Is it okay to use plasma volume expanders combined with noradrenaline for initial treatment when differential diagnosis between dengue shock and septic shock hasn't been made?

Management of Undifferentiated Shock: Dengue vs. Sepsis

Yes, it is appropriate to use plasma volume expanders (crystalloids) combined with noradrenaline when the differential diagnosis between dengue shock and septic shock has not been established, as both conditions require aggressive fluid resuscitation and vasopressor support follows similar principles. 1

Initial Fluid Resuscitation Strategy

Begin with crystalloid resuscitation regardless of the underlying etiology:

• Administer at least 30 mL/kg of crystalloid solution within the first 3 hours for any patient presenting with shock 1, 2
• Use balanced crystalloids (Ringer's lactate or Plasma-Lyte) as the preferred initial fluid over normal saline to reduce risk of hyperchloremic metabolic acidosis 2
• For pediatric patients, administer crystalloid boluses of 20 mL/kg over 5-10 minutes, repeating as needed based on clinical response 1

This approach is safe for both conditions: Randomized trials in dengue shock syndrome demonstrated near 100% survival with crystalloid resuscitation, and crystalloids are the recommended first-line fluid for septic shock 1, 3

When to Add Vasopressor Support

Initiate noradrenaline if hypotension persists despite adequate fluid resuscitation:

• Noradrenaline is the first-choice vasopressor for septic shock (strong recommendation, moderate quality evidence) 1
• Target mean arterial pressure (MAP) ≥65 mmHg initially 1
• For pediatric patients, begin peripheral inotropic support until central venous access can be obtained if not responsive to fluid resuscitation 1

Important distinction: While noradrenaline is standard for septic shock, resource-limited settings guidelines suggest dopamine or epinephrine as alternatives when noradrenaline is unavailable 1. However, when available, noradrenaline should be preferred as it has been associated with improved outcomes in septic shock 4

Fluid Administration Technique

Use a fluid challenge approach with continuous reassessment:

• Continue fluid administration as long as hemodynamic parameters improve (pulse pressure, stroke volume variation, arterial pressure, heart rate, mental status, urine output) 1, 2
• Stop fluid administration when: no improvement in tissue perfusion occurs, signs of fluid overload develop (hepatomegaly, rales), or hemodynamic parameters stabilize 1
• Monitor for hepatomegaly and pulmonary rales as indicators to cease fluids and consider inotropic support instead 1

Critical Differences to Monitor

While initial management overlaps, key clinical features can help differentiate:

• Dengue shock typically presents with: narrower pulse pressure (25 ± 8 mmHg), lower heart rate (120 ± 39 bpm), higher hematocrit (42 ± 6%), lower platelet count (median 29,000/mm³), and better preserved mental status 5
• Septic shock typically presents with: wider pulse pressure (43 ± 8 mmHg), higher heart rate (158 ± 35 bpm), lower hematocrit (29 ± 7%), higher platelet count (median 115,500/mm³), and more likely to meet systemic inflammatory response syndrome criteria 5

Colloid Considerations

Avoid hydroxyethyl starch products in both conditions:

• Hydroxyethyl starches are contraindicated in critically ill patients and sepsis due to increased mortality and renal replacement therapy risk 6
• For severe dengue shock (pulse pressure <10 mmHg), colloids may provide benefit, but crystalloids remain first-line for moderate dengue shock 1
• If substantial crystalloids are required, albumin may be considered as an adjunct 1

Common Pitfalls to Avoid

Do not delay resuscitation while awaiting definitive diagnosis - delayed fluid resuscitation increases mortality in both conditions 2

Do not withhold vasopressors if fluid-refractory hypotension persists - early vasopressor support improves outcomes when combined with adequate fluid resuscitation 7, 4

Do not use dopamine as first-line vasopressor when noradrenaline is available - noradrenaline has superior outcomes in septic shock 1

Monitor closely for fluid overload - dengue shock patients are particularly prone to massive plasma leakage and may develop pleural effusions and ascites; avoid drainage as it can precipitate hemorrhage and circulatory collapse 8

Reassess frequently - vital signs, hematocrit, platelet count, and clinical perfusion markers should guide ongoing therapy adjustments 1, 5, 8