Acute vomiting in infants and children: Case

This toddler has acute viral gastroenteritis with some dehydration. The vomiting followed by watery diarrhoea, the low-grade fever, the sick household contact, the non-bilious vomit and the soft non-tender abdomen point clearly to gastroenteritis, and the sunken eyes and dry mucous membranes with preserved tears and normal capillary refill place her in the mild-to-moderate dehydration range. The task is to rehydrate her by the least invasive effective route while actively confirming that this is not a surgical or metabolic mimic. [1]

Clinical findings

The reassuring findings are as important as the abnormal ones. Her vomit is milky and never green, her abdomen is soft, non-tender and not distended with active bowel sounds, and she is consolable and produces tears, all of which argue against a surgical abdomen and against severe dehydration or shock. The abnormal findings are the tachycardia, the slightly sunken eyes and the dry mucous membranes, which together indicate some dehydration but not the severe end. [2]

The candidate should grade the dehydration formally rather than by impression. On the Clinical Dehydration Scale, which scores general appearance, eyes, mucous membranes and tears, this child sits in the some-dehydration band, and this validated score predicts the need for intravenous fluids and length of stay better than clinician gestalt. The problem representation is a well-appearing toddler with gastroenteritis and some dehydration, suitable for a trial of oral rehydration. [2]

Investigations

This child needs no blood tests. A well toddler with a clear gastroenteritis story, a benign abdomen and only some dehydration can be managed on clinical assessment alone, and routine electrolytes are not required before oral rehydration. Investigation would be triggered only by moderate-to-severe dehydration, by starting intravenous fluids, or by any feature that raised a surgical or metabolic mimic. [1]

If the picture changed, the candidate should know what to send: a glucose and venous gas with ketones if she became drowsy or the dehydration seemed out of proportion, a urine culture if a urinary tract infection were suspected, and an abdominal ultrasound if the abdomen became distended or tender. Keeping these triggers explicit prevents both over-investigation of the well child and under-investigation of the deteriorating one. [1]

Management

Management begins with oral rehydration solution, given in small frequent amounts to replace the estimated deficit over about four hours, with breastfeeding or normal feeds resumed early once the vomiting settles. Oral rehydration is first-line for mild and moderate dehydration and is as effective as intravenous fluids with fewer complications. Plain water and sugary drinks are avoided in favour of a balanced hypo-osmolar solution. [1]

Because she keeps vomiting the small sips, a single dose of oral ondansetron is a reasonable adjunct, as it reduces vomiting, improves the success of oral rehydration and lowers the need for intravenous fluids and admission. If she then tolerates the oral rehydration solution, intravenous fluids are avoided; if she cannot, nasogastric or intravenous rehydration is the next step. Probiotics are not routinely recommended, and antibiotics have no role in uncomplicated viral gastroenteritis. [3]

Disposition and safety-netting

The disposition depends on the response to oral rehydration. If she tolerates fluids in the department, is not clinically worsening, and has a caregiver who understands the plan, she can go home; admission is reserved for failed oral rehydration, worsening or severe dehydration, a suspected surgical or metabolic cause, or unsafe home circumstances. The candidate should re-examine her hydration after the rehydration trial before deciding. [1]

The safety-net is the key communication skill. The candidate should tell the family in plain language to give small frequent sips of oral rehydration solution, to expect the diarrhoea to outlast the vomiting, and to return immediately if the vomit turns green or bloody, if the child becomes drowsy or floppy, if there is severe or constant abdominal pain, or if she cannot keep any fluid down or stops passing urine. Asking the family to repeat these warning signs confirms understanding and is the best protection against a missed deterioration at home. [1]