Assessment of nausea and vomiting in children

Nausea and vomiting are very common symptoms in the paediatric population. Whether presenting in the emergency department or in an outpatient clinic, they are a frequent reason for parents and caregivers to seek medical attention.

Definitions

Nausea is the subjective unpleasant sensation of imminent vomiting. It is frequently accompanied by autonomic symptoms such as dizziness, pallor, and sweating.

According to the Rome foundation, chronic nausea is defined as bothersome nausea occurring several times per week, not usually associated with vomiting, in the absence of endoscopic or metabolic disease. These criteria must be fulfilled for the last 3 months, with the symptom onset at least 6 months prior to diagnosis.[1]Hyams JS, Di Lorenzo C, Saps M, et al. Functional disorders: children and adolescents. Gastroenterology. 2016 Feb 15;150:1456-68. http://www.ncbi.nlm.nih.gov/pubmed/27144632?tool=bestpractice.com In the latest Rome IV consensus, a specific definition of chronic nausea for young children or adolescents was not included.[2]Benninga MA, Faure C, Hyman PE, et al. Childhood functional gastrointestinal disorders: neonate/toddler. Gastroenterology. 2016 Feb 15;150:1443-55. http://www.ncbi.nlm.nih.gov/pubmed/27144631?tool=bestpractice.com [1]Hyams JS, Di Lorenzo C, Saps M, et al. Functional disorders: children and adolescents. Gastroenterology. 2016 Feb 15;150:1456-68. http://www.ncbi.nlm.nih.gov/pubmed/27144632?tool=bestpractice.com

Nausea is not always followed by vomiting, as in conditions such as chronic functional nausea, postural nausea, and functional dyspepsia.

Vomiting is defined as the vigorous oral expulsion of the gastric or intestinal contents associated with increased intra-abdominal pressure. Oral regurgitation refers to the effortless, usually postprandial, emesis of food content.

Vomiting is usually preceded by nausea; the only exceptions are rumination syndrome, in which oral regurgitation is not preceded by nausea, and possibly gastro-oesophageal reflux disease.

Aetiology

There are various established mechanisms that are known to cause nausea and vomiting, including:[3]Sondheimer JM. Vomiting. In: Walker WA, Goulet O, Kleinman RE, et al (Eds). Walker's pediatric gastrointestinal disease: pathophysiology, diagnosis, management. 4th ed. Ontario, Canada. BD Decker Inc; 2004:203.

• Stimulation of chemoreceptors situated in the area postrema (medullary structure located in the fourth ventricle of the brain)

• Movement-induced stimulation of the labyrinth

• Irritation or over-distension of the mechanically sensitive vagal afferents in the gastrointestinal tract.

The aetiology of nausea and vomiting is often age-dependent, with a wide spectrum of gastrointestinal, non-gastrointestinal, and environmental causes, including:

• Inflammatory changes causing infection of the gastrointestinal system or other body systems

• Anatomical abnormalities resulting in bowel obstruction

• Functional disorders or malignancy of the gastrointestinal tract

• Neurological causes, which can be one of the most ominous causes, particularly in the presence of increased intracranial hypertension or central nervous system infection

• Metabolic or endocrine abnormalities such as diabetic ketoacidosis, adrenal insufficiency, and protein or carbohydrate metabolism disorders

• Urological/gynaecological or renal causes such as gonadal torsion

• Renal causes such as haemolytic uraemic syndrome and nephrolithiasis

• Psychiatric causes such as eating disorders, rumination, or factitious disorder

• Environmental causes such as toxic ingestions and adverse effects associated with the use of medications or illicit drugs.

Diagnosis

A complete history and meticulous physical examination is essential and provides the clues for appropriate diagnosis and management. Diagnostic testing should be directed by the clinical picture.[4]American Gastroenterological Association. American Gastroenterological Association medical position statement: nausea and vomiting. Gastroenterology. 2001 Jan;120(1):261-3. http://www.ncbi.nlm.nih.gov/pubmed/11208735?tool=bestpractice.com

Urgent considerations, particularly neurological compromise, need to be addressed first and may prompt more immediate therapeutic management. Red-flag symptoms that may require urgent management include: lethargy, fever, volume depletion, weight loss, bilious vomiting, haematemesis, papilloedema, abdominal tenderness, or the presence of a mass.