What is the appropriate approach to managing a patient with suspected dengue fever?

Approach to Dengue Fever Management

Initial Assessment and Diagnosis

Suspect dengue in any patient with fever plus at least one of the following: headache, retro-orbital pain, myalgia, arthralgia, rash, nausea, vomiting, or positive tourniquet test, particularly with travel to endemic areas within 14 days. 1

Diagnostic Testing Strategy

• Order dengue PCR/NAAT on serum for patients with symptoms ≤7 days, as this is the preferred initial test during the acute phase 1
• Order IgM capture ELISA for patients with symptoms >7 days, as viral RNA levels decline and antibody response becomes detectable 1
• Obtain complete blood count with hematocrit and platelet count at presentation, as thrombocytopenia and rising hematocrit are key diagnostic and prognostic markers 2
• The absence of thrombocytopenia significantly reduces the probability of dengue, making it a useful rule-out finding 1
• Document vaccination history to avoid cross-reactivity with other flaviviruses such as yellow fever, Japanese encephalitis, and tick-borne encephalitis 1

Risk Stratification and Classification

The WHO classification system divides dengue into three categories that determine management: dengue without warning signs, dengue with warning signs, and severe dengue. 3

Dengue Without Warning Signs

• Patients can be managed as outpatients with aggressive oral hydration (>2500 mL daily), acetaminophen for symptom relief, and daily monitoring for warning signs 1
• Target fluid intake of approximately 2,500-3,000 mL daily using oral rehydration solutions, water, cereal-based gruels, soup, or rice water 3
• Avoid soft drinks due to high osmolality 3

Dengue With Warning Signs - Requires Hospitalization

Warning signs that mandate hospitalization include: 2

• Severe abdominal pain or persistent vomiting
• Mucosal bleeding (gum bleeding, epistaxis, hematemesis)
• Lethargy, restlessness, or altered mental status
• Rising hematocrit (>20% increase from baseline) with rapidly falling platelet count
• Hepatomegaly
• Clinical fluid accumulation (pleural effusion, ascites)

Severe Dengue - Requires ICU Admission

Severe dengue includes dengue shock syndrome (narrow pulse pressure ≤20 mmHg or hypotension), severe bleeding, or organ impairment, with mortality of 1-5% without proper management but <0.5% with appropriate care. 3

Daily Monitoring Protocol

All hospitalized patients require daily complete blood count monitoring to track platelet counts and hematocrit levels, particularly during the critical phase (days 3-7 of illness) 1, 3

• Rising hematocrit indicates ongoing plasma leakage and need for continued resuscitation 3
• Falling hematocrit suggests successful plasma expansion 3
• Monitor for warning signs progression: persistent vomiting, abdominal pain, lethargy, restlessness, mucosal bleeding 1

Fluid Management

For Patients Without Shock

• Oral rehydration is the cornerstone for stable patients, with goal of exceeding 2500 mL daily using oral rehydration solutions 2
• Resume age-appropriate diet as soon as appetite returns 3

For Dengue Shock Syndrome

Administer 20 mL/kg isotonic crystalloid (Ringer's lactate or 0.9% normal saline) as rapid bolus over 5-10 minutes, with immediate reassessment after each bolus. 3, 2

• Repeat crystalloid boluses up to 40-60 mL/kg in the first hour if shock persists before escalating therapy 3
• Moderate-quality evidence shows colloids (dextran, gelafundin, or albumin) 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) 3
• Consider colloid solutions for severe shock with pulse pressure <10 mmHg 1

Critical Monitoring During Resuscitation

• Watch for signs of adequate tissue perfusion: normal capillary refill time, absence of skin mottling, warm and dry extremities, well-felt peripheral pulses, return to baseline mental status, adequate urine output (>0.5 mL/kg/hour) 3
• Stop fluid resuscitation immediately if hepatomegaly or pulmonary rales develop, signaling fluid overload 3

Management of Refractory Shock

If shock persists despite 40-60 mL/kg crystalloid in the first hour, switch from aggressive fluid administration to inotropic support rather than continuing fluid boluses. 3

• For cold shock with hypotension: titrate epinephrine as first-line vasopressor 3
• For warm shock with hypotension: titrate norepinephrine as first-line vasopressor 3
• Target mean arterial pressure appropriate for age and maintain ScvO2 >70% 3
• Begin peripheral inotropic support immediately if central venous access is not readily available, as delays in vasopressor therapy increase mortality 3

Pain and Fever Management

Acetaminophen at standard doses is the ONLY acceptable analgesic for pain and fever control. 2

• Never use aspirin or NSAIDs under any circumstances due to increased bleeding risk and platelet dysfunction 1, 3, 2
• Consider alternative cooling measures such as tepid water sponging if fever recurs rather than increasing acetaminophen dose 1

Management of Complications

Bleeding

• Blood transfusion may be necessary for significant bleeding, with target hemoglobin >10 g/dL if ScvO2 <70% 3, 2
• Obtain coagulation profile if bleeding is present 2

Fluid Overload During Recovery Phase

• After initial shock reversal, judicious fluid removal may be necessary during the recovery phase 3
• Evidence shows aggressive shock management followed by fluid removal decreased pediatric ICU mortality from 16.6% to 6.3% 3
• Consider continuous renal replacement therapy (CRRT) if fluid overload >10% develops 3

Special Populations

Pregnant Women

• Test pregnant women by NAAT for both dengue and Zika virus regardless of outbreak patterns due to risk of maternal death, hemorrhage, preeclampsia, and vertical transmission 1
• Pregnant women with confirmed or suspected dengue should be hospitalized 1
• Acetaminophen remains the safest analgesic option 1

Children

• Acetaminophen dosing should be carefully calculated based on weight 1
• Same fluid resuscitation principles apply: 20 mL/kg boluses with careful reassessment 3

Critical Pitfalls to Avoid

The most dangerous errors in dengue management include: 1, 3

• Administering routine bolus IV fluids to patients with "severe febrile illness" who are NOT in shock - this increases fluid overload and respiratory complications without improving outcomes 3
• Delaying fluid resuscitation in established dengue shock syndrome - once hypotension occurs, cardiovascular collapse may rapidly follow 3
• Continuing aggressive fluid resuscitation once signs of fluid overload appear - switch to inotropic support instead 3
• Using aspirin or NSAIDs when dengue cannot be excluded 1
• Failing to recognize the critical phase (typically days 3-7 of illness) when plasma leakage can rapidly progress to shock 3
• Prescribing antibiotics empirically without evidence of bacterial co-infection - bacterial co-infection occurs in <10% of cases and empiric antibiotics contribute to antimicrobial resistance 1

Discharge Criteria

Patients can be safely discharged when ALL of the following criteria are met: 1, 2

• Afebrile for ≥48 hours without antipyretics
• Resolution or significant improvement of symptoms
• Stable hemodynamic parameters for ≥24 hours without support (normal heart rate, stable blood pressure, normal capillary refill time)
• Adequate oral intake
• Adequate urine output (>0.5 mL/kg/hour in adults)
• Laboratory parameters returning to normal ranges

Post-Discharge Instructions

• Monitor and record temperature twice daily 1
• Return immediately for: persistent or recurrent vomiting unable to tolerate oral fluids, fever ≥38°C on two consecutive readings, any warning signs (abdominal pain, bleeding, lethargy) 1
• Repeat complete blood count and liver function tests at 3-5 days post-discharge 1
• If transaminases were elevated 2-5× normal at discharge, monitor weekly until normalized 1
• If transaminases were >5× normal at discharge, monitor every 3 days initially 1