Causes and risk factors of pleural empyema and complicated parapneumonic pleural effusion

Rolandas Zablockis¹, Rūta Petruškevičienė², Remigijus Valdemaras Nargėla¹

¹Clinic of Chest Diseases, Allergology and Radiology, Vilnius University, ²Center of Laboratory Diagnostics, Vilniaus University Hospital Santariškių Klinikos, Lithuania

Key words: pleura; pleuritis; pleural empyema; parapneumonic effusion.

Summary. Objective. To analyze the causes and risk factors of pleural empyema and complicated parapneumonic pleural effusion and to evaluate age, sex, concomitant pathology of the patients studied, time of consulting a doctor, and antibacterial treatment before the diagnosis.

Material and methods. A total of 120 patients with pleural empyema (n=67) and complicated parapneumonic pleural effusion (n=53) were studied. When pus in the pleural space was present, pleural empyema was considered. Complicated parapneumonic pleural effusion was diagnosed when multiloculated fluid in the pleural cavity by ultrasound examination, more than 50% neutrophils of all leukocytes in the pleural fluid, and pleural fluid pH <7.0 were found.

Results. Most patients with pleural empyema and complicated parapneumonic pleural effusion were middle aged (53±17 years); men were twice as likely as women to have these conditions. Less than half (46%) of patients had at least one risk factor such as neoplasia (37%), treatment with immunosuppressive medicine (15%), alcohol abuse (15%). Persons consulted a doctor after 12 days, on the average, following the onset of the symptoms of the illness. The risk factors were found more often for the patients with pleural empyema than with complicated parapneumonic pleural effusion (50.75% versus 39.62%). Patients with pleural empyema consulted a doctor later than patients with complicated parapneumonic pleural effusion (21±28.6 days versus 9.5±9.8 days, P=0.0052). Three-fourths (75%) of the patients were treated with antibiotics, and monotherapy was applied most frequently (86% of cases). Penicillins (28%), cephalosporins (26%), aminoglycosides (20%), and macrolides (10%) were prescribed most commonly. One-quarter (25%) of patients were not treated with antibiotics mostly because of misdiagnosed intercostal neuralgia.

Conclusions. Causes of pleural empyema and complicated parapneumonic pleural effusion are multifactorial. Patients consult a doctor too late after the onset of the symptoms, nearly half of the studied patients were found to have conditions that might cause immunosuppression, and a part of patients did not receive antibiotics or antibacterial treatment was administered improperly.

Correspondence to R. Zablockis, Center of Pulmonology and Allergology, Vilniaus University Hospital Santariškių Klinikos, Santariškių 2, 08661 Vilnius, Lithuania. E-mail: rzablockis@takas.lt, rolandas.zablockis@santa.lt

Received 19 December 2007, accepted 4 February 2010