A 32-year-old man from Kolkata presents to the emergency department with acute onset watery diarrhea and vomiting for 6 hours. He reports 8–10 episodes of rice-water stools. Vital signs show BP 90/60 mmHg, HR 120/min, and severe dehydration. Stool culture is pending. What is the most appropriate immediate management?

Explanation

## Management of Acute Cholera: Immediate Priorities **Key Point:** The cornerstone of cholera management is rapid fluid and electrolyte replacement; antibiotics are adjunctive and reduce duration/severity but are NOT life-saving. ### Pathophysiology Reminder Vibrio cholerae produces cholera toxin → ↑ cAMP → secretory diarrhea (rice-water stools) → massive fluid loss → hypovolemic shock if untreated. [cite:Park 26e Ch 27] ### Management Algorithm ```mermaid flowchart TD A[Suspected Cholera]:::outcome --> B{Assess dehydration severity}:::decision B -->|Severe| C[IV rehydration: Normal saline/Ringer's lactate]:::action B -->|Moderate| D[Oral rehydration solution ORS]:::action C --> E[Correct electrolyte abnormalities]:::action D --> F[Monitor urine output & vital signs]:::action E --> G[Add empiric antibiotic: Doxycycline/Azithromycin]:::action F --> G G --> H[Confirm with culture & susceptibility]:::outcome ``` ### Why Doxycycline? - **Single dose:** 300 mg PO (or 100 mg BD × 3 days) - **Reduces:** Duration of diarrhea by ~50%, stool output by ~60%, antibiotic dependence period - **Does NOT replace** fluid therapy — fluid is the priority - **Alternatives:** Azithromycin 1 g single dose (especially in pregnancy/children), ciprofloxacin 1 g single dose **High-Yield:** In this patient with **severe dehydration** (BP 90/60, HR 120), IV fluids are the FIRST and MOST CRITICAL intervention. Doxycycline is started concurrently to shorten illness duration. **Clinical Pearl:** Rice-water stools + acute watery diarrhea in an endemic region (Kolkata) is pathognomonic for cholera until proven otherwise. Do NOT wait for culture confirmation to start empiric therapy. ### Fluid Replacement Targets | Phase | Fluid | Route | Target | |-------|-------|-------|--------| | **Rehydration** | Normal saline or Ringer's lactate | IV | Restore BP, urine output | | **Maintenance** | ORS (glucose:sodium 1:1) | PO | Replace ongoing losses | | **Electrolyte correction** | K^+^ supplementation | IV/PO | Prevent hypokalemia-induced arrhythmias | **Warning:** Do NOT delay IV fluids while awaiting culture or waiting for oral tolerance. Severe dehydration can progress to hypovolemic shock within hours.