In a 70‑year‑old dialysis‑dependent patient with epigastric cramping‑type pain that improves when sitting upright and leaning forward, severe hypoxemia (oxygen saturation 75 %), heart rate 95 bpm, normal blood pressure and normal cardiovascular and respiratory examination, what is the most likely diagnosis and what immediate work‑up and management should be pursued?

Uremic Pericarditis with Cardiac Tamponade

In this dialysis-dependent patient presenting with epigastric pain relieved by sitting forward and severe hypoxemia (oxygen saturation 75%), the most likely diagnosis is uremic pericarditis with impending or early cardiac tamponade, and immediate management requires high-flow oxygen, urgent echocardiography, cessation of ultrafiltration, and preparation for potential pericardiocentesis or surgical drainage.

Diagnostic Reasoning

Classic Presentation in Dialysis Patients

• Pericarditis classically presents with chest pain that is sharp, pleuritic, and improved by sitting up or leaning forward, though the pain may manifest as epigastric discomfort in dialysis patients 1
• Approximately 20% of uremic patients requiring chronic dialysis develop uremic pericarditis or dialysis pericarditis, with cardiac tamponade being the main danger 2
• Chest pain occurs less frequently in ESRD patients with pericardial involvement compared to non-uremic patients, making the diagnosis more challenging 3
• The severe hypoxemia (75% saturation) in this case likely reflects hemodynamic compromise from early tamponade physiology affecting cardiac output and tissue oxygen delivery 4

Key Distinguishing Features

• In uremic patients, frequent autonomic impairment and decreased cardiac adenylate cyclase limit heart rate increases during pericarditis, even during tamponade, so the heart rate of 95 bpm may be deceptively slow despite hypotension risk 2
• The normal blood pressure and cardiovascular examination do not exclude early tamponade, as these findings can be preserved until late in the disease course 5
• Dialysis patients have a markedly increased risk for dysrhythmias and cardiac arrest due to dynamic changes in electrolytes, volume status, and blood pressure 1

Immediate Management Protocol

Oxygen and Hemodynamic Support

• Administer high-flow supplemental oxygen (non-rebreather mask at 40-60 L/min) immediately and titrate to maintain peripheral oxygen saturation ≥92% 4
• Place the patient in a position of comfort (typically sitting upright and leaning forward for pericarditis) while monitoring hemodynamics 4
• Cease or markedly reduce ultrafiltration immediately to avoid further blood-pressure decline, even though current blood pressure appears normal 4

Urgent Diagnostic Work-up

Perform these tests immediately and simultaneously:

• 12-lead ECG to detect widespread ST-elevation with PR depression (the electrocardiographic hallmark of pericarditis, though changes may be nonspecific and transient) 1
• Transthoracic echocardiography (TTE) is effective to determine the presence of pericardial effusion, ventricular wall motion abnormalities, valvular abnormalities, or restrictive physiology 1
• Look specifically for right ventricular diastolic compression, septated or fibrinoid pericardial effusion, and signs of tamponade physiology 6
• Chest radiograph to identify pulmonary edema, cardiomegaly, or other causes of hypoxemia 4
• Arterial blood gas analysis to confirm the degree of hypoxemia and evaluate acid-base status 4

Laboratory Evaluation

• Cardiac biomarkers (troponin) and natriuretic peptide (BNP) when epigastric pain accompanies hypoxemia, as dialysis patients frequently present cardiac ischemia with atypical pain 4
• Complete blood count targeting hemoglobin ≥11 g/dL to improve oxygen-carrying capacity 4
• Electrolytes to assess for dysrhythmia risk 1

Definitive Treatment Based on Echocardiographic Findings

If Hemodynamically Stable Without Tamponade

• Intensive hemodialysis with careful hemodynamic and echocardiographic monitoring as primary treatment for patients with pericarditis and no hemodynamic alterations 5
• Adequate renal dialysis effectively ends uremic pericarditis 2
• Resolution with conservative therapy is more frequent with first episodes than with recurrences, and when pericarditis occurs within 3 months of initiation of chronic dialysis 5

If Tamponade or Pretamponade Develops

Invasive intervention is indicated if:

• Cardiac tamponade or pretamponade develops
• Pericardial effusion increases progressively in size
• Large effusion persists after 10-14 days of intensive dialysis 5

Preferred surgical approaches:

• Formal pericardiectomy or subxiphoid pericardiotomy with intrapericardial steroid instillation are the interventions of choice 5
• Pericardiocentesis is a high-risk procedure reserved for emergency circumstances, preferably performed in the operating room just prior to induction of anesthesia for definitive surgical drainage 5
• For massive hemorrhage into the pericardial sac (which usually involves clotting), pericardiotomy and evacuation of clot are required 7

Critical Pitfalls to Avoid

• Do not assume normal blood pressure and heart rate exclude tamponade in dialysis patients due to autonomic dysfunction 2
• Do not continue ultrafiltration in a hypoxemic dialysis patient, as this can precipitate cardiovascular collapse 4
• Do not dismiss epigastric pain as gastrointestinal in origin without cardiac evaluation, as this may represent atypical cardiac or pericardial pain 1, 4
• Do not delay echocardiography for other testing; it is the definitive diagnostic modality for pericardial effusion and tamponade 1
• Cardiovascular disease is responsible for approximately 50% of deaths in the chronic dialysis population; therefore, any hypoxemic presentation warrants immediate cardiac evaluation 4

Alternative Diagnoses to Consider

While uremic pericarditis is most likely given the classic positional relief, also evaluate for:

• Acute coronary syndrome (may manifest as epigastric discomfort in dialysis patients and should be ruled out urgently) 4
• Pulmonary embolism (obtain D-dimer if suspected) 1, 4
• Pneumothorax or hemothorax (especially in patients with central venous catheter) 4
• Rapid-onset pulmonary edema (can occur even with normal physical exam; early imaging is essential) 4