What are the initial admitting orders for a patient with acute gastroenteritis?

Admitting Orders for Acute Gastroenteritis

For patients requiring admission with acute gastroenteritis, initiate intravenous fluid resuscitation with isotonic crystalloid, provide antiemetics (ondansetron for children >4 years and adults), avoid routine antibiotics unless sepsis or specific bacterial infection is suspected, correct electrolyte abnormalities, administer thromboprophylaxis, and allow early oral feeding once vomiting is controlled. 1, 2

Initial Assessment and Stabilization

Fluid Resuscitation

• Administer intravenous isotonic fluids immediately for patients with moderate to severe dehydration who have failed oral rehydration therapy 1, 3
• For patients with tachycardia or potential sepsis, give an initial fluid bolus of 20 mL/kg 1
• Continue fluid replacement at a rate greater than ongoing losses 1
• Consider dextrose-supplemented normal saline (D5NS) or lactated Ringer's solution over plain normal saline, as these have more favorable effects on plasma bicarbonate and metabolic balance 3
• Dextrose supplementation may help terminate vomiting and prevent hypoglycemia, particularly in pediatric patients 4, 3

Antiemetic Therapy

• Administer ondansetron to facilitate oral rehydration in children >4 years of age and adults with significant vomiting 2
• Ondansetron reduces immediate need for hospitalization and intravenous rehydration, though it may increase stool volume 2
• Antiemetics should only be given once adequate hydration is initiated, not as a substitute for fluid therapy 2

Laboratory and Diagnostic Orders

Essential Laboratory Testing

• Complete blood count 1
• Comprehensive metabolic panel including electrolytes, blood urea nitrogen, creatinine, and glucose 1
• Correct electrolyte abnormalities and anemia as identified 2

Stool Studies (When Indicated)

• Stool examination for blood 1
• Clostridium difficile testing 1, 5
• Bacterial culture for Salmonella, Escherichia coli, and Campylobacter 1
• Consider testing for infectious colitis pathogens based on clinical presentation 1

Important caveat: Routine laboratory testing is of limited value in uncomplicated acute gastroenteritis and should be reserved for patients with severe dehydration, suspected electrolyte abnormalities, or those requiring admission 6

Antimicrobial Therapy

When to Avoid Antibiotics

• Do not routinely administer antibiotics in uncomplicated acute gastroenteritis 2, 1
• Routine antibiotic use leads to antibiotic resistance and provides no benefit in viral or most bacterial gastroenteritis 1

When to Initiate Antibiotics

• Administer empiric broad-spectrum antibiotics when clinical or epidemiologic features suggest treatable bacterial infection 1, 5
• Use antibiotics for patients with signs of sepsis or suspected intra-abdominal abscess 2, 1
• Cover enteric gram-negative organisms, gram-positive streptococci, and obligate anaerobic bacilli 2
• Consider fluoroquinolones or third-generation cephalosporin plus metronidazole as empiric therapy 2

Thromboprophylaxis and Supportive Care

Venous Thromboembolism Prevention

• Administer low molecular weight heparin for thromboprophylaxis in all admitted patients 2

Nutritional Management

• Allow early oral feeding within 24 hours rather than prolonged bowel rest 2, 1
• Early feeding protects gut mucosal barrier and reduces bacterial translocation 1
• The BRAT diet and dairy avoidance have limited supporting evidence 2
• Instructing patients to refrain from solid food for 24 hours is not useful 2

Antimotility Agents: Critical Restrictions

Absolute Contraindications

• Never give antimotility drugs (loperamide) to children <18 years of age with acute diarrhea 2
• Avoid loperamide at any age in suspected or proven inflammatory diarrhea, bloody diarrhea, or diarrhea with fever due to risk of toxic megacolon 2
• Do not use in patients with suspected Shigella or Shiga toxin-producing E. coli (STEC) infections, as this increases risk of hemolytic uremic syndrome 2

Limited Use in Adults

• Loperamide may be given to immunocompetent adults with acute watery diarrhea only 2
• Maximum dose: 4 mg initially, then 2 mg after each loose stool, not exceeding 16 mg daily 1

Monitoring and Multidisciplinary Care

Clinical Monitoring

• Serial abdominal examinations for patients with complicated enteritis 1
• Monitor for signs of clinical deterioration requiring escalation of care 1
• Reassess response to therapy within 3-5 days 2

Multidisciplinary Approach

• Involve gastroenterology consultation for patients with complicated enteritis, persistent symptoms, or suspected inflammatory bowel disease 1, 2

Special Populations

Neutropenic Patients

• Administer broad-spectrum antibiotics covering enteric gram-negative organisms, gram-positive organisms, and anaerobes 1
• Consider amphotericin if no response to antibacterial agents 1
• Avoid anticholinergic, antidiarrheal, and opioid agents as they may aggravate ileus 1
• Close monitoring is essential as mortality can be high 5

Immunocompromised Patients

• Consider opportunistic pathogens including CMV, Mycobacterium avium-intracellulare, Cryptosporidium, and Microsporidium 5
• Clinical signs may not be reliable; diagnosis requires combining symptoms, history, and radiological evaluation 5

Common Pitfalls to Avoid

• Do not delay oral feeding unnecessarily once vomiting is controlled 2, 1
• Do not use antimotility agents in children or in patients with fever/bloody diarrhea 2
• Do not routinely prescribe antibiotics without clear indication, as this promotes resistance 1
• Do not forget thromboprophylaxis in admitted patients 2
• Do not use plain normal saline when dextrose-supplemented saline or lactated Ringer's provides better metabolic balance 3