A 28-year-old man from Delhi presents on day 6 of illness with sudden cessation of fever, abdominal pain, and bleeding from gums. Vital signs: BP 94/58 mmHg, HR 110/min, RR 24/min, temperature 37.2°C (afebrile). Laboratory results: WBC 2,800/μL, platelets 35,000/μL, haematocrit 48% (baseline 42%), AST 320 U/L, ALT 180 U/L. Dengue IgM antibody is positive. Abdominal ultrasound shows free fluid in the pelvis. What is the most appropriate immediate management?

Explanation

## Critical Phase Dengue with Plasma Leakage — Fluid Management This patient is in the **critical phase** of dengue with **dengue haemorrhagic fever (DHF)** and **plasma leakage**. The immediate management is **isotonic crystalloid fluid resuscitation**. ### Clinical Evidence of Critical Phase | Finding | Significance | |---------|---------------| | Day 6 + defervescence (afebrile) | Marks onset of critical phase | | BP 94/58 + HR 110 | Compensated shock (early shock) | | Platelets 35,000/μL | Severe thrombocytopenia (DHF criterion) | | Haematocrit 48% (↑ from 42%) | **Plasma leakage** (>20% rise) | | Free fluid on ultrasound | Confirms plasma leakage into third space | | Positive IgM | Secondary dengue (more severe) | ### Dengue Shock Syndrome (DSS) Grading **Key Point:** This patient has **Grade I DSS** (compensated shock): - Rapid, weak pulse - Narrow pulse pressure (BP 94/58 → PP 36 mmHg) - Orthostatic hypotension or restlessness - **No hypotension yet** ### Fluid Resuscitation Algorithm ```mermaid flowchart TD A[Critical phase dengue<br/>with plasma leakage]:::outcome --> B{Shock signs?}:::decision B -->|No shock| C[Maintenance fluids<br/>+ careful monitoring]:::action B -->|Grade I/II<br/>compensated shock| D[IV isotonic crystalloid<br/>10 mL/kg bolus<br/>over 15-30 min]:::action D --> E{Response?}:::decision E -->|BP normalizes<br/>HR decreases| F[Reduce to maintenance<br/>+ 5 mL/kg/hr]:::action E -->|No response| G[Repeat bolus<br/>Consider colloid]:::action B -->|Grade III/IV<br/>profound shock| H[Aggressive resuscitation<br/>+ vasopressor<br/>+ blood products]:::urgent F --> I[Avoid over-hydration<br/>risk of pulmonary edema]:::action ``` **High-Yield:** The **first-line fluid** is **isotonic crystalloid (normal saline or Ringer's lactate)**, NOT hypotonic dextrose or colloids as first-line. ### Why Normal Saline Bolus Is Correct 1. **Restores circulating volume** lost to plasma leakage 2. **Isotonic** — does not worsen cerebral or pulmonary oedema 3. **Rapid infusion** (15–30 min) restores perfusion pressure 4. **Reassessment after bolus** — if shock persists, consider colloid or vasopressor **Clinical Pearl:** The goal is to restore **perfusion**, not to "fill the tank." Over-hydration in dengue causes pulmonary oedema and ARDS — a major cause of death in critical phase. ### Mnemonic for Dengue Fluid Management **"SALT First"** — **S**aline **A**s **L**ine **T**herapy (isotonic crystalloid first-line) - Bolus 10 mL/kg over 15–30 min for shock - Then reduce to maintenance + 5 mL/kg/hr - Reassess every 1–2 hours - If no response → colloid or vasopressor ### What NOT to Do **Warning:** - ~~Hypotonic dextrose~~ → worsens cerebral oedema and hyponatraemia - ~~Aggressive transfusion~~ → increases viscosity, worsens stasis, increases bleeding risk - ~~Prophylactic platelet transfusion~~ → reserved for active bleeding or count <10,000/μL with bleeding risk - ~~Antibiotics~~ → dengue is viral; antibiotics are not indicated unless secondary bacterial infection