Hyperammonemia Due to Empyema

Area of Science:

• Medicine
• Pulmonology
• Infectious Diseases

Background:

• Hyperammonemia is typically associated with liver dysfunction.
• Empyema is a serious infection of the pleural space.

Observation:

• A 91-year-old woman presented with altered consciousness and markedly elevated ammonia levels (468 μg/dL) despite normal liver function.
• Chest imaging revealed massive right-sided pleural effusion with loculation.

Findings:

• Diagnostic thoracentesis showed a pleural fluid pH of 8.5.
• The patient was diagnosed with right empyema leading to hyperammonemia.
• Treatment with ampicillin/sulbactam was initiated, but the patient developed progressive renal failure and died.

Implications:

• This case suggests that empyema, particularly if caused by urease-producing bacteria, can lead to significant hyperammonemia.
• This is the first reported instance of hyperammonemia secondary to empyema in the English literature.
• Clinicians should consider empyema as a potential cause of hyperammonemia in patients with respiratory symptoms and altered consciousness, even with preserved liver function.