What is the management of acute gastroenteritis in the Emergency Room (ER) setting?

Management of Acute Gastroenteritis in the Emergency Room

Core Management Principle

The cornerstone of ER management for acute gastroenteritis is rapid assessment of dehydration severity and immediate initiation of appropriate rehydration therapy, with oral rehydration solution being first-line for mild-to-moderate dehydration. 1, 2

Initial Assessment

Clinical Evaluation Priority

• Obtain accurate body weight immediately - this is the most reliable indicator of fluid status, though premorbid weight is often unknown 1
• Rule out non-GI emergencies first: meningitis, bacterial sepsis, pneumonia, otitis media, urinary tract infection, metabolic disorders, congestive heart failure, toxic ingestions, or trauma can all present with vomiting and diarrhea 1
• Auscultate for adequate bowel sounds before initiating oral therapy 1
• Visual stool examination to confirm abnormal consistency and identify blood or mucus 1

Dehydration Assessment

Use the following clinical signs to stratify dehydration severity:

• Mild (3-5% fluid deficit): Increased thirst, slightly dry mucous membranes 1
• Moderate (6-9% fluid deficit): Loss of skin turgor, skin tenting when pinched, dry mucous membranes 1
• Severe (≥10% fluid deficit): Severe lethargy or altered consciousness, prolonged skin tenting (>2 seconds), cool and poorly perfused extremities, decreased capillary refill, rapid deep breathing (acidosis) 1

Most reliable predictors of dehydration: Rapid deep breathing, prolonged skin retraction time, and decreased perfusion are more reliable than sunken fontanelle or absence of tears 1

Treatment Algorithm

Mild-to-Moderate Dehydration (Most Common ER Presentation)

Oral rehydration therapy is as effective as IV rehydration for preventing hospitalization and return to the ER 2

• First-line: Oral rehydration solution (ORS) 1, 2
• Alternative approach: Half-strength apple juice followed by preferred liquids is equally effective 2
• Add ondansetron if needed to prevent vomiting and improve ORS tolerance 2
• Avoid nasogastric hydration unless oral route fails 3

Severe Dehydration

Hospitalization with intravenous fluids is mandatory for:

• Signs of shock 1
• Severe lethargy or altered consciousness 1
• Failure to respond to oral rehydration therapy plus antiemetic 2
• More than 10% dehydration 2

Medications in the ER

What NOT to Use

Avoid nonspecific antidiarrheal agents - adsorbents (kaolin-pectin), antimotility agents (loperamide), antisecretory drugs, or toxin binders (cholestyramine) 1

Rationale for avoidance:

• No demonstrated effectiveness in reducing diarrhea volume or duration 1
• Serious side effects including opiate-induced ileus, drowsiness, nausea, and severe abdominal distention with documented deaths 1
• Shifts therapeutic focus away from appropriate fluid and electrolyte therapy 1

What TO Use

Antiemetics (ondansetron): Decreases need for IV fluids and hospitalization when used appropriately 3, 2

Laboratory Testing

Supplementary laboratory studies are rarely needed 1

Order serum electrolytes only when:

• Clinical signs suggest abnormal sodium or potassium concentrations 1

Order stool cultures/testing when:

• Bloody stool present 4
• Symptoms lasting >1 week 4
• Severe symptoms 4
• Recent antibiotic exposure (test for Clostridioides difficile) 4
• Use multiplex antimicrobial testing - stool cultures and microscopic examinations are no longer first-line 4

Antimicrobial Therapy

Antibiotics are NOT routinely indicated for viral gastroenteritis 1

Antibiotics ARE indicated for:

• C. difficile infections 4
• Travel-related diarrhea 4
• Bacterial infections with severe symptoms 4
• Parasitic infections 4

Disposition Decisions

Safe for Discharge

• Mild dehydration successfully rehydrated with ORS 2
• Tolerating oral fluids without vomiting (with or without ondansetron) 2
• No signs of severe illness or alternative diagnosis 1

Requires Admission

• Severe dehydration (≥10%) 2
• Failed oral rehydration therapy despite antiemetic 2
• Signs of shock or hemodynamic instability 1
• Altered mental status 1
• Inability to maintain adequate oral intake 3

Critical Pitfalls to Avoid

• Do not rely solely on sunken fontanelle or absent tears - these are less reliable than perfusion status and skin turgor 1
• Do not prescribe loperamide or other antimotility agents - documented cases of death, especially in children 1
• Do not delay IV rehydration in severe dehydration - attempting oral rehydration in severely dehydrated patients wastes critical time 1, 2
• Do not order routine stool studies for mild viral gastroenteritis - this adds unnecessary cost without changing management 4