What are the Australian guidelines for managing dengue fever in patients, particularly those at risk of severe disease or shock?

Australian Guidelines for Managing Dengue Fever

Initial Risk Stratification and Management Approach

Classify all dengue patients into three categories—dengue without warning signs, dengue with warning signs, and severe dengue—as this classification directly determines the management pathway and prevents both under-treatment and harmful over-resuscitation. 1

Warning Signs Requiring Escalation of Care

Monitor specifically for these clinical indicators that signal progression to severe disease: 1

• High hematocrit with rapidly falling platelet count
• Severe abdominal pain or persistent vomiting
• Lethargy, restlessness, or altered mental status
• Mucosal bleeding
• Clinical fluid accumulation (ascites, pleural effusion)
• Liver enlargement

The critical phase typically occurs on days 3-7 of illness when plasma leakage can rapidly progress to shock—this is when most deaths occur if not properly managed. 1

Management of Dengue Without Shock

Oral Rehydration Protocol

For patients without warning signs or shock, oral rehydration is the cornerstone of management—avoid routine bolus intravenous fluids as this increases fluid overload and respiratory complications without improving outcomes. 1

Specific oral rehydration approach: 1

• Encourage 5 or more glasses of fluid throughout the day
• Target total daily fluid intake of 2,500-3,000 mL
• Use any locally available fluids: water, oral rehydration solutions, cereal-based gruels, soup, rice water
• Avoid soft drinks due to high osmolality

Supportive Care and Monitoring

• Use acetaminophen (paracetamol) only for pain and fever management 1
• Strictly avoid aspirin and NSAIDs due to increased bleeding risk 1
• Resume age-appropriate diet as soon as appetite returns 1
• Perform daily complete blood count monitoring to track platelet counts and hematocrit levels 1

Management of Dengue Shock Syndrome

Initial Fluid Resuscitation Protocol

Administer 20 mL/kg of isotonic crystalloid (Ringer's lactate or 0.9% normal saline) as a rapid bolus over 5-10 minutes, with immediate reassessment after each bolus. 1, 2

Escalation algorithm for persistent shock: 1

1. If shock persists after initial bolus, repeat crystalloid boluses up to a total of 40-60 mL/kg in the first hour
2. After 40-60 mL/kg of crystalloid without adequate response, switch strategy from aggressive fluid administration to colloid solutions
3. If shock remains refractory despite colloids, initiate vasopressor support rather than continuing fluid boluses

Evidence for Colloid Use in Severe Cases

Moderate-quality evidence demonstrates that colloids achieve faster resolution of shock (RR 1.09,95% CI 1.00-1.19) and require less total volume (mean 31.7 mL/kg versus 40.63 mL/kg for crystalloids) compared to crystalloids alone. 1, 2 Three randomized controlled trials in Vietnamese children with dengue shock syndrome achieved near 100% survival with appropriate fluid management, with only one death among 512 patients (<0.2% mortality). 1, 3

Alternative colloid options if primary choice unavailable: 2

• 6% hydroxyethyl starch (preferred over dextran due to fewer adverse reactions) 3
• Gelafundin
• Albumin

Clinical Endpoints for Adequate Resuscitation

Monitor these specific indicators rather than relying solely on blood pressure (which is an unreliable endpoint in children): 1, 2

• Normal capillary refill time (<2 seconds)
• Absence of skin mottling
• Warm and dry extremities
• Well-felt peripheral pulses
• Return to baseline mental status
• Adequate urine output (>1 mL/kg/hour)
• Improvement in tachycardia and tachypnea

Management of Refractory Shock

If shock persists despite adequate fluid resuscitation (40-60 mL/kg in first hour), initiate vasopressor therapy immediately—delays in vasopressor therapy are associated with major increases in mortality. 1

Vasopressor selection based on hemodynamic state: 1, 2

• Cold shock with hypotension: Titrate epinephrine as first-line vasopressor
• Warm shock with hypotension: Titrate norepinephrine as first-line vasopressor
• Target mean arterial pressure appropriate for age and maintain ScvO2 >70%
• Begin peripheral inotropic support immediately if central venous access is not readily available

Critical Pitfalls to Avoid

Fluid Overload in Non-Shocked Patients

The most common and dangerous error is administering routine bolus IV fluids to patients with "severe febrile illness" who are not in shock—this increases risk of fluid overload and respiratory complications without improving outcomes. 1, 2 Restrictive fluid strategies have no survival benefit in established dengue shock syndrome and may worsen outcomes. 1, 2

Recognizing When to Stop Fluid Resuscitation

Stop fluid resuscitation immediately if these signs of fluid overload develop: 1, 2

• Hepatomegaly
• Pulmonary rales on lung examination
• Respiratory distress
• Rising hematocrit despite adequate resuscitation (suggests successful plasma expansion)

Switch to inotropic support rather than continuing fluid boluses once fluid overload appears. 1, 2

Post-Resuscitation Fluid Management

After initial shock reversal, judicious fluid removal may be necessary during the recovery phase—evidence shows that aggressive shock management followed by fluid removal decreased pediatric ICU mortality from 16.6% to 6.3%. 1, 4 Consider continuous renal replacement therapy (CRRT) if fluid overload >10% develops, as outcomes are better when CRRT is initiated early. 1

Management of Complications

Bleeding Management

• Blood transfusion may be necessary in cases of significant bleeding 1, 5
• Target hemoglobin >10 g/dL if ScvO2 <70% 1
• Continue to avoid aspirin and NSAIDs throughout illness course 1, 5

Symptomatic Abdominal Compartment Syndrome

Proactive monitoring for symptomatic abdominal compartment syndrome is essential in severe cases, as invasive percutaneous drainage may be required (occurs in approximately 7.7% of optimally managed cases versus 30% with standard therapy alone). 4

Respiratory Support

Intubation and positive pressure ventilation requirements can be reduced from 53.3% to 18.4% with targeted ICU supportive measures including early albumin for crystalloid-refractory shock and proactive fluid management. 4