Vomiting in Children with emphasis on Cyclical Vomiting Syndrome

1. Vomiting in Children with emphasis on Cyclical Vomiting Syndrome

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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 PR not done • CNS – Awake, but withdrawn.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

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

9. 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in ward for about 2 days • Temperature settled in ward • Did not require nebuliser for bronchospasm • Very quiet, withdrawn and miserable for 2 days • By third day, was walking around looking better and vomiting had settled

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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

16. 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

17. 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

18. 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

19. 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

20. 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

21. 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

22. If no diagnosis still, consider • Upper GI contrast study, ultrasound abdomen • Gastroscopy PLUS biopsy – high diagnostic yield, ease of performance, safe

23. 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

24. 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

25. 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!

26. 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

27. 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

28. Cyclic • Idiopathic • If other cause – extraintestinal • Neurologic • Renal • Metabolic • Endocrine • Chronic • GIT disorders • Peptic oesophagitis

30. 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”

31. 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

32. 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

33. 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

34. 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

35. 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

36. 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

37. 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

38. 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

39. 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

40. 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

41. 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

42. 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

43. Family support • Crucial – unpredictable, disruptive, unexplained illness, often misdiagnosed, few definitive answers