In a patient with severe renal impairment (estimated glomerular filtration rate ≈ 17 mL/min/1.73 m²) presenting with abdominal distension and dyspnea but a clear pulmonary examination, what is the most likely diagnosis and what immediate management should be undertaken?

Uremic Pericarditis with Pericardial Effusion and Tamponade Physiology

This patient with GFR 17 mL/min/1.73 m² presenting with abdominal distension and dyspnea despite clear lung sounds most likely has uremic pericarditis with pericardial effusion causing tamponade physiology, and requires urgent echocardiography followed by immediate initiation of dialysis. 1

Immediate Diagnostic Approach

Obtain an urgent transthoracic echocardiogram to assess for pericardial effusion and signs of tamponade (right atrial/ventricular collapse, respiratory variation in mitral inflow >25%, plethoric IVC). 1 The combination of severe renal impairment (stage 4-5 chronic kidney disease), abdominal distension, and dyspnea with clear lungs is pathognomonic for pericardial effusion rather than pulmonary edema.

• Check jugular venous pressure and assess for pulsus paradoxus (>10 mmHg drop in systolic BP with inspiration), which confirms tamponade physiology even before imaging. 1
• The "swollen abdomen" represents hepatic congestion and ascites from elevated right-sided pressures due to impaired ventricular filling, not volume overload in the lungs. 1

Immediate Management Algorithm

If Tamponade is Confirmed:

Initiate urgent hemodialysis as the definitive treatment for uremic pericarditis, which resolves pericardial effusion in 70-80% of cases within 1-2 weeks of starting dialysis. 1, 2 This patient with GFR 17 mL/min/1.73 m² (stage 4 chronic kidney disease approaching stage 5) meets criteria for dialysis initiation based on uremic symptoms rather than GFR threshold alone. 3

• If hemodynamically unstable (systolic BP <90 mmHg, altered mental status, or severe dyspnea at rest), perform urgent pericardiocentesis before or concurrent with dialysis initiation. 1
• If hemodynamically stable, proceed directly to dialysis without pericardiocentesis, as drainage alone does not address the underlying uremia and effusion will reaccumulate. 1

Dialysis Prescription Specifics:

• Start with daily or every-other-day hemodialysis sessions for the first 1-2 weeks to rapidly clear uremic toxins. 2, 3
• Use heparin-free dialysis initially if pericardial effusion is large (>2 cm diastolic separation) to avoid hemorrhagic conversion of the effusion. 4
• Target ultrafiltration cautiously (remove <2 liters per session initially) to avoid hypotension and worsening tamponade physiology. 3

Critical Pitfalls to Avoid

Do not administer aggressive diuretics (loop diuretics like furosemide) in this setting, as the patient is not volume overloaded in the lungs but rather has impaired cardiac filling from tamponade—diuresis will worsen hypotension and organ perfusion. 5, 6 The clear lung sounds confirm this is not pulmonary edema.

Do not delay dialysis initiation waiting for the GFR to fall below 10 mL/min/1.73 m², as uremic symptoms (pericarditis) constitute an absolute indication for dialysis regardless of GFR value. 3 The IDEAL study showed that asymptomatic patients can safely delay dialysis until GFR 5-7 mL/min/1.73 m², but symptomatic uremia mandates immediate initiation. 3

Do not use NSAIDs or colchicine for presumed "pericarditis" in this setting, as these agents are either contraindicated (NSAIDs worsen renal function) or ineffective (colchicine does not treat uremic pericarditis) and will delay definitive therapy. 1

Monitoring After Dialysis Initiation

• Repeat echocardiography after 1 week of intensive dialysis to assess effusion size reduction. 2
• If effusion persists or enlarges after 2 weeks of adequate dialysis, consider pericardial window or pericardiectomy, as this suggests dialysis-associated pericarditis rather than uremic pericarditis. 1
• Monitor for hemodynamic stability during each dialysis session, as rapid fluid removal can precipitate hypotension in patients with tamponade physiology. 3

Alternative Diagnoses to Exclude

If echocardiography shows no pericardial effusion, consider:

• Hepatorenal syndrome with ascites: Perform diagnostic paracentesis to assess for ascitic fluid and calculate serum-ascites albumin gradient (SAAG ≥1.1 g/dL suggests portal hypertension). 1
• Peritoneal dialysis-related complications: If patient is already on peritoneal dialysis, cloudy peritoneal fluid suggests peritonitis requiring urgent culture and antibiotics. 2

However, the combination of severe renal impairment (GFR 17) with dyspnea and clear lungs makes uremic pericarditis the most likely diagnosis requiring immediate action. 1, 2