A 48-year-old woman with alcohol-induced cirrhosis (Child-Pugh B) presents with progressive abdominal distension, weight gain of 3 kg over 2 weeks, and ankle swelling. She denies fever, abdominal pain, or recent infections. Examination reveals tense ascites, no rebound tenderness, and mild hepatomegaly. Serum sodium is 128 mEq/L (normal 135–145). Abdominal ultrasound shows ascites without free fluid loculation. What is the most appropriate next step in management?

Explanation

## Management of Cirrhotic Ascites with Hyponatraemia ### Clinical Context This patient has: - **Uncomplicated ascites** (no peritonitis, no loculation, no acute kidney injury) - **Cirrhotic hyponatraemia** (dilutional, due to SIADH and renal sodium wasting) - **Stable haemodynamics** (no shock, no spontaneous bacterial peritonitis signs) ### First-Line Management: Sodium Restriction + Diuretics **High-Yield:** The cornerstone of cirrhotic ascites management is: 1. **Sodium restriction** (500–1000 mg/day, typically 800 mL fluid restriction if Na <125 mEq/L) 2. **Spironolactone** (aldosterone antagonist) — first-line diuretic 3. **Furosemide** (loop diuretic) — added if inadequate response 4. **Albumin** — reserved for large-volume paracentesis (>5 L) or SBP **Key Point:** Spironolactone is preferred over furosemide as monotherapy because it addresses the underlying pathophysiology (secondary hyperaldosteronism) and causes less hypokalaemia. The ratio of spironolactone:furosemide is typically 100:40 mg when both are needed [cite:Harrison 21e Ch 297]. ### Hyponatraemia Management in Cirrhosis **Clinical Pearl:** Cirrhotic hyponatraemia is **dilutional** (SIADH + renal sodium wasting), NOT hypovolaemic. Therefore: - **Avoid normal saline** — it worsens hyponatraemia by increasing free water reabsorption - **Fluid restriction** (800 mL/day) is the primary treatment - **Correct slowly** — rapid correction risks osmotic demyelination syndrome (ODS) - **Target correction:** 4–8 mEq/L per 24 hours; max 10 mEq/L per 24 hours **Warning:** IV normal saline in cirrhotic hyponatraemia paradoxically worsens Na^+^ because the kidney preferentially reabsorbs water (due to SIADH), leading to further dilution. ### Diuretic Dosing Strategy | Scenario | First-Line | Dose | Notes | | --- | --- | --- | --- | | **Uncomplicated ascites** | Spironolactone alone | 100 mg daily | Increase by 100 mg every 3–5 days (max 400 mg) | | **Inadequate response** | Add furosemide | 40 mg daily | Maintain 100:40 ratio; max furosemide 160 mg/day | | **Refractory ascites** | Consider TIPS | — | If diuretics fail after 2 weeks at max dose | | **Large-volume paracentesis** | Albumin infusion | 6–8 g/L ascites removed | Prevents post-paracentesis circulatory dysfunction | **Mnemonic:** **SAFE ASCITES** — **S**odium restriction, **A**ldosterone antagonist (spironolactone), **F**urosemide (if needed), **E**arly monitoring; **A**lbumin (for large paracentesis), **S**low fluid correction (hyponatraemia), **C**heck K^+^ and Cr, **I**ncremental diuretic titration, **T**herapeutic paracentesis (refractory), **E**valuation for TIPS, **S**pironolactone first. ### Management Algorithm for Cirrhotic Ascites ```mermaid flowchart TD A[Cirrhotic ascites diagnosed]:::outcome --> B{Uncomplicated or complicated?}:::decision B -->|Uncomplicated| C[Sodium restriction 800 mg/day]:::action B -->|Complicated: SBP/AKI/shock| D[Therapeutic paracentesis + albumin]:::action C --> E[Start spironolactone 100 mg daily]:::action E --> F{Response at 5-7 days?}:::decision F -->|Yes: wt loss 0.5-1 kg/day| G[Continue, monitor K+ and Cr]:::action F -->|No| H[Increase spironolactone to 200 mg]:::action H --> I{Response at 5-7 days?}:::decision I -->|Still no| J[Add furosemide 40 mg daily]:::action I -->|Yes| G J --> K{Refractory after 2 weeks?}:::decision K -->|Yes| L[Consider TIPS]:::urgent K -->|No| G C --> M{Hyponatraemia Na &lt;125?}:::decision M -->|Yes| N[Fluid restriction 800 mL/day]:::action M -->|No| O[No fluid restriction]:::action ``` ### Monitoring Parameters - **Weight:** Target loss 0.5–1 kg/day (uncomplicated); up to 1 kg/day if peripheral oedema present - **Serum electrolytes:** K^+^, Na^+^, Cr — check at baseline, then every 3–5 days during titration - **Renal function:** Creatinine should not increase >0.3 mg/dL; if it does, reduce diuretics - **Ascites:** Clinical exam; ultrasound if concern for loculation or SBP ### Why This Approach Works 1. **Spironolactone** blocks aldosterone → ↑ Na^+^ excretion, ↓ K^+^ loss 2. **Sodium restriction** + **fluid restriction** → ↓ free water reabsorption, gradual Na^+^ correction 3. **Monitoring** prevents electrolyte derangement and acute kidney injury