What condition is indicated by pleural effusion with low glucose levels?

• A. Chronic bronchitis
• B. Pneumonia
• C. Empyema
• D. Heart failure

Answer: (C)

Pleural effusion with low glucose levels is typically indicative of empyema. This condition arises when there is an accumulation of pus in the pleural space, often due to an underlying infection like pneumonia. In empyema, the inflammatory process consumes glucose as immune cells attempt to combat the infection, leading to decreased levels of glucose in the pleural fluid.

Additionally, the presence of low glucose levels in pleural fluid is often associated with the significant inflammatory response seen in empyema. This distinguishes it from other conditions where pleural effusion may occur, such as heart failure or chronic bronchitis, as these usually do not cause a notable decrease in glucose levels.

Pneumonia can lead to effusions as well, but the glucose levels remain normal unless it progresses to empyema. In conditions like heart failure, the effusion is typically transudative, characterized by higher glucose levels. Thus, the key relevance of low glucose levels points towards empyema as the underlying cause of the pleural effusion.