Transthoracic Ultrasound to Predict Exudative Pleural Effusion Etiology

Area of Science:

• Pulmonology
• Radiology
• Medical Diagnostics

Background:

• Pleural effusions require diagnosis for effective treatment.
• Invasive sampling is often necessary, posing risks.
• Transthoracic ultrasound (TUS) shows diagnostic potential but lacks standardized application.

Purpose of the Study:

• To evaluate the diagnostic utility of specific TUS findings for exudative pleural effusions.
• To identify TUS features predictive of complex parapneumonic effusion and empyema.

Main Methods:

• Retrospective review of 389 ultrasound-guided pleural effusion drainage cases (July 2015 - May 2023).
• Analysis of TUS findings including anechoic, fibrin, septation, loculation, and others.
• Calculation of sensitivity, specificity, PPV, NPV, and LR+ for predicting effusion nature and etiology.
• Multivariable logistic regression to assess TUS findings' association with complicated parapneumonic effusion and empyema.

Main Results:

• Exudative effusions (64.8%) showed more septation, loculation, and pleural thickening than transudative effusions.
• Absence of fibrin, septation, and loculation had 83% sensitivity for transudative effusion.
• Septation and loculation demonstrated 98% specificity and 94% PPV for exudative effusion.
• Concurrent fibrin, loculation, and septation had 99% specificity and 96% PPV for exudative effusion.
• Septation (OR 5.3) and loculation (OR 3.3) were independently associated with complicated parapneumonic effusion/empyema.

Conclusions:

• TUS features of loculation or septation are specific predictors of exudative pleural effusion.
• The presence of septation and loculation increases the likelihood of complicated parapneumonic effusion or empyema.
• Further research is needed to integrate TUS with clinical data for comprehensive pleural effusion diagnosis.