A 35-year-old man from Mumbai presents on day 7 of illness with high fever, severe abdominal pain, persistent vomiting, and a single episode of melaena. His blood pressure is 92/58 mmHg (baseline unknown), heart rate 118/min, respiratory rate 24/min. Platelet count is 42,000/μL, haematocrit 48% (previous haematocrit 2 days ago was 42%), haemoglobin 13.8 g/dL, AST 340 U/L, ALT 210 U/L, albumin 2.8 g/dL. Abdominal ultrasound shows free fluid in the pelvis and ascites. What is the most appropriate immediate intervention?

Explanation

## Severe Dengue with Shock and Gastrointestinal Bleeding **Key Point:** This patient has **severe dengue** (dengue haemorrhagic fever progressing to dengue shock syndrome). The combination of plasma leakage (ascites, free fluid, haematocrit rise), thrombocytopenia, organ dysfunction (hepatitis), and bleeding (melaena) with hypotension defines DSS and requires immediate aggressive fluid resuscitation and transfusion support. ### Diagnostic Criteria for Severe Dengue (This Patient) | Criterion | Finding | Present? | |-----------|---------|----------| | **Plasma leakage** | Ascites + free fluid on ultrasound | ✓ | | **Haematocrit rise** | 48% vs 42% (6% rise in 2 days) | ✓ | | **Thrombocytopenia** | Platelet 42,000/μL | ✓ | | **Bleeding manifestation** | Melaena (GI bleed) | ✓ | | **Organ dysfunction** | AST 340, ALT 210, albumin 2.8 (hepatic impairment) | ✓ | | **Shock** | SBP 92/58 mmHg, HR 118, RR 24 (narrow pulse pressure, tachycardia, tachypnoea) | ✓ | **High-Yield:** Dengue shock syndrome (DSS) is defined by plasma leakage causing hypovolaemic shock. The critical phase (days 3–7) is when plasma leakage peaks and shock develops. Once shock is present, mortality rises sharply without aggressive management. ### Pathophysiology of Shock in Dengue ```mermaid flowchart TD A[Dengue viraemia + immune activation]:::outcome --> B[Increased vascular permeability]:::outcome B --> C[Plasma leakage into third spaces]:::outcome C --> D[Ascites, pleural effusion, pericardial effusion]:::outcome D --> E[Intravascular volume depletion]:::outcome E --> F{Adequate fluid resuscitation?}:::decision F -->|Yes| G[Restore perfusion, prevent organ failure]:::action F -->|No| H[Progressive shock, multi-organ failure, death]:::urgent B --> I[Thrombocytopenia + coagulopathy]:::outcome I --> J[Bleeding manifestations]:::outcome J --> K[Further volume loss, worsening shock]:::urgent ``` **Clinical Pearl:** In dengue shock, the haematocrit is **paradoxically elevated** despite bleeding because plasma loss exceeds red cell loss. A rising haematocrit (even if absolute Hb is normal) is a critical sign of plasma leakage and shock. ### Immediate Management of DSS **Fluid Resuscitation Protocol:** 1. **IV access:** Establish 2 large-bore IV lines 2. **Fluid bolus:** 10–20 mL/kg of isotonic crystalloid (normal saline or Ringer's lactate) over **15–30 minutes** - For a 70 kg man: 700–1400 mL over 15–30 min - Goal: Restore systolic BP to >90 mmHg, urine output >0.5 mL/kg/hr, improved perfusion 3. **Reassess after bolus:** - If shock resolves: continue maintenance fluids (3–5 mL/kg/hr) and taper as haematocrit stabilizes - If shock persists: repeat bolus and consider vasopressors (dopamine 5–10 μg/kg/min) 4. **Avoid fluid overload:** Once haematocrit stabilizes, reduce fluids to prevent pulmonary oedema and ascites worsening **Transfusion Strategy:** | Product | Indication | Timing | |---------|-----------|--------| | **Platelet concentrate** | Platelet <20,000/μL + bleeding OR <10,000/μL regardless | After fluid bolus; do not delay resuscitation | | **Fresh frozen plasma (FFP)** | Coagulopathy (PT/INR prolonged) + bleeding | After fluid bolus | | **Packed RBCs** | Hb <7 g/dL (or <10 g/dL if ongoing bleeding/shock) | After fluid bolus; transfuse slowly to avoid volume overload | | **Whole blood** | Not routinely used; prefer component therapy | **In this patient:** - Platelet 42,000/μL + melaena → **transfuse platelets after fluid bolus** - AST/ALT elevation + coagulopathy risk → **consider FFP if PT/INR prolonged** - Hb 13.8 g/dL (adequate) → **no RBC transfusion yet; transfuse if Hb drops <7 g/dL or ongoing bleeding with shock** **Monitoring:** - Vital signs q15 min during resuscitation - Urine output (target >0.5 mL/kg/hr) - Haematocrit q2–4 hr (goal: stabilization, not rise) - Platelet count, coagulation profile - Abdominal examination (ascites progression) **Supportive Care:** - ICU admission - Continuous cardiac monitoring - Oxygen if SpO~2~ <94% - Avoid NSAIDs (increase bleeding risk) - Treat any secondary infections **High-Yield:** The **fluid resuscitation window** in DSS is critical. Delayed or inadequate fluids lead to multi-organ failure, DIC, and death. Conversely, over-resuscitation after shock resolves causes pulmonary oedema and worsening ascites. The key is **titration to clinical endpoints** (BP, urine output, perfusion) and **haematocrit monitoring** to guide fluid tapering. [cite:Harrison 21e Ch 197; WHO Dengue Guidelines 2009]