Vomiting in Children with emphasis onCyclical Vomiting

Syndrome

The patient• 10 year old girl• Admitted with acute onset vomiting

for 1 day. Started as food, then became yellow/green

• Abdominal pain• Weakness, lethargy• Precipitated by “ asthma attack” –

used asthma inhaler• Previous similar episodes• No diarrhoea or constipation

• Past medical history– Recurrent episodes of vomiting – since

infancy– Diagnosed with gastro-oesophageal reflux

disease as infant– Episodes of vomiting more frequent, severe

in past 2 years (occur every 1-3 months)– Almost always preceded/ precipitated by

“asthma attack”. Sometimes even by laughing a lot

– Frequently resulting in hospital admission – not for bronchospasm but for dehydration and intractable vomiting

– Been extensively investigated (Cape Town) – barium meal, Xrays, gastroscopy, ?others => all negative

– Apparently given medication in hospital each time admitted, but not on chronic medication other than steroid inhaler and bronchodilator

– Parents have not been given a diagnosis as yet – very distressed

• Past surgical history– Nil

• Birth history– Term, nil of significance

• Social– Recently moved from Cape Town (in past

month)– Grade 4 at school, doing well, apparently

happy– 8 year old brother, well– Stable, caring family environment

• Family History– Father has asthma (mild)– No known history of migraine in family

Clinical Findings• Well–grown child• Miserable, lethargic, and uncomfortable

due to abdominal pain, but awake and cooperative

• Haemodynamically stable but looked 5% dehydrated with sunken eyes

• BP – 104/65mmHg• Low-grade fever – 37.5deg• Chest – clear• CVS – normal

• Abdomen – scaphoid, soft but generally tender. No masses felt, bowel sounds heard. PR not done

• CNS – Awake, but withdrawn. No meningism, no focal signs. No papilloedema.

• FBC, urea and electrolytes normal except potassium borderline low (3.1 mmol/l)

• Urine Dipstix – nil of note. No glycosuria• Ultrasound abdomen – normal• CT scan brain - normal

Management• Admitted to ward• Rehydrated with IV fluids• Allowed to take orally as desired• Panado, Cyclizine for vomiting

Progress• Still vomiting in ward for about 2

days• Temperature settled in ward• Did not require nebuliser for

bronchospasm• Very quiet, withdrawn and miserable

for 2 days• By third day, was walking around

looking better and vomiting had settled

Vomiting in Children• Vomiting is a symptom, presenting

complaint in multitude of disorders– Range from gastrointestinal pathology to

disease in distant organ (otitis media or intracranial lesion)

• In children, especially infants, must distinguish from regurgitation – effortless expulsion of gastric contents

• Integrated response to noxious stimuli, coordinated by central nervous system

Centres responsible for vomiting

• Vomiting centre– Nucleus solitarius and series of nuclei in

brainstem medulla– Stimulation results in • integrated motor responses involved in

vomiting• associated vasomotor activity (pallor,

flushing), salivation, bulbar responses

– Afferent input arises from• posterior pharynx, GIT, brain

• Chemoreceptor trigger zone– Stimulated by humoral stimuli such as

opiates, cytotoxins, ketones, ammonia– Lies in area postrema – floor of 4th

ventricle, outside blood-brain barrier– Processes most of afferent input for

the vomiting centre

• Receptors and neurotransmitters involved– Dopamine (D2), histamine (H1), serotonin

(5-HT3), vasopressin, substance P

Diagnostic evaluation• Before finding cause of vomiting, in any

child should first– Assess hydration status, attend to life-

threatening complications– Ascertain whether • Bilious – suggests gastrointestinal

obstruction• Blood is present – diagnosis and

management different• If non-bilious and non-bloody, 2

important variables => temporal pattern and age of patient

• Duration either –Acute – short-term episode, abrupt

onset

–Recurrent – at least 3 episodes over 3-month period => chronic - relatively mild episodes that occur frequently

=> cyclic – recurrent, intense episodes separated by asymptomatic periods

Acute Vomiting

• Neonate/ Infant– With fever

• Sepsis, meningitis, UTI

• Tonsillitis, otitis media, gastroenteritis

– If no signs sepsis• Pyloric stenosis/

outlet obstruction• Metabolic• Neurologic• Endocrine

• Child/ adolescents– With fever (but

otherwise well)• Gastroenteritis,

esp if also have diarrhoea

– With lethargy/ altered mental status• Neurologic• Metabolic• Endocrine• Drugs, toxins,

alcohol

Investigations for acute vomiting

• Thorough examination• “Septic workup” – blood cultures,

urine, FBC, CRP, LP• Upper GI radiology – Barium swallow/

meal, AXR, ultrasound abdomen, endoscopy

• Metabolic investigations – blood gas, ammonia, blood and urine organic acids

Management

• Depends on specific cause• While investigating/ treating underlying

pathology – replace lost fluids, maintain hydration

• If mild and child able to drink, can try oral rehydration. Intravenous may also be required

• Pharmacologic agents not usually recommended– May mask signs of serious disease– Undesirable side-effects in children

Recurrent vomiting

• Ongoing underlying pathology, therefore may be more worrying

• Numerous causes– GIT • Infections – H. pylori, Giardia,

oesophageal candidiasis• Hepatitis, pancreatitis, partial

intestinal obstruction–Metabolic, neurologic, renal

Recurrent Vomiting

• Infants– GIT – feed

intolerance– Renal– Metabolic –

lethargy, poor feeding, failure to thrive, seizures, abnormal tone

– Neurologic – raised pressure – meningitis, tumour, hydrocephalus

• Older child/ Adolescent– GIT– Chronic sinusitis– Drug intoxication– Migraine– Bulimia– Pregnancy

Investigations

• Guided by history– Timing - early morning (or nocturnal) –

reflux, peptic ulcer (empty stomach), intracranial mass lesion, pregnancy

– Relation to eating - worse with food- suggests upper GIT abnormalities.

– Description – • projectile suggests outlet obstruction

(stomach, duodenum, more distal intestine) • faeculent – colonic obstruction, intestinal

stasis, bowel ischaemia

• Examination– Jaundice – liver/ gallbladder pathology– Neurologic examination important

• Special investigations– Sinus Xrays–MRI/CT brain– Stool occult blood/ parasites– FBC, LFT, U&E, Amylase, ESR– Urinalysis and culture– Toxicology screen

• If no diagnosis still, consider– Upper GI contrast study, ultrasound

abdomen – Gastroscopy PLUS biopsy – high

diagnostic yield, ease of performance, safe

Cyclic Vomiting Syndrome (CVS)

• Paroxysmal, especially severe, recurrent vomiting disorder

• Mysterious disorder, unknown aetiology, and pathophysiology

• Substantial increase in interest and understanding of disease in past decade

• Previously considered rare, may be 2nd only to GORD as cause of recurrent vomiting in children

– Under-recognised• No specific laboratory, radiographic or

endoscopic markers for CVS• Typically misdiagnosed for years – viral GE, food

poisoning, GORD, psychogenic vomiting => leads to inappropriate therapy– Surgery– Psychiatric hospitalisation– Very distressing to patients and families

– Prevalence• Being diagnosed with increasing frequency, but

actual prevalence remains unknown• 0.04-2% among school-aged children

– Overdiagnosed sometimes, and often underdiagnosed

Age and Sex distribution

• Females>males– Similar to distribution in migraine sufferers

• All races, nut more in Caucasians

• Usually affects children of 4-7 yrs but some as young as 6 mths– Bimodal peaks: 4.8 and 35 yrs!

Course

• Often delays in diagnosis– Average 2.7 years = ±20 episodes in children

• Median age of resolution 10 years– In those whose vomiting resolves, about 1/3

develop migraine headaches around same time

• Children ill <10% of time, but causes substantial medical and academic morbidity– Recurrent school absences– Recurrent admissions for IV fluids– Recurrent outpatient visits, hospital stays,

missed work for parents

FeaturesHallmark – cyclic vomiting pattern => severe,

recurring, discrete, stereotypical• Cyclic

– high intensity, low frequency

– More often require IV rehydration

– Higher incidence of family members with migraine

– Migraine symptoms – headaches, photophobia, phonophobia

– Investigate causes outside GIT

• Chronic – low intensity, high

frequency, daily pattern

– Investigate causes inside GIT

• Cyclic– Idiopathic– If other cause –

extraintestinal• Neurologic• Renal• Metabolic• Endocrine

• Chronic– GIT disorders

• Peptic oesophagitis

Clinical Features• Short prodromal phase– 1.5 hours– Nonspecific premonitory signs such as

pallor, lethargy, anorexia, nausea

• Episode itself– Defined by median of 15 emeses, duration

of 24 hours

• Recovery phase– From last emesis to point of tolerating

liquids and food, resume play – remarkably short 6 hours, often marked by sleep. “Turning off a switch”

Other Symptoms

• Other than vomiting• 3 categories– Systemic• Lethargy &/or pallor, withdrawal,

flushing, fever, drooling• Extreme pallor could even mimic

shock• Profound lethargy , inability to walk,

talk, or interact can simulate semi-coma, confuse with meningitis, toxin ingestion

• GI symptoms– Anorexia, nausea, retching, abdominal pain

(common), diarrhoea – fever and diarrhoea could confuse with viral GE

– except for stereotypical recurrences. Also CVS patients look sicker, are often more dehydrated

– Abdominal pain can mimic acute abdomen

• Neurologic symptoms– Headache, photophobia, phonophobia, vertigo– <50% have classic migraine symptoms, but

high occurrence of these symptoms supports link to migraines

– Adolescents may assume foetal position to cope with hypersensitivity to light, sound, touch, upright positioning

Features (cont)

• Periodicity– Over 24 period – most common onset

between 2am-4am and 6am-8am• ?relationship to Corticotropin Releasing

Factor

– Over 1-3 month period – commonly every 4 weeks, but only half can predict next episode within 1 week on either side. Rest are sporadic

– Seasonal – many worse in winter

• Triggers– Numerous events can trigger episode– Parents can often identify trigger–Most common• Psychologic – usually positive excitement

rather than negative• Infectious – URTI’s, sinusitis, streptococcal

pharyngitis

– Also physical exhaustion, lack of sleep, dietary (chocolate, cheese, MSG), menstruation, motion sickness, asthma, allergies

Differential Diagnosis• Recurrent vomiting may be caused by

neurologic, metabolic, endocrine, renal, gastrointestinal pathology

• Cyclic vomiting - 12% have surgically-correctable lesion or metabolic disorder => therefore not Idiopathic CVS– NB: exclude malrotation, intermittent volvulus

=> if unrecognised could result in bowel resection

– Genitourinary – acute hydronephrosis due to uretero-pelvic junction obstruction mimics CVS. Also nephrolithiasis

– CNS – subtentorial neoplasms

– Non-surgical GIT problems – GORD, food allergy to milk, wheat proteins

– Chronic sinusitis–Metabolic – mitochondrial

enzymopathies – infants, toddlers. Acute intermittent porphyria – adolescents – fasting and alcohol

– Endocrine – Addison’s disease– Psychological – Munchausen-by-proxy,

anxiety

Diagnosis• Approach guided by need to exclude

treatable underlying disorders• Imaging– First-line => Small bowel radiography,

abdominal ultrasound/CT – exclude structural defects

– Usually when child well – so can retain oral contrast

– Second-line => sinus CT, CT or MRI head. Also gastroscopy if peptic disorders suspected

• Laboratory Investigations– U&E, Glucose, lactate, ammonia, amino

acids, urine organic acids• Assess complications (dehydration) and

assist with diagnosis (metabolic disorders)• Screening for metabolic, endocrine disorders

best done during episode as may be intermittently symptomatic

• How much testing should be done?– High cost of complete testing vs

potential morbidity of missed diagnosis• Single most useful test is small bowel series

–Move on to 2nd line tests OR repeat 1st line tests for• Frequent, severe, prolonged episodes

requiring repeated hospitalisations• Atypical features – severe headache• Refractory to medical management

Relationship to migraine

• CVS thought to be migraine variant• Often family history of migraine• High rate of improvement on anti-

migraine therapy• Can progress to migraine headaches

once CVS episodes have ceased

Treatment

• Only empiric therapy at present• 5 aspects– Avoidance of precipitating factors• Food and stressful events possible• Mostly unavoidable

– Prophylactic agents• Anti-migraine – propranolol, amitryptiline• Anti-epileptic – phenobarbital, valproate• Prokinetic agents – erythromycin

– Abortive agents

• Parenteral

• Anti-migraine agents – Sumatriptan (5HT1B/1D

agonist)

• Anti-emetic agents – Ondansetron (5HT3 antagonist), even more effective with benzodiazepine (Lorazepam)

– Supportive care• IV fluids – 10% dextrose-containing electrolyte

solution – rehydration, terminate ketosis• Quiet, dark, non-stimulating environment• Sedatives –help to sleep, sleep may initiate

recovery phase• Phenothiazine anti-emetics INEFFECTIVE in CVS• Opiates for pain may help but can worsen

nausea

– Family support• Crucial – unpredictable, disruptive,

unexplained illness, often misdiagnosed, few definitive answers