with metabolic disorders and hormones.

Once the vomiting response is triggered, a pattern of somatic muscle action occurs with abdominal, thoracic, and diaphragm muscles contracting against a closed glottis. The resulting increased intra-abdominal pressure reverses the negative pressure of the esophagus and forces gastric contents upwards. The vomiting response also alters intestinal motility by generating a retroperistaltic contractile complex that moves intestinal contents towards the esophagus.

Classification

Spitting up: small volumes (usually < 5-10 mL) of vomit during or shortly after feeding, often when being burped; typically caused by rapid/overfeeding and air swallowing
Infant regurgitation: vomiting occurring ≥ 2 times per day for at least 3 weeks in the first 1-12 months of life in an otherwise healthy infant; often transient in nature and due to immature gastrointestinal tract

Central

Vestibular – motion-sickness and vertigo
Infectious – gastroenteritis, septicemia, non-GI infections
Cortical – pain, strong emotions, smell, taste
Drugs – chemotherapy, opiates
Hormonal – pregnancy
Metabolic – acidosis, uremia, hyperthyroidism, hypercalcemia, adrenal disorders

Peripheral

Pharyngeal stimulation
Gastric mucosal irritation
Gastric and intestinal distension

History

History of Presenting Illness

Characteristics of vomitus
- Smell
- Quantity
- Colour
- Blood – bright red/dark red/coffee-ground
- Bilious
Timing
- Onset
- Duration
- Frequency
- Time of day
- Triggers
Associated Symptoms
- Diarrhea
- Fever
- Abdominal pain/distension
- Anorexia
- Stool frequency
- Urinary Output
- Headache
- Vertigo
- Lethargy
- Stiff neck
- Cough
- Sore throat

Past medical history

Chronic illnesses (diabetes)
Travel history (infectious gastroenteritis)
Sexual history (pregnancy)
- Ineffective use of birth control
- Last menstrual period
Recent head trauma
Toxin exposure

Medications

Allergies

Differential Diagnosis: Common causes of vomiting by age group

Age

Acute

Chronic

Infant

1 month to 1 year

Gastroenteritis

Pyloric stenosis

Hirschsprung’s disease

Acutely evolving surgical abdomen

Congenital atresias and stenosis
Malrotation
Intussusception

Sepsis and non-GI infection

Metabolic disorders

Gastroesophageal reflux disease

Food intolerance

Congenital atresias and stenosis

Malrotation

Intussusception

Children and adolescents

Gastroenteritis

Appendicitis

Sepsis and non-GI infection

Metabolic disorders

Pregnancy

Toxic ingestion

Gastroesophageal reflux disease

Gastritis

Food intolerance

Cyclic vomiting

Intracranial hypertension

Inborn errors of metabolism

Eating disorders

Physical Exam Findings

Vitals

Fever – sign of infection
Hypotension, tachycardia – volume loss

Inspection

Consciousness – intracranial hypertension, meningitis, metabolic disorders, toxic ingestion
Weight loss – eating disorders, obstruction

Head and Neck

Red, bulging tympanic membrane – ear infection
Bulging anterior fontanelle and nuchal rigidity – meningitis
Erythematous tonsils – upper respiratory tract infection

Cardiovascular system

Tachycardia – infection, dehydration

Abdominal exam

Abdominal distention – obstruction, mass, congenital abnormality, organomegaly
Bowel sounds – high pitched tinkle (obstruction), absent (ileus)
Guarding, rigidity, rebound tenderness – appendicitis, peritoneal inflammation

Skin and extremities

Petechiae or purpura – serious infection
Skin turgor, capillary refill – dehydration
Jaundice – metabolic disorder
Rashes – food intolerance, viral infection

Red flags: The following findings are of particular concern:

Lethargy and listlessness
Inconsolability and bulging fontanelle in an infant
Nuchal rigidity, photophobia, and fever in an older child
Peritoneal signs or abdominal distention (“surgical” abdomen)
Persistent vomiting with poor growth or development

Procedure for Investigation (this will be based on the differential diagnosis)

Condition	History and Physical	Diagnostic approach
Gastroenteritis	Diarrhea (usually), history of infectious contact, fever (sometimes)	Clinical evaluation
GERD	Fussiness after feeding, poor weight gain	Empiric trial of acid suppression
Pyloric stenosis	Recurrent projectile vomiting in neonates aged 3-6 weeks, emaciated and dehydrated	Ultrasound
Congenital atresia or stenosis	Abdominal distension, bilious emesis in first 24-48 hours of life	Abdominal X ray Contrast enema
Malrotation	Bilious emesis, abdominal distention, abdominal pain, bloody stool	Abdominal X ray Upper GI series with contrast under fluoroscopy
Sepsis	Fever, lethargy, tachycardia, tachypnea, widening pulse pressure, hypotension	CBC, Cultures (blood, urine, CSF)
Food intolerance	Abdominal pain, urticarial, eczematous rash	Elimination diet
Metabolic disorders	Poor feeding, failure to thrive, hepatosplenomegaly, jaundice, dysmorphic features, developmental delays, unusual odors	Electrolytes, ammonia, liver function tests, BUN, creatinine, serum glucose, total and direct bilirubin, CBC, PT/PTT Further specific tests based on findings
Non-GI infection	Fever, localized findings (sore throat, dysuria, flank pain) depending on source	Clinical evaluation Further tests if needed
Serious infection	Meningitis photophobia, nuchal rigidity, headaches Pyelonephritis fever, back pain, dysuria	CBC, Cultures (CSF, blood, urine) gram stains CBC, Cultures (urine, blood)
Cyclic vomiting	At least 3 self-limited episodes of vomiting lasting 12 h, 7 days between episodes, no organic cause of vomiting	Diagnosis of exclusion
Intracranial hypertension	Nocturnal wakening, progressive recurrent headache made worse by coughing or Valsalva maneuver, nuchal rigidity, visual changes, weight loss, photophobia	Brain CT (without contrast)
Eating disorders	Body dysmorphism, teeth erosions, skin lesions on hand (Russell’s sign), binge eating behavior	Clinical evaluation
Pregnancy	Amenorrhea, morning sickness, breast tenderness, bloating, history of sexual activity and improper contraception use	Urine pregnancy test
Toxic ingestion	History of ingestion, findings vary depending on substance and pattern of ingestion	Varies depending on substance

Conclusion

Vomiting is a symptom that can be caused by a variety of conditions that affect different organ systems. When evaluating a child with vomiting it is important to identify conditions in which immediate medical intervention is needed.

The most common causes of vomiting are age dependent and can cross over age ranges (see the above table for differential diagnosis based on age). If a child has prolonged vomiting (>12 hours in a neonate, >24 hours in children younger than two years of age, or >48 hours in older children) they should have appropriate investigations.

If a patient displays any of the following red flags, it is important to watch them carefully and have a low threshold for intervention:

Lethargy and listlessness
Inconsolability and bulging fontanelle in an infant
Nuchal rigidity, photophobia, and fever in an older child
Peritoneal signs or abdominal distention (“surgical” abdomen)
Persistent vomiting with poor growth or development

References

(1) AccessMedicine | How to Cite Available at: http://www.accessmedicine.com.ezproxy.library.ubc.ca/citepopup.aspx?aid=5242514&citeType=1. Accessed 1/1/2011, 2011.

(2) Pediatric Care Online : Definition of Age Group Terminology Available at: http://www.pediatriccareonline.org/pco/ub/view/Pediatric-Drug-Lookup/153856/0/definition_of_age_group_terminology. Accessed 1/1/2011, 2011.

(3) Nausea and Vomiting In Infants and Children: Approach to the Care of Normal Infants and Children: Merck Manual Professional Available at: http://www.merckmanuals.com/professional/sec19/ch266/ch266l.html?qt=vomiting&alt=sh#sec19-ch266-ch266i-204f. Accessed 1/15/2011, 2011.

(4) Allen K. The vomiting child–what to do and when to consult Aust.Fam.Physician 2007 Sep;36(9):684-687.

(5) Scorza K, Williams A, Phillips JD, Shaw J. Evaluation of nausea and vomiting Am.Fam.Physician 2007 Jul 1;76(1):76-84.

Acknowledgements

Writer: Bing Wei Wang

Edited: Dianna Louie