How is Dengue shock syndrome identified in children?

Identifying Dengue Shock Syndrome in Children

Dengue shock syndrome (DSS) in children should be identified by recognizing the clinical triad of suspected dengue infection (fever/hypothermia), signs of inadequate tissue perfusion, and evidence of plasma leakage, with particular attention to warning signs including abdominal pain, persistent vomiting, lethargy, and hepatomegaly. 1

Clinical Diagnostic Criteria

Primary Signs of DSS

• Suspected dengue infection: Manifested by fever or hypothermia 2
• Signs of inadequate tissue perfusion (any of the following):
  • Altered mental status (irritability, inappropriate crying, drowsiness, confusion, poor interaction with parents, lethargy) 2
  • Prolonged capillary refill >2 seconds (cold shock) 2
  • Diminished pulses (cold shock) 2
  • Mottled cool extremities (cold shock) 2
  • Flash capillary refill (warm shock) 2
  • Bounding peripheral pulses and wide pulse pressure (warm shock) 2
  • Decreased urine output <1 ml/kg/h 2

Warning Signs

• Abdominal pain or tenderness 1, 3
• Persistent vomiting 1
• Fluid accumulation (ascites, pleural effusion) 1
• Mucosal bleeding 1
• Lethargy or restlessness 1, 3
• Hepatomegaly 1, 3
• Increased hematocrit with rapid decrease in platelet count 1

Laboratory Findings

Critical Laboratory Values

• Hematocrit ≥50% or increase of ≥22% from baseline 4, 3
• Platelet count ≤75,000/mm³ 3
• Prolonged activated partial thromboplastin time 5
• Low fibrinogen levels 5

Additional Laboratory Tests

• Complete blood count with hematocrit and platelets 1
• Liver function tests 1
• Coagulation tests 1
• Specific diagnostic tests:
  • RT-PCR for dengue virus RNA (≤7 days from symptom onset) 1
  • NS1 antigen detection (acute phase) 1
  • IgM antibody detection (>5-7 days) 1
  • IgG antibody titers (to identify secondary infection) 1

Risk Factors for DSS

• Age >5 years 5
• Secondary dengue infection (21.8 times higher risk) 4
• Bleeding manifestations (5.1 times higher risk) 4
• Hemoconcentration >22% from baseline (15.5 times higher risk) 4
• Abdominal pain (2.5 times higher risk) 5
• Coagulation abnormalities 5

Monitoring Parameters

• Vital signs (heart rate, blood pressure, respiratory rate) 2, 1
• Pulse pressure and diastolic pressure (wide pulse pressure indicates low SVR; narrow pulse pressure indicates high SVR) 2
• Capillary refill time 2
• Mental status 2
• Urine output (target >1 mL/kg/h) 2, 1
• Temperature 2
• Blood glucose and ionized calcium 2
• Serial hematocrit measurements 1

Clinical Pearls and Pitfalls

1. Hypotension is not necessary for diagnosis: DSS can be diagnosed before hypotension develops; waiting for hypotension may delay critical interventions 2

2. Differentiate shock types:

   • Cold shock: prolonged capillary refill, diminished pulses, mottled extremities
   • Warm shock: flash capillary refill, bounding pulses, wide pulse pressure 2

3. Watch for fluid overload: Development of hepatomegaly or rales indicates fluid overload and the need to switch from fluid resuscitation to inotropic support 2

4. Recognize obstructive shock: In severe cases, increased thoracic pressure from plasma leakage and mechanical ventilation can lead to obstructive shock requiring careful fluid management guided by point-of-care ultrasound 6

5. Monitor for progression: DSS typically occurs during the critical phase (days 3-7 of illness), often coinciding with defervescence 1

Special Considerations

• Infants: More susceptible to fluid overload; require more careful fluid management 1
• Comorbidities: Cardiac or renal disease requires more intensive monitoring 1
• Secondary infection: Significantly increases risk of progression to DSS 4

By systematically evaluating these clinical and laboratory parameters, clinicians can identify dengue shock syndrome early and initiate appropriate management to reduce morbidity and mortality in children.