What is the initial management for a patient presenting with severe acute diarrhoea?

Management of Severe Acute Diarrhoea

Immediate Assessment and Fluid Resuscitation

For patients with severe acute diarrhoea, immediate aggressive fluid resuscitation is the cornerstone of management, with intravenous isotonic fluids (lactated Ringer's or normal saline) administered as 20 mL/kg boluses for those with tachycardia, signs of shock, or severe dehydration (≥10% fluid deficit), followed by transition to oral rehydration solution once circulation is restored. 1

Initial Clinical Evaluation

Rapidly assess for:

• Signs of severe dehydration: prolonged capillary refill (>2 seconds), altered mental status, severe lethargy, cool poorly perfused extremities, rapid deep breathing indicating acidosis, and prolonged skin tenting 2, 3
• Hemodynamic instability: tachycardia, hypotension, weak pulse, or signs of shock 1
• Red flag features: bloody stools, fever >38.5°C, severe abdominal pain, or clinical features of sepsis that necessitate additional interventions 1, 2

Fluid Resuscitation Protocol

For severe dehydration with shock or altered mental status:

• Administer 20 mL/kg boluses of 0.9% normal saline or lactated Ringer's intravenously immediately 1
• Repeat boluses until pulse, perfusion, and mental status normalize 1
• Continue rapid fluid replacement until clinical signs of hypovolaemia improve 1
• Target adequate central venous pressure and urine output >0.5 mL/kg/h 1

Once circulation is restored:

• Transition to oral rehydration solution (ORS) for the remaining fluid deficit 1, 2
• The rate of fluid administration must exceed ongoing losses (urine output + insensible losses of 30-50 mL/h + gastrointestinal losses) 1

Oral Rehydration Therapy

After initial stabilization, reduced osmolarity ORS containing 50-90 mEq/L sodium is the preferred method for completing rehydration and replacing ongoing losses. 1

• Administer ORS at volumes appropriate to remaining deficit after initial IV resuscitation 1, 2
• Replace ongoing losses with 10 mL/kg ORS for each watery stool 2, 3
• For patients with persistent vomiting, consider nasogastric administration of ORS 1

Critical Pitfall

Patients who develop oliguric acute kidney injury (<0.5 mL/kg/h) despite adequate volume resuscitation require urgent consultation with intensive care or nephrology, as they are at high risk for pulmonary oedema 1

Antimicrobial Therapy

Empiric antimicrobial therapy is NOT recommended for most patients with severe acute watery diarrhoea unless specific high-risk features are present. 1

Indications for Antibiotics

Consider empiric antibiotics only when:

• Patient is immunocompromised or a young infant appearing ill 1
• Clinical features of sepsis, neutropaenia, or fever with bloody diarrhoea are present 1
• Diarrhoea persists >5 days or stool studies identify a specific treatable pathogen 1, 3

Antibiotic Selection for Complicated Cases

When antibiotics are indicated:

• For suspected bacterial enteritis with sepsis: fluoroquinolones or metronidazole 1
• For neutropaenic enterocolitis: broad-spectrum coverage with piperacillin-tazobactam or imipenem-cilastatin as monotherapy, OR cefepime/ceftazidime plus metronidazole 1
• Coverage must include gram-negative organisms, gram-positive organisms, and anaerobes 1
• If no response to antibacterials, consider amphotericin as fungaemia is common in severely ill patients 1

Stool Evaluation

Obtain stool work-up for blood, Clostridium difficile, Salmonella, E. coli, Campylobacter, and infectious colitis in complicated cases 1

Adjunctive Pharmacotherapy

Antidiarrhoeal Agents

Loperamide is CONTRAINDICATED in children <18 years of age and should be avoided in adults with severe diarrhoea, fever, or bloody stools. 1, 4

• In immunocompetent adults with non-bloody, afebrile severe watery diarrhoea, loperamide may be used cautiously ONLY after adequate rehydration 1
• Initial dose: 4 mg followed by 2 mg after each unformed stool (maximum 16 mg/day) 1, 4
• Avoid in suspected toxic megacolon, inflammatory diarrhoea, or any patient with fever 1

Octreotide for Refractory Cases

For severe diarrhoea not responding to standard measures:

• Starting dose: 100-150 mcg subcutaneously or intravenously three times daily 1
• Can titrate up to 500 mcg subcutaneously three times daily or 25-50 mcg/h by continuous IV infusion 1

Antiemetics

Ondansetron may be given to facilitate tolerance of oral rehydration in patients with persistent vomiting 1, 2

Nutritional Management

Resume age-appropriate normal diet immediately after rehydration is completed or during the rehydration process. 1, 2

• Continue breastfeeding throughout the illness without interruption 1, 2, 3
• Early feeding promotes intestinal cell renewal and prevents nutritional deterioration 2
• Avoid foods high in simple sugars and fats during acute phase 3
• Eliminate lactose-containing products temporarily if lactose intolerance is suspected 1

Monitoring and Reassessment

Monitor continuously during resuscitation:

• Vital signs (pulse, blood pressure, respiratory rate) 1, 2
• Mental status and perfusion 1, 2
• Urine output (target >0.5 mL/kg/h) 1
• Ongoing stool losses 1
• Electrolytes, particularly potassium, as hypokalemia is common and often undertreated 5

Criteria for Successful Rehydration

• Normal pulse and perfusion 1, 2
• Improved mental status 1, 2
• Moist mucous membranes 2
• Adequate urine output 2
• Ability to tolerate oral fluids 2

Hospitalization Criteria

Admit patients with:

• Severe dehydration (≥10% deficit) or shock 1, 2
• Failure of ORS therapy despite proper technique 1, 2
• Altered mental status 1
• Suspected neutropaenic enterocolitis 1
• Persistent vomiting preventing oral intake 1
• Stool output exceeding 10 mL/kg/hour 2
• Oliguric acute kidney injury despite adequate resuscitation 1

Special Considerations for Neutropaenic Enterocolitis

This is a life-threatening complication requiring aggressive management:

• Broad-spectrum antibiotics covering enteric organisms 1
• Granulocyte colony-stimulating factors (G-CSF) 1
• Nasogastric decompression and bowel rest 1
• Avoid anticholinergic, antidiarrhoeal, and opioid agents as they may aggravate ileus 1
• Blood transfusions may be necessary for bloody diarrhoea 1
• Surgical consultation for persistent bleeding, perforation, abscess formation, or clinical deterioration despite aggressive measures 1

Common Pitfall

Failure to remove necrotic focus in severely immunocompromised patients is often fatal; however, primary anastomosis is not recommended due to increased risk of anastomotic leak 1