Approach to vomiting (pediatrics): Clinical sciences

Vomiting refers to the forceful expulsion of the stomach contents that is usually related to gastrointestinal illness, but it can also be a manifestation of other systemic conditions. Vomiting can be acute, occurring over hours to days; chronic, persisting for days to weeks; or episodic, which is characterized by a pattern of acute episodes separated by asymptomatic periods.

When a pediatric patient presents with vomiting, first, perform an ABCDE assessment to determine if they are stable or unstable.

If unstable, stabilize the airway, breathing, and circulation, obtain IV access, and begin IV fluids. You might also need to keep your patient NPO and insert a nasogastric tube. Finally, if needed, put your patient on continuous vital sign monitoring and provide supplemental oxygen and antibiotics.

Next, perform a focused history and physical examination and assess for signs and symptoms suggesting diabetic ketoacidosis, or DKA. These include polydipsia, polyuria, polyphagia; weight loss; fruity breath, dry mucous membranes, and Kussmaul respirations, or a rapid, deep pattern of breathing.

If any of these signs and symptoms are present, consider DKA, and order labs,

including a basic metabolic panel, venous blood gas, urine dipstick, and a serum beta-hydroxybutyrate.

If the blood glucose is greater than 200 mg/dl, pH is less than 7.3 or bicarbonate levels are less than 15 mEq/L, the urine ketones are positive, and beta-hydroxybutyrate is 3 mmol/L or higher, diagnose DKA.

On the other hand, if signs or symptoms of DKA are absent, consider acute “surgical” abdomen.

These include a sudden onset of severe, acute abdominal pain with abdominal tenderness, rebound, and guarding. Also, you might notice a rigid abdomen. These findings suggest peritoneal inflammation and indicate an acute, or “surgical” abdomen.

This commonly occurs as a result of appendicitis, but also intussusception and incarcerated hernia.

Okay, now let’s return to the ABCDE assessment and talk about stable patients, starting with acute onset vomiting.

If your patient reports acute vomiting, the first step is to assess for bilious emesis. If present, consider intestinal obstruction and assess the underlying condition, which is often seen in the superior mesenteric artery syndrome or pancreatitis.

First, let’s focus on the superior mesenteric artery, or SMA syndrome.

In SMA syndrome, the third part of the duodenum becomes compressed between the superior mesenteric artery and the aorta. This might occur due to weight loss and depletion of the mesenteric fat pad.

History typically reveals adolescents with early satiety, severe postprandial emesis, and recent weight loss. Remember that these individuals will typically report abdominal pain relieved by a prone or knee-to-chest position, and their physical exam will show abdominal tenderness. At this point, consider SMA syndrome.

Then, obtain an upper GI series.

If you see a sharp cutoff sign with dilation of the first two portions of the duodenum and compression of the third; with a to-and-fro motion of the contrast column; obtain an abdominal CT scan. Decreased aortomesenteric angle confirms the diagnosis of SMA syndrome.

Next, let’s look at pancreatitis! In this case, history will reveal no weight loss before the onset of symptoms and abdominal pain that decreases when sitting upright and worsens while supine.

Patients often describe boring, sharp, and knifelike epigastric pain with fever.

And the exam typically shows epigastric tenderness. With these findings, consider pancreatitis.

Be sure to order labs, primarily amylase and lipase levels, and obtain an abdominal ultrasound. If amylase and lipase levels are elevated, usually three times normal levels, and the ultrasound shows pancreatic enlargement with or without a surrounding fluid collection, diagnose pancreatitis.

Okay, now let’s go back and focus on children with no bilious emesis.

In this case, your first step is to assess for diarrhea.

If present, consider infectious gastroenteritis, which is usually associated with fever, crampy abdominal pain, and possibly sick contacts or recent travel.

The physical exam typically demonstrates abdominal tenderness without rebound or guarding but often in combination with signs of dehydration, like reduced skin turgor and dry mucous membranes. Next, obtain stool viral antigen testing or stool culture with a microscopic examination. If you identify the causative pathogen, diagnose infectious gastroenteritis.

On the other hand, if diarrhea is absent, assess for non-gastrointestinal symptoms. The presence of urinary symptoms should make you consider a urinary tract infection or UTI. Children with UTI often have a fever, and those under two months of age might have foul-smelling urine and irritability. Older infants and children typically have dysuria, urgency, and frequent urination.

The physical exam often reveals body temperature above 38 degrees Celsius, possibly in combination with suprapubic tenderness or costovertebral angle tenderness.

Next, obtain a urinalysis and urine culture. If the urinalysis is positive for leukocyte esterase and nitrites, and the culture grows more than 50,000 colony-forming units per milliliter, diagnose urinary tract infection.

Finally, let’s discuss patients with acute vomiting and sore throat. In this case, consider group A streptococcal pharyngitis. If your patient reports fever, headache, and sore throat; and their exam shows pharyngeal erythema, possibly with tonsillar exudates and cervical lymphadenopathy.

Then, perform a rapid strep test. A positive test confirms group A streptococcal pharyngitis.

Here’s a clinical pearl! Other infections like acute hepatitis and pneumonia can also cause vomiting. Many children with respiratory infections also have post-tussive emesis, which is triggered by forceful coughing.

Okay, now let’s take a look at patients with chronic vomiting.

To narrow your differential, start by assessing for a change in bowel habits.